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1
Saxe, Samuel, Terri S. Hogue e Lauren Hay. "Characterization and evaluation of controls on post-fire streamflow response across western US watersheds". Hydrology and Earth System Sciences 22, n. 2 (13 febbraio 2018): 1221–37. http://dx.doi.org/10.5194/hess-22-1221-2018.
Testo completoAbstract (sommario):
Abstract. This research investigates the impact of wildfires on watershed flow regimes, specifically focusing on evaluation of fire events within specified hydroclimatic regions in the western United States, and evaluating the impact of climate and geophysical variables on response. Eighty-two watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. Percent change in annual runoff ratio, low flows, high flows, peak flows, number of zero flow days, baseflow index, and Richards–Baker flashiness index were calculated for each watershed using pre- and post-fire periods. Independent variables were identified for each watershed and fire event, including topographic, vegetation, climate, burn severity, percent area burned, and soils data. Results show that low flows, high flows, and peak flows increase in the first 2 years following a wildfire and decrease over time. Relative response was used to scale response variables with the respective percent area of watershed burned in order to compare regional differences in watershed response. To account for variability in precipitation events, runoff ratio was used to compare runoff directly to PRISM precipitation estimates. To account for regional differences in climate patterns, watersheds were divided into nine regions, or clusters, through k-means clustering using climate data, and regression models were produced for watersheds grouped by total area burned. Watersheds in Cluster 9 (eastern California, western Nevada, Oregon) demonstrate a small negative response to observed flow regimes after fire. Cluster 8 watersheds (coastal California) display the greatest flow responses, typically within the first year following wildfire. Most other watersheds show a positive mean relative response. In addition, simple regression models show low correlation between percent watershed burned and streamflow response, implying that other watershed factors strongly influence response. Spearman correlation identified NDVI, aridity index, percent of a watershed's precipitation that falls as rain, and slope as being positively correlated with post-fire streamflow response. This metric also suggested a negative correlation between response and the soil erodibility factor, watershed area, and percent low burn severity. Regression models identified only moderate burn severity and watershed area as being consistently positively/negatively correlated, respectively, with response. The random forest model identified only slope and percent area burned as significant watershed parameters controlling response. Results will help inform post-fire runoff management decisions by helping to identify expected changes to flow regimes, as well as facilitate parameterization for model application in burned watersheds.
2
Munoth, Priyamitra, Lalit Kumar Gehlot, P. L. Patel, Sumit Khandelwal, P. V. Timbadiya e Rohit Goyal. "Integrated hydrological modelling of two contrasting watersheds with a terminal reservoir in the Upper Tapi River basin, India". Water Supply 23, n. 12 (30 novembre 2023): 4891–907. http://dx.doi.org/10.2166/ws.2023.314.
Testo completoAbstract (sommario):
Abstract The present study developed an integrated hydrologic model for sustainable utilisation and water management in two complex watersheds with varying physioclimatic features and reservoirs. The soil and water assessment tool (SWAT) is used for predicting integrated inflows into the Hatnur reservoir from the Burhanpur and Purna watersheds of the Upper Tapi River basin, while outflows are simulated using a rule curve. The influence of watershed complexities on hydrological model parameters and the watershed processes are investigated using extensive multisite and multivariable calibration (1998–2007) and validation (2008–2013) approaches, including sensitivity and uncertainty analyses. The sensitive parameters are related to curve number (CN), groundwater, slope, and main channel characteristics. The annual streamflow (m3/km2/mm of rainfall) in the Burhanpur watershed is 568.7, which is 4.2 times higher than the Purna watershed's streamflow of 136.2. The hypsometric analysis, areal rainfall, and flow duration curves revealed a substantially different streamflow pattern and a larger coefficient of variation in the spatial distribution of water balance components over sub-watersheds in the Burhanpur watershed compared to the Purna watershed due to diverse topographic features. The developed model would be useful for planning controlled releases from the terminal reservoir to mitigate hazards in the downstream reaches of the Tapi River basin.
3
Kumar, Shailesh, Sarita Meshram, Rupesh Patil e Sanjay Tignath. "Hypsometric Analysis Using Geographical Information System of Gour River Watershed, Jabalpur, Madhya Pradesh, India". Current World Environment 11, n. 1 (25 aprile 2016): 56–64. http://dx.doi.org/10.12944/cwe.11.1.07.
Testo completoAbstract (sommario):
Hypsometric analysis of drainage basins reveals the geological stage of watershed and is a measure of its maturity, indicating the susceptibility of the watershed to erosion. In the present study sub watersheds of Khurji Nala and Dala Nala watersheds which are tributaries of GourRiver located in Jabalpur district of Madhya Pradesh was considered as the case study area. The watersheds were delineated into sub watersheds and hypsometric analysis was carried out for all of them using the digital contour map, which was generated using Arc GIS. The hypsometric integral values of Khurji Nala and Dala Nala sub watersheds reveals that sub watershed 2 of Khurji Nala and sub watershed 7 of Dala Nala watershed should be given top priority for soil and water conservation.
4
Goyo, Shiella Lynn, e George Puno. "Usage of Land Use/Land Cover and Anthropogenic Parameters in Prioritizing Conservation in Sub Watersheds of Upper Pulangi River". East Asian Journal of Multidisciplinary Research 2, n. 5 (30 maggio 2023): 2081–98. http://dx.doi.org/10.55927/eajmr.v2i5.4012.
Testo completoAbstract (sommario):
Most part of the Philippines are located within watersheds. The best unit for managing natural resources like land and water is a watershed. This study aimed to prioritize the nine sub watersheds of Upper Pulangi River for conservation and rehabilitation using land use and land cover and anthropogenic parameters. Land cover and land use was analysed using remote sensing and GIS techniques to identify and delineate its categories. In terms of anthropogenic parameters, watersheds with the most extensive and highest human alterations, such as surface mining/quarries, illegal logging, land conversion to agriculture, kaingin, built-up areas, and upland settlers, were assigned the top priority for conservation. Watershed prioritization is the process of ranking different sub-watersheds in the order in which they must be addressed for soil conservation measures. Out of the nine sub watersheds being studied, the results showed that Sawaga sub watershed has the high priority for conservation followed by Maapag, Upper Pulangi, Taganibong, and Malingun sub watersheds with medium priority. Panlibatuhan, Tigwa and Taganibong sub watersheds fall under low priority while Manupali sub watersheds has the lowest priority due to its favourable vegetation cover and existing conservation and rehabilitation projects. It is recommended to watershed managers of Upper Pulangi river to prioritize and consider for funding the rehabilitation and soil conservation measures for Sawaga sub watershed. The methods used in this study can be applied to other watershed management under limited resources.
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Joshi, Mallika, Pankaj Kumar e Purabi Sarkar. "Morphometric parameters based prioritization of a Mid-Himalayan watershed using fuzzy analytic hierarchy process". E3S Web of Conferences 280 (2021): 10004. http://dx.doi.org/10.1051/e3sconf/202128010004.
Testo completoAbstract (sommario):
Watershed prioritization has become increasingly crucial for managing natural resources, especially the watersheds. A useful decision support tool to provide appropriate weights to different morphological attributes with lineage with soil erosion is required to identify environmentally stressed areas for the watershed resources. This study examines the Western Nayar watershed delineation and further examination of the watershed’s morphometric parameters. The morphometric parameters were quantified under the linear, areal, and relief heads for the watershed. The prioritization of sub-watersheds was done by the fuzzy analytic hierarchy process (FAHP). The study included nine morphometric parameters for forming a pairwise comparison matrix. The fuzzy analytic hierarchy process was employed for assigning the suitable weights to morphometric parameters, and further, these weights are normalized to assign the final ranks to the sub-watershed. In Western Nayar, SW9 got the highest priority, and SW1 was categorized as the least priority. The results were validated by the consistency ratio index, which depends on the matrix consistency index’s size that should be less than 10%. The consistency index of the present study was found to be 2%.
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Wahyuni, Andang Suryana Soma, Usman Arsyad, Riska Sariyani e Baharuddin Mappangaja. "Prediction of erosion and sedimentation rates using SWAT (Soil and Water Assessment Tool) method in the Jenelata Sub Watershed". IOP Conference Series: Earth and Environmental Science 886, n. 1 (1 novembre 2021): 012097. http://dx.doi.org/10.1088/1755-1315/886/1/012097.
Testo completoAbstract (sommario):
Abstract Erosion and sedimentation are problems that often occur in watershed ecosystems. The SWAT model (Soil and Water Assessment Tool) can be used to determine the output of a watershed’s performance. Jenelata sub-watershed area is one of the largest sub-watersheds of the Jeneberang watershed with 22.800 ha. This study aims to determine the spatial distribution of the hydrologic response unit (HRU) and analyze the rate of erosion and sedimentation in the Jenelata sub-watershed. The results showed that most HRUs are in secondary dryland forests with 447 HRU (19.09%). The level of erosion in the very light category, namely 5.74 ton/ha/year (37.53%) and light 34.71 ton/ha/year (27.76%), was in the villages of Moncongloe, Tana Karaeng, Sicini, Paladindang, Towata, Parang Lampoa, Manuju, and Buakkang. Meanwhile, moderate erosion was 104.07 ton/ha/year (23.92%), high 289.65 ton/ha/year (9.59%), and very high 553.74 ton/ha/year (1.20%) located in the villages of Pattallikang, Mangempang, Bontomanai, Bissoloro, Rannaloe, Jenebatu, and Sapaya. The largest sedimentation is 133.18 ton/ha/year in sub-watershed17, located in Bissoloro and Rannaloe villages.
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Lee, Jong-Won, Se-Rin Park e Sang-Woo Lee. "Effect of Land Use on Stream Water Quality and Biological Conditions in Multi-Scale Watersheds". Water 15, n. 24 (6 dicembre 2023): 4210. http://dx.doi.org/10.3390/w15244210.
Testo completoAbstract (sommario):
Understanding the relation between watershed land use and stream conditions is critical for watershed planning and management. This study investigated the effects of land use on stream water quality and biological conditions in sub-watersheds and micro-watersheds across the Han River watershed in South Korea. We developed random forest models for each water quality and biological indicator using the proportions of urban, agricultural, and forested areas. Our results indicate that water quality and biological indicators were significantly affected by forest area at both scales, and the sub-watershed models performed better than the micro-watershed models. Accumulated local effects were used to interpret the effect of each explanatory variable on the response variable. The plots for water quality and biological indicators with proportions of watershed land use demonstrated similar patterns at both scales, although the relation between land use and stream conditions was slightly more sensitive in micro-watersheds than in sub-watersheds. Urban and agricultural areas showed a lower proportion of water quality and biological condition variability in the micro-watersheds than in the sub-watersheds, while forests showed the opposite results. The findings of this study suggest that different spatial scales should be considered when developing effective watershed management strategies to maintain stream ecosystems.
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Indarto, Indarto, e Entin Hidayah. "Preliminary Assessment of Morphometric and Hydrological Properties of Six Watersheds in the Eastern Part of East Java". Forum Geografi 33, n. 1 (2 agosto 2019): 114–29. http://dx.doi.org/10.23917/forgeo.v33i1.7858.
Testo completoAbstract (sommario):
A hydrological process on the watersheds is driven by rainfall as the input. Physical properties also affect the magnitude response of the watershed to produce run-off. This paper presents the identification, assessment and visualisation of morphometric and hydrological properties of the watersheds. Six watersheds in the eastern part of East Java were used for the analysis. Physical characteristics obtained by cropping the GIS layer with a watershed. Topographic and morphometric properties of the watersheds derived from the ASTER G-DEM2. Furthermore, hydrological properties are derived statistically by analysing available rainfall and discharge data. Hydrological data (rainfall and discharge) are available from 1996 – 2014. Finally, simple statistical analysis by plotting obtained values are used to interpret the relation between morphometric and hydrological properties of the watersheds. The results show the quantitative number (unit) to describe the morphometric and hydrological properties of the six watersheds that can be used for watershed classification.
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Gadakh, S., SS Wandre, MA Patil, A. Jadhav, V. Shinde, J. Ghatge e K. Prathapan. "Quantitative analysis of morphometric parameters for prioritization of Warana river basin using remote sensing and GIS". Journal of Agriculture and Ecology 18 (30 maggio 2024): 32–38. http://dx.doi.org/10.58628/jae-2418-105.
Testo completoAbstract (sommario):
An attempt has been made in this paper to study the morphometric characteristics and prioritization of watersheds of the Warana river basin, which falls in the districts of Ratnagiri, Kolhapur, and Sangli and is a major one among five river basins of Maharashtra state, India. As a result, the entire research area has been subdivided into 15 sub-watersheds for prioritization based on morphometric analysis utilizing GIS and remote sensing techniques. The compound parameters were calculated by averaging the priority based on the severity ranking of each watershed. The watersheds were given ultimate priority based on the values of compound parameters. The compound parameter ranged from 6.5 to 9.83 for all 15 watersheds. The watershed 8th (compound parameter value 6.5) obtains the greatest priority value and hence becomes a prospective and prioritized candidate for adopting soil conservation measures, whilst the other watersheds with lesser priorities experience less erosion. Such watershed prioritization is beneficial to overall watershed management planning. The morphometric parameters established for this basin as a whole and each watershed will be important for sound water harvesting and groundwater recharge project design on a watershed basis.
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Wang, Chunbo, Chengtao Huang, Shuai Zhang, Lei Zhang, Tingzhen Li, Jiyou Peng e Liuyi Zhang. "Research Progress on Nitrogen and Phosphorus Loss in Small Watersheds: A Regional Review". Water 15, n. 16 (10 agosto 2023): 2894. http://dx.doi.org/10.3390/w15162894.
Testo completoAbstract (sommario):
As an ecological subsystem, a small watershed is mainly located upstream from lakes, rivers, or other water bodies. The characteristics of non-point source (NPS) pollution in a small watershed are random and complex. Rainfall is the direct driving force of NPS pollution, and different land-use types are the main factors affecting NPS output in small watersheds. At present, the NPS pollution of small watersheds is serious, and the problem of eutrophication of watershed water is prominent. Nitrogen (N) and phosphorus (P) are essential nutrients for aquatic organisms, but excessive amounts can lead to water pollution and ecological imbalances. The study of N and P loss in small watersheds can provide a decision-making basis for NPS pollution control in small watersheds. This paper introduces the research progress on small watersheds in detail, focusing on the main influencing factors of N and P output in small watersheds, including rainfall, different land-use types, N and P loss prevention, and control measures; it also provides a prospective view of the current problems, hoping to provide references for the study of NPS pollution in small watersheds.
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Elvir, Jose Alexander, Lindsey Rustad, G. Bruce Wiersma, Ivan Fernandez, Alan S. White e Gregory J. White. "Eleven-year response of foliar chemistry to chronic nitrogen and sulfur additions at the Bear Brook Watershed in Maine". Canadian Journal of Forest Research 35, n. 6 (1 giugno 2005): 1402–10. http://dx.doi.org/10.1139/x05-072.
Testo completoAbstract (sommario):
The foliar chemistry of sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Ehrh.), and red spruce (Picea rubens Sarg.) was studied from 1993 to 2003 at the Bear Brook Watershed in Maine (BBWM). The BBWM is a paired-watershed forest ecosystem study, with one watershed treated bimonthly since 1989 with ammonium sulfate ((NH4)2SO4) at a rate of 25.2 kg N·ha1·year1. Foliar N concentrations were higher in all tree species within the treated watershed compared with trees within the reference watershed. Foliar Ca and Mg concentrations were lower in American beech and red spruce within the treated watershed. There were no significant differences in foliar K concentrations between watersheds. Foliar P and Mn concentration differences between watersheds were inconsistent among years. Differences in foliar N concentrations between watersheds declined over time in sugar maple but not in red spruce or American beech. Differences in foliar Ca and Mg concentrations between the treated and reference watersheds increased over time for American beech and red spruce, primarily because of a consistent decline in concentrations of these nutrients in trees within the treated watershed. No temporal trends in foliar Ca and Mg concentration differences between watersheds were observed for sugar maple.
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Barh, Sajal. "Morphometric study and watershed prioritization for soil conservation in Kalinjar micro-watersheds, Odisha". National Geographical Journal of India 68, n. 4 (31 dicembre 2022): 311–23. http://dx.doi.org/10.48008/ngji.1819.
Testo completoAbstract (sommario):
The detailed study of morphometry is very important to understand the hydrological comportment and characteristics of the watershed. The morphometric parameters are used for prioritization of the micro-watersheds based on WSA (weighted sum analysis) for sustainable watershed management. In this study, a collective approach of using remotely sensed DEM, topographical map and ArcGIS (10.1) has been applied to define morphometric parameters of the Kalinjar river basin, a sub-basin of Baitarani River which is prone to gully erosion. Seven micro-watersheds of Kalinjar River have been prioritized by applying the morphometric parameters and ranking them according to their liability to soil erosion. According to results, Kalinjar River is a 6th order stream having four 5th order and one 6th order sub-watershed, having a total drainage area of 506.34 km². High values of infiltration number are indicative of low infiltration which may cause high surface runoff and soil erosion. The micro-watershed prioritization implied that MW-4 (16.79% area) is an extremely vulnerable micro-watershed that requires better attention for soil and water conservation measures. The result of the prioritization shows that micro-watersheds MW-1 and MW-3 (13.33% area) are the most vulnerable micro-watersheds to erosion, micro-watersheds MW-2 and MW-5 (13.97% area) are moderately vulnerable and micro-watersheds MW-6 and MW-7 (23.16% area) are the least vulnerable to erosion.
13
Lo, WeiCheng, Chang-Mien Wang, Chih-Tsung Huang e Meng-Hsuan Wu. "Impact of Human Development on the Phenomenon of Surface Runoff Crossing Adjacent Watershed Boundaries". Water 16, n. 13 (27 giugno 2024): 1831. http://dx.doi.org/10.3390/w16131831.
Testo completoAbstract (sommario):
The concept of watersheds, also called catchments, is fundamental to both flood mitigation and water resource management, as it greatly aids in the calculation of overland flow attributes. Watershed boundaries are typically determined by elevation, as water adheres to the geological characteristics of watersheds under natural circumstances and does not cross watershed boundaries. However, advances in human development have caused elevation and land usage changes, and boundaries between adjacent watersheds in downstream areas with flat terrain have become unclear and unstable. This study chose the Kaoping River watershed and Donggang River watershed as the study area, to investigate the cross-watershed runoff phenomenon under different return period rainfall. Based on land use surveys of the study area, the area in proximity to the boundary between the two watersheds was highly developed, with land primarily used for agriculture, buildings, and transportation. As the study area was highly developed, cross-watershed runoff was observed, even in the 2-year return period rainfall simulation case. The size and depth of the areas where cross-watershed runoff occurred became stable in the simulation cases, with return periods of 25 years or greater due to the surrounding high-elevation terrain obstructing further surface runoff development. Thus, when planning for flood mitigation, cross-watershed runoff from adjacent watersheds must also be considered, in addition to normal surface runoff.
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Tamanna, Marzia, Soni M. Pradhanang, Arthur J. Gold, Kelly Addy, Philippe G. Vidon e Ronald L. Bingner. "Evaluation of AnnAGNPS Model for Runoff Simulation on Watersheds from Glaciated Landscape of USA Midwest and Northeast". Water 12, n. 12 (15 dicembre 2020): 3525. http://dx.doi.org/10.3390/w12123525.
Testo completoAbstract (sommario):
Runoff modeling of glaciated watersheds is required to predict runoff for water supply, aquatic ecosystem management and flood prediction, and to deal with questions concerning the impact of climate and land use change on the hydrological system and watershed export of contaminants of glaciated watersheds. A widely used pollutant loading model, Annualized Agricultural Non-Point Source Pollution (AnnAGNPS) was applied to simulate runoff from three watersheds in glaciated geomorphic settings. The objective of this study was to evaluate the suitability of the AnnAGNPS model in glaciated landscapes for the prediction of runoff volume. The study area included Sugar Creek watershed, Indiana; Fall Creek watershed, New York; and Pawcatuck River watershed, Rhode Island, USA. The AnnAGNPS model was developed, calibrated and validated for runoff estimation for these watersheds. The daily and monthly calibration and validation statistics (NSE > 0.50 and RSR < 0.70, and PBIAS ± 25%) of the developed model were satisfactory for runoff simulation for all the studied watersheds. Once AnnAGNPS successfully simulated runoff, a parameter sensitivity analysis was carried out for runoff simulation in all three watersheds. The output from our hydrological models applied to glaciated areas will provide the capacity to couple edge-of-field hydrologic modeling with the examination of riparian or riverine functions and behaviors.
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Soulis, Konstantinos X., Konstantina Amalia Generali, Christina Papadaki, Christos Theodoropoulos e Emmanouil Psomiadis. "Hydrological Response of Natural Mediterranean Watersheds to Forest Fires". Hydrology 8, n. 1 (22 gennaio 2021): 15. http://dx.doi.org/10.3390/hydrology8010015.
Testo completoAbstract (sommario):
Fires are common in forested Mediterranean-climate watersheds. Forest fires cause abrupt land use/cover (LULC) changes affecting soil properties and hydrological processes within and across watersheds. A major forest fire in Attica, Greece, that affected the Lykorrema stream experimental watershed provided the opportunity for an in-depth study of the impact of forest fires on the hydrological balance of natural Mediterranean watersheds. To this end, detailed hydrometeorological data recorded for five years before and for five years after the fire incidence were utilized. SWAT model was also used to consider the potential influence of meteorological conditions temporal variability on the results of the analysis. Specifically, SWAT model was parameterized calibrated and validated for the pre-fire and the post-fire conditions using the corresponding detailed hydrometeorological data for the respective periods. Then the two versions of the model were applied for the entire period providing comprehensive time series for all the flows and storages in the studied watershed. In this way, the post-fire LULC and soil properties changes were the only influencing factors driving the alterations in the hydrological balance allowing an impartial comparison. The obtained results highlighted the considerable impact of forest fires on the watersheds’ hydrological functioning. Specifically, the maximum direct runoff depths and the maximum flow rates were substantially higher in the post-fire conditions. In contrast, actual evapotranspiration was reduced, when the effect of fire was considered. The obtained results indicate that the altered post-fire LULC and soil properties are major drivers of the watershed’s hydrological balance changes. SWAT model performed sufficiently well for both the pre- and post-fire conditions and provided a deeper insight into the impact of forest fires on the hydrological functioning of natural Mediterranean watersheds.
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Basavraj, Chikkansamshi, A. Ajgaonkar Swanand, J. Devaraju e S. Manjunatha. "Prioritization of Sub-watersheds through morphometric analysis in the Lower Hiranyakeshi Sub-basin, Karnataka". Disaster Advances 16, n. 4 (15 marzo 2023): 16–26. http://dx.doi.org/10.25303/1604da016026.
Testo completoAbstract (sommario):
In the present study, eight sub-watersheds are prioritized in Hiranyakeshi lower sub-basin based on the morphometric analysis using Remote Sensing and Geographical Information System. An evaluation of morphometric parameters is conducted to determine the potential of sub-watersheds. Sub-watersheds were prioritised as they are the most vulnerable and require more attention for water conservation and exploration measures. According to the results, three sub-watersheds are falling under high category, four are moderate and one sub-watershed falls under low category. The findings of this study may be useful to numerous stakeholders involved in watershed development and management projects.
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NOBLE, BRAM F., POORNIMA SHEELANERE e ROBERT PATRICK. "ADVANCING WATERSHED CUMULATIVE EFFECTS ASSESSMENT AND MANAGEMENT: LESSONS FROM THE SOUTH SASKATCHEWAN RIVER WATERSHED, CANADA". Journal of Environmental Assessment Policy and Management 13, n. 04 (dicembre 2011): 567–90. http://dx.doi.org/10.1142/s1464333211004012.
Testo completoAbstract (sommario):
Watersheds are under increasing pressures from the cumulative environmental effects of human actions. Reviews of recent practice suggest that cumulative effects assessment and management (CEAM) has failed to capture the full range of stressors to Canada's watersheds. Indeed, the limitations to CEAM have been well documented; yet, there has been limited constructive evaluation to help explain why CEAM has failed to advance. In this paper we examine the underlying challenges to the assessment and management of cumulative effects in a watershed context. Based on lessons emerging from the South Saskatchewan watershed, Canada, challenges to CEAM in watersheds include stakeholder understanding and interpretation of cumulative effects; limitations in the scale of current EA practices in watersheds; data challenges; the lack of established thresholds for watershed effects; and lack of clarity regarding watershed science and regulatory capacity. The merits of a watershed-based approach to CEAM to help address these challenges to practice are explored.
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Udawatta, Ranjith P., Gray S. Henderson, John R. Jones e R. David Hammer. "Runoff and Sediment from Row-crop, Row-crop with Grass Strips, Pasture, and Forest Watersheds". Revue des sciences de l'eau 19, n. 2 (9 giugno 2006): 137–49. http://dx.doi.org/10.7202/013047ar.
Testo completoAbstract (sommario):
Abstract Comparisons of runoff and sediment loss from row-crop with and without riparian buffers, pasture and grass filter strips are limited. Effects of precipitation, landuse and buffer condition on runoff and sediment loss were examined from 1997 to 1999 in eight watersheds with varying proportions of row-crop, pasture, riparian buffers and grass filter strips. Runoff volume and sediment mass from row-crop watersheds were inversely related to the percentage of forest and pasture cover. Forest (n = 2), pasture (n = 3), row-crop (n = 2) and a row-crop watershed with grass filter strips (RC-GFS) had 3‑yr mean runoff of 939, 1,560, 3,434 and 1,175 m3 ha‑1 yr‑1, respectively. Runoff was greater from all landuses in a year when precipitation was 36% above normal (1998). The largest single runoff event from each watershed accounted for 11 to 25% of its total runoff. Forest, pasture, row-crop and RC-GFS watersheds lost 1,017, 1,241, 3,679 and 2,129 kg ha‑1 yr‑1 of sediment, respectively. In 1998, the RC-GFS watershed lost more sediment than row-crop watersheds and had less runoff and sediment loss in years with normal or below normal precipitation. Row-crop watersheds with 55% pasture reduced runoff and sediment loss by 55 and 66%, respectively, compared to row-crop watersheds. During 90% of the runoff events, more soil was lost from row-crop watersheds than pasture or forest watersheds. Results suggest that 3‑4 m grass filter strips, maintenance of 55% or more pasture/CRP land within row-crop watersheds and intact riparian buffers significantly reduce runoff and sediment losses from row-crop watersheds.
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Maman Noprayamin, Anis Saggaff, Arie Setiadi Moerwanto e Kiagus Muhammad Aminuddin. "Identification of Watershed Conditions and Formulation of Watershed Management Strategies". JOURNAL OF CIVIL ENGINEERING BUILDING AND TRANSPORTATION 7, n. 1 (1 marzo 2023): 301–10. http://dx.doi.org/10.31289/jcebt.v7i1.9185.
Testo completoAbstract (sommario):
In Indonesia, 39 watersheds were deemed essential in 1994, and the importance of watersheds grew in 2000. The existence of a watershed has the role of being able to sustain water availability, maintain the balance of the ecosystem and as a container for flowing water. The Musi-Sugihan-Banyuasin-Lemau River Area (WS MSBL), which has an area of 86680 km2 and is made up of 23 primary watersheds, is one of the largest watersheds in the Sumatra region. Research was done to determine the state of the watershed so that a strategy for watershed conservation could be chosen. In-depth interviews with stakeholders in the form of focus group discussions (FGD) were utilized as the study method to collect both secondary and primary data about the circumstances of the watershed as well as to gain in-depth management outcomes. The study's findings demonstrate that managing the WS MSBL watershed involves more than only technical issues; it also necessitates involving associated institutions and stakeholders, necessitating the creation of operational watershed management strategies.
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Keshri, Ravish, M. P. Tripathi, Dhiraj Khalkho e Benukantha Das. "Prioritization of Milli Watershed of Kodar River Catchment Based on Integrated Approach of Morphometric and Land Use Land Cover Analysis". Asian Journal of Current Research 9, n. 1 (7 febbraio 2024): 71–85. http://dx.doi.org/10.56557/ajocr/2024/v9i18532.
Testo completoAbstract (sommario):
Watershed prioritisation is now important for effective natural resource planning and management in sustainable development, however, their implementation necessitates a careful examination of the morphometric and hydrological characteristics existing in the watershed. In the present study an attempts has been made to prioritize the Kantori nala milli watersheds of the Kodar river catchment using integrated approach of morphometric features and land use/landcover. Study area watershed was automatically delineated and divided into eleven micro watersheds Micro Watershed-1 to Micro Watershed-11 (MWS-1 to MWS-11) on the basis of topography from the Depression less DEM) prepared by Inverse Distance Weighted (IDW) interpolation technique. Morphometric analysis was done using DEM and each parameter has been assigned their ranks according to their value. Thereafter, an average value of the rank score for each of the micro watershed is calculated. The micro watershed with the lowest compound factor (Cp) was given the highest prioritized rank out of the group of micro watersheds, and vice versa. Land Use Land Cover (LULC) analysis was also done using sentinel 2 satellite data. The result from the priority ranking of morphometric analysis shows that MWS 7 is having high priority ranking while MWS 8 is having low priority ranking, while the results of the LULC analysis-based prioritizing showed that the micro watersheds MWS 10 and MWS 5 micro watersheds are of are of highest and lowest priority respectively. It is observed that upon integration of morphometric and land use/ land cover compound factor values information, MWS 3 and MWS 10 found to receive common priority falls under the highest priority, though MWS 6 and MWS 8 falls under the lowest priority ranking. The results of the study can be employed for identifying the sub-watersheds that require immediate restoration and ultimately help in managing watershed resources for sustainable development.
21
Habtu, Worku, e Jayappa K. S. "Use of ASTER DEM data for Morphometric Analysis of Megech Dirma-Watersheds, Blue Nile Basin, Ethiopia: Implications for Soil and Water Conservation". Remote Sensing of Land 5, n. 1 (10 aprile 2021): 27–40. http://dx.doi.org/10.21523/gcj1.2021050103.
Testo completoAbstract (sommario):
Quantitative morphometric analysis was carried out for Megech-Dirma, sub-basin of the Blue Nile, by estimating (1) linear, (2) aerial, and (3) relief aspects. An endeavor has been made to measure the Megech-Dirma watershed’s morphometric characteristics to implement conservation methods for soil and water properly. ASTER DEM has been used as input data for extracting morphometric parameters. Strahler’s classification scheme was used to classify the extracted drainage network in ArcGIS extension ArcMap 10.4. The watershed covers a total surface area of 1309.56 km2. The shape of the watersheds as calculated from elongation, circularity, and form factors reveals the elongated shape and the watersheds parade dendritic pattern. The sub-watersheds include third-order for Megech and sixth-order streams. Lower stream orders, in particular first-order streams, dominate the sub-watersheds. The length of overland flow has a higher value (1.06) for Megech indicates low relief, whereas the values of length of overland flow, which are relatively low (0.20) for Dirma, indicate high relief. The drainage density of the study watershed was morphometrically analyzed and obtained 0.47 km/km2 for the Megech sub-basin, which indicates the basin is highly permeable and result in better underground water storage capacity and 2.46 for the Dirma sub-basin indicating very coarse and coarse channel, respectively. The ruggedness number for Megech and Dirma sub-basins was 0.56 and 0.07, respectively, indicating moderate and long, rugged topography, which could be susceptible to flash flood and soil erosion. The dissection index values for Megech 0.40 and 0.36 for Dirma show river sub-basins are moderately dissected. The ruggedness number is 0.56 for Megech implies moderate soil erosion probability, whereas the high infiltration number (14.29) for Dirma river shows the high runoff potential in the sub-basin. The findings of this study include drainage morphometry data that can be used to better understand watershed characteristics and serve as a framework for better planning, management, and decision-making to ensure the long-term use of watershed resources of water and soil.
22
Zhang, Ri Jun. "Construction of Digital Aojiang Watershed". Applied Mechanics and Materials 687-691 (novembre 2014): 2157–60. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.2157.
Testo completoAbstract (sommario):
Based on Digital Elevation Model and watershed hydrology software WMS, Digital Aojiang Watershed was established.it Used the grid DEM and Position of watershed outlet and Computed according to Topographic Parameterization Program (TOPAZ), this paper delineated watershed boundary and structure of River, built the Topological relationships of River networks and defined Seven sub-watersheds. Then Parameters for sub-watersheds were computed, such as sub-watershed area, perimeter, shape factor and slope.
23
YAMIN, MUHAMAD, e BAGUS WIDHI DHARMA S. "KALIBRASI PARAMETER HIDROGRAF SATUAN SINTETIK NAKAYASU (STUDI SUNGAI-SUNGAI DI SULAWESI SELATAN )". GANEC SWARA 13, n. 2 (2 settembre 2019): 369. http://dx.doi.org/10.35327/gara.v13i2.104.
Testo completoAbstract (sommario):
Many synthetic unit hydrographs have been developed including the Nakayasu Synthetic Hydriograph based on empirical observations in Japan. Although the determination of parameters has been presented with various criteria, so far the results are still relatively distorted if applied to watersheds in Indonesia, so it is necessary to calibrate some of the parameters used. This research is a research study conducted in 3 sub-watersheds in South Sulawesi Province by using a type of spread, namely the Maros sub-watershed, Tallo sub-watersheds and Jeneberang sub-watersheds. There are 2 parameters to be calibrated, namely the coefficient α and Ctg with tg = 0.04-0.0058L, the calibration done is obtained α and Ctg values corresponding to each watershed. The results of the study indicate that the use of the Nakayasu method for the purposes of the analysis of flood hydrographs which is a change in the variety of rainfall data in Indonesia, needs to be modified, especially to the parameters used. To get a range of parameters based on the parameters of watershed characteristics, it is necessary to conduct further studies on many watersheds based on the type of watershed.
24
Park, Minji, Yongchul Cho, Kyungyong Shin, Hyungjin Shin, Sanghun Kim e Soonju Yu. "Analysis of Water Quality Characteristics in Unit Watersheds in the Hangang Basin with Respect to TMDL Implementation". Sustainability 13, n. 18 (7 settembre 2021): 9999. http://dx.doi.org/10.3390/su13189999.
Testo completoAbstract (sommario):
Spatiotemporal water quality tendencies before and after total maximum daily load (TMDL) implementation in the Hangang basin were analyzed to determine the water quality improvement resulting from the TMDL policy. The periodicities of water quality indicators were also analyzed and water quality characteristics corresponding to different unit watershed units were identified in terms of pollution source. Considering five water quality indicators, including biochemical oxygen demand and total phosphorus, it was observed that water quality indicator concentrations were low in the upstream areas of the Bukhangang and Namhangang watersheds. However, they were high between the downstream areas of the Namhangang watershed and the Imjingang watershed and in the Hangang downstream and Jinwicheon watersheds. Additionally, the concentrations of water quality indicators in most of the unit watersheds where TMDL had been implemented decreased after TMDL implementation. However, increasing tendencies in the concentrations of water quality indicators continued to be observed in some of the watershed units in the upstream areas of the Bukhangang and Namhangang watersheds, possibly because these watersheds are affected by nonpoint source pollution owing to rainfall. Therefore, in the future, it would be necessary to implement policies that take these findings into consideration.
25
Adham, M. I., S. M. Shirazi, F. Othman, S. Rahman, Z. Yusop e Z. Ismail. "Runoff Potentiality of a Watershed through SCS and Functional Data Analysis Technique". Scientific World Journal 2014 (2014): 1–15. http://dx.doi.org/10.1155/2014/379763.
Testo completoAbstract (sommario):
Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling.
26
Gagnon, P., B. Konan, A. N. Rousseau e M. Slivitzky. "Hydrometeorological validation of a Canadian Regional Climate Model simulation within the Chaudière and Châteauguay watersheds (Québec, Canada)". Canadian Journal of Civil Engineering 36, n. 2 (febbraio 2009): 253–66. http://dx.doi.org/10.1139/l08-125.
Testo completoAbstract (sommario):
This study involved regional validation of a recently developed Canadian Regional Climate Model (CRCM) simulation (version 4.1.1). Four hydrometeorological variables, minimum and maximum daily temperatures, total precipitation, and total runoff, were examined within the Châteauguay and Chaudière watersheds, Québec, Canada. These watersheds, located in southern Québec, are smaller in area (2530 and 6682 km2, respectively) than the size of watersheds usually used to validate this type of model (104–106 km2). The objective of the study was to evaluate if the model could reproduce data similar to field observations within these watersheds. A successful model could be used to produce reliable predictions regarding future climate change effects on watershed hydrology within any given watershed demonstrating similar climatological variables. Results show that even though the CRCM can produce reliable results, there remains a significant bias for each variable at least during one season. Analyses show that the bias for maximum temperature is not very strong (<1 °C) within either of the studied watersheds. However, minimum temperature is clearly underestimated (≈2 °C) in winter and in spring within both watersheds. Total precipitation is significantly overestimated in winter, spring and summer within the Châteauguay watershed (11%, 35%, and 30%, respectively), but for the Chaudière watershed overestimation is less than 5%. Total runoff is strongly overestimated in both watersheds for most of the annual cycle (>30%) and is highly variable in winter and spring. Ideally, the results of this study will be used to guide future studies on the causes of CRCM bias and ultimately lead to model improvement.
27
Assani, Ali A., Raphaëlle Landry, Christophe Kinnard, Ouassila Azouaoui, Christine Demers e Karine Lacasse. "Comparison of the Spatiotemporal Variability of Temperature, Precipitation, and Maximum Daily Spring Flows in Two Watersheds in Quebec Characterized by Different Land Use". Advances in Meteorology 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/3746460.
Testo completoAbstract (sommario):
We compared the spatiotemporal variability of temperatures and precipitation with that of the magnitude and timing of maximum daily spring flows in the geographically adjacent L’Assomption River (agricultural) and Matawin River (forested) watersheds during the period from 1932 to 2013. With regard to spatial variability, fall, winter, and spring temperatures as well as total precipitation are higher in the agricultural watershed than in the forested one. The magnitude of maximum daily spring flows is also higher in the first watershed as compared with the second, owing to substantial runoff, given that the amount of snow that gives rise to these flows is not significantly different in the two watersheds. These flows occur early in the season in the agricultural watershed because of the relatively high temperatures. With regard to temporal variability, minimum temperatures increased over time in both watersheds. Maximum temperatures in the fall only increased in the agricultural watershed. The amount of spring rain increased over time in both watersheds, whereas total precipitation increased significantly in the agricultural watershed only. However, the amount of snow decreased in the forested watershed. The magnitude of maximum daily spring flows increased over time in the forested watershed.
28
Kelaiya, J. H., H. D. Rank e D. K. Dwivedi. "Evaluation of morphometric characteristics and watershed prioritization of Bhadar basin of Saurashtra region, Gujarat". Journal of Applied and Natural Science 11, n. 2 (10 giugno 2019): 273–80. http://dx.doi.org/10.31018/jans.v11i2.2032.
Testo completoAbstract (sommario):
Morphometric analysis is one of the important aspects of quantitative geomorphology which is primarily used to study the geometrical aspects of the landforms. The study was undertaken with the objectives of evaluating morphometric characteristic and prioritizing the watersheds of Bhadar basin based on its morphometric characteristics. Linear, relief and aerial aspects were calculated for watershed characterization. The watersheds were ranked on the basis of high values of linear parameters and low values of shape parameters. A total of 16 watersheds 5G1B1, 5G1B2, 5G1B3, 5G1B4, 5G1B5, 5G1B6, 5G1B7, 5G1B8, 5G1B9, 5G1B10, 5G1B11, 5G1B12, 5G1B13, 5G1B14, 5G1B15 and 5G1B16 were identified in the Bhadar basin and morphometric characteristic of each watershed was determined. Highest priority indicated the greater degree of erosion in the particular watershed and it therefore priority should be given in applying soil conservation measures. It was concluded that the watershed 5G1B15 should be given highest priority because of higher erosion problems over other watersheds of Bhadar basin while 5G1B4 should be given the least priority.
29
Muzdalifah, Safa Muzdalifah. "Local Government Subwatershed Management". International Journal of Southeast Asian Studies (IJSAS) 1, n. 2 (12 settembre 2023): 62–66. http://dx.doi.org/10.20527/ijsas.v1i2.12.
Testo completoAbstract (sommario):
The purpose of this study is to analyze the management of local government in the management of sub-watersheds affected by floods in Banjar Regency, South Kalimantan. The background of the research is the occurrence of floods in the sub-watershed in Banjar Regency. The provincial government has the authority to manage watersheds within the province, on the authority of the government, so an in-depth analysis is needed regarding the management of local governments in the management of sub watersheds in Banjar Regency. So, to answer the research problem, the research used descriptive qualitative method. The location of this research is in Banjar Regency. The key informants of the research are the South Kalimantan provincial government, especially those authorized in the Martapura Sub-watershed management, namely the Kayu Tangi Forest Management Unit Organization, and the Head of the South Kalimantan Province Environmental Service. The results of this study indicate that local governments in managing flood-affected sub-watersheds in Banjar Regency, South Kalimantan Province are formulated through basic watershed management steps. Watershed management steps taken include identification of watershed characteristics, analysis of problems, determination of technical alternatives for watershed management, preparation of watershed management plans, implementation of watershed management, and monitoring and evaluation of watershed management.
30
Sriyana, Ignatius. "Evaluation of Micro Hydro Power Plants in Central Java toward Sustainability against Hydrology Condition of Watershed". E3S Web of Conferences 73 (2018): 01017. http://dx.doi.org/10.1051/e3sconf/20187301017.
Testo completoAbstract (sommario):
Land degradation on the upstream of watershed will affect hydrology condition in a way that it will disrupt the sustainability of its existing micro hydro. The purpose of this study is to evaluate micro hydro power plant in central Java toward sustainability against hydrology condition of watershed. This study is using River Regime Coefficient (RRC) approach where hydrology of watershed with coefficient value less than 50 is classified as non-critical, between 50 and 120 is moderate and more than 120 is critical. Result of the study that was done on 33 micro hydro power plants scattered on 9 watersheds is showing that there are 2 power plants on 2 watersheds have hydrology condition in non-critical status (9.09%), 1 power plant on 1 watershed is in between critical and non-critical status (3.03%), 21 power plants on 3 watersheds are in between critical and moderate status (63.64%), 8 power plants on 6 watersheds are in critical status (21.21%) and 1 power plant on 1 watershed is in between moderate and critical status (3.03%).
31
Göncü, S., e E. Albek. "Modeling the effects of climate change on different land uses". Water Science and Technology 56, n. 1 (1 luglio 2007): 131–38. http://dx.doi.org/10.2166/wst.2007.444.
Testo completoAbstract (sommario):
This study deals with the effects of the expected climate change on the hydrology of watersheds. The watershed response in terms of the water produced by the watershed has been modeled using HSPF (Hydrological Simulation Program-FORTRAN) for a time period which encompasses the first half of the twenty-first century. Climate change scenarios have been prepared based on trends expected in western Turkey and a hypothetical watershed with different land uses has been simulated. The trends have been extracted from the results of a general circulation model. The simulations have revealed that watersheds with no vegetative cover will respond to the trends in temperature and precipitation more rigorously than vegetated watersheds. Pasture or watersheds with deciduous or coniferous forests respond less to climate change due to the buffering mechanism of the vegetative cover and also due to the large quantities of water they transpire. It has also been found that monthly variations are important in predicting the future response of watersheds. While changes might seem small on a yearly scale, there are large differences in response among seasons.
32
HlásnyT, SitkováZ e I. Barka. "Regional assessment of forest effect on watershed hydrology: Slovakia as a case study 405". Journal of Forest Science 59, No. 10 (29 novembre 2013): 405–15. http://dx.doi.org/10.17221/55/2013-jfs.
Testo completoAbstract (sommario):
Recently, the importance of forest effect on watershed hydrology has been increasingly recognized due to an elevated threat of floods and expected alterations of water regime in watersheds induced by climate change. We assessed the trade-off between natural conditions of 61 basic watersheds in Slovakia and expected water-regulatory capacity of forest in these watersheds. A multi-criteria decision-making scheme was proposed to calculate a coefficient for each watershed indicating the need to regulate its water regime as given by natural conditions, and another coefficient indicating the magnitude of forest water-regulatory capacity given by forest structure and distribution. Factors indicating the forest water-regulatory capacity were extent of forest cover, forest fragmentation and distribution in watersheds relative to the spring area, forest stand density and vertical structure, and tree species composition. The results indicate that the present structure and distribution of forests in Slovakia has potential to moderately regulate the water regime at the scale of basic watersheds. We identified critical watersheds where natural conditions imply the unfavourable water regime and/or the forest water-regulatory capacity is weak. Limits of forest effect on watershed hydrology and caveats for interpreting the presented findings are discussed.
33
Jin, Youngkyu, Sangho Lee, Taeuk Kang, Yeulwoo Kim e Namjoo Lee. "Framework for Healthiness Assessment of Water Cycle to Decide the Priority of Enhancement and Restoration Plans". Water 15, n. 1 (20 dicembre 2022): 6. http://dx.doi.org/10.3390/w15010006.
Testo completoAbstract (sommario):
The water cycle in watersheds is vulnerable due to climate change; hence, the need for sustainable watershed management is increasing. This paper suggests a framework for a healthiness assessment of the water cycle to provide a guideline for systematic watershed management considering the previous and current states. The suggested framework aims to prioritize restoration and enhancement plans based on the graded healthiness of the water cycle elements by the watersheds. The framework is composed of two assessment procedures: a problem-focused assessment to identify problems such as flood, drought, and river depletion in the watershed and the highest priority assessment to select the watershed for enhancement and restoration plans. The healthiness assessment method for each metric is suggested based on the Korean Framework Act on Water Management. The framework was applied to four different watersheds in South Korea. The framework is proven to be an effective method to identify practical emerging problems for the water cycle in each watershed. The framework can contribute to providing technical information to detect the water problem of the watershed by objectively diagnosing the watersheds with various potential water problems via the healthiness assessment.
34
Leta, Olkeba, Aly El-Kadi, Henrietta Dulai e Kariem Ghazal. "Assessment of SWAT Model Performance in Simulating Daily Streamflow under Rainfall Data Scarcity in Pacific Island Watersheds". Water 10, n. 11 (27 ottobre 2018): 1533. http://dx.doi.org/10.3390/w10111533.
Testo completoAbstract (sommario):
Evaluating the performance of watershed models is essential for a reliable assessment of water resources, particularly in Pacific island watersheds, where modeling efforts are challenging due to their unique features. Such watersheds are characterized by low water residence time, highly permeable volcanic rock outcrops, high topographic and rainfall spatial variability, and lack of hydrological data. The Soil and Water Assessment Tool (SWAT) model was used for hydrological modeling of the Nuuanu area watershed (NAW) and Heeia watershed on the Island of Oahu (Hawaii). The NAW, which had well-distributed rainfall gauging stations within the watershed, was used for comparison with the Heeia watershed that lacked recoded rainfall data within the watershed. For the latter watershed, daily rain gauge data from the neighboring watersheds and spatially interpolated 250 m resolution rainfall data were used. The objectives were to critically evaluate the performance of SWAT under rain gauge data scarce conditions for small-scale watersheds that experience high rainfall spatial variability over short distances and to determine if spatially interpolated gridded rainfall data can be used as a remedy in such conditions. The model performance was evaluated by using the Nash–Sutcliffe efficiency (NSE), the percent bias (PBIAS), and the coefficient of determination (R2), including model prediction uncertainty at 95% confidence interval (95PCI). Overall, the daily observed streamflow hydrographs were well-represented by SWAT when well-distributed rain gauge data were used for NAW, yielding NSE and R2 values of > 0.5 and bracketing > 70% of observed streamflows at 95PCI. However, the model showed an overall low performance (NSE and R2 ≤ 0.5) for the Heeia watershed compared to the NAW’s results. Although the model showed low performance for Heeia, the gridded rainfall data generally outperformed the rain gauge data that were used from outside of the watershed. Thus, it was concluded that finer resolution gridded rainfall data can be used as a surrogate for watersheds that lack recorded rainfall data in small-scale Pacific island watersheds.
35
Jayakaran, A. D., T. M. Williams, H. Ssegane, D. M. Amatya, B. Song e C. C. Trettin. "Hurricane impacts on a pair of coastal forested watersheds: implications of selective hurricane damage to forest structure and streamflow dynamics". Hydrology and Earth System Sciences 18, n. 3 (26 marzo 2014): 1151–64. http://dx.doi.org/10.5194/hess-18-1151-2014.
Testo completoAbstract (sommario):
Abstract. Hurricanes are infrequent but influential disruptors of ecosystem processes in the southeastern Atlantic and Gulf coasts. Every southeastern forested wetland has the potential to be struck by a tropical cyclone. We examined the impact of Hurricane Hugo on two paired coastal South Carolina watersheds in terms of streamflow and vegetation dynamics, both before and after the hurricane's passage in 1989. The study objectives were to quantify the magnitude and timing of changes including a reversal in relative streamflow difference between two paired watersheds, and to examine the selective impacts of a hurricane on the vegetative composition of the forest. We related these impacts to their potential contribution to change watershed hydrology through altered evapotranspiration processes. Using over 30 years of monthly rainfall and streamflow data we showed that there was a significant transformation in the hydrologic character of the two watersheds – a transformation that occurred soon after the hurricane's passage. We linked the change in the rainfall–runoff relationship to a catastrophic change in forest vegetation due to selective hurricane damage. While both watersheds were located in the path of the hurricane, extant forest structure varied between the two watersheds as a function of experimental forest management techniques on the treatment watershed. We showed that the primary damage was to older pines, and to some extent larger hardwood trees. We believe that lowered vegetative water use impacted both watersheds with increased outflows on both watersheds due to loss of trees following hurricane impact. However, one watershed was able to recover to pre hurricane levels of evapotranspiration at a quicker rate due to the greater abundance of pine seedlings and saplings in that watershed.
36
Jayakaran, A. D., T. M. Williams, H. Ssegane, D. M. Amatya, B. Song e C. C. Trettin. "Hurricane impacts on a pair of coastal forested watersheds: implications of selective hurricane damage to forest structure and streamflow dynamics". Hydrology and Earth System Sciences Discussions 10, n. 9 (12 settembre 2013): 11519–57. http://dx.doi.org/10.5194/hessd-10-11519-2013.
Testo completoAbstract (sommario):
Abstract. Hurricanes are infrequent but influential disruptors of ecosystem processes in the southeastern Atlantic and Gulf coasts. Every southeastern forested wetland has the potential to be struck by a tropical cyclone. We examined the impact of Hurricane Hugo on two paired coastal watersheds in South Carolina in terms of stream flow and vegetation dynamics, both before and after the hurricane's passage in 1989. The study objectives were to quantify the magnitude and timing of changes including a reversal in relative streamflow-difference between two paired watersheds, and to examine the selective impacts of a hurricane on the vegetative composition of the forest. We related these impacts to their potential contribution to change watershed hydrology through altered evapotranspiration processes. Using over thirty years of monthly rainfall and streamflow data we showed that there was a significant transformation in the hydrologic character of the two watersheds – a transformation that occurred soon after the hurricane's passage. We linked the change in the rainfall-runoff relationship to a catastrophic shift in forest vegetation due to selective hurricane damage. While both watersheds were located in the path of the hurricane, extant forest structure varied between the two watersheds as a function of experimental forest management techniques on the treatment watershed. We showed that the primary damage was to older pines, and to some extent larger hardwood trees. We believe that lowered vegetative water use impacted both watersheds with increased outflows on both watersheds due to loss of trees following hurricane impact. However, one watershed was able to recover to pre hurricane levels of canopy transpiration at a quicker rate due to the greater abundance of pine seedlings and saplings in that watershed.
37
Liu, Wenfei, Xiaohua Wei, Qiang Li, Houbao Fan, Honglang Duan, Jianping Wu, Krysta Giles-Hansen e Hao Zhang. "Hydrological recovery in two large forested watersheds of southeastern China: the importance of watershed properties in determining hydrological responses to reforestation". Hydrology and Earth System Sciences 20, n. 12 (1 dicembre 2016): 4747–56. http://dx.doi.org/10.5194/hess-20-4747-2016.
Testo completoAbstract (sommario):
Abstract. Understanding hydrological responses to reforestation is an important subject in watershed management, particularly in large forested watersheds ( > 1000 km2). In this study, we selected two large forested watersheds (Pingjiang and Xiangshui) located in the upper reach of the Poyang Lake watershed, southeastern China (with an area of 3261.4 and 1458 km2, respectively), along with long-term data on climate and hydrology (1954–2006) to assess the effects of large-scale reforestation on streamflow. Both watersheds have similar climate and experienced comparable and dramatic forest changes during the past decades, but with different watershed properties (e.g., the topography is much steeper in Xiangshui than in Pingjiang), which provides us with a unique opportunity to compare the differences in hydrological recovery in two contrasted watersheds. Streamflow at different percentiles (e.g., 5, 10, 50 and 95 %) were compared using a combination of statistical analysis with a year-wise method for each watershed. The results showed that forest recovery had no significant effects on median flows (Q50%) in both watersheds. However, reforestation significantly reduced high flows in Pingjiang, but had limited influence in Xiangshui. Similarly, reforestation had significant and positive effects on low flows (Q95%) in Pingjiang, while it did not significantly change low flows in Xiangshui. Thus, hydrological recovery is limited and slower in the steeper Xiangshui watershed, highlighting that watershed properties are also important for determining hydrological responses to reforestation. This finding has important implications for designing reforestation and watershed management strategies in the context of hydrological recovery.
38
Gaikwad, Ravindra, e Vijay Bhagat. "Multi-Criteria Watershed Prioritization of Kas Basin in Maharashtra India: AHP and Influence Approaches". Hydrospatial Analysis 1, n. 1 (21 gennaio 2018): 41–61. http://dx.doi.org/10.21523/gcj3.17010105.
Testo completoAbstract (sommario):
Watershed is unique bio-physical unit of the Earth’s surface and source of resources to the people. These resources are being exploited for various purposes. AHP based multi-criteria analysis is useful for prioritization of watersheds for planning, management and development. Nineteen criterion i.e. Rb, Lb, A, Lb, P, Dd, P, Fs, Rf, Re, CC, Dt, T, Di, If, Rh1, Rn , slope and soils were selected for prioritization of sub-watersheds of Kas basin in Maharashtra (India). Correlation analysis suitable for robust judgment for ranking the criterion was used for prioritization of selected watersheds. Drainage intensity (27.80%), texture ratio (13.90%), bifurcation ratio (9.27%), geology (6.95%) and basin length (5.56%) show higher influence on formation of watershed structure in the region. Influences of criterion were estimated based on weights calculated using AHP techniques. Values of influences were normalized using distribution of selected criterion within the sub-watersheds. Watersheds were classified into three categories of priorities: high, moderate and low priorities. The methodology formulated in this study can be efficient tool for rapid prioritization of watersheds for planning and management for development.
39
Peterson, Tim J., M. Saft, M. C. Peel e A. John. "Watersheds may not recover from drought". Science 372, n. 6543 (13 maggio 2021): 745–49. http://dx.doi.org/10.1126/science.abd5085.
Testo completoAbstract (sommario):
The Millennium Drought (southeastern Australia) provided a natural experiment to challenge the assumption that watershed streamflow always recovers from drought. Seven years after the drought, the runoff (as a fraction of precipitation) had not recovered in 37% of watersheds, and the number of recovered watersheds was not increasing. When recovery did occur, it was not explained by watershed wetness. For those watersheds not recovered, ~80% showed no evidence of recovering soon, suggesting persistence within a low-runoff state. The post-drought precipitation not going to runoff was found to be likely going to increased evapotranspiration per unit of precipitation. These findings show that watersheds can have a finite resilience to disturbances and suggest that hydrological droughts can persist indefinitely after meteorological droughts.
40
Faski, G. I. S. L., Ig L. S. Purnama e S. Suprayogi. "Application of hydrometeorological data to analyze water balance conditions in Bengkulu watershed". IOP Conference Series: Earth and Environmental Science 893, n. 1 (1 novembre 2021): 012078. http://dx.doi.org/10.1088/1755-1315/893/1/012078.
Testo completoAbstract (sommario):
Abstrak Water balance serves to determine hydrological conditions in a watershed, one of which is by analyzing the surplus (excess water) and deficit (water shortage) that occurs. Extreme surpluses or deficits can cause hydrometeorological disasters, such as floods or droughts. This study aims to calculate the monthly water balance using the Thornthwaite-Mather method to determine variations in the incidence of surplus and deficit months in all three sub-watersheds in Bengkulu Watershed, namely Rindu Hati, Susup, and Bengkulu Hilir sub-watershed. The data used are monthly hydrometeorological data for 2009-2018 (10 years) were divided into two periods of water balance based on land use data. Water balance period 1 (2009-2013) uses 2009 land use data, while period 2 (2014-2018) uses 2014 land use data. The results show that the surplus, deficit, runoff, and discharge in the three sub-watersheds in the Bengkulu watershed are affected by rainfall. In general, the deficit incidents in all three sub-watersheds occur almost every three years. The Rindu Hati and Susup sub-watersheds have the same variations of surplus and deficit month incidents, while the Bengkulu Hilir sub-watershed is different, both in periods 1 and 2. It is not only the rainfall that affects the variation in the events of surplus and deficit in all three sub-watersheds of the Bengkulu watershed, but also the amount of water holding capacity (WHC). Therefore, the application of hydrometeorological data to analyze the water balance conditions in the Bengkulu watershed provides information on climate impact on water resources and environmental impact on flows in the watershed.
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N. Sahoo, T.B. S. Rajput e A. R. Rao. "Geomorphological Parameters Based Watershed Sediment Yield Estimation". Journal of Agricultural Engineering (India) 45, n. 1 (31 marzo 2008): 47–56. http://dx.doi.org/10.52151/jae2008451.1313.
Testo completoAbstract (sommario):
Most models available for computation of sediment yield of watersheds use inter-correlated geomorphologic parameters of the watershed which is against the principle of regression analysis. Principal components which are transformed but unrelated were derived from the set of correlated geomorphological parameters of watersheds. In this study eleven watersheds were selected. Out of which the data of term watersheds were utilized for the development of models and the data of one watershed were utilized for validation of the models. Twenty-two numbers of geomorphological parameters were quantified for each selected watershed. It was found that the geomorphological parameters are correlated among themselves. So these parameters were transformed into the scores of principal components to make them uncorrelated. Then multiple regression models between sediment production rate (SPR) and scores of principal components were developed using principal component regression in Statistical Analysis System (SAS) environment. The average absolute deviation of predicted SPR was found within 10.55% and 5.43% for different percent ranges of runoff and ranges of rainfall. Hence the developed model can be used for better prediction of SPR for other similar ungauged watershed.
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Liu, Cheng-Chien, Ming-Hsun Ko, Huei-Lin Wen, Kuei-Lin Fu e Shu-Ting Chang. "Instability Index Derived from a Landslide Inventory for Watershed Stability Assessment and Mapping". ISPRS International Journal of Geo-Information 8, n. 3 (19 marzo 2019): 145. http://dx.doi.org/10.3390/ijgi8030145.
Testo completoAbstract (sommario):
Watersheds represent natural units of social–ecological systems and affect crop productivity. Extreme weather events accelerate the natural erosion process by triggering more landslides in watersheds. To achieve the land degradation neutrality set up by the UN’s Sustainable Development Goals, it is necessary to assess and map spatiotemporal landslides in watersheds. This paper proposes an innovative approach to calculating the instability index by preparing an annual landslide inventory, determining the optimum sub-watershed, compensating for shadow effects on the time series of the landslide area ratio, and classifying the standard deviations to different levels of instability. Taking the Qingquan watershed as an example, the instability index calculated for 22 sub-watersheds makes it possible to identify hot spots that are prone to collapse. This new index can also be used to evaluate the effectiveness of watershed management before and after completion of a specific engineering project, as well as to update the latest upriver situation to evaluate current management practices and develop strategies for future planning. Based on this new approach, the Soil and Water Conservation Bureau of Taiwan assesses the stability of 28 watersheds, and the results are made available on the Big Geospatial Information System.
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Puspitasari, Titik, Chay Asdak e Martha Fani Cahyandito. "Factors affecting payments for environmental services (PES) implementation in the Garang watershed management". E3S Web of Conferences 249 (2021): 01006. http://dx.doi.org/10.1051/e3sconf/202124901006.
Testo completoAbstract (sommario):
Watersheds has essential functions in human life and other living things that include hydrological and ecological functions. However, the number of critical watershed conditions are increasing and resulting in the degradation of the watershed function. The number of critical watersheds according to the 2009 forestry ministerial decree is 108 watersheds including Garang watershed. The landscape degradation of the upper areas will significantly affect hydrological conditions in downstream areas. Payment for environmental services (PES) is one of the alternatives of watershed management that combines interests in the upstream - downstream watersheds, especially in the form of water distribution. This study aims to identify important factors or criteria needed, especially related to the water environment services as a part of the integrated watershed management. The qualitative and quantitative method was used in this study with descriptive and CVM analysis used through the review literature, interview and survey. The analysis identifies important factors for PES in a sustainable watershed management which include its context, actors, financing systems, operations, and monitoring evaluation. The study also shows that some factors need improvement such as context (local regulation), actors (public understanding of the PES mechanism), operation (planning design), and low willingness to pay for PES implementation in Garang watershed. By properly defining the criteria of PES, watershed management can be managed in a way that the upper and downstream areas can be linked in an integrated way.
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Suryani, Ade Irma suryani, Yuherman Yuherman e Lamina Siregar. "Technical Assistance on Plant Cultivation Landslide Prevention in the River Flow Area in Kampung Bendang Nagari River Sariak VII Koto Padang Pariaman District". Asian Journal of Community Services 3, n. 5 (31 maggio 2024): 429–38. http://dx.doi.org/10.55927/ajcs.v3i5.9367.
Testo completoAbstract (sommario):
Watershed areas (watersheds are divided into upstream, middle and downstream areas. Upstream watersheds are characterized as conservation areas, have a higher drainage density and are areas with slopes of more than 15%, lower watersheds are characterized by areas with small slopes (less than 8% ) to flat, in some places it is a flood or puddle area. Water management is determined by irrigation water structures. The middle watershed is a transition area between upstream and downstream. (Asdak, 1995). main, (1) vegetative method, (2) Mechanical method, (3) Chemical method (Arsyad, 2010). In watershed spatial planning, vegetative methods and mechanical methods are recommended There are several methods that can be used to prevent landslides in watershed areas, both upstream, middle and downstream, but what is highly recommended is the Vegetative method and cultivating these plants
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Iverson, Guy, Christa Sanderford, Charles P. Humphrey, J. Randall Etheridge e Timothy Kelley. "Fecal Indicator Bacteria Transport from Watersheds with Differing Wastewater Technologies and Septic System Densities". Applied Sciences 10, n. 18 (18 settembre 2020): 6525. http://dx.doi.org/10.3390/app10186525.
Testo completoAbstract (sommario):
Wastewater contains elevated concentrations of fecal indicator bacteria (FIB). The type of wastewater treatment technology and septic system density may influence the FIB concentration and exports at the watershed scale. The goal of this study was to gain a better understanding of FIB concentrations and exports from watersheds served by conventional septic (CS) systems, sand filter (SF) septic systems, and a municipal sewer (SEW) system. Seven watersheds (3 CS, 3 SF, and 1 SEW) were monitored to quantify FIB concentration and export monthly from April 2015 to March 2016. The type of wastewater treatment did not yield significant differences in FIB concentration or exports when pooling watersheds using similar wastewater treatment. Watersheds with the highest septic densities (approximately 0.4 systems ha−1) contained greater FIB concentrations and exports than watersheds with the lowest (approximately 0.1–0.2 systems ha−1), but only FIB concentrations significantly differed. These findings suggest that when the septic system density exceeds 0.4 systems ha−1, water quality degradation from septic leachate may be observable at the watershed scale, especially in watersheds dominated by residential development. More research is recommended to determine if this density threshold is similar for other water pollutants and/or in watersheds with differing hydrogeological, land use, and wastewater characteristics.
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Singh, Gurbir, Gurpreet Kaur, Karl W. Williard, Kelly A. Nelson e Jon E. Schoonover. "Cover crops and topography differentially influence weeds at a watershed scale". Weed Technology 34, n. 1 (23 agosto 2019): 73–81. http://dx.doi.org/10.1017/wet.2019.83.
Testo completoAbstract (sommario):
AbstractCover crops (CCs) play an important role in integrated weed management. Data necessary to evaluate the role of CCs in weed management at the watershed scale with topographic positions are lacking. We evaluated the effects of cereal rye and hairy vetch CCs on weed suppression at different topographic positions (shoulder, backslope, and footslope) at a watershed scale. Watersheds with a CC treatment followed a crop rotation of corn–cereal rye–soybean–hairy vetch, whereas watersheds without a CC (no-CC) had a crop rotation of corn–winter fallow–soybean–winter fallow. A negative relationship was present between CCs and weed biomass at the shoulder, backslope, and footslope topographic landscape positions, with R2 values of 0.40, 0.48, and 0.50, respectively. In 2016, a cereal rye CC reduced weed biomass 46% to 50% at footslope and shoulder positions compared to no CC. In 2018, a cereal rye CC reduced weed biomass between 52% and 85% at all topographic positions in CC treatment watersheds compared to no-CC watersheds. Hairy vetch in 2017 reduced weed biomass 62% to 72% at footslope and shoulder topographic positions in CC watersheds compared to no-CC. The C:N ratio of weed biomass in CC treatment watersheds was generally higher compared to watersheds without CCs. In this study, several significant interactions were found between the topographic positions and CC treatments. Cover crop–induced weed suppression at different topographic positions can lead to developing better site-specific weed control strategies. Therefore, CC interactions with topography, weed germination potential, and the role of soil moisture at the watershed scale should be further evaluated.
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Keshri, Ravish, M. P. Tripathi, Dhiraj Khalkho, S. K. Verma e Shruti Verma. "Evaluation of Morphometric Parameter for Prioritization of Kantori Nala Milli Watershed". Current Journal of Applied Science and Technology 42, n. 40 (31 ottobre 2023): 1–13. http://dx.doi.org/10.9734/cjast/2023/v42i404257.
Testo completoAbstract (sommario):
Watershed morphological and hydrological properties can be derived from the drainage morphometric parameter. Morphometric analysis with the help of remote sensing and GIS techniques is considered to be the most useful approach for prioritization of watersheds. The main aim of the study is to evaluate the morphometric parameters of Kantori nala milli watershed located at Mahasamund district of Chhattisgarh state, India. This study outlines the significance of digital elevation model for assessment of drainage pattern and extraction of relative parameters. Milli watershed was automatically delineated and divided into eleven micro watersheds MWS 1 to MWS 11 on the basis of topography from the Depression less Digital Elevation Model (DEM) with 10 m resolution prepared by Inverse Distance Weighted (IDW) interpolation technique. Stream order in study area milli watershed ranges from one to two. Each parameter has been assigned their ranks according to their value. Thereafter, an average value of the rank score for each of the micro watershed is calculated. The micro watershed with the lowest compound factor (Cp) was given the highest prioritized rank out of the group of micro watersheds, and vice versa. The result from the priority ranking of morphometric analysis shows that MWS 7 is having high priority while MWS 8 is having low priority. Micro watersheds MWS 9 and MWS 11 falls under same priority i.e. 6 and also micro watersheds MWS 2 and MWS 4 falls under same priority i.e. 7. To control soil erosion, various land rehabilitation programmes and bioengineering methods should be adopted on the micro watershed of high priority categories, followed by medium and low priority categories.
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A. K. Bhattacharya e Jyoti P. Patil. "Abstraction Ratio in the Curve Number Method of Runoff Estimation". Journal of Agricultural Engineering (India) 45, n. 1 (31 marzo 2008): 17–22. http://dx.doi.org/10.52151/jae2008451.1309.
Testo completoAbstract (sommario):
Abstraction ratio refers to the ratio of initial abstraction to the maximum potential retention from rainfall in a watershed. This ratio is an input parameter in the Curve Number method of runoff estimation. The standard value of this ratio is 0.2, which was worked out by analysis of rainfall and stream gauging data of a large number of watersheds in the USA. The Central Unit for Soil Conservation (Hydrology and Sedimentation), Soil Conservation Division, Ministry of Agriculture, Govt. of India. New Delhi had recommended using two values of this ratio namely, 0.1 and 0.3 depending on watershed wetness and soil type. The above two values were recommended based on the analysis of limited stream gauging data for watersheds in India. In the work reported in this paper, the stream gauging data of28 watersheds in India and 4 watersheds in the USA were considered to work out the abstraction ratio. The analysis revealed that the abstraction ratio varied from O. I5 to 0.67 with a 28-watershed mean of0.3 and a 32-watershed mean of0.2941. It was further found that the abstraction ratio data fitted to a normal distribution at 0.04 probability level with a mean of0.2941 and a standard deviation of 0.1019. The analysis results suggest the possibility of adopting a single value of abstraction ratio as 0.3 for small agricultural watersheds in India.
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Parra, Víctor, Enrique Muñoz, José Luis Arumí, Yelena Medina e Robert Clasing. "Identifying a Minimum Time Period of Streamflow Recession Records to Analyze the Behavior of Groundwater Storage Systems: A Study in Heterogeneous Chilean Watersheds". Water 16, n. 12 (20 giugno 2024): 1741. http://dx.doi.org/10.3390/w16121741.
Testo completoAbstract (sommario):
Aquifers are complex systems that present significant challenges in terms of characterization due to the lack or absence of watershed-scale hydrogeological information. An alternative to address the need to characterize watershed-scale aquifer behavior is recession flow analysis. Recession flows are flows sustained by groundwater release from the aquifer. Aquifer behavior can be characterized using recession flow records available from gauging stations, and therefore an indirect measure of aquifer behavior is obtained through watershed-scale recession flow records and analysis. This study seeks to identify the minimum time period necessary to characterize the behavior of groundwater storage systems in watersheds with different geological, morphological, and hydrological characteristics. To this end, various watersheds in south-central Chile underwent recession flow analysis, with eight time periods considered (2, 3, 4, 5, 10, 15, 20, and 25 years). The results indicate that 25 years of records are sufficient for the characterization of watershed-scale aquifer behavior, along with the representation of the groundwater storage-release (S-Q) process in watersheds with different geological, morphological, and hydrological characteristics. Additionally, the results show that an initial characterization of the groundwater system behavior in watersheds with different geological characteristics can be carried out with two years of records. This information could be important for practical engineering and the study of groundwater systems in watersheds with limited hydrological and hydrogeological information.
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Shin, Hyungjin, Hyeokjin Lim, Jaenam Lee, Seulgi Lee, Youngkyu Jin, Heesung Lim, Chul-sung Lee, Gyumin Lee, Sehoon Kim e Changi Park. "Hydrological Analysis of Agricultural Reservoir Watersheds Based on Water Utilization System Using the Catchment Hydrology Cycle Analysis Tool Model". Sustainability 16, n. 10 (7 maggio 2024): 3887. http://dx.doi.org/10.3390/su16103887.
Testo completoAbstract (sommario):
In this study, the catchment hydrology cycle analysis tool (CAT) model was used to conduct a comprehensive hydrological analysis of the water balance of agricultural reservoirs. Data from 2010 to 2017, including precipitation, water level data in the reservoir, groundwater usage, and wastewater discharge, were collected and compiled for the upper reaches of the Hantan River Dam. The current conditions and content curves of the 11 reservoirs within the watershed were investigated and recorded. The results were analyzed by simulating three scenarios: treating the entire watershed as 1 unit, dividing the watershed into 5 sub-watersheds according to the standard watershed criteria, and further subdividing it into 27 watersheds, taking into account the presence of agricultural reservoirs. In cases where watershed information is lacking, it is deemed that subdividing the watershed can enhance efficiency. The highest model efficiency was observed in the 27 sub-basins, particularly when accounting for agricultural reservoirs. This study proposed an efficient method for hydrological analysis of watersheds including ungauged areas.