Dissertations / Theses: 'Land surface'

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Jiang, Geng-Ming Li Zhao-Liang. "Retrievals of land surface emissivity and land surface temperature from MSG1-SEVIRI data." Strasbourg : Université Louis Pasteur, 2008. http://eprints-scd-ulp.u-strasbg.fr:8080/848/01/JIANG_Geng_Ming_2007.pdf.

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Jiang, Geng-Ming. "Retrievals of land surface emissivity and land surface temperature from MSG1-SEVIRI data." Université Louis Pasteur (Strasbourg) (1971-2008), 2007. https://publication-theses.unistra.fr/public/theses_doctorat/2007/JIANG_Geng-Ming_2007.pdf.

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Les objectifs de cette thèse sont concentrés sur la détermination de l’émissivité (LSE) et de la température de surface (LST) des surfaces terrestres à partir des données de MSG 1 -SEVIRI. Dans un premier temps l’inter-calibrage des canaux infrarouges 4, 9 et 10 de MSG I -SEVIRI avec les canaux de Terra-MODIS est réalisé. Deux méthodes, la méthode «ray-matching» et une méthode basée sur l’équation transfert radiatif ont été appliqués. Les résultats indiquent que les anomalies de calibrage existent entre les canaux de SEVIRI et de MODIS. L’utilisation des résultats obtenus par la méthode basée sur le transfert radiatif pour recalibrer les données de SEVIRI est recommandée. Ce recalibrage permet de supprimer la surestimation des LSTs obtenues à partir des données de SEVIRI avec une méthode SplitWindow. Les émissivités sont ensuite estimées dans les canaux 4, 7, 9 et 10 sur des grandes étendues spatiales et temporelles en utilisant une méthode basée sur le concept des TISI. Une nouvelle méthode de corrections atmosphériques a été développée, principalement basée sur le modèle de DTC (Diumal Time Cycle), et deux modèles de BRDF, le modèle du Minnaert modifié et le modèle de RossThick-LiSparse-R, ont été évalués. Les températures de surface sont déterminées à partir des données MSGI-SEVIRJ et AATSR. La méthode mono canal simple et la méthode Split Window ont été utilisées. Les algorithmes généralisés de Split Window ont été développés pour les instruments SEVIRI et AATSR en utilisant le code MODTRAN et les profils atmosphériques standards et ont été appliqués avec succès aux déterminations des LST à partir des données de SEVIRI et d’AATSR. Les températures de surface obtenues à partir de SEVERI ont été validées par comparaison directe avec les produits MODIS/Terra LST et les AATSR LST estimées par la Split Window généralisée au-dessus de la péninsule ibérienne et d’une région de l’Egypte et du 1Moyen-est. Les résultats indiquent que les LST SEVIRJ sont conformes au LST extraites des produits MODIS/Terra LST et AATSR LST avec une exactitude comprise entre l-2 K.

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Westberg, Daniel. "A sensor fusion method for detection of surface laid land mines." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10479.

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Landminor är ett stort problem både under och efter krigstid. De metoder som används för att detektera minor har inte ändrats mycket sedan 1940-talet. Forskning med mål att utvärdera olika elektro-optiska sensorer och metoder som skulle kunna användas för att skapa mer effektiv min-detektion genomförs på FOI. Försök som har gjorts med data från bland annat laser-radar och IR-sensorer har gett intressanta resultat.

I det här examensarbetet utvärderades olika fenomen och egenskaper i laser-radar- och IR-data. De testade egenskaperna var intensitet, IR, ytlikhet och höjd.

En metod som segmenterar intressanta objekt och bakgrundsdata utformades och implementerades. Metoden använde sig av expectation-maximization-skattning och ett minimum message length-kriterium. Ett scatter separability-kriterium användes för att bestämma kvalitén på de olika egenskaperna och på den resulterande segmenteringen.

Data insamlad under en mätkampanj av FOI användes för att testa metoden. Resultatet visade bland annat att ytlikhetsmåttet gav en bra segmentering för stora objekt med släta ytor, men var sämre för små objekt med skrovliga ytor. Vid jämförelse med en manuellt skapad mål-mask visade det sig att metoden klarade av att välja ut egenskaper som i många fall gav en godkänd segmentering.

Land mines are a huge problem in conflict time and after. Methods used to detect mines have not changed much since the 1940's. Research aiming to evaluate output from different electro-optical sensors and develop methods for more efficient mine detection is performed at FOI. Early experiments with laser radar sensors show promising results, as do analysis of data from infrared sensors.

In this thesis, an evaluation is made of features found in laser radar- and in infrared -sensor data. The tested features are intensity, infrared, a surfaceness feature extracted from the laser radar data and height above an estimated ground plane.

A method for segmenting interesting objects from background data using theexpectation-maximization algorithm and a minimum message length criterion is designed and implemented. A scatter separability criterion is utilized to determine the quality of the features and the resulting segmentation.

The method is tested on real data from a field trial performed by FOI. The results show that the surfaceness feature supports the segmentation of larger object with smooth surfaces but gives no contribution to small object with irregular surfaces. The method produces a decent result of selecting contributing features for different neighbourhoods of a scene. A comparison with a manually created target mask of the neighbourhood and the segmented components show that in most cases a high percentage separation of mine data and background data is possible.

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Panin, Gennadij N., Gerd Tetzlaff, Armin Raabe, Hans-Jürgen Schönfeldt, and A. E. Nasonov. "Inhomogeneity of the land surface and the parameterization of surface fluxes." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-213104.

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Modem measurement methods ofthe surface turbulent fluxes (STF) of heat, moisture and momentum in the near surface atmospheric layer by the eddy correlation method and their calculation, relay on the validity of the similarity theory of Monin-Obukhov, which requests stationarity and horizontal homogeneity. Experimental data taken at specially selected sites allowed to develop this concept. Recently performed experiments, purposely conducted in non-ideal conditions showed an underestimation ofthe STF values. To systematise this effect it is suggested to parameterize such underestimation as the influence of inhomogeneity and nonstationarity of the landscape and the atmosphere around the point of observation. This scheme might prove to be useful for the design of new validation experiments in non-ideal terrain
Modeme Meßmethoden zur Erfassung der turbulenten Oberflächenflüsse für fühlbare und latente Wärme sowie Impuls mit Hilfe der Eddy-Korrelations-Methode basieren für die bodennahe Grenzschicht auf der Monin-Obukhov-Turbulenztheorie, die stationäre und horizontal homogene Verhältnisse voraussetzt. Über speziell ausgewählten Oberflächen wurde dieses Konzept häufig mit Erfolg überprüft. Experimente jedoch, die gezielt unter inhomogenen Verhältnissen durchgeführt werden, zeigen oft eine Unterschätzung der turbulenten Oberflächenflüsse. Es wird vorgeschlagen, diese Unterschätzungen als einen Einfluß inhomogener Umbegungsbedingungen und instationärer atmosphärischer Prozesse zu interpretieren und zu systematisieren. Dieses Schema kann dazu beitragen, eine neue Art von Validierungsexperimenten unter natürlichen Verhältnissen einer inhomogenen Umgebung zu entwerfen

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Panin, Gennadij N., Gerd Tetzlaff, Armin Raabe, Hans-Jürgen Schönfeldt, and A. E. Nasonov. "Inhomogeneity of the land surface and the parameterization of surface fluxes." Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 4 = Meteorologische Arbeiten aus Leipzig ; 2 (1996), S. 204-215, 1996. https://ul.qucosa.de/id/qucosa%3A15066.

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Modem measurement methods ofthe surface turbulent fluxes (STF) of heat, moisture and momentum in the near surface atmospheric layer by the eddy correlation method and their calculation, relay on the validity of the similarity theory of Monin-Obukhov, which requests stationarity and horizontal homogeneity. Experimental data taken at specially selected sites allowed to develop this concept. Recently performed experiments, purposely conducted in non-ideal conditions showed an underestimation ofthe STF values. To systematise this effect it is suggested to parameterize such underestimation as the influence of inhomogeneity and nonstationarity of the landscape and the atmosphere around the point of observation. This scheme might prove to be useful for the design of new validation experiments in non-ideal terrain.
Modeme Meßmethoden zur Erfassung der turbulenten Oberflächenflüsse für fühlbare und latente Wärme sowie Impuls mit Hilfe der Eddy-Korrelations-Methode basieren für die bodennahe Grenzschicht auf der Monin-Obukhov-Turbulenztheorie, die stationäre und horizontal homogene Verhältnisse voraussetzt. Über speziell ausgewählten Oberflächen wurde dieses Konzept häufig mit Erfolg überprüft. Experimente jedoch, die gezielt unter inhomogenen Verhältnissen durchgeführt werden, zeigen oft eine Unterschätzung der turbulenten Oberflächenflüsse. Es wird vorgeschlagen, diese Unterschätzungen als einen Einfluß inhomogener Umbegungsbedingungen und instationärer atmosphärischer Prozesse zu interpretieren und zu systematisieren. Dieses Schema kann dazu beitragen, eine neue Art von Validierungsexperimenten unter natürlichen Verhältnissen einer inhomogenen Umgebung zu entwerfen.

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Yang, Jiansheng. "Remote sensing modeling of land surface temperature /." View online ; access limited to URI, 2003. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3112133.

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Altaf, Muhammad 1961. "Area-average representation of land surface covers in large atmospheric models based on remotely sensed land surface cover data." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282572.

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The research described in this dissertation is predicted on the hypothesis that remotely sensed information on vegetation cover classes can be used to improve the representation of heterogeneous continental surfaces in global climate models. The problem it addressed was that current understanding of soil-vegetation-atmosphere interactions is considered only to be relevant to small plots of uniform vegetation with dimensions of the order 10-1000 m but, in order to provide realistic simulation of climate, General Circulation Models require description of such interactions for large areas of mixed vegetation with dimensions of the order 100-1000 km. The methods used to investigate this issue was to create and apply a coupled model that provided realistic representation of both surface and atmospheric boundary layer processes, and to use this model to simulate surface-atmosphere interactions with explicit representation of patches of vegetation on the one hand, and with a single, area-average representation of exchanges on the other. These modeling studies were given credibility by initiating and validating the coupled model using appropriate data from the FIFE site in Kansas and the ABRACOS site in Brazil. The results showed that when quite simple aggregation rules are used to derive the effective area-average values of the vegetation-related parameters, these parameters give adequate simulation of surface-atmosphere interactions. These aggregation rules were then applied using remotely sensed maps of land cover to derive parameter values. Significant differences were found in the resulting parameters, and in the surface energy fluxes and modeled climate calculated using those parameters. Thus, it has been shown that remotely sensed data can indeed be used to improve the representation of heterogeneous land surfaces in global climate models using the methods developed in this research, and that using these data significantly alters the simulated global climate.

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Ghent, Darren John. "Land surface modelling and Earth observation of land/atmosphere interactions in African savannahs." Thesis, University of Leicester, 2011. http://hdl.handle.net/2381/10274.

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Land/atmosphere feedback processes play a significant role in determining climate forcing on monthly to decadal timescales. Considerable uncertainty however exists in land surface model representation of these processes. This investigation represents an innovative approach to understanding key land surface processes in African savannahs in the framework of the UK‘s most important land surface model – the Joint UK Land Environment Simulator (JULES). Findings from an investigation into the carbon balance of Africa for a 25-year period from 1982 to 2006 inclusive show that JULES estimated Africa to behave as a carbon sink for most of the 1980‘s and 1990‘s punctuated by three periods as a carbon source, which coincided with the three strongest El Niño events of the period. From 2002 until 2006 the continent was also estimated to be a source of carbon. Overall, the JULES simulation suggests a weakening of the African terrestrial carbon sink during this period primarily caused by hot and dry conditions in savannahs. Applying the model further, land surface temperature (LST) displayed large uncertainty with respect to savannah field measurements from Kruger National Park, South Africa, and JULES systematically underestimated LST with respect to Earth Observation data continent-wide. The postulation was that a reduction in the uncertainty of surface-to-atmosphere heat and water fluxes could be achieved by constraining JULES simulations with satellite-derived LST using an Ensemble Kalman Filter. Findings show statistically significant reductions in root mean square errors with data assimilation than without; for heat flux simulations when compared with Eddy Covariance measurements, and surface soil moisture when compared with derivations from microwave scatterometers. The improved representation of LST was applied to map daily fuel moisture content – one of the most important wildfire determinants - over the mixed tree/grass landscapes of Africa, whereby values were strongly correlated with field measurements acquired from three savannah locations.

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White, Cary Blake, and Cary Blake White. "Soil Moisture Variability in Land Surface-Atmosphere Interactions." Thesis, The University of Arizona, 1996. http://hdl.handle.net/10150/626791.

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Meteorological measurements in the Walnut Gulch catchment in Arizona were used to synthesize a distributed, hourly-average time series of data across a 26.9 by 12.5 km area with a grid resolution of 480 m for a continuous 18-month period which included two seasons of monsoonal rainfall. Coupled surface-atmosphere model runs established the acceptability (for modeling purposes) of assuming uniformity in all meteorological variables other than rainfall. Rainfall was interpolated onto the grid from an array of 82 recording rain gauges. These meteorological data were used as forcing variables for an equivalent array of stand-alone Biosphere-Atmosphere Transfer Scheme (BATS) models to describe the evolution of soil moisture and surface energy fluxes in response to the prevalent, heterogeneous pattern of convective precipitation. The calculated area-average behavior was compared with that given by a single aggregate BATS simulation forced with area-average meteorological data. Heterogeneous rainfall gives rise to significant but partly compensating differences in the transpiration and the intercepted rainfall components of total evaporation during rain storms. However, the calculated area-average surface energy fluxes given by the two simulations in rain-free conditions with strong heterogeneity in soil moisture were always close to identical, a result which is independent of whether default or site-specific vegetation and soil parameters are used. Because the spatial variability in soil moisture throughout the catchment has the same order of magnitude as the amount of rain falling in a typical convective storm (commonly 10% of the vegetation's root zone saturation), in a semi-arid environment, any non-linearity in the relationship between transpiration and the soil moisture available to the vegetation has limited influence on area-average surface fluxes.

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Luke, Catherine M. "Modelling aspects of land-atmosphere interaction : thermal instability in peatland soils and land parameter estimation through data assimilation." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3229.

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The land (or ‘terrestrial’) biosphere strongly influences the exchange of carbon, energy and water between the land surface and the atmosphere. The size of the land carbon store and the magnitude of the interannual variability of the carbon exchange make models of the land surface a vital component in climate models. This thesis addresses two aspects of land surface modelling: soil respiration and phenology modelling, using different techniques with the goal of improving model representation of land-atmosphere interaction. The release of heat associated with soil respiration is neglected in the vast majority of large-scale models but may be critically important under certain circumstances. In this thesis, the effect of this heat release is considered in two ways. Firstly, a deliberately simple model for soil temperature and soil carbon, including biological heating, is constructed to investigate the effect of thermal energy generated by microbial respiration on soil temperature and soil carbon stocks, specifically in organic soils. Secondly, the mechanism for biological self-heating is implemented in the Joint UK Land Environment Simulator (JULES), in order to investigate the impacts of the extra feedback in a complex model. With the intention of improving estimates of the parameters governing modelled land surface processes, a data assimilation system based on the JULES land surface model is presented. The ADJULES data assimilation system uses information from the derivative of JULES (or adjoint) to search for a locally optimum parameter set by calibrating against observations. In this thesis, ADJULES is used with satellite-derived vegetation indices to improve the modelling of phenology in JULES.

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Beroud, Jean-Marc. "On the influence of land-surface processes on the near-surface atmospheric state /." [S.l.] : [s.n.], 1999. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13006.

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Zabel, Florian. "Land-atmosphere coupling between a land surface hydrological model and a regional climate model." Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-151446.

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Abusuwar, Awad Osman Mohmed 1952. "Land imprinting as an effective way of soil surface manipulation to revegetate arid lands." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/191107.

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Research was conducted over a 2-year period at the University of Arizona Campus and Oracle Agricultural Centers to evaluate the effectiveness of surface imprintation in revegetating arid lands. Introduction of forage leguminous species into arid rangelands through land imprintat ion was another objective of this study. The soil at the Campus Center is a Brasito, mixed thermic, typic torripsamment with a sandy-loam texture. This was compared with a White House, fine mixed thermic, Ustollic haplargid with a sandyloam texture at the Oracle Center. Natural rains were the only source of irrigation at Oracle. At the Campus Center, however, a sprinkler irrigation system was installed to match rains with that at the Oracle Center. Three cover treatments together with four surface treatments were used at both sites. The cover treatments included a pure stand of grasses, a pure stand of legumes, and a mixture of both grasses and legumes. The surface treatments were imprinted, mulched, imprinted-mulched, and an untreated surface as a check. Surface imprintation was performed by a land imprinter at Oracle and by a hand imprinter at Campus. The imprinted surface significantly increased soil moisture retention, number of plants per unit area, plant height, plant cover, and biomass compared to the untreated surface. At the Oracle Center, the imprinted surface improved legume germination by 800% over the untreated surface, and by 367% over the mulched one. Corresponding percentages at Campus were 48 and 4% over the untreated and the mulched surfaces, respectively. Increases in biomass production achieved through surface imprintation were 102% over the untreated surface and 35% over the mulched surface at the Oracle Center. Corresponding increases at Campus were 63 and 33% over the untreated and the mulched surfaces, respectively. Plants grown on imprinted surfaces exhibited higher transpiration rates, lower diffusive resistance, and cooler leaf temperature compared to those grown on the untreated surfaces. Addition of mulch to the imprinted surface made no significant differences with respect to the parameters measured when compared to the imprinted surface without mulch. When mulch was used as a separate treatment, however, it significantly increased the parameters measured over the untreated surface. The effect of cover treatments on growth parameters and biomass production was masked by seasonality. Grasses tended to be superior over legumes in samples taken during the fall and the opposite was true during the summer. Mixing legumes with grasses, however, resulted in significantly taller grasses compared to grasses grown as a pure stand.

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Bateni, Sayed Mohyeddin. "Estimation of turbulent surface heat fluxes using sequences of remotely sensed land surface temperature." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/66850.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 330-366).
Fluxes of heat and moisture at the land-surface play a significant role in the climate system. These fluxes interact with the overlying atmosphere and influence the characteristics of the planetary boundary layer (e.g. temperature and water vapor content), ultimately influencing the presence and growth of low level clouds and precipitation. Nevertheless, there is currently no network of in situ sensors that can map these fluxes globally. Recently a number of studies have focused on the estimation of surface energy flux components based on the assimilation of land surface temperature (LST) within a variational data assimilation (VDA) framework. This study provides the theoretical basis for why sequences of LST contain the necessary information to estimate surface fluxes with minimal reliance on ancillary data and empirical parameterizations. Furthermore this study addresses one of the main drawbacks of the existing VDA models. They use the simple force-restore equation for soil heat diffusion as a physical constraint. The force-restore equation provides a simplified description of the LST dynamics. Also, its performance is highly affected by the specification of a deep ground temperature. These shortcomings cause significant errors in the diurnal dynamics of heat diffusion in the soil and ultimately the retrieval of components of surface energy balance. This study advances the VDA scheme by using the full heat diffusion equation as a constraint in lieu of the forcerestore approximation. The new VDA scheme is tested over several experimental field sites. The results show that inclusion of the heat diffusion equation decreases the phase error associated with the ground heat flux diurnal cycle, and improves surface heat flux estimation. The VDA scheme is further advanced by incorporating model uncertainty in order to account for measurement and model errors. Tests indicate that the VDA scheme with model uncertainty captures measurement errors as well as structural model errors. In order to provide coupled estimates of surface heat fluxes and vegetation dynamics, remotely sensed LST and fraction of photosynthetically active radiation are assimilated into a surface energy balance and a vegetation dynamics model. The application of the assimilation over West Africa shows that the scheme provides reliable estimates of important vegetation dynamics parameters that are required for understanding the role of plant phenology on surface energy balance and vice-versa.
by Sayed Mohyeddin Bateni.
Ph.D.

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Germer, Sonja. "Near-surface hydrology and hydrochemistry under contrasting land-cover." Phd thesis, Universität Potsdam, 2008. http://opus.kobv.de/ubp/volltexte/2008/1904/.

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Human transformation of the Earth’s land surface has far-reaching and important consequences for the functioning of hydrological and hydrochemical processes in watersheds. In nowadays land-use change from forest to pasture is a major issue in particular in the tropics. A sustainable management of deforested areas requires an in-depth understanding of the water and nutrient cycle. On this basis we compared the involved hydrological pathways for rainfall to reach streams and the nutrient budgets of a tropical rainforest and a pasture. In addition we studied the links of hydrochemical differences to differences of the relative importance of flowpaths. This study was conducted in the southwestern part of the Brazilian Amazon basin. An intensive hydrological and hydrochemical sampling and monitoring network was set up. The results indicate that the hydrology was modified in many ways due to land-use change. The most important alteration was the increased importance of the fast flowpath overland flow. Solute exports were in particular linked to the increased volume of overland flow that resulted from the land-use change. An additional reason for the increased nutrient exports from the pasture are the high concentrations of these nutrients in pasture overland flow probably as a due to cattle excrements. Tight nutrient cycles with minimal nutrient losses could not be maintained after the land-use change. This study provides the first attempt to quantify the respective nutrient losses.
Die Zerstörung von natürlicher Vegetation kann weit reichende Folgen auf den Wasser- und Nährstoffhaushalt von Ökosystemen haben. Der Landnutzungswandel vom Wald zur Weide ist heute in den Tropen ein wichtiges Thema. Eine nachhaltige Nutzung abgeholzter Gebiete setzt ein fundiertes Wissen des Wasser- und Nährstoffhaushaltes voraus. Darauf aufbauend wurden in dieser Studie das Abflussverhalten und die Nährstoffbilanzen von einem tropischem Regenwald und einer Weide verglichen. Außerdem wurde untersucht inwieweit die Nährstoffbilanzen vom Abflussverhalten abhängen. Die Untersuchungsgebiete liegen im südwestlichen brasilianischen Amazonasgebiet. Ein umfangreiches System zur Aufnahme von hydrologischen Daten und zum Sammeln von Wasserproben wurde aufgebaut. Die Ergebnisse haben gezeigt, dass sich das Abflussverhalten durch die Landnutzung geändert hat. Die wichtigste Änderung vom Wald zur Weide war der gesteigerte Anteil des schnellen Wasserabflusses auf der Geländeoberfläche. Hieraus resultierten gesteigerte Nährstoffausträge aus der Weide gegenüber dem Wald. Ein weiterer Grund für die gesteigerten Nährstoffausträge sind die hohen Konzentrationen dieser Stoffe im Oberflächenabfluss der Weide, die vermutlich mit den Ausscheidungen des Viehs zusammenhängen. Es hat sich also gezeigt, dass der quasi-geschlossene Nährstoffkreislauf nach der Landnutzungsänderung nicht aufrecht erhalten werden konnte. Diese Arbeit liefert den ersten Versuch diese Nährstoffverluste zur quantifizieren.

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Dash, Prasanjit. "Land surface temperature and emissivity retrieval from satellite measurements." Karlsruhe : Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft, 2005. http://bibliothek.fzk.de/zb/berichte/FZKA7095.pdf.

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Elbag, Mark A. "Impact of surrounding land uses on surface water quality." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050306-155834/.

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Thesis (M.S.)--Worcester Polytechnic Institute.
Keywords: Conductivity, pH, Dissolved Oxygen, UV absorbance, Source Water, Surface Water, Dissolved Organic Carbon, Total Organic Carbon, Particle Counts, Turbidity, E. coli, Fecal Coliforms, West Boylston Brook, Wachusett Reservoir, source water protection, surface water protection Includes bibliographical references (p.73-77).

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Gustafsson, David. "Land surface heat exchange over snow and frozen soil." Licentiate thesis, KTH, Land and Water Resources Engineering, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1231.

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The energy exchange in the soil-snow-vegetation-atmospheresystem was studied to improve the quantitative knowledge of thegoverning processes. The lack of such knowledge contributes tothe uncertainty in the applicability of many existing modelsindependent of the temporal or spatial scale. The theoreticalbackground and available methods for measurements and numericalsimulations were reviewed. Numerical simulation models andavailable data sets representing open land and boreal forestwere evaluated in both diurnal and seasonal time-scales.Surface heat fluxes, snow depth, soil temperatures andmeteorological conditions were measured at an agriculturalfield in central Sweden over two winters, 1997-1999. Twoone-dimensional simulation models of different complexity wereused to simulate the heat and water transfer in thesoil-snow-atmosphere system and compared with the measurements.Comparison of simulated and observed heat fluxes showed thatparameter values governing the upper boundary condition weremore important than the formulation of the internal mass andheat balance of the snow cover. The models were useful toevaluate the lack of energy balance closure in the observedsurface heat fluxes, which underlined the importance ofimproved accuracy in eddy correlation measurements of latentflow during winter conditions.

The representation of boreal forest in the land surfacescheme used within a weather forecast model was tested with athree-year data set from the NOPEX forest site in centralSweden. The formulation with separate energy balances forvegetation and the soil/snow beneath tree cover improvedsimulation of the seasonal and diurnal variations of latent andsensible heat flux compared with an older model version.Further improvements of simulated surface heat fluxes could beexpected if the variation of vegetation properties within andbetween years and a new formulation of the boundary conditionsfor heat flux into the soil is included.

Keywords: Surface energy balance, Snow, Boreal forest,SVAT models, Eddy-correlation Measurements, Latent heat flux,Sensible heat flux, Net radiation, Soil temperature,Aerodynamic roughness, Surface resistance

QC 20100614

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Liu, Yuqiong. "Parameter Estimations For Locally Coupled Land Surface-Atmosphere Models." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/191262.

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As land-surface modeling moves from the off-line mode to the coupled mode, it is also highly desirable to extend the off-line calibration of land-surface models to coupled applications. Using the NCAR SCCM as an example, this study proposed and implemented some effective schemes for the application of automatic parameter estimation procedures in a locally coupled environment, where other relevant issues such as parameterization tests, sensitivity analyses, and off-line calibrations were also involved. A parameterization deficiency having serious negative impacts on the performance of the NCAR SCCM was identified and rectified in this work, which led to significantly improved model performances and formed the basis for the subsequent sensitivity analysis and calibration experiments. To facilitate the calibration studies, an independent sensitivity analysis was conducted to identify some sensitive model parameters, followed by a multi-objective sensitivity analysis using the MOGSA algorithm to obtain better understanding of the model. Some off-line calibrations using the NCAR LSM were also conducted for comparison purposes. In the locally coupled environment, both land-surface and atmospheric variables/parameters were involved in the calibration processes of 14 different predesigned calibration cases. In brief, the results show that atmospheric parameters are of critical importance for the calibration of a coupled land surface-atmosphere model, and atmospheric forcing variables generally contain more useful information for calibration than land-surface fluxes/variables. In the coupled environment, step-wise calibration schemes, with land-surface and atmospheric parameters optimized successively in the off-line and coupled modes, respectively, appear to be superior to the single-step calibration schemes which optimize land-surface and atmospheric parameters simultaneously in the coupled environment, in that the former can provide better converged optimal solutions with less uncertainties. In addition, the results also show that better optimization effects can be achieved in the partially decoupled environment by replacing the model-generated precipitation and net radiation with the corresponding observations to drive the land-surface part of the model, indicating the dominant importance of precipitation and radiation in a coupled land surface-atmosphere model.

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Rosolem, Rafael. "Land Surface Processes In Natural and Artificial Tropical Ecosystems." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194510.

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Land Surface Parameterization (LSP) schemes have evolved from simple tipping-bucket models to fully interactive models, including parameterizations which account for exchanges of momentum, energy, mass, and biogeochemistry. As the demand for greater realism has increased, so has the complexity of LSPs which now includes some parameters that may not be universally relevant to all regions of the globe. The performance of LSP schemes depends on the magnitude of structural, data-related (input and output), and parameter uncertainties in the model. Parameter estimation uncertainty can be reduced by calibrating LSPs against measurements available at field sites. Given the multiple outputs of the models, multi-objective optimization approaches are performed. Some of the parameter values used in LSPs have originally obtained from laboratory studies which analyzed plant behavior under a range of conditions in enclosed chambers. The research described in this dissertation takes advantage of currently available data from several eddy covariance flux towers located mainly in the Brazilian Amazon basin to estimate parameter values of a widely-used LSP scheme, version 3 of the Simple Biosphere model (SiB3). Background climatological data was used to assess the representativeness of the data collection period that might have affected model calibration. Variance-based sensitivity analysis was then used to investigate potential structural deficiencies in SiB3 and to reduce the dimensionality of the subsequent optimization by identifying those model parameters that merit calibration. Finally, some structural and conceptual aspects of SiB3 were tested inside Biosphere 2 Tropical Rain Forest biome (B2-TRF) under meteorological conditions that resemble those predicted in future climate scenarios for the Amazon basin.

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Decker, Mark Ryan. "IMPROVING THE HYDROLOGICAL CYCLE IN LAND SURFACE CLIMATE MODELS." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/195627.

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The hydrological components of land surface climate models have increased greatly in complexity over the past decade, from simple bucket models to multilayer models including separate and distinct soil water and ground water components. While the parameterizations included in these models have also increased in complexity, the fundamental ability of the numerical solution for the vertical movement of soil water in the Community Land Model (or other land surface models) to simply maintain the hydrostatic solution of the original partial differential equation has yet to be determined.Also, the ability of current generation reanalysis products to simulate near surface quantities as gauged by flux tower measurements has yet to be determined.This study demonstrates that the numerical solution as used in CLM3.5 cannot maintain the hydrostatic state. An alternate form of the equation, titled the Modified Richards equation is presented so that the numerical solution maintains steady statesolutions. Also, an improved and simple bottom boundary condition is derived that itself doesn't destroy hydrostatic initial conditions. The new solution is demonstrated to be as accurate as proven numerical solutions while being one to three orders more computationally efficient. The Modified Richards equation together with the new bottom boundary condition is shown to improve the ability of CLM to simulate soil water, water table depth, and near surface turbulent fluxes.Comparison with flux tower observations shows that ERA-Interim better simulates near surface temperature and wind speed than other current generation reanalysis products. Reanalysis products are able to reproduce the flux tower observations on monthly timescales, and the errors between the products and the measurements are primarily due to biases. However, at six hourly timescales the errors are not only larger but also caused primarily by a lack of correlation with the observations.

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22

Ashton, Heather Suzanne. "Evaluating land surface model simulations of European summertime evapotranspiration." Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529966.

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23

Mitchell, Bruce Coffyn. "Urbanization and Land Surface Temperature in Pinellas County, Florida." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3250.

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Since the early 1800's, many studies have recognized increased heat in urban areas, known as the urban heat island (UHI) effect, as one of the results of human modification to the natural landscape. UHI is related to differences in land surface temperature (LST) between rural areas and urban areas where factors of the built environment such as the thermodynamic capacities of materials, structural geometry, and heat generating activities cause increased storage and re-radiation of heat to the atmosphere. This thesis examines the correlation between factors of urbanization and differences in land surface temperature (LST) in the subtropical climate of Pinellas County, Florida using remote sensing techniques. It describes the spatial pattern of LST, analyzes its relationship to factors of urbanization relative to NDVI, percentage of impervious surface, and land use land cover in the study area. It also assesses the effectiveness of remote sensing as an efficient method of identifying LST patterns at the local and neighborhood level for mitigation strategies. Landsat TM thermal band imagery for three dates; April 1986, 2001 and 2009 was processed using Qin's mono-window algorithm (MWA) technique to derive LST levels. This data was compared to in-situ readings, then normalized and statistically analyzed for correlation with vegetation ratio (NDVI) and imperviousness percentages derived using linear spectral mixing/unmixing, and also with land use/land cover classification. The resulting LST spatial pattern is a gradient across the peninsular landscape, from cooler water and wetland areas to a generally warmer interior, interspersed with micro-urban heat islands (MUHIs), corresponding to urban structures and "cool-islands" of parkland and lakes. Correspondence between LST pattern and urban structures and land use demonstrates the suitability of medium resolution remote sensing data and techniques for identifying micro-urban heat islands (MUHIs) for possible mitigation. Mitigation could include relatively low-cost measures like replacement of inefficient asphalt roofs with more reflective and emissive "cool roofs," placement of "street trees" to enhance shade, and replacement of impervious pavements by permeable surfaces. The thesis concludes that Landsat TM imagery processed with the MWA provides an efficient, relatively low-cost method for locating MUHIs. Satellite remote sensing, combined with aerial photography can facilitate neighborhood level analysis for the implementation of low-cost mitigation techniques. Previous studies have demonstrated that these are successful ways to mitigate the UHI effect at the micro-scale level; lowering urban heat and saving energy, and also facilitating the reintegration of natural elements into the urban environment.

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Kim, Hye-Yun. "Estimation of land surface radiation budget from MODIS data." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8577.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2008.
Thesis research directed by: Dept. of Geography. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Hamman, Joseph, Bart Nijssen, Michael Brunke, John Cassano, Anthony Craig, Alice DuVivier, Mimi Hughes, et al. "Land Surface Climate in the Regional Arctic System Model." AMER METEOROLOGICAL SOC, 2016. http://hdl.handle.net/10150/621720.

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The Regional Arctic System Model (RASM) is a fully coupled, regional Earth system model applied over the pan-Arctic domain. This paper discusses the implementation of the Variable Infiltration Capacity land surface model (VIC) in RASM and evaluates the ability of RASM, version 1.0, to capture key features of the land surface climate and hydrologic cycle for the period 1979-2014 in comparison with uncoupled VIC simulations, reanalysis datasets, satellite measurements, and in situ observations. RASM reproduces the dominant features of the land surface climatology in the Arctic, such as the amount and regional distribution of precipitation, the partitioning of precipitation between runoff and evapotranspiration, the effects of snow on the water and energy balance, and the differences in turbulent fluxes between the tundra and taiga biomes. Surface air temperature biases in RASM, compared to reanalysis datasets ERA-Interim and MERRA, are generally less than 2 degrees C; however, in the cold seasons there are local biases that exceed 6 degrees C. Compared to satellite observations, RASM captures the annual cycle of snow-covered area well, although melt progresses about two weeks faster than observations in the late spring at high latitudes. With respect to derived fluxes, such as latent heat or runoff, RASM is shown to have similar performance statistics as ERA-Interim while differing substantially from MERRA, which consistently overestimates the evaporative flux across the Arctic region.

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26

Elbag, Jr Mark A. "Impact of Surrounding Land Uses on Surface Water Quality." Digital WPI, 2006. https://digitalcommons.wpi.edu/etd-theses/665.

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Source water protection is important to maintain public health by keeping harmful pathogens out of drinking water. Non-point source pollution is often times a major contributor of pollution to surface waters, and this form of pollution can be difficult to quantify. This study examined physical, chemical, and microbiological water quality parameters that may indicate pollution and may help to identify sources of pollution. These included measures of organic matter, particles, and indicator organisms (fecal coliforms and E. coli). The parameters were quantified in the West Boylston Brook, which serves as a tributary to the Wachusett Reservoir and is part of the drinking water supply for the Metropolitan Boston area. Water quality was determined over four seasons at seven locations in the brook that were selected to isolate specific land uses. The water quality parameters were first analyzed for trends by site and by season. Then, a correlation analysis was performed to determine relationships among the water quality parameters. Lastly, ANOVA analyses were used to determine statistically significant variations in water quality along the tributary.

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Bi, Yuyun. "Estimation of land surface evapotranspiration from remotely sensed data." Strasbourg, 2010. https://publication-theses.unistra.fr/public/theses_doctorat/2010/BI_Yuyun_2010.pdf.

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L’évapotranspiration (ET) joue un rôle important en hydrologie, météorologie et en agriculture et l’estimation précise de l’ET régionale à différentes échelles temporelles et spatiales est essentielle pour ces disciplines. La télédétection est identifiée comme le seul moyen rationnel de cartographier l’ET de la surface terrestre à l’échelle régionale de façon globale, cohérente et économiquement raisonnable. Cette thèse porte donc sur l’élaboration et la mise au point de méthodes permettant de déterminer l’ET régionale des surfaces terrestres à partir des données de l’instrument MODIS à bord des satellites polaires Terra et Aqua. Le travail de cette thèse a permis de montrer les atouts de la méthode de triangle Ts-VI par rapport aux autres méthodes traditionnellement utilisées pour la détermination de l’ET régionale et de proposer des méthodes permettant de calculer la température de surface et l’émissivité de surface à partir des luminances mesurées par les satellites. Cette thèse a montré également qu’il était possible d’estimer l’ET sur des régions arides et semi-arides à partir uniquement de données satellitaires et ce avec une précision acceptable. Elle ouvre des perspectives intéressantes. Dans la restitution de l’ET régionale, l'exactitude de cette restitution dépend principalement de l'exactitude de la détermination quantitative des limites sèche et humide dans le triangle Ts-VI et de la performance du modèle d'interpolation impliqué dans l'évaluation de la fraction évaporative. Les performances du modèle et du nouvel algorithme développé dans cette étude devront donc être évaluées de façon précise et avec attention
Evapotranspiration (ET) plays an important role in hydrology, meteorology, and agriculture. Accurate estimates of regional ET at different temporal and spatial scales are essential in these disciplines. Remote sensing technology is recognized as the only viable means to map regional- and meso-scale patterns of ET at the earth’s surface in a globally consistent and economically feasible manner and surface temperature helps to establish the direct link between surface radiances and the components of surface energy balance. This thesis thus concerns the methodological development permitting to determine the regional land surface ET from the MODIS data onboard the polar satellites Terra and Aqua. The work of this thesis showed the advantage of the Ts-VI triangle method compared to the other methods traditionally employed for the determination of the regional ET and proposed methods to calculate land surface temperature and emissivity from the radiances measured by the satellites. This thesis showed also that it was possible to estimate ET in arid and semi-arid areas only from the satellite data with an acceptable precision. This work opens interesting prospects. In the restitution of regional ET, the exactitude of this restitution depends mainly on the exactitude of the dry and wet edges determination in the Ts-VI triangle and on the performance of the interpolation model involved in the evaluation of the evaporative fraction in the ET estimation model. The performances of the model and the new algorithm developed in this study have to be evaluated in the future in a precise and attentive way

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Kariyeva, Jahan. "LAND SURFACE PHENOLOGICAL RESPONSES TO LAND USE AND CLIMATE VARIATION IN A CHANGING CENTRAL ASIA." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/193619.

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During the last few decades Central Asia has experienced widespread changes in land cover and land use following the socio-economic and institutional transformations of the region catalyzed by the USSR collapse in 1991. The decade-long drought events and steadily increasing temperature regimes in the region came on top of these institutional transformations, affecting the long term and landscape scale vegetation responses. This research is based on the need to better understand the potential ecological and policy implications of climate variation and land use practices in the contexts of landscape-scale changes dynamics and variability patterns of land surface phenology responses in Central Asia. The land surface phenology responses - the spatio-temporal dynamics of terrestrial vegetation derived from the remotely sensed data - provide measurements linked to the timing of vegetation growth cycles (e.g., start of growing season) and total vegetation productivity over the growing season, which are used as a proxy for the assessment of effects of variations in environmental settings. Local and regional scale assessment of the before and after the USSR collapse vegetation response patterns in the natural and agricultural systems of the Central Asian drylands was conducted to characterize newly emerging links (since 1991) between coupled human and natural systems, e.g., socio-economic and policy drivers of altered land and water use and distribution patterns. Spatio-temporal patterns of bioclimatic responses were examined to determine how phenology is associated with temperature and precipitation in different land use types, including rainfed and irrigated agricultural types. Phenological models were developed to examine relationship between environmental drivers and effect of their altitudinal and latitudinal gradients on the broad-scale vegetation response patterns in non-cropland ecosystems of the desert, steppe, and mountainous regional landscapes of Central Asia.The study results demonstrated that the satellite derived measurements of temporal cycles of vegetation greenness and productivity data was a valuable bioclimatic integrator of climatic and land use variation in Central Asia. The synthesis of broad-scale phenological changes in Central Asia showed that linkages of natural and human systems vary across space and time comprising complex and tightly integrated patterns and processes that are not evident when studied separately.

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Kandel, Hari P. "Land Use /Land Cover Driven Surface Energy Balance and Convective Rainfall Change in South Florida." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2198.

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Modification of land use/land cover in South Florida has posed a major challenge in the region’s eco-hydrology by shifting the surface-atmosphere water and energy balance. Although drainage and development in South Florida took place extensively between the mid- and late- 20th century, converting half of the original Everglades into agricultural and urban areas, urban expansion still accounts for a dominant mode of surface cover change in South Florida. Changes in surface cover directly affect the radiative, thermophysical and aerodynamic parameters which determine the absorption and partitioning of radiation into different components at the Earth surface. The alteration is responsible for changing the thermal structure of the surface and surface layer atmosphere, eventually modifying surface-induced convection. This dissertation is aimed at analyzing the extent and pattern of land cover change in South Florida and delineating the associated development of urban heat island (UHI), energy flux alteration, and convective rainfall modification using observed data, remotely sensed estimates, and modeled results. Urban land covers in South Florida are found to have increased by 10% from 1974 to 2011. Higher Landsat-derived land surface temperatures (LST) are observed in urban areas (LSTu-r =2.8°C) with satisfactory validation statistics for eastern stations (Nash-Sutcliffe coefficient =0.70 and R2 =0.79). Time series trends, significantly negative for diurnal temperature range (DTR= -1°C, p=0.005) and positive for lifting condensation level (LCL > 20m) reveal temporal and conspicuous urban-rural differences in nocturnal temperature (ΔTu-r = 4°C) shows spatial signatures of UHI. Spatially higher (urban: 3, forest: 0.14) and temporally increasing (urban: 1.67 to 3) Bowen’s ratios, and sensible heat fluxes exceeding net radiation in medium and high-intensity developed areas in 2010 reflect the effect of urbanization on surface energy balance. Radar reflectivity-derived surface-induced convective rainfall reveals significantly positive mean differences (thunderstorm cell density: 6/1000 km2and rain rate: 0.24 mm/hr/summer, p < 0.005) between urban and entire South Florida indicating convective enhancement by urban covers. The research fulfils its two-fold purposes: advancing the understanding of post-development hydrometeorology in South Florida and investigating the spatial and temporal impacts of land cover change on the microclimate of a subtropical city.

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Manrique-Sunen, A. "The treatment of vegetation in land surface models : implications for predictions of land-atmosphere exchange." Thesis, University of Reading, 2016. http://centaur.reading.ac.uk/68719/.

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Plant processes affect fluxes of energy, moisture and CO2 between the land and the atmosphere. Land surface models need to correctly represent the vegetation functioning and its response to environmental conditions. Due to anthropogenic carbon emissions rising, and global warming, plant processes are being affected and in turn modulate the terrestrial carbon sink. However, models still disagree on the response of plants to changing conditions. This work analyses how vegetation is treated in two land surface models: the Joint UK Land Environment Simulator (JULES) and Carbon Hydrology Tiled ECMWF Scheme for Surface Exchanges over Land (CTESSEL). The aim is to analyse how environmental variables control the vegetation processes at daily and seasonal timescales at present day climate and the changes that arise in a scenario of double atmospheric CO2 and higher temperature. The analyses are carried out at the leaf level and at the canopy level. To investigate the responses at the leaf level, the photosynthesis scheme used in each model was extracted, thereby providing a submodel that can be run in stand alone mode. The photosynthesis submodel provides a means to analyse the leaf level response of each photosynthesis model to environment variables as well as the internal model parameters that characterise each plant type. In JULES the environmental controls on photosynthesis are explicitly introduced by three limiting regimes: light, rubisco (carbon) or export limiting regime. In CTESSEL the carbon and light limitations are implicitly represented but there is no export limitation. Due to the lack of export limiting regime, CTESSEL presents higher sensitivity to CO2 concentration resulting in a stronger CO2 fertilization effect. The carbon and energy fluxes produced by the full land surface models were tested and compared at 10 European FLUXNET sites. The main differences between modellled carbon fluxes were found to be the treatment of soil moisture stress and the lack of export limiting regime in CTESSEL. The optimum temperature for photosynthesis in models is the result of model parameters’ dependence on temperature and the combination of limiting regimes. The optimum temperature for photosynthesis was found to be a determining element in the strength and sign of the vegetation modelled feedback to climate change.

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31

Chingombe, Wisemen. "Effects of land-cover - land-use on water quality within the Kuils - Eerste River catchment." Thesis, University of Western Cape, 2012. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5893_1373463134.

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The most significant human impacts on the hydrological system are due to land-use change. The conversion of land to agricultural, mining, industrial, or residential uses significantly alters the hydrological characteristics of the land surface and modifies pathways and rates of water flow. If this occurs over large or critical areas of a catchment, it can have significant short and long-term impacts, on the quality of water. While there are methods available to quantify the pollutants in surface water, methods of linking non-point source pollution to water quality at catchment scale are lacking. Therefore, the research presented in this thesis investigated modelling techniques to estimate the effect of land-cover type on water quality. The main goal of the study was to contribute towards improving the understanding of how different land-covers in an urbanizing catchment affect surface water quality. The aim of the research presented in this thesis was to explain how the quality of surface runoff varies on different land-cover types and to provide guidelines for minimizing water pollution that may be occurring in the Kuils-Eerste River catchment. The research objectives were
(1) to establish types and spatial distribution of land-cover types within the Kuils-Eerste River catchment, (2) to establish water quality characteristics of surface runoff from specific land-cover types at the experimental plot level, (3) to establish the contribution of each land-cover type to pollutant loads at the catchment scale. Land-cover characteristics and water quality were investigated using GIS and Remote Sensing tools. The application of these tools resulted in the development of a land-cover map with 36 land classifications covering the whole catchment. Land-cover in the catchment is predominantly agricultural with vineyards and grassland covering the northern section of the catchment. Vineyards occupy over 35% of the total area followed by fynbos (indigenous vegetation) (12.5 %), open hard rock area (5.8 %), riparian forest (5.2 %), mountain forest

(5 %), dense scrub (4.4 %), and improved grassland (3.6 %). The residential area covers about 14 %. Roads cover 3.4 % of the total area. Surface runoff is responsible for the transportation of large quantities of pollutants that affect the quality of water in the Kuils-Eerste River catchment. The different land-cover types and the distribution and concentration levels of the pollutants are not uniform. Experimental work was conducted at plot scale to understand whether land-cover types differed in their contributions to the concentration of water quality attributes emerging from them. Four plots each with a length of 10 m to 12 m and 5 m width were set up. Plot I was set up on open grassland, Plot II represented the vineyards, Plot III covered the mountain forests, and Plot IV represented the fynbos land-cover. Soil samples analyzed from the experimental plots fell in the category of sandy soil (Sa) with the top layer of Plot IV (fynbos) having loamy sand (LmSa). The soil particle sizes range between fine sand (59.1 % and 78.9 %) to coarse sand (between 7 % and 22 %). The content of clay and silt was between 0.2 % and 2.4 %. Medium sand was between 10.7 % and 17.6 %. In terms of vertical distribution of the particle sizes, a general decrease with respect to the size of particles was noted from the top layer (15 cm) to the bottom layer (30 cm) for all categories of the particle sizes. There was variation in particle size with depth and location within the experimental plots.Two primary methods of collecting water samples were used
grab sampling and composite sampling. The quality of water as represented by the samples collected during storm events during the rainfall season of 2006 and 2007 was
used to establish
water quality characteristics for the different land-cover types. The concentration of total average suspended solids was highest in the following land-cover types, cemeteries (5.06 mg L^-1), arterial roads/main roads (3.94 mg L^-1), low density residential informal squatter camps (3.21 mg L^-1) and medium density residential informal townships (3.21 mg L^-1). Chloride concentrations were high on the following land-cover types, recreation grass/ golf course (2.61 mg L^-1), open area/barren land (1.59 mg L^-1), and improved grassland/vegetation crop (1.57 mg L^-1). The event mean concentration (EMC) values for NO₃-N were high on commercial mercantile (6 mg L^-1) and water channel (5 mg L^-1). The total phosphorus concentration mean values recorded high values on improved grassland/vegetation crop (3.78 mg L^-1), medium density residential informal townships (3mgL^-1) and low density residential informal squatter camps (3 mg L^-1). Surface runoff may also contribute soil particles into rivers during rainfall events, particularly from areas of disturbed soil, for example areas where market gardening is taking place. The study found that different land cover types contributed differently to nonpoint source pollution. A GIS model was used to estimate the diffuse pollution of five pollutants (chloride, phosphorus, TSS, nitrogen and NO₃-N) in response to land cover variation using water quality data. The GIS model linked land cover information to diffuse nutrient signatures in response to surface runoff using the Curve Number method and EMC data were developed. Two models (RINSPE and N-SPECT) were used to estimate nonpoint source pollution using various GIS databases. The outputs from the GIS-based model were compared with recommended water quality standards. It was found that the RINSPE model gave accurate results in cases where NPS pollution dominate the total pollutant inputs over a given land cover type. However, the N-SPECT model simulations were too uncertain in cases where there were large numbers of land cover types with diverse NPS pollution load. All land-cover types with concentration values above the recommended national water quality standard were considered as areas that needed measures to mitigate the adverse effects of nonpoint pollution. The expansion of urban areas and agricultural land has a direct effect on land cover types within the catchment. The land cover changes have adverse effect which has a potential to contribute to pollution.

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James, Tosin. "Changes in Land Use Land Cover (LULC), Surface Water Quality and Modelling Surface Discharge in Beaver Creek Watershed, Northeast Tennessee and Southwest Virginia." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etd/3747.

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Beaver Creek is an impaired streams that is not supporting its designated use for recreation due to Escherichia coli (E.coli), and sediment. To address this problem, this thesis was divided into two studies. The first study explored changes in Land Use Land Cover (LULC), and its impact on surface water quality. Changes in E.coli load between 1997-2001 and 2014-2018 were analyzed. Also, Landsat data of 2001, and 2018 were examined in Terrset 18.31. Mann-Whitney test only showed a significant reduction in E.coli for one site. Negative correlation was established between E.coli load, and Developed LULC, Forest LULC, and Cultivated LULC. The second study modelled discharge for Beaver Creek watershed using HEC-HMS. This study simulated discharge in an upstream sub-watershed of Beaver Creek, and the full Beaver Creek with a Nash-Sutcliffe of 0.007, and R2 0.20. Sub-basins with high discharge were identified for further examination for possible high sediment load.

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Goncalves, de Goncalves Luis Gustavo. "LAND SURFACE-ATMOSPHERE INTERACTIONS IN REGIONAL MODELING OVER SOUTH AMERICA." Diss., The University of Arizona, 2005. http://hdl.handle.net/10150/195893.

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Land surface processes play an important role when modeling weather and climate, and understanding and representing such processes in South America is a particular challenge because of the large variations in regional climate and surface features such as vegetation and soil. Numerical models have been used to explore the climate and weather of continental South America, but without appropriate initiation of land surface conditions model simulations can rapidly diverge from reality. This initiation problem is exacerbated by the fact that conventional surface observations over South America are scarce and biased towards the urban centers and coastal areas. This dissertation explores issues related to the apt representation of land surface processes and their impacts in numerical simulations with a regional atmospheric model (specifically the Eta model) over South America. The impacts of vegetation heterogeneity in regional weather forecast were first investigated. A South American Land Data Assimilation System (SALDAS) was then created analogous to that currently used in North America to estimate soil moisture fields for initializing regional atmospheric models. The land surface model (LSM) used in this SALDAS is the Simplified Simple Biosphere (SSiB). Precipitation fields are critical when calculating soil moisture and, because conventional surface observations are scarce in South America, some of the most important remote sensed precipitation products were evaluated as potential precipitation forcing for the SALDAS. Spin up states for SSiB where then compared with climatological estimates of land surface fields and significant differences found. Finally, an assessment was made of the value of SALDAS-derived soil moisture fields on Eta model forecasts. The primary result was that model performance is enhanced over the entire continent in up to 72h forecasts using SALDAS surface fields

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Bobrinskaya, Maria. "Remote Sensing for Analysis of Relationships between Land Cover and Land Surface Temperature in Ten Megacities." Thesis, KTH, Geodesi och geoinformatik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-121277.

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Urbanization is one of the most significant phenomena of the anthropogenic influence on the Earth’s environment. One of the principal results of the urbanization is the creation of megacities, with their local climate and high impact on the surrounding area. The design and evolution of an urban area leads to higher absorption of solar radiation and heat storage in which is the foundation of the urban heat island phenomenon. Remote sensing data is a valuable source of information for urban climatology studies. The main objective of this thesis research is to examine the relationship between land use and land cover types and corresponding land surface temperature, as well as the urban heat island effect and changes in these factors over a 10 year period. 10 megacities around the world where included in this study namely Beijing (China), Delhi (India), Dhaka (Bangladesh), Los Angeles (USA), London (UK), Mexico City (Mexico), Moscow (Russia), New York City (USA), Sao Paulo (Brazil) and Tokyo (Japan). Landsat satellite data were used to extract land use/land cover information and their changes for the abovementioned cities. Land surface temperature was retrieved from Landsat thermal images. The relationship between land surface temperature and landuse/land-cover classes, as well as the normalized vegetation index (NDVI) was analyzed. The results indicate that land surface temperature can be related to land use/land cover classes in most cases. Vegetated and undisturbed natural areas enjoy lower surface temperature, than developed urban areas with little vegetation. However, the cities show different trends, both in terms of the size and spatial distribution of urban heat island. Also, megacities from developed countries tend to grow at a slower pace and thus face less urban heat island effects than megacities in developing countries.

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Yang, Zhao, and Zhao Yang. "Land-Atmosphere Interactions Due to Anthropogenic and Natural Changes in the Land Surface: A Numerical Modeling." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/623069.

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Alterations to the land surface can be attributed to both human activity and natural variability. Human activities, such as urbanization and irrigation, can change the conditions of the land surface by altering albedo, soil moisture, aerodynamic roughness length, the partitioning of net radiation into sensible and latent heat, and other surface characteristics. On the other hand, natural variability, manifested through changes in atmospheric circulation, can also induce land surface changes. These regional scale land surface changes, induced either by humans or natural variability, can effectively modify atmospheric conditions through land-atmosphere interactions. However, only in recent decades have numerical models begun to include representations of the critical processes driving changes at the land surface, and their associated effects on the overlying atmosphere. In this work we explore three mechanisms by which changes to the land surface–both anthropogenic and naturally induced–impact the overlying atmosphere and affect regional hydroclimate. The first land-atmosphere interaction mechanism explored here is land-use and land-cover change (LULCC) due to urban expansion. Such changes alter the surface albedo, heat capacity, and thermal conductivity of the surface. Consequently, the energy balance in urban regions is different from that of natural surfaces. To evaluate the changes in regional hydroclimate that could arise due to projected urbanization in the Phoenix–Tucson corridor, Arizona, my first study applied the Weather Research and Forecasting (WRF) with an Urban Canopy Model (UCM; which includes a detailed urban radiation scheme) coupled to the Noah land surface model to this region. Land-cover changes were represented using land-cover data for 2005 and projections to 2050, and historical North American Regional Reanalysis (NARR) data were used to specify the lateral boundary conditions. Results suggest that temperature changes are well defined, reflecting the urban heat island (UHI) effect within areas experiencing LULCC, whereas changes in precipitation are less certain (statistically less robust). However, the study indicates the likelihood of reductions in precipitation over the mountainous regions northeast of Phoenix and decreased evening precipitation over the newly urbanized area. The second land-atmosphere interaction mechanism explored here is irrigation which, while being an important anthropogenic factor affecting the local to regional water cycle, is not typically represented in regional climate models. In this (second) study, I incorporated an irrigation scheme into the Noah land surface scheme coupled to the WRF model. Using a newly developed water vapor tracer package (developed by Miguez-Macho et al. 2013), the study tracks the path of water vapor that evapotranspires from the irrigated regions. To assess the impact of irrigation over the California Central Valley (CCV) on the regional climate of the U.S. Southwest, I ran six simulations (for three dry and three wet years), both with and without the irrigation scheme. Incorporation of the irrigation scheme resulted in simulated surface air temperature and humidity that were closer to observations, decreased the depth of the planetary boundary layer over the CCV, and increased the convective available potential energy. The results indicated an overall increase in precipitation over the Sierra Nevada Range and the Colorado River Basin during the summer, with water vapor rising from the irrigated region moving mainly northeastward and contributing to precipitation in Nevada and Idaho. The results also indicate an increase in precipitation on the windward side of the Sierra Nevada Range and over the Colorado River Basin. The former is possibly linked to a sea-breeze type circulation near the CCV, while the latter is likely associated with a wave pattern related to latent heat release over the moisture transport belt. In the third study, I investigated the role of large-scale and local-scale processes associated with heat waves using the Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis, and evaluate the performance of the regional climate model ensemble used in the North America Regional Climate Change Program (NARCCAP) in reproducing these processes. The Continental US is divided into different climate divisions (following the convention of the National Climate Assessment) to investigate different mechanisms associated with heat waves. At the large scale, warm air advection from terrestrial sources is a driving factor for heat waves in the Northeast and Midwest. Over the western United States, reduced maritime cool air advection results in local warming. At the local scale, an antecedent precipitation deficit leads to the continuous drying of soil moisture, more energy being partitioned into sensible heat flux and acting to warm surface air temperatures, especially over the Great Plains. My analysis indicates that the NARCCAP simulated large-scale meteorological patterns and temporal evolution of antecedent local-scale terrestrial conditions are very similar to those of MERRA. However, NARCCAP overestimates the magnitude and underestimates the frequency of Northeastern and Midwestern US heat waves, partially due to anomalous heat advection through large-scale forcing. Overall, the aforementioned studies show that utilization of new parameterizations in land surface models, such as the urban canopy scheme and the irrigation scheme, allow us to understand the detailed physical mechanisms by which anthropogenic changes in the land surface can affect regional hydroclimate, and may thus help with informed decision making and climate adaptation/mitigation. In addition to anthropogenic changes of the land surface, humans are of course affecting the overlying atmosphere. Currently, NARCCAP is the best available tool we have to help us understand the effects of changes greenhouse gas induced climate change at the regional scale. The regional climate models participating in NARCCAP are able to realistically represent the dominant processes associated with heat waves, including the atmospheric circulation changes and the land-atmosphere interactions that drive heat waves. This lends credibility, when analyzing the projections of these models with increased GHG emissions, to the assessment of changes in heat waves under a future climate.

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Gutmann, Ethan D. "The determination of soil hydraulic properties in land surface models from remotely sensed surface temperature." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3303868.

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Park, Jeonghwan. "Investigations of GNSS-R for Ocean Wind, Sea Surface Height, and Land Surface Remote Sensing." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1512095954817037.

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El, Vilaly Mohamed Abd salam Mohamdy. "Drought Monitoring with Remote Sensing Based Land Surface Phenology Applications and Validation." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/301553.

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Droughts are a recurrent part of our climate, and are still considered to be one of the most complex and least understood of all natural hazards in terms of their impact on the environment. In recent years drought has become more common and more severe across the world. For more than a decade, the US southwest has faced extensive and persistent drought conditions that have impacted vegetation communities and local water resources. The focus of this work is achieving a better understanding of the impact of drought on the lands of the Hopi Tribe and Navajo Nation, situated in the Northeastern corner of Arizona. This research explores the application of remote sensing data and geospatial tools in two studies to monitor drought impacts on vegetation productivity. In both studies we used land surface phenometrics as the data tool. In a third related study, I have compared satellite-derived land surface phenology (LSP) to field observations of crop stages at the Maricopa Agricultural Center to achieve a better understanding of the temporal sensitivity of satellite derived phenology of vegetation and understand their accuracy as a tool for monitoring change. The first study explores long-term vegetation productivity responses to drought. The paper develops a framework for drought monitoring and assessment by integrating land cover, climate, and topographical data with LSP. The objective of the framework is to detect long-term vegetation changes and trends in the Normalized Difference Vegetation Index (NDVI) related productivity. The second study examines the major driving forces of vegetation dynamics in order to provide valuable spatial information related to inter-annual variability in vegetation productivity for mitigating drought impacts. The third study tests the accuracy of remote sensing-derived LSP by comparing them to the actual seasonal phases of crop growth. This provides a way to compare and validate the various LSP algorithms, and more crucially, helps to characterize the remote sensing-based metrics that contrast with the actual biological phenophases of the crops. These studies demonstrate how remote sensing data and simple statistical tools can be used to assess drought effects on vegetation productivity and to inform about land conditions, as well as to better understand the accuracy of satellite derived LSP.

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Snelgrove, Kenneth Ross. "Implications of Lateral Flow Generation on Land-Surface Scheme Fluxes." Thesis, University of Waterloo, 2002. http://hdl.handle.net/10012/865.

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This thesis details the development and calibration of a model created by coupling a land surface simulation model named CLASS with a hydrologic model named WATFLOOD. The resulting model, known as WatCLASS, is able to serve as a lower boundary for an atmospheric model. In addition, WatCLASS can act independently of an atmospheric model to simulate fluxes of energy and moisture from the land surface including streamflow. These flux outputs are generated based on conservation equations for both heat and moisture ensuring result continuity. WatCLASS has been tested over both the data rich BOREAS domains at fine scales and the large but data poor domain of the Mackenzie River at coarse scale. The results, while encouraging, point to errors in the model physics related primarily to soil moisture transport in partially frozen soils and permafrost. Now that a fully coupled model has been developed, there is a need for continued research by refining model processes and test WatCLASS's robustness using new datasets that are beginning to emerge. Hydrologic models provide a mechanism for the improvement of atmospheric simulation though two important mechanisms. First, atmospheric inputs to the land surface, such as rainfall and temperature, are transformed by vegetation and soil systems into outputs of energy and mass. One of these mass outputs, which have been routinely measured with a high degree of accuracy, is streamflow. Through the use of hydrologic simulations, inputs from atmospheric models may be transformed to streamflow to assess reliability of precipitation and temperature. In this situation, hydrologic models act in an analogous way to a large rain gauge whose surface area is that of a watershed. WatCLASS has been shown to be able to fulfill this task by simulating streamflow from atmospheric forcing data over multi-year simulation periods and the large domains necessary to allow integration with limited area atmospheric models. A second, more important, role exists for hydrologic models within atmospheric simulations. The earth's surface acts as a boundary condition for the atmosphere. Besides the output of streamflow, which is not often considered in atmospheric modeling, the earth's surface also outputs fluxes of energy in the form of evaporation, known as latent heat and near surface heating, known as sensible heat. By simulating streamflow and hence soil moisture over the land surface, hydrologic models, when properly enabled with both energy and water balance capabilities, can influence the apportioning of the relative quantities of latent and sensible heat flux that are required by atmospheric models. WatCLASS has shown that by improving streamflow simulations, evaporation amounts are reduced by approximately 70% (1271mm to 740mm) during a three year simulation period in the BOREAS northern old black spruce site (NSA-OBS) as compared to the use of CLASS alone. To create a model that can act both as a lower boundary for the atmosphere and a hydrologic model, two choices are available. This model can be constructed from scratch with all the caveats and problems associated with proving a new model and having it accepted by the atmospheric community. An alternate mechanism, more likely to be successfully implemented, was chosen for the development of WatCLASS. Here, two proven and well tested models, WATFLOOD and CLASS, were coupled in a phased integration strategy that allowed development to proceed on model components independently. The ultimate goal of this implementation strategy, a fully coupled atmospheric - land surface - hydrologic model, was developed for MC2-CLASS-WATFLOOD. Initial testing of this model, over the Saguenay region of Quebec, has yet to show that adding WATFLOOD to CLASS produces significant impacts on atmospheric simulation. It is suspected, that this is due to the short term nature of the weather simulation that is dominated by initial conditions imposed on the atmospheric model during the data assimilation cycle. To model the hydrologic system, using the domain of an atmospheric model, requires that methods be developed to characterize land surface forms that influence hydrologic response. Methods, such as GRU (Grouped Response Unit) developed for WATFLOOD, need to be extended to taken advantage of alternate data forms, such as soil and topography, in a way that allows parameters to be selected a priori. Use of GIS (Geographical Information System) and large data bases to assist in development of these relationships has been started here. Some success in creating DEMs, (Digital Elevation Model) which are able to reproduce watershed areas, was achieved. These methods build on existing software implementations to include lake boundaries information as a topographic data source. Other data needs of hydrologic models will build on relationships between land cover, soil, and topography to assist in establishing grouping of these variables required to determine hydrologic similarity. This final aspect of the research is currently in its infancy but provides a platform from which to explore for future initiatives. Original contributions of this thesis are centered on the addition of a lateral flow generation mechanism within a land surface scheme. This addition has shown a positive impact on flux returns to the atmosphere when compared to measured values and also provide increased realism to the model since measured streamflow is reproduced. These contributions have been encapsulated into a computer model known as WatCLASS, which together with the implementation plan, as presented, should lead to future atmospheric simulation improvements.

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Franks, Stewart William. "The representation of land surface - atmosphere fluxes for atmospheric modelling." Thesis, Lancaster University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387430.

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Shepherd, Andrew. "Land surface temperature derived from the Along Track Scanning Radiometer." Thesis, University of Leicester, 1999. http://hdl.handle.net/2381/27902.

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Terrestrial radiometric surface temperatures were recorded at multiple observation angles in conjunction with satellite overpasses of the Along Track Scanning Radiometer (ATSR) over two florally distinct regions of Zimbabwe. The experimental sites were, respectively, an open grassland savannah and a medium density natural woodland, each of which extended over some 1000 square kilometers of predominantly flat terrain. The principal surface components at each location were vegetation and soil in varying proportions. Infrared brightness temperatures were corrected for atmospheric effects using solutions to the radiative transfer equation with coefficients derived from local atmospheric radiosoundings. The empirical equations of Idso (1981) and the RADGEN radiative transfer model (Zavody et al., 1995) were used to derive atmospheric emittance and transmittance for the in-situ and ATSR data respectively. Both in situ and ATSR derived radiative temperatures exhibited a pronounced angular variation over each surface, with differences upwards of 5°C between measurements at nadir and forward (55°) zenith angles. This effect has been attributed to the temperature differentials that exist within heterogeneous canopies, which typically display variations in vegetation cover related to the observation angle. A simple two component canopy architecture was coupled with a linear mixture model to partition the ensemble surface emission. The fractional vegetation cover was estimated using multi-angle radiative temperatures and was in excellent agreement with in situ estimates. Empirical equations were derived from the in situ data which related vegetation and soil temperatures at each location. These relationships were used to constrain the surface component temperature regime so that ATSR dual-angle radiative surface temperatures were sufficient to derive the vegetation and soil temperatures and fractional cover. The difference between canopy and soil temperatures separated using the dual-angle data was greater than 30°C at certain times of the year, and the modal standard deviation for all component temperature estimates was 3.2°C.

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Torbert, John Lee. "Reclamation of surface-mined forest land in the southern Appalachians /." This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-12232009-020803/.

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Shannon, Debbie Anne. "Land surface response to climate change forcing over Southern Africa." Doctoral thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/5286.

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The land surface is important to the climate system for the exchanges of moisture, momentum and heat. Momentum, radiation, and sensible and latent heat fluxes between the atmosphere and the surface will likely affect atmospheric dynamics, temperature, precipitation and humidity fields (Sato et ai., 1989). These may subsequently feed back into the land surface processes as part of a cyclical system. Therefore it is evident that our livelihood is largely dependent on interactions and exchanges between the land surface and climate system (Henderson-Sellers et ai., 1993) and it is thus essential that we gain a better understanding of the interactive sensitivity. This is of particular relevance in the context of the portended future global climate change. In the present study the interactions between the land surface and the atmosphere are considered over the southern African region. This region has a climate showing a high degree of spatial and temporal variability, most notably with rainfall. Regional climates are characterised by summer, winter and all-year-round rainfall. There are steep vegetation gradients and a wide range of vegetation types adapted to suit the variable climate. These factors, combined with the societal implications of changes in the climate and land surface systems, make southern Africa a challenging and important study domain for examining the sensitivity between the different elements of the atmosphere and biosphere. This research makes use of a biosphere model driven by climate change data derived from a general circulation model (GCM). Regions susceptible and sensitive to changes on an annual and seasonal basis are identified and examined. The thesis comprises 8 chapters. The first chapter, Chapter 1, provides some background information on climate change, biosphereatmosphere interactions, GCMs and transient simulations, vegetation models and vegetation representation over southern Africa. This chapter also sets out the research objectives. The following chapter, Chapter 2, introduces the atmospheric GCM model data from the Hadley Centre Model (HadCM2) used in the analysis. The chapter additionally provides a detailed description of the biosphere model, the Integrated Biosphere Simulator (IBIS). Chapter 3 examines the Hadley Centre HadCM2 GCM input data used in driving the biosphere model, while Chapter 4 presents the input forcing data and configuration of the IBIS model. In Chapter 5 the results of the IBIS model simulation are examined on the annual scale and in Chapter 6 the results are examined on the seasonal scale. Some of the implications of climate change are considered in Chapter 7. This chapter also places the HadCM2 GCM model data used in driving IBIS into the context of the latest emissions scenarios. In the final chapter, Chapter 8, an overview summary is provided and conclusions are drawn.

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Torbert, John L. "Reclamation of surface-mined forest land in the southern Appalachians." Diss., Virginia Tech, 1995. http://hdl.handle.net/10919/40485.

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Bibi, Umar Muhammed. "The impact of climate variability and land cover change on land surface conditions in North-eastern Nigeria." Thesis, University of Leicester, 2013. http://hdl.handle.net/2381/28170.

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Recent droughts in the West African Sahel have been the most catastrophic since modern records began posing a threat to the economy and security of the region. Two contending views have evolved in the scientific community to explain the causes of re-occurring droughts in the West African Sahel Region. These themes are “the regional land-atmosphere feedback” mechanism and “ocean-atmosphere interaction”. This study is specific to a part of West Africa the North-eastern part of Nigeria and attempts to examine the impact of climate variability and land cover change on land surface conditions of fluxes in energy and momentum in the past (1980-2000) and in the future (2046-2065) based on the IPCC A2 emission scenario. The level of recovery of the region from previous droughts in the 1980s was evaluated using the Standardised Precipitation Index (SPI) and linear regression to identify trends in monthly rainfall and number of rainy days in a month using monthly rainfall time series data between 1980 and 2006. The study further applies a range of stochastic linear models (ARIMA) to predict monthly rainfall time series over a 24 month period, a Cellular Automata –Markov model to project land cover for the year 2046, and a more dynamic land surface scheme the Joint UK Land Environment Simulator (JULES) for simulating past (1980-2000) and future (2046-2065) land surface conditions of soil moisture, soil temperature, surface runoff, Gross Primary Productivity (GPP), latent and sensible heat fluxes. GIS techniques are used to assemble data on soil texture and fractional land cover types used as boundary conditions required by JULES in some of the simulations. As part of the model evaluation process the JULES land surface model output of surface soil moisture is evaluated with an European Remote Sensing (ERS) satellite product. The sensitivity of the model to input data is examined through changes in scale and non-linearity in the calculation of soil hydraulic parameters. Results suggest that despite a recovery in rainfall in the 1990s from the previous droughts there is no significant recovery in monthly rainfall in the months following the onset of the wet season. The JULES model is more sensitive to scale than non-linearity in the calculation of soil hydraulic parameters. A strong correlation between the model’s near surface soil moisture and the ERS satellite near surface soil moisture product in areas where the satellite is believed to perform well, the RMSE and the similarities in the pattern of anomalies between the model and ERS satellite surface soil moisture is an indication of the ability of the model to successfully simulate land surface conditions in the study area. Simulations into the future (2046-2065) using the IPCC A2 emission scenario suggest a significant change in the land surface conditions due to changes in climatic conditions rather than changes in land cover fraction, despite a projected change in land cover based on previous trends from a predominantly broadleaf trees to a dominance of C4 grass (mostly croplands).

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Blyth, Eleanor M. "The effect of small scale heterogeneity on surface heat and moisture fluxes." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239806.

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McClean, Colin John. "The scale-free and scale-bound properties of land surfaces : fractal analysis and specific geomorphometry from digital terrain models." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/5999/.

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The scale-bound view of landsurfaces, being an assemblage of certain landforms, occurring within limited scale ranges, has been challenged by the scale-free characteristics of fractal geometry. This thesis assesses the fractal model by examining the irregularity of landsurface form, for the self-affine behaviour present in fractional Brownian surfaces. Different methods for detecting self-affine behaviour in surfaces are considered and of these the variogram technique is shown to be the most effective. It produces the best results of two methods tested on simulated surfaces, with known fractal properties. The algorithm used has been adapted to consider log (altitude variance) over a sample of log (distances) for: complete surfaces; subareas within surfaces; separate directions within surfaces. Twenty seven digital elevation models of landsurfaces arc re-examined for self- affine behaviour. The variogram results for complete surfaces show that none of these are self-affine over the scale range considered. This is because of dominant slope lengths and regular valley, spacing within areas. For similar reasons subarea analysis produces the non-fractal behaviour of markedly different variograms for separate subareas. The linearity of landforms in many areas, is detected by the variograms for separate directions. This indicates that the roughness of landsurfaces is anisotropic, unlike that of fractal surfaces. Because of difficulties in extracting particular landforms from their landsurfaces, no clear links between fractal behaviour, and landform size distribution could be established. A comparative study shows the geomorphometric parameters of fractal surfaces to vary with fractal dimension, while the geomorphometry of landsurfaces varies with the landforms present. Fractal dimensions estimated from landsurfaces do not correlate with geomorphometric parameters. From the results of this study, real landsurfaces would not appear to be scale- free. Therefore, a scale-bound approach towards landsurfaces would seem to be more appropriate to geomorphology than the fractal alternative.

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Löw, Alexander. "Coupled modelling of land surface microwave interactions using ENVISAT ASAR data." Diss., lmu, 2004. http://nbn-resolving.de/urn:nbn:de:bvb:19-27646.

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Shafley, William K. "Business architecture model for network centric surface combatant land attack warfare." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA397350.

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Thesis (M.S. in Information Technology Management) Naval Postgraduate School, Sept. 2001.
Thesis advisor(s): Jansen, Erik; Brock, Floyd. "September 2001." Includes bibliographical references (p.115-116). Also available in print.

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Ali, Inamullah. "Surface irrigation adapted to the land spreading of dairy farm effluent." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=83961.

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An important number of Canadian dairy farms manage their manure as solids and in doing so, must handle large volumes of manure seepages and milk house wastewater (dairy farm effluent-DFE). The present project adapted surface irrigation as a more economical and sustainable method of disposing of this large volume of DFE on cropped land near their storage facility. The experimental surface irrigation system consisted of a gated pipe installed perpendicular to the slope of the field allowing the discharged DFE to run down the slope.
The adaptation of the system and the measurement of its environmental impact were conducted on two dairy farms, A and B, in the region South West of Montreal where their DFE were characterized. In 2003 and 2004, DFE was applied on one of two 0.5 and 0.3ha plots, on each farm, to observe losses through the subsurface drainage system, by means of sampling wells, and effects on soil nutrient levels.
The DFE collected in 2002 and 2003 had a lower nutrient content than that collected in 2004 because of higher precipitations. The DFE generally contained between 150-500 mg/L of TKN, 15 to 40 mg/L of TP and 500 to 700 mg/L of TK.
DFE losses through the subsurface drainage system were observed on both farms during each irrigation test. Nevertheless, outlet losses were observed only when irrigating under wet soil conditions or when applying more than 50mm of DFE. Outlet losses represented at the most 1.2% of the total DFE volume applied and 0.32% of the nutrient and bacterial loads.
Although only 65 to 75% of the soil surface was covered by the applied DFE, the irrigation sessions did provide some additional soil moisture for crops, increasing yield by 31% in 2004. Once absorbed by the soil, the applied DFE did not increase the soil nutrient level and variability in the presence of crop. Thus, the DFE contributed to the irrigation and fertilization of the plots.
Surface irrigation to spread low nutrient DFE, as compared to the conventional tanker system reduced the application costs from $3.05/m3, to $0.95/m3.

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Dissertations / Theses on the topic 'Land surface'

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