Academic literature on the topic 'Spatial rainfall fields'
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Journal articles on the topic "Spatial rainfall fields"
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Wheater, H. S., V. S. Isham, D. R. Cox, R. E. Chandler, A. Kakou, P. J. Northrop, L. Oh, C. Onof, and I. Rodriguez-Iturbe. "Spatial-temporal rainfall fields: modelling and statistical aspects." Hydrology and Earth System Sciences 4, no. 4 (December 31, 2000): 581–601. http://dx.doi.org/10.5194/hess-4-581-2000.
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Abstract. The HYREX experiment has provided a data set unique in the UK, with a dense network of raingauges available for studying the rainfall at a fine local scale and a network of radar stations allowing detailed examination of the spatial and temporal structure of rainfall at larger scales. In this paper, the properties and characteristics of the rainfall process, as measured by the HYREX recording network of rainguages and radars, are studied from a statistical perspective. The results of these analyses are used to develop various models of the rainfall process, for use in hydrological applications. Some typical results of these various modelling exercises are presented. Keywords: Rainfall statistics, rainfall models, hydrological design
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De Oliveira, V. "A simple model for spatial rainfall fields." Stochastic Environmental Research and Risk Assessment (SERRA) 18, no. 2 (April 1, 2004): 131–40. http://dx.doi.org/10.1007/s00477-003-0146-4.
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Pathirana, A., and S. Herath. "Multifractal modelling and simulation of rain fields exhibiting spatial heterogeneity." Hydrology and Earth System Sciences 6, no. 4 (August 31, 2002): 695–708. http://dx.doi.org/10.5194/hess-6-695-2002.
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Abstract. Spatial multifractals are statistically homogeneous random fields. While being useful to model geophysical fields exhibiting a high degree of variability and discontinuity and including rainfall, they ignore the spatial trends embedded in the variability that are evident from large temporal aggregation of spatial fields. The modelling of rain fields using multifractals causes the information related to spatial heterogeneity, immensely important at some spatial scales, to be lost in the modelling process. A simple method to avoid this loss of the heterogeneity information is proposed. Instead of modelling rain fields directly as multifractals, a derived field M is modelled; this is the product of filtering observed rainfall snapshots with spatial heterogeneity as indicated by long term accumulations of rain fields. The validity of considering the field M as multifractal is investigated empirically. The applicability of the proposed method is demonstrated using a discrete cascade model on gauge-calibrated radar rainfall of central Japan at a daily scale. Important parameters of spatial rainfall, like the distribution of wet areas, spatial autocorrelation and rainfall intensity distributions at different geographic locations with different amounts of average rainfall, were faithfully reproduced by the proposed method. Keywords: spatial rainfall, downscaling, multifractals
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Gebremichael, Mekonnen, and Witold F. Krajewski. "Effect of Temporal Sampling on Inferred Rainfall Spatial Statistics." Journal of Applied Meteorology 44, no. 10 (October 1, 2005): 1626–33. http://dx.doi.org/10.1175/jam2283.1.
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Abstract On the basis of temporally sampled data obtained from satellites, spatial statistics of rainfall can be estimated. In this paper, the authors compare the estimated spatial statistics with their “true” or ensemble values calculated using 5 yr of 15-min radar-based rainfall data at a spatial domain of 512 km × 512 km in the central United States. The authors conducted a Monte Carlo sampling experiment to simulate different sampling scenarios for variable sampling intervals and rainfall averaging periods. The spatial statistics used are the moments of spatial distribution of rainfall, the spatial scaling exponents, and the spatial cross correlations between the sample and ensemble rainfall fields. The results demonstrated that the expected value of the relative error in the mean rain-rate estimate is zero for rainfall averaged over 5 days or longer, better temporal sampling produces average fields that are “less noisy” spatially, an increase in the sampling interval causes the sampled rainfall to be increasingly less correlated with the true rainfall map, and the spatial scaling exponent estimators could give a bias of 40% or less. The results of this study provide a basis for understanding the impact of temporal statistics on inferred spatial statistics.
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Hu, Qingfang, Zhe Li, Leizhi Wang, Yong Huang, Yintang Wang, and Lingjie Li. "Rainfall Spatial Estimations: A Review from Spatial Interpolation to Multi-Source Data Merging." Water 11, no. 3 (March 20, 2019): 579. http://dx.doi.org/10.3390/w11030579.
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Rainfall is one of the most basic meteorological and hydrological elements. Quantitative rainfall estimation has always been a common concern in many fields of research and practice, such as meteorology, hydrology, and environment, as well as being one of the most important research hotspots in various fields nowadays. Due to the development of space observation technology and statistics, progress has been made in rainfall quantitative spatial estimation, which has continuously deepened our understanding of the water cycle across different space-time scales. In light of the information sources used in rainfall spatial estimation, this paper summarized the research progress in traditional spatial interpolation, remote sensing retrieval, atmospheric reanalysis rainfall, and multi-source rainfall merging since 2000. However, because of the extremely complex spatiotemporal variability and physical mechanism of rainfall, it is still quite challenging to obtain rainfall spatial distribution with high quality and resolution. Therefore, we present existing problems that require further exploration, including the improvement of interpolation and merging methods, the comprehensive evaluation of remote sensing, and the reanalysis of rainfall data and in-depth application of non-gauge based rainfall data.
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Rebora, N., L. Ferraris, J. von Hardenberg, and A. Provenzale. "Rainfall downscaling and flood forecasting: a case study in the Mediterranean area." Natural Hazards and Earth System Sciences 6, no. 4 (July 12, 2006): 611–19. http://dx.doi.org/10.5194/nhess-6-611-2006.
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Abstract. The prediction of the small-scale spatial-temporal pattern of intense rainfall events is crucial for flood risk assessment in small catchments and urban areas. In the absence of a full deterministic modelling of small-scale rainfall, it is common practice to resort to the use of stochastic downscaling models to generate ensemble rainfall predictions to be used as inputs to rainfall-runoff models. In this work we present an application of a new spatial-temporal downscaling procedure, called RainFARM, to an intense precipitation event predicted by the limited-area meteorological model Lokal Model over north-west Italy. The uncertainty in flood prediction associated with the small unresolved scales of forecasted precipitation fields is evaluated by using an ensemble of downscaled fields to drive a semi-distributed rainfall-runoff model.
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Mackay, N. G., R. E. Chandler, C. Onof, and H. S. Wheater. "Disaggregation of spatial rainfall fields for hydrological modelling." Hydrology and Earth System Sciences 5, no. 2 (June 30, 2001): 165–73. http://dx.doi.org/10.5194/hess-5-165-2001.
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Abstract. Meteorological models generate fields of precipitation and other climatological variables as spatial averages at the scale of the grid used for numerical solution. The grid-scale can be large, particularly for GCMs, and disaggregation is required, for example to generate appropriate spatial-temporal properties of rainfall for coupling with surface-boundary conditions or more general hydrological applications. A method is presented here which considers the generation of the wet areas and the simulation of rainfall intensities separately. For the first task, a nearest-neighbour Markov scheme, based upon a Bayesian technique used in image processing, is implemented so as to preserve the structural features of the observed rainfall. Essentially, the large-scale field and the previously disaggregated field are used as evidence in an iterative procedure which aims at selecting a realisation according to the joint posterior probability distribution. In the second task the morphological characteristics of the field of rainfall intensities are reproduced through a random sampling of intensities according to a beta distribution and their allocation to pixels chosen so that the higher intensities are more likely to be further from the dry areas. The components of the scheme are assessed for Arkansas-Red River basin radar rainfall (hourly averages) by disaggregating from 40 km x 40 km to 8 km x 8 km. The wet/dry scheme provides a good reproduction both of the number of correctly classified pixels and the coverage, while the intensitiy scheme generates fields with an adequate variance within the grid-squares, so that this scheme provides the hydrologist with a useful tool for the downscaling of meteorological model outputs. Keywords: Rainfall, disaggregation, General Circulation Model, Bayesian analysis
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Nourani, Vahid, Armin Farshbaf, and S. Adarsh. "Spatial downscaling of radar-derived rainfall field by two-dimensional wavelet transform." Hydrology Research 51, no. 3 (March 27, 2020): 456–69. http://dx.doi.org/10.2166/nh.2020.165.
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Abstract Downscaling of rainfall fields, either as images or products of global circulation models, have been the motive of many hydrologists and hydro-meteorologists. The main concern in downscaling is to transform high-resolution properties of the rainfall field to lower resolution without introducing erroneous information. In this paper, rainfall fields obtained from Next Generation Weather Surveillance Radar (NEXRAD) Level III were examined in the wavelet domain which revealed sparsity for wavelet coefficients. The proposed methodology in this work employs a concept named Standardized Rainfall Fluctuation (SRF) to overcome the sparsity of rainfall fields in wavelet domain which also exhibited scaling behaviors in a range of scales. SRFs utilizes such scaling behaviors where upscaled versions of the rainfall fields are downscaled to their actual size, using a two-dimensional discrete wavelet transform, to examine the reproduction of the rainfall fields. Furthermore, model modifications were employed to enhance the accuracy. These modifications include removing the negative values while conserving the mean and applying a non-overlapping kernel to restore high-gradient clusters of rainfall fields. The calculated correlation coefficient, statistical moments, determination coefficient and spatial pattern display a good agreement between the outputs of the downscaling method and the observed rainfall fields.
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Isham, V., D. R. Cox, I. Rodríguez-Iturbe, A. Porporato, and S. Manfreda. "Representation of space–time variability of soil moisture." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 461, no. 2064 (October 10, 2005): 4035–55. http://dx.doi.org/10.1098/rspa.2005.1568.
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A simplified spatial-temporal soil moisture model driven by stochastic spatial rainfall forcing is proposed. The model is mathematically tractable, and allows the spatial and temporal structure of soil moisture fields, induced by the spatial-temporal variability of rainfall and the spatial variability of vegetation, to be explored analytically. The influence of the main model parameters, reflecting the spatial scale of rain cells, the soil storage capacity, the rainfall interception and the soil water loss rate (representing evaporation and deep infiltration) is investigated. The variabilities of the spatially averaged soil moisture process, and that averaged in both space and time, are derived. The present analysis focuses on spatially uniform vegetation conditions; a follow-up paper will incorporate stochastically heterogeneous vegetation.
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Rahill-Marier, Bianca, Naresh Devineni, and Upmanu Lall. "Technical note: Modeling spatial fields of extreme precipitation – a hierarchical Bayesian approach." Hydrology and Earth System Sciences 26, no. 21 (November 11, 2022): 5685–95. http://dx.doi.org/10.5194/hess-26-5685-2022.
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Abstract. We introduce a hierarchical Bayesian model for the spatial distribution of rainfall corresponding to an extreme event of a specified duration that could be used with regional hydrologic models to perform a regional hydrologic risk analysis. An extreme event is defined if any gaging site in the watershed experiences an annual maximum rainfall event and the spatial field of rainfall at all sites corresponding to that occurrence is modeled. Applications to data from New York City demonstrate the effectiveness of the model for providing spatial scenarios that could be used for simulating loadings into the urban drainage system. Insights as to the homogeneity in spatial rainfall and its implications for modeling are provided by considering partial pooling in the hierarchical Bayesian framework.
Dissertations / Theses on the topic "Spatial rainfall fields"
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Northrop, Paul James. "Modelling and statistical analysis of spatial-temporal rainfall fields." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340891.
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Bennett, Bree Sarah. "Stochastic spatial rainfall modelling for hydrological design: development of a parsimonious simulation approach and virtual hydrological evaluation framework." Thesis, 2016. http://hdl.handle.net/2440/106435.
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The management of water, viewed either as a natural hazard or a vital resource, is critical for the safety and prosperity of communities. The risks associated with managing water availability, whether in scarcity or excess, are critical concerns for the design and operation of infrastructure as well as the implementation of public policy. The spatial variability of rainfall is a known driving force of catchment dynamics and water availability, but despite this, it is often poorly represented in hydrologic studies and designs. This thesis focuses on improvements to the estimation, simulation and evaluation of spatial rainfall. Specifically these developments include: (i) the development of a generalised approach for spatial extreme rainfall estimation; (ii) the development of a flexible, continuous, and spatial stochastic model of rainfall and its corresponding evaluation; and (iii) an innovative framework for critically evaluating the performance of stochastic rainfall models via the assessment of simulated streamflow. Australian case study locations, with varying climates, are used to present and investigate these approaches. A new approach for estimating extreme spatial rainfall intensities and a critical evaluation of current approaches for estimation are presented. Current techniques for estimating extreme spatial rainfall are reliant on areal reduction factors (ARF) to convert intensity estimates of extreme point rainfall to extreme spatial rainfall. It is common practice to ignore spatial variation in rainfall intensity and assume a constant ARF over a large region. Approaches using ARFs for estimating extreme spatial rainfall were demonstrated to be in error by 5% to 15%. A new approach that explicitly incorporates the variation of spatial rainfall over an area, referred to as Intensity Frequency Duration Area (IFDA) was developed to address this issue. IFDAs use spatially interpolated rainfall grids to directly estimate how extreme rainfall intensity varies with frequency, duration and area for a given location. The IFDA approach overcomes the shortcomings of existing approaches by avoiding the need to assume a fixed regional ARF value. IFDA provide direct and unbiased estimates of extreme spatial rainfall. An alternative approach to spatially interpolated observations of extremes is to use data generated by a stochastic spatial rainfall model. A new model for continuously simulating fields of daily spatial rainfall in a parsimonious manner is developed in this thesis. A Gaussian latent variable approach is used because it is able to simultaneously generate rainfall occurrences as well as amounts. Parameter surfaces are produced via kriging which enables the model to produce stochastic replicates for any location of interest in the catchment. Additional benefits of the model are that it removes the need for interpolation to construct catchment average rainfall estimates, preserves the rainfall’s volumetric properties and can be used with distributed hydrologic models. A comprehensive evaluation approach was developed to identify model strengths and weaknesses. This included a performance classification system that provided a systematic, succinct and transparent method to assess and summarize model performance over a range of statistics, sites and scales. The model showed many strengths in reproducing observed rainfall characteristics with the majority of statistics classified as either statistically indistinguishable from the observed or within 5% of the observed across the majority of sites and seasons. A significant challenge when evaluating rainfall models is that the key variable of interest is resultant streamflow, not generated rainfall. Typical evaluation methods use a variety of rainfall statistics, but they provide limited understanding on (i) how rainfall influences streamflow generation; (ii) which rainfall characteristics are most important; and (iii) the trade-offs made when one or more features of rainfall are poorly reproduced. An innovative virtual hydrological evaluation framework is developed to evaluate whether deficiencies in simulated rainfall lead to deficiencies in resultant streamflow. The key feature of the framework is the use of a hydrological model to compare streamflow derived from observed and simulated rainfall at the same location. The framework allows the impact of an influencing month of simulated rainfall on streamflow in an evaluated month of interest to be isolated. Application of the virtual hydrological evaluation framework identified the importance of transition months May and June (late autumn/early winter) in the ‘wetting-up’ phase of the catchment cycle. Despite their low monthly flow volumes, the transition months contributed significantly to error in the annual total flow. With improved representation and evaluation of spatial rainfall, this thesis ultimately demonstrates more realistic and accurate methods for hydrological estimation.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Civil, Environmental and Mining Engineering, 2016.
Book chapters on the topic "Spatial rainfall fields"
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Gutierrez-López, Alfonso, Marilú Meza-Ruiz, and Jose Vargas-Baecheler. "Analysis of the Spatial Dependence of Rainfall Fields in the Southeast of Mexico, Using Directional Variograms." In Water Resources of Mexico, 255–70. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-40686-8_14.
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Mabhuye, Edmund B., and Pius Z. Yanda. "Locally based responses to impacts of climate change in pastoral landscapes of Northern Tanzania." In Climate change impacts and sustainability: ecosystems of Tanzania, 101–21. Wallingford: CABI, 2020. http://dx.doi.org/10.1079/9781789242966.0101.
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Abstract The impacts of climate change and variability have manifested themselves throughout the world, but considerable temporal and spatial variations exist across various places and countries. Given the variation in vulnerability, this study was undertaken in pastoral landscapes in northern Tanzania to assess the impacts of climate change, adaptation strategies and their implications to communities' livelihoods and ecosystem integrity. It examined: (i) climate trends and associated impacts on communities' livelihood options; (ii) climate change coping and adaptation strategies adopted by selected communities to reduce the severity of climate change impacts; and (iii) the challenges associated with climate change adaptation strategies in the pastoral landscape. Primary data were collected using household surveys, interviews with key informants, focus group discussions, direct field observation using transect walks and institutional analysis. Secondary data were obtained through documentary review and theme-content analysis. Results indicate that there are slight increases in temperature and wind speed as well as decreasing trends and erratic patterns of rainfall which cause drought and extended dry spells. Fluctuation in temperature and rainfall patterns affects livestock keeping through recurrent drought that has negative implications on pasture and water availability. Communities are responding to the changes through traditional response mechanisms and have embraced a few new adaptation strategies against these climate extremes, particularly drought. Generally, strategies for adaptation are likely to be successful in the near future, subject to review and harmonization of policies, institutional and legal frameworks to harness existing opportunities for management of natural resources for sustainable development and build the long-term balance between ecosystem integrity and human needs.
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Polyak, Ilya. "Second Moments of Rain." In Computational Statistics in Climatology. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195099997.003.0010.
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The first part of this chapter presents a description of the GATE rain rate data (Polyak and North, 1995), its two-dimensional spectral and correlation characteristics, and multivariate models. Such descriptions have made it possible to show the concentration of significant power along the frequency axis in the spatial-temporal spectra; to detect a diurnal cycle (a range of variation of which is about 3.4 to 5.4 mm/hr); to study the anisotropy (as the result of the distinction between the north-south and east-west transport of rain) of spatial rain rate fields; to evaluate the scales of the distinction between second-moment estimates associated with ground and satellite samples; to determine the appropriate spatial and temporal scales of the simple linear stochastic models fitted to averaged rain rate fields; and to evaluate the mean advection velocity of the rain rate fluctuations. The second part of this chapter (adapted from Polyak et al., 1994) is mainly devoted to the diffusion of rainfall (from PRE-STORM experiment) by associating the multivariate autoregressive model parameters and the diffusion equation coefficients. This analysis led to the use of rain data to estimate rain advection velocity as well as other coefficients of the diffusion equation of the corresponding field. The results obtained can be used in the ground truth problem for TRMM (Tropical Rainfall Measuring Mission) satellite observations, for comparison with corresponding estimates of other sources of data (TOGA-COARE, or simulated by physical, models), for generating multiple rain samples of any size, and in some other areas of rain data analysis and modeling. For many years, the GATE data base has served as the richest and most accurate source of rain observations. Dozens of articles presenting the results of the GATE rain rate data analysis and modeling have been published, and more continue to be released. Recently, a new, valuable set of rain data was produced as a result of the TOGA-COARE experiment. In a few years, it will be possible to obtain satellite (TRMM) rain information, and a rain statistical description will be needed in the analysis of the observations obtained on an irregular spatial and temporal grid.
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Chen, Yu. "Application of Analytic Hierarchy Process (AHP) and Simple Additive Weighting (SAW) Methods in Mapping Flood-Prone Areas." In Frontiers in Artificial Intelligence and Applications. IOS Press, 2021. http://dx.doi.org/10.3233/faia210274.
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The first step of formulating flood risk management strategies is to identify the flood at-hazard areas. This study aims to map flood-prone areas with different hazard levels in the Dadu River basin, using simple additive weighting (SAW) and analytic hierarchy process (AHP) methods and the geographic information systems (GIS) tool. The grid map of selected criteria, rainfall, topography, drainage, and the usage of land were processed and applied to estimate the flood hazard index (FHI) values in the basin in the GIS environment. The resultant map illustrates the spatial distribution of basin-scale flood at-hazard areas, can be used as powerful guidance of implementing preventing and alleviating flood risk for decision-makers and managers, and extended application in other basins or disaster fields.
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Rogelis Prada, María Carolina. "Spatial interpolation for real-time rainfall field estimation in areas with complex topography." In Operational Flood Forecasting, Warning and Response for Multi-Scale Flood Risks in Developing Cities, 71–101. CRC Press, 2020. http://dx.doi.org/10.1201/9780138745011-4.
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Wang, Manyu, Yong Liu, Lu Yang, Jing Wu, and Guilin Niu. "Coupled Hydro-Mechanical Analysis of Rainfall-Induced Instability of Non-Uniform Soil Slopes." In Advances in Transdisciplinary Engineering. IOS Press, 2021. http://dx.doi.org/10.3233/atde210191.
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In recent years, more considerable attentions are paying on the hazards of large-scale landslides induced by heavy rainfall. However, the heterogeneity in hydraulic properties of soils may affect the seepage pattern of water infiltrated into soil slopes. Inspired by this fact, this paper aimed to evaluate the effect of the spatial variability in hydraulic conductivity on failure mechanism of an unsaturated soil slope subjected to rainfall infiltration, being implemented in the framework of a transient coupled hydro-mechanical analysis. The concept of random field was adopted to model the spatial randomness of saturated hydraulic conductivity ks following a uniform distribution. The finite element method was then incorporated to conduct Monte Carlo simulations. The resultant findings show that the mode of shallow slope failure is more likely to occur than the deep one due mainly to the highly variable distribution of ks near slope surface. Note that the decrease in the effective stress of soils resulting from the increase of pore water pressure is the most critical reason for the occurrence of slope failure. In addition, from the random element analyses results, it indicates that the value of Qari calculated by performing a deterministic analysis based on arithmetic average value kari gives a prediction of flow rate on average, but the calculated Qmax based on maximum value kmax provides a more conservative assessment on total flow rate across soil slope, which can offer useful suggestions for practitioners to take available measures to drain in advance.
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Elsner, James B., and Thomas H. Jagger. "Time Series Models." In Hurricane Climatology. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199827633.003.0014.
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In this chapter, we consider time series models. A time series is an ordered sequence of numbers with respect to time. In climatology, you encounter time-series data in a format given by . . . {h}Tt=1 = {h1,h2,. . . ,hT} (10.1) . . . where the time t is over a given season, month, week, or day and T is the time series length. The aim is to understand the underlying physical processes that produced the series. A trend is an example. Often by simply looking at a time series plot, you can pick out a trend that tells you that the process generating the data is changing. A single time series gives you a sample from the process. Yet under the ergodic hypothesis, a single time series of infinite length contains the same information (loosely speaking) as the collection of all possible series of finite length. In this case, you can use your series to learn about the nature of the process. This is analogous to spatial interpolation encountered in Chapter 9, where the variogram was computed under the assumption that the rainfall field is stationary. Here we consider a selection of techniques and models for time series data. We begin by showing you how to overlay plots as a tool for exploratory analysis. This is done to compare the variation between two series qualitatively. We demonstrate large variation in hurricane counts arising from a constant rate process. We then show techniques for smoothing. We continue with a change-point model and techniques for decomposing a continuous-valued series. We conclude with a unique way to create a network graph from a time series of counts and suggest a new definition of a climate anomaly. A plot showing your variables on a common time axis is an informative exploratory graph. Values from two different series are scaled to have the same relative range so the covariation in the variables can be compared visually. Here you do this with hurricane counts and sea-surface temperature (SST). Begin by loading annual.RData. These data were assembled in Chapter 6.
Conference papers on the topic "Spatial rainfall fields"
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Konuk, I., U. O. Akpan, and D. P. Brennan. "Random Field Modeling of Rainfall-Induced Soil Movement." In 2002 4th International Pipeline Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/ipc2002-27165.
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Natural oil and gas transmission pipeline networks often traverse regions where potential slow ground movements may affect pipeline structural integrity. One of the primary causes of slow ground movement in any region involves the duration, amount, and intensity of rainfall. The phenomenon of rainfall-induced slow ground movement is characterized by both spatial and temporal variability, and involves uncertainties that are best modeled using a probabilistic methodology. A random field modeling strategy is formulated in this study, in which spatial and temporal correlations between rainfall and ground movement are accounted for. The random field formulation advanced in the current study has a number of significant features and capabilities, including modeling the spatial and temporal relationship between rainfall and slope movement for specified pipeline routes, predicting the likelihood of exceeding slope movement thresholds for various precipitation levels and intensities, and providing maps of risk for slope movement, which can be used as a guide in pipeline route planning, selection, and adaptation strategies for the design and maintenance of oil and gas infrastructure. These capabilities have been implemented and encapsulated into the software tool VSLOPE, which has been tested using monthly rainfall and field data for various locations.
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Cerdà, Artemi, and Enric Terol. "SUSTAINABLE AGRICULTURE MANAGEMENTS TO CONTROL SOIL EROSION." In 3rd Congress in Geomatics Engineering. Valencia: Universitat Politècnica de València, 2021. http://dx.doi.org/10.4995/cigeo2021.2021.13258.
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High rates of soil erosion compromise sustainable agriculture. In rainfed agricultural fields, erosion rates several orders ofmagnitude higher than the erosion rates considered tolerable have been quantified. In Mediterranean rainfed crops suchas vineyards, almonds and olive groves, and in the new sloping citrus and persimmon plantations, the rates of soil lossmake it necessary to apply measures to reduce them to avoid collapse in agricultural production. Managements such asweeds, catch crops and mulches (straw and pruning remains) are viable options to achieve sustainability. This work appliesmeasurements through plots, simulated rainfall experiments and ISUM (Improved Stock-Unearhing method) to quantifythe loss of soil at different temporal and spatial scales in fields of traditional management (herbicide or tillage) and underalternative management (mulches and plant covers). The work carried out at the experimental station for the study of soilerosion in the Sierra de Enguera and those of Montesa and Les Alcusses provide information on erosion plots undernatural rain. Experiments carried out with simulated rain in fields of olive, almond, citrus, persimmon, vineyard and fruittrees report the hydrological and erosive response under low frequency and high intensity rains. And finally, the ISUMtopographic method report the impact of long-term management, from the plantation. The results indicate that the loss ofsoil is greater (x10-1000) in soils under traditional management (tillage and herbicide) due to the fact that they remain barefor most of the year. The use of straw mulch immediately reduces soil erosion by two orders of magnitude. Also mulchesfrom chipped pruned branches remains are very efficient but require more years to reduce soil loss. Weeds and catchcrops are very efficient in controlling erosion.
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Jia, Shaohui, Lei Guo, Qingshan Feng, Lijian Zhou, and Yan Huang. "A New Method for Protecting Pipeline in Summer Monsoon." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-39885.
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In annual summer monsoon, geo-hazard is common. Monsoon-caused casualties and economic losses throughout the year accounted for 70% ∼ 80% of the total annual losses. Also, geo-hazard is a serious threat for pipeline operators to manage. Over 12,000 kilometers of pipelines with crude oil, gas, and refined oil are operated by PetroChina Pipeline Company. The pipelines, through sixteen provinces and cities, have been operated for over forty years. Geographic Information System (GIS) technology, as an effective spatial analysis tool, provides advanced analysis for pipeline geo-hazard prediction and early warning during summer monsoon based on field data and historical precipitation records. After many years of research and application of our prediction model of pipeline geo-hazard, an important link between geo-hazard and rainfall is understood. Rainfall is the main triggering factor of geo-hazards such as landslide and debris flow leading to heavy losses, especially rainstorm and heavy rainstorm. We use GIS technology to perform spatial analysis with predicted rainfall data the next twenty-four hours and the data of pipeline geo-hazard susceptibility, and predict the severity of pipeline impacts caused by geo-hazards during the next twenty-four hours. Finally, the result is modified by existed geo-hazards data. The pipeline geo-hazard early warning is divided into five ranks which are displayed by different colors, and pipelines damaged by geo-hazards and protection measures are also proposed. During July 16 and 17 of 2009 years, we released geo-hazard early warning four rank of Lanzhou-Chengdu-Chongqing Oil Pipeline through PetroChina Pipeline Company web page and the communication software of Instant Messaging. The Lanzhou-Chengdu-Chongqing Oil Pipeline Company acted promptly with a detailed deployment and emergency plan to ensure pipeline safety.
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Jia, Shaohui. "Pipeline Geo-Hazard Prediction and Early Warning During Summer Monsoon Based on GIS Technology." In 2010 8th International Pipeline Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ipc2010-31032.
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In annual summer monsoon, geo-hazard is common. Monsoon-caused casualties and economic losses throughout the year accounted for 70% ∼ 80% of the total annual losses. Also, geo-hazard is a serious threat for pipeline operators to manage. Over 12,000 kilometers of pipelines with crude oil, gas, and refined oil are operated by PetroChina Pipeline Company. The pipelines, through sixteen provinces and cities, have been operated for over forty years. Geographic Information System (GIS) technology, as an effective spatial analysis tool, provides advanced analysis for pipeline geo-hazard prediction and early warning during summer monsoon based on field data and historical precipitation records. After many years of research and applicaton of our prediction model of pipeline geo-hazard, an important link between geo-hazard and rainfall is understood. Rainfall is the main triggering factor of geo-hazards such as landslide and debris flow leading to heavy losses, especially rainstorm and heavy rainstorm. We use GIS technology to perform spatial analysis with predicted rainfall data the next twenty-four hours and the data of pipeline geo-hazard susceptibility, and predict the severity of pipeline impacts caused by geo-hazards during the next twenty-four hours. Finally, the result is modified by existed geo-hazards data. The pipeline geo-hazard early warning is divided into five ranks which are displayed by different colors, and pipelines damaged by geo-hazards and protection measures are also proposed. During July 16 and 17 of 2009 years, we released geo-hazard early warning four rank of Lanzhou-Chengdu-Chongqing Oil Pipeline through PetroChina Pipeline Company web page (http://www.gdgs.petrochina) and the communication software of IM. The Lanzhou-Chengdu-Chongqing Oil Pipeline Company acted promptly with a detailed deployment and emergency plan to ensure pipeline safety.
Reports on the topic "Spatial rainfall fields"
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Heitman, Joshua L., Alon Ben-Gal, Thomas J. Sauer, Nurit Agam, and John Havlin. Separating Components of Evapotranspiration to Improve Efficiency in Vineyard Water Management. United States Department of Agriculture, March 2014. http://dx.doi.org/10.32747/2014.7594386.bard.
Full textAbstract:
Vineyards are found on six of seven continents, producing a crop of high economic value with much historic and cultural significance. Because of the wide range of conditions under which grapes are grown, management approaches are highly varied and must be adapted to local climatic constraints. Research has been conducted in the traditionally prominent grape growing regions of Europe, Australia, and the western USA, but far less information is available to guide production under more extreme growing conditions. The overarching goal of this project was to improve understanding of vineyard water management related to the critical inter-row zone. Experiments were conducted in moist temperate (North Carolina, USA) and arid (Negev, Israel) regions in order to address inter-row water use under high and low water availability conditions. Specific objectives were to: i) calibrate and verify a modeling technique to identify components of evapotranspiration (ET) in temperate and semiarid vineyard systems, ii) evaluate and refine strategies for excess water removal in vineyards for moist temperate regions of the Southeastern USA, and iii) evaluate and refine strategies for water conservation in vineyards for semi-arid regions of Israel. Several new measurement and modeling techniques were adapted and assessed in order to partition ET between favorable transpiration by the grapes and potentially detrimental water use within the vineyard inter-row. A micro Bowen ratio measurement system was developed to quantify ET from inter-rows. The approach was successful at the NC site, providing strong correlation with standard measurement approaches and adding capability for continuous, non-destructive measurement within a relatively small footprint. The environmental conditions in the Negev site were found to limit the applicability of the technique. Technical issues are yet to be solved to make this technique sufficiently robust. The HYDRUS 2D/3D modeling package was also adapted using data obtained in a series of intense field campaigns at the Negev site. The adapted model was able to account for spatial variation in surface boundary conditions, created by diurnal canopy shading, in order to accurately calculate the contribution of interrow evaporation (E) as a component of system ET. Experiments evaluated common practices in the southeastern USA: inter-row cover crops purported to reduce water availability and thereby favorably reduce grapevine vegetative growth; and southern Israel: drip irrigation applied to produce a high value crop with maximum water use efficiency. Results from the NC site indicated that water use by the cover crop contributed a significant portion of vineyard ET (up to 93% in May), but that with ample rainfall typical to the region, cover crop water use did little to limit water availability for the grape vines. A potential consequence, however, was elevated below canopy humidity owing to the increased inter-row evapotranspiration associated with the cover crops. This creates increased potential for fungal disease occurrence, which is a common problem in the region. Analysis from the Negev site reveals that, on average, E accounts for about10% of the total vineyard ET in an isolated dripirrigated vineyard. The proportion of ET contributed by E increased from May until just before harvest in July, which could be explained primarily by changes in weather conditions. While non-productive water loss as E is relatively small, experiments indicate that further improvements in irrigation efficiency may be possible by considering diurnal shading effects on below canopy potential ET. Overall, research provided both scientific and practical outcomes including new measurement and modeling techniques, and new insights for humid and arid vineyard systems. Research techniques developed through the project will be useful for other agricultural systems, and the successful synergistic cooperation amongst the research team offers opportunity for future collaboration.