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In the context of the sustainable management of the Mulet River watershed, a set of conservation and restoration measures have been identified through a participatory and contributory approach supported by scientific literature. In order to assess these measures according to their overall performance and to bundle them into robust baskets of measures, a multi-criteria decision aid approach in a multi-stakeholder context was employed. This approach allows comparison and ranking of the identified measures while considering the values and the preferences of the various actors involved, in order to facilitate negotiations towards the building of a consensual and shared solution, consisting in baskets of measures. Through the application of this approach leading to a good level of agreement between the actors of the watershed area, several measures of agronomic, plant, mechanical, socio-cultural and socio-political categories were selected, and structured into intervention baskets according to the degredation levels of the watershed. The implementation of these measures aims at making the watershed better adapted to the impacts of climate variability and change, while improving the living conditions of the local communities.

To address the degradation of water quality in France, legislators established innovative mechanisms for autonomous water management in 1964, specifically the creation of agencies and basin committees, organized according to hydrographic basins. Over the subsequent fifty years, French legislation followed by European directives have cultivated a distinctive solidarity in environmental policies, operating across three dimensions : hydrographic, financial, and territorial. This article explores the uniqueness of this solidarity and its development, leveraging the evolution of regulations and analyzing the functioning of agencies and basin committees as their mandates expanded. The recent national acknowledgment of quantitative pressure on water resources, manifested in 2023 through the adoption of 53 measures aimed at resilient and coordinated water management, reaffirms the central role of agencies and basin committees in water governance. However, this recognition follows a decade characterized by diminishing financial and technical resources, alongside a delegation of flood and environmental management responsibilities to intercommunalities, often without regard for hydrographic considerations. This article highlights the inherent risks of undermining the current pillars of solidarity in water resource management and aquatic ecosystems, particularly as the impacts of climate change heighten the necessity of this solidarity.

In last decade, a lot of road detection algorithms are researched in remote sensing and aerial images, but they are not valuable for very dark and vague road images, hence, a new algorithm for road detection in a vaguer image is studied in this paper. It firstly uses a Gaussian filter to enhance the original image; then, an new edge detection algorithm is utilized to result in a gradient magnitude image by using different orientation information; subsequently, the road segments in the magnitude image is detected by applying a Watershed based algorithm, and a binary image is obtained; and last, in the binary image, the roads are finalized by removing noise in the image and filling gaps between the segments. To validate the proposed algorithm, the testing images were selected from both public dataset and our own dataset, and the testing results show that the new algorithm results are better than several traditional algorithms and recent semantic methods for the road detection, and the road detection accuracy between 92% and 95%. It is satisfactory for the road detection not only for normal images and also for the dark and vague road images. The new algorithm can be also applied into other applications, such as river detection and image enhancement, etc.

There is growing concern globally to conserve natural systems including watersheds due to increasing forest degradation and deforestation. The Barekese and Owabi watersheds provide several ecosystem services to communities, health facilities and industries. The watersheds are found in a rapidly degrading environment due to increasing anthropogenic activities. This paper addressed the neglected, but critical, question of the importance of watershed ecosystem services. The objective of the study was to determine willingness of households in downstream communities to pay for watershed conservation and the drivers of WTP. Households were willing to pay a mean of $1.5 ± 0.2 additional on their monthly water bills. Quotations for Willingness to pay varied from as low as $0.02 to as high as $ 20.58 per month. Age, household size and years of residence were significantly related with willingness to pay, amount to pay and reasons for protest bids. The younger generations and women were ready to pay extra amount for watershed management. The results indicated that downstream communities are willing to support conservation and that demographic factors influence the amount people are willing to pay. The concept of WTP is useful and applicable to conservation of watersheds in the tropics through the design and implementation of PES schemes. It also provides important information for conservation and development policies related to watershed management in developing countries.

The degradation of soil and water resources has underpinned the chronic household level food insecurity in Ethiopia. The Purpose of the study was to assess the perceived effectiveness of soil and water conservation practices in the study area, and recommend sustainable planning, and management measures. The data for this study were collected via household interview schedule, focus group discussion, key informant interview, and personal observation. Data collected through household survey questionnaire were analysed with the help of simple ddescriptive statistics (mean, standard deviations, percentages, frequencies, and cross tabulation). Chi-squire test was used to see the difference between nominal/categorical dependent variable and the nominal independent variable. Qualitative data were analysed through thematic analysis, and narration. Over cultivation, deforestation, overgrazing, runoff from upslope and the easily erodible nature of the soil, poor agricultural practices, absence of appropriate soil conservation practices, over Population, intensity of rainfall, and cultivation of steep slopes and marginal lands without adequate erosion-controlling measures were identified as causes of soil erosion in the study area. The major structural soil and water conservation measures identified in the study area include: waterway, contour ploughing, cultural ditches, mulching, fallowing, soil bund, agroforestry, tree planting, area closure, cut off-drains, and wood check dams. The major challenges for implementing structural soil and water conservation measures identified in the study area include: physical soil conservation structures were not supported by biological works, lack of regular maintenance of soil and water conservation structures, and absence of care for trees planted on physical structures. A combination of structural and non-structural soil and water conservation measures should be practiced in the study area to achieve the sustainable development goals in agricultural development sector.

Introduction: Global watershed sustainable development has experienced world-wide threats from continuing anthropogenic stressors, and the need to deepen and broaden research encompassing the intersection in global environmental change as well as environmentally oriented watershed sustainable development (EOWSD) has been noticed. However, there is not yet a widely recognized cognition on the applicability and scope of various EOWSD issues, and the zoning of global EOWSD issues is remains uncertain despite it is crucial for achieving global watershed sustainable development.Methods: This research was conducted to both clarify the zoning and evolution of various EOWSD issues around the world, and differentiate the relative impacts on EOWSD of climate change and human activities. The global EOWSD issues were summarized from 62 watersheds around the world as 6 categories associated with different aspects of global watershed sustainability. And the partition method, in which the spatial and temporal variations of global summer Normalized Difference Vegetation Index in summer were examined and the quantitative climate classification were conducted, indicates a clear and definite relationship between the zoning of EOWSD issues and 8 natural geographical zones. Meanwhile, we selected 34 watersheds either or both are the 100 most populous river basins and the 100 largest (by area) river basins in the world from the 62 watersheds to assess relative effects of human impact on watershed sustainability.Results: Results from the numerical analyses of baseline water stress (BWS) values, which was used to provide a robust measure of human impact and evaluate the impact and relative importance of human-induced changes on watershed sustainability, indicate that the human activities do not affect the zoning of EOWSD issues at global scale while the environmental change induced by water engineering development should be certain to affect that on the long-term.Discussion: Our findings present a new perspective to illustrate the relationship among global EOWSD, environmental change and human impacts, and will also provide a scientific basis on setting future emphasizes of global watershed sustainable development and furthering the related disciplines.

In this study, we develop a machine-learning (ML)-enabled strategy for selecting hillslope-scale ecohydrological monitoring sites within snow-dominated mountainous watersheds, with a particular focus on snow-soil–plant interactions. Data layers rely on spatial data layers from both remote sensing and hydrological model simulations. Specifically, a Landsat-based foresummer drought sensitivity index is used to define the dependency of the annual peak plant productivity on the Palmer drought severity index in the early growing season. Hydrological simulations provide the spatiotemporal dynamics of near-surface soil moisture and snow depth. In this framework, a regression analysis identifies the key hydrological variables relevant to the spatial heterogeneity of drought sensitivity. We then apply unsupervised clustering to these key variables, using the Gaussian mixture model, to group hillslopes into several zones that have divergent relationships regarding soil moisture, snow dynamics, and drought sensitivity. Using the datasets collected in the East River Watershed (Crested Butte, Colorado, United States), results show that drought sensitivity is significantly correlated with model-derived soil moisture and snow-free timing over space and time. The relationship is, however, non-linear, such that the correlation decreases above a threshold elevation and in a heavy snow year due to large snowpacks, lateral flow, and soil storage limitations. Clustering is then able to define the zones that have high or low sensitivity to drought, as well as the mid-elevation regions where sensitivity is associated with the topographic aspect and net potential radiation. In addition, the algorithm identifies the most representative hillslopes with road/trail access within each zone for installing monitoring sites. Our method also aims to significantly increase the use of ML and model-simulation results to guide critical zone and watershed monitoring activities.

This study focused on the urban river management using geospatial techniques of the Dehradun Municipal Corporation (DMC) and its associated watersheds of the Bindal River and Rispana River. Shutter Radar Topography Mission (SRTM) Digital Elevation Model (DEM) data with a spatial resolution of 30 m was used for the delineation of watershed boundaries and drainage networks and for identifying topographic features. Additionally, Sentinel-2 data with a spatial resolution of 10 m were utilized to analyze change in land use in 2017 and 2022. The drainage patterns in the Bindal and Rispana watersheds were dendritic in shape with moderate relief. The study found a significant decline in agricultural land from 17.94% in 2017 to 14.66% in 2022. This decline was accompanied by an increase in built-up area from 32.53% to 35.44%. The increased biotic pressure poses a critical threat to river health and biodiversity. This study highlights the urgent need for comprehensive river management strategies to efficiently monitor biotic pressure due to transformations in land use. This research will be beneficial to diverse stakeholders, including decision-makers and urban planners engaged in the sustainable management of water resources and urban development. [ABSTRACT FROM AUTHOR]

This article examines the erosion hazard in the Walanae watershed in Indonesia and proposes land conservation strategies to mitigate the erosion rate. The study utilizes the Universal Soil Loss Equation (USLE) to model erosion control and evaluate the effectiveness of various land conservation scenarios. The findings indicate that erosion rates have been increasing over time, but implementing land conservation measures can significantly reduce the erosion rate. The study underscores the importance of sustainable land and water resource management in addressing environmental challenges. The article provides detailed information on erosion factors, land cover, and recommended conservation measures in the Walanae watershed. It emphasizes the need for conservation efforts to reduce erosion rates and protect the soil. The implementation of these measures in the watershed has resulted in a substantial decrease in the erosion rate. [Extracted from the article]

Decision-making tools have become a prominent methodology in watershed management for many years due to the complexity of environmental systems and requirement for multi-disciplinary expertise. Multi-Criteria Decision Analysis (MCDA) is a systematic methodology, which combines hierarchical structures of a problem and priorities for the alternatives in many fields. This study reviews MCDA applications in pollution risk assessment in the abiotic environments of watersheds for multi-pollutants. Over 80 papers published between 2000 and 2021 are identified in three categories of the Web of Science Core Collection database: "Environmental Sciences", "Environmental Studies", and "Water Resources". The publications are further classified according to different environmental compartments: surface water, groundwater, and soil to investigate MCDA applications in these matrices. Finally, the distribution of the publications according to contaminants and MCDA methods used are also examined. The results reveal that the number of the studies focusing on pollution risk assessment within watersheds has been significantly increasing, especially over the last decade. However, there are still limited MCDA applications linking environmental compartments. Despite several MCDA studies focusing on the vulnerability of watersheds to multiple pollutants, studies related with emerging pollutants are scarce. Moreover, compared to non-point source pollution, studies adopting MCDA to investigate pollutant concentrations coming from point sources are relatively few. According to the overall distributions of MCDA methods, Analytic Hierarchy Process, a commonly found method in the literature that adopts a technique of pairwise comparison to prioritize criteria of prominence, dominates 34% of the publications. [ABSTRACT FROM AUTHOR]

In an upland forested micro-catchment during the growing season, we tested soil responses to precipitation events as well as soil water content (SWC). We asked ourselves if what is the difference of SWC response to precipitation events depending on the presence and proximity of a tree? The environmental heterogeneity of the small 7.5-ha headwater area was captured by soil probes at specific locations: (i) probe measurements of SWC at 10-, 30-, 60-, and 100-cm depths; (ii) resolution of near-tree (NT) and between-tree (BT) positions; and (iii) resolution of four slope classes. The results revealed significant differences between the hydrological responses of the soil. NT soils had faster infiltration but were also faster to dry out when compared to BT soils, which were less affected by the presence of trees. Water input threshold values, measured as the precipitation amount needed to cause a significant increase in SWC, were also significantly different, with NT positions always lower than BT positions. Total infiltration of the topmost NT and BT soil layers reached 185 and 156 mm during the study period, corresponding to 43% and 36% of the total 434 mm of precipitation, respectively. Infiltration into the deepest horizon was significantly higher in NT soils, where it reached 114 mm (26%) as opposed to 9 mm (2%) in BT soils, and was indicative of significant vertical hydraulic bypass flow in the proximity of trees. These observations contribute to better understanding the hydrological processes, their nonlinearity, and the expansion of conceptual hydrological models. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Remote Sensing / Türkiye Uzaktan Algılama Dergisi is the property of Turkish Journal of Remote Sensing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microplastics (i.e., plastic particles <5 mm in size) are aquatic contaminants of emerging concern but are poorly quantified in flowing waters of the midwestern USA. Microplastics enter streams and rivers through a variety of pathways (e.g., wastewater effluent, breakdown of larger plastic debris, atmospheric deposition) and can potentially harm aquatic organisms through both direct consumption and indirect contamination from sorbed toxins. In this study, we quantified microplastic concentrations and types (i.e., beads, fibers, films, foams, fragments) in nine Indiana watersheds representing a gradient of dominant land use (i.e., agricultural, urban, and forested). We predicted that microplastic concentration would be higher in watersheds with higher percentages of urban and agricultural land use than in forested watersheds. Our results revealed measurable quantities of microplastics in samples from all watersheds, but microplastic concentration did not vary significantly with land use or longitudinally within watersheds. Fibers were the dominant form of microplastic at all sites, suggesting that fibers may be transported primarily through atmospheric deposition rather than via direct runoff from the surrounding landscape. We conclude that rivers have a different microplastic "signature" than large lakes, likely due to retention characteristics of flowing water ecosystems, unique microplastic sources, and a shorter legacy of microplastic pollution. [ABSTRACT FROM AUTHOR]

Recently, New Jersey has experienced several droughts and declared several critical water shortage areas, spurring interest in reducing freshwater resource depletion. Japanese knotweed (Reynoutria japonica Houtt.) is an invasive plant species that may have a significant effect on stream water loss. In order to assess the impact of this species on river‐level water flow, we estimated total knotweed distribution along two tributaries of the Passaic River in New Jersey, USA using a combination of field measurements and GIS to calculate total daily water loss to the atmosphere from three stands of knotweed along these rivers. We measured total leaf area of each stand and transpiration rates across each stand from sun‐up to sun‐down. The average water loss was 8.5 L wate/day/m2 of ground area covered in knotweed. Knowing the total distribution of knotweed along each river, the amount of river length covered by knotweed stands and the total water lost to the atmosphere per amount of knotweed along each river we were able to estimate the total amount of water transpired to the atmosphere by knotweed per river on a daily basis during its growing season. These results were compared to summer low flow rates to assess the impact on river flow during the growing season for Japanese knotweed. Our results suggest that knotweed along these rivers is reducing total flow by an average of 8% (approximately 800,000–1,400,000 L/day) during the summer months. This is important as the impact of invasive species on water resources in temperate areas is currently under‐studied in ecohydrology. [ABSTRACT FROM AUTHOR]

Watershed dynamics are governed by geomorphic indices, which include both surface and subsurface characteristics. In this study, several hydrological indices investigate the dynamics of the Asan watershed in Uttarakhand, India focusing on the interplay between human activities and natural processes using geomorphic indices and remote sensing techniques. The research aims to achieve a planned sustainable development by understanding various geo-environmental aspects related to stream network analysis, evaluation of different terrain attributes and land-use patterns. Utilizing the use of highresolution satellite data, such as DEM and satellite images, enhances the impact on land surface management and strengthens the overall research. The Asan watershed, designated as the 6 th ordered dendritic network, exhibits the dominance of moderately permeable strata with significant discharge potential and a tectonic tilt that favours fluvial erosion. Structural influence is observed to be more pronounced in longitudinal profiles of various higher-order streams. The research shed light on rapid industrialization and urbanisation. Through the generation of decadal LULC maps from 1980 to 2016, the study reveals a four-fold increase in the urban area over the last four decades. Economic, topographic, and commercial factors contribute to these dynamic changes, which alarmed environmental scientists and planners for effective management and development. [ABSTRACT FROM AUTHOR]

Water erosion is a major problem in the semi-arid environments of Algeria. In this vein, the objective of this study is to use the Revised Universal Soil Loss Equation (RUSLE) on the watershed of Medjerda which is located at the extreme of the North-Eastern part of the Algerian territory. Based on the crossing of various factors in raster mode under ArcGIS allows the production of diverse thematic maps corresponding to multiple factors: erosivity of precipitations, erodibility of soils, topography, the vegetal cover and the anti-erosive practices. Moreover, the risks' map of water soil erosion was obtained depending on the combination of the previous thematic maps with four class risks has been made up indicating an average erosion value of 2.68 t/ha/year. However, this value is relatively reasonable in relation to the given rate by the interpretation of the bathymetric measures carried out in the Ain Dalia dam. [ABSTRACT FROM AUTHOR]

Copyright of International Forestry Review is the property of Commonwealth Forestry Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wetlands play an essential role in overland flow generation by retaining water and providing an environment for the hydrogeochemical functions of a watershed. Few studies have addressed the restoration of past wetlands using wetland-corrected land-use land-cover (LULC) datasets. We evaluated the impacts of wetlands on hydrology and nutrient (nitrogen) loading by comparing Present, Past, and Restored scenarios. A GIS-based data processing procedure was proposed for generating a wetland-corrected proxy LULC raster to mimic the past wetland distribution. This was subsequently incorporated in the Soil and Water Assessment Tool (SWAT) to simulate discharge and nitrogen loading. In addition, two models, with and without using the proxy LULC dataset, were developed to examine the impacts of the proxy LULC on the model performance. The effect of hydroclimatic variations was also assessed by comparing the simulated peak flows and nutrient loads in dry and wet years. The results demonstrated the necessity of using the wetland-corrected proxy LULC data in the water quantity and quality modeling, especially for wet years. Our modeling approach and wetland-oriented LULC correction procedure can be applied to other wetland-dominated watersheds to improve hydrologic and water quality modeling. [ABSTRACT FROM AUTHOR]

To solve the problem of low efficiency and high cost of conventional manual inspection of warp-knitted vamp fabrics, an algorithm for quantity statistics and quality inspection of warp-knitted vamps based on an improved MatchNet model is proposed. The noise in the warp-knitted vamp images was removed using median filtering and the filtering speed was accelerated using the mean division method. To extract the vamp image from the cloth image, an adaptive thresholding watershed algorithm was designed to remove the background texture information from the warp-knitted vamp and extract the vamp features. Based on the MatchNet model, the feature extraction network for warp-knitted vamps was redesigned and the model was optimised using the AdaDelta algorithm to improve the model training efficiency. A sampler was used to generate a sample set of warp-knitted vamp data with a balanced number of positive and negative samples to train the improved MatchNet model. A warp-knitted vamp fabric detection platform was built to verify the effectiveness and real-time performance of the improved algorithm. The MatchNet model and the improved MatchNet model algorithm were applied to three different vamps to perform comparison test verification. The results show that the average detection accuracy of the improved Match Net algorithm reached 97.7%, and the detection speed is improved by 3–4 times compared with that of the the conventional manual inspection method. [ABSTRACT FROM AUTHOR]

Studies of changes in the parameters of effective fertility in space and with time under the effect of forest shelter belts allocated to various landscapes (forest belt no. 40 on the watershed and forest belt no. 72 on the slope) were performed within the framework of the theme of state task at the Dokuchaev Voronezh Federal Agricultural Scientific Center in 2021–2022. It was found that the soils of the watershed area were characterized by the greatest mobility of available phosphorus and exchangeable potassium. The provision of soils with nitrate nitrogen on the watershed and on the slope during the growing season was similar. The watershed area was characterized by a decrease in the amount of mineral elements in soils of the fallow land and at the edges of forest belt no. 40. As for the forest belt itself, the parameters were maximal in its center and gradually decreased towards the edges. The parameters of plow land fertility increased with the distance from the forest belt to the maximum at a distance of 75–150 m from the forest belt. On the plowed land adjacent to ravine forest belt no. 72, the content of mobile phosphorus and exchangeable potassium increased towards the forest belt. The content of nitrate nitrogen, on the contrary, decreased down the slope, reaching a minimum near the forest belt. It was proved that, on the watershed, the content of nitrate nitrogen and exchangeable potassium increased by the end of the growing season, and the content of mobile phosphorus decreased. On the slope plot, there was an increase in all the studied fertility parameters by the end of the growing season. [ABSTRACT FROM AUTHOR]

Soil erosion has caused a heavy threat to agriculture production in China at the present stage. The accurate identification of priority small watersheds is one of the most important tasks for implementing control and prevention in batches. However, it is still lacking in the intelligent decision-making and implementation of soil loss control at present. Among them, the severity of soil erosion is an important indicator of priority small watersheds. Previous studies have been focused on the simple and single indicator during evaluation and consideration. Many subjective factors have also made the evaluation complex and less accessible. Therefore, it is very urgent to identify the management priority for the scientific, reasonable, and efficient application of soil loss control for better conservation. This study aims to evaluate the management priority of soil erosion control in small watersheds. The key area of soil erosion was selected at Zigui County in the Three Gorges Reservoir Area. The double goals were taken as the 'reduction and degradation 'of soil and water loss. Two dimensions were also integrated with the soil and water loss area and soil erosion intensity. The results show that the current soil and water conservation rate in 2021 was 69.12%, and the long-term (in 2050) soil and water conservation rate was 81.74%, with an overall increase of 12.62 percentage point. The soil erosion modulus in 2021 was 758.50 t/(km² ·a) at present, where the minimum modulus of soil erosion was 408.71 t/(km² ·a) with an overall decline ratio of 46%. However there were great differences among the soil and water conservation rates under current and long-term situations, as well as the current and the minimum soil erosion modulus in each small watershed. The long-term soil and water conservation rate and the minimum soil erosion modulus were generally similar to the spatial distribution, compared with the current. But there were great changes in some areas and values. Most areas shared a large potential for the soil and water conservation rate, as well as the soil erosion control degree. Erosion plots were widely distributed to be completely managed and downgraded, especially in the small watersheds in the central and western parts of the county. Large areas were found for the soil erosion area abatement and soil erosion intensity downgrading. The spatial distribution pattern was observed in the priority of soil erosion control in each small watershed: high in the central part, while relatively low in the eastern and southern parts. The number of small watersheds with a management priority greater than 0.6 accounted for 11.76% of the total. The management priority can be expected to cover both soil erosion area and soil erosion intensity. The goals and the relative size were determined for their reduction space. An accurate and rapid detection can also be achieved for the decision-making on the small watershed. The finding can provide technical support to identify the priority of soil corrosion in small watersheds. [ABSTRACT FROM AUTHOR]

The rapid increase in the intensity of human activities has continuously changed the global underlying surface, resulting in ecological risks to the regional landscape. In this study, an ecological risk system was constructed for the watershedscale landscape using a variety of landscape pattern indices. The global major basins and sub-basins were taken as the research objects. The land use raster data was collected for 34 consecutive years from 1982 to 2015. The spatiotemporal ecological risk of the global landscape was analyzed at the watershed scale. The various driving factors of landscape ecological risks were then quantified using geo-detectors. At the same time, the spatiotemporal variation was determined for the global net primary productivity (NPP) of vegetation at the watershed scale, in order to reveal the impact of global landscape ecological risks. The results showed that: 1) The range of spatial variation was 0-0.29 for the multi-year average ecological risk of the global landscape at the watershed scale. Specifically, the high-value areas were distributed mainly in the temperate and cold temperate zones, arid climate zone, and polar zone near the Arctic. Meanwhile, 17.44% and 23.45% of the watershed landscape ecological risks showed a significant increase and decrease trend from 1982 to 2015, respectively (P<0.05). 2) There was a large spatial variation in the coefficient of variation of landscape ecological risk in the arid climate, subtropical, and tropical zones. Furthermore, 36.82% watershed of significant change-points were found in the landscape ecological risk from 1988 to 2006. The spatial distribution of the watersheds with the significant changes in the landscape ecological risk was basically consistent with that of watersheds with significant change-points (P<0.05). The global underlying surface changed greatly in the 1990s, indicating the great variation in the landscape ecological risk. 3) There was the greatest impact of precipitation on the landscape ecological risk of major- and sub-watersheds at the multi-year scale. The influencing factors on the landscape ecological risk of watersheds were ranked the descending order of the precipitation, temperature, NDVI, population density, altitude, slope, and gross domestic product. There were also complex interactions among the various influencing factors on the landscape ecological risk. 4) The annual NPP of 52.32% and 12.60% of the watersheds increased and decreased significantly from 1982 to 2015, respectively. The landscape ecological risk was conducive to the NPP in the 9.11% watershed with a significant positive correlation between annual landscape ecological risk and annual NPP (P<0.05). By contrast, the annual landscape ecological risk was significantly negatively correlated with the annual NPP in the 11.43% watershed (P<0.05), where the reduction of landscape ecological risk was conducive to the NPP. The finding can also provide a solid scientific basis for global carbon neutrality and carbon sinks in the terrestrial ecosystems under climate change. [ABSTRACT FROM AUTHOR]

Reservoirs are increasingly valuable worldwide as potable source waters, yet in many geographic regions, their limnology and trophic status are poorly known. We characterized 14 drinking water reservoirs and their watersheds across the warming temperate/subtropical southeastern USA. Selected reservoirs had at least three years of accessible summer water quality data during 2010–2020, including Secchi depth, nutrients, and algal biomass as chlorophyll a, and depth profiles for temperature and dissolved oxygen. Most watersheds, including lands within a 10-km radius of the reservoirs, had sustained substantial urbanization and/or intensive industrialized animal production, in some cases including the discharge of partially treated human sewage or livestock slaughterhouse wastes near or into the reservoirs. Five reservoirs were assessed as mesotrophic; the others were eutrophic. Most were stratified, but ephemeral near-surface thermoclines were common, and many were too shallow (median depth 5.0 m) to maintain uniform temperatures in the relatively warm hypolimnia. Bottom-water hypoxia/anoxia occurred throughout the summers but, surprisingly, in 8 of 14 reservoirs hypoxia commonly extended to surface waters. In the Southeast as in many regions, drinking water reservoirs are poorly protected and degrading as livestock production and/or urban development increasingly characterize their watersheds. The eutrophication trajectory of these valuable resources should be used as an indicator of ecosystem health and water quality in developing more protective management and policy actions. [ABSTRACT FROM AUTHOR]

Over the last three decades, the Government of India (GOI) has used watershed management as a solution to solve issues concerning sustainable agricultural output in rainfed areas. Additionally, since 2003, the GOI has made watershed management a national policy. A lot of thought is given to all of the significant crops that have disappeared from farming systems in the watershed development programs (WDPs) of India's current development plans, which are primarily focused on increasing and sustaining productivity levels. In the Sarguja division of Chhattisgarh, the present study attempted to document the on-site and off-site effects of these watershed development programs, as it observed an increase in the ground water level, a rise in the surface water and stream flow levels, a reduction in runoff as well as in soil erosion, increased agricultural and dairy production, improved livelihood and employment generation, and changes in the land use and farming patterns. These findings showed that the percentage of cropland increased in both Kharif and Rabi, because they started planting crops in Zaid, particularly cucumber, melon, and vegetables, that had been kept fallow. The patterns of land usage in the WDP regions have improved over time; due to farmers utilizing more wasteland for productive reasons, there has been a rise in the net sown area of these locations. Additionally, it has been claimed that many crops that were previously abandoned due to water shortages and other requirements are now being cultivated. Responses from the region's population have been in favor of the introduction of innovative techniques like Agroforestry systems. [ABSTRACT FROM AUTHOR]

Introduction and Objective: A spatial survey of the degree of vulnerability is an important step in order to identify vulnerable areas and make decisions to protect natural resources and achieve sustainable development. Therefore. the present research the present study was conducted with the aim of spatially investigating the degree of vulnerability of Dorodzan Dam watershed in Fars’s province with a climatic approach. Material and Methods: Climatic data of 9 climatology station in the period 1991-2020 was used. indicators affecting the vulnerability of the watershed were extracted. including wet season. dry season. cold season temperature. hot season temperature. maximum wind speed. and height above sea level. After determining the aforementioned indicators. the overall vulnerability index (OVP) was calculated. Results: In this method. vulnerability indicates the performance. nature. rate of climate change in the watershed. The results showed that the dry season index ranged from 6.40 to 66.19 mm for Chamriz and Emamzadeh Ismail stations and the wet season index ranged from 70.67 to 538.03 mm for Eghlid and Chamriz is variable. Also. the cold period index was 1.77 to 2.65 °C for Dorodzan and Zarghan stations. respectively. and the warm period index was 1.52 to 2.21 °C for Chamriz and Zarghan stations. respectively. The maximum wind speed index was calculated between 0.08 and 0.85 km/h for Eghlid and Dorodzan stations. respectively. Altitude was also assessed. The results based on the analysis of climatic indicators show that the total vulnerability index in the Dorodzan dam reservoir is between 25.7 to 34.2 and fall within reversible class. Conclusion: Given the results obtained and considering the good Potential of this watershed. the need to consider management and preventive measures against drought and flood threats caused by climate change and human change is important. Considering that according to the standard of the mentioned method. the index is less than 40 in the reversible range. therefore. according to the location of the vulnerability index of the studied area with the climatic approach. it can be concluded that although the region has undergone many changes especially in recent years however. due to the slight changes in climatic indicators in the long term. this watershed is still far from the limits of resilience from physical aspects. and with the adoption of suitable management patterns. it has the ability to return to ideal conditions. The results of the research. in addition to expressing the importance of the effects of climate change. will help their application in the application of correct and compatible management with climate change in future watershed management policies. [ABSTRACT FROM AUTHOR]

Anthropogenic nitrogen (N) inputs to the landscape have serious consequences for inland and coastal waters. Reservoirs are effective at mitigating downstream N fluxes but measurements have generally focused on large reservoirs and have not considered seasonal variability or all N forms. In this study, we conducted an N mass balance in eight small reservoirs (surface area <0.55 km2) in coastal New England over annual time periods, including both inorganic and organic forms of N. We found that small reservoirs have high capacity for dissolved inorganic N (DIN) retention during low and moderate discharge, but are roughly in balance for DIN at higher discharge. Because proportional DIN retention occurred when N inputs were at their lowest, their effect on downstream N fluxes is small over annual time frames. Further, dissolved organic N (DON) was also evident during low flow late in the warm season. Accounting for DON production, the net effect of reservoirs on total dissolved N (TDN) fluxes was limited. These transformations between inorganic and organic N should be considered when evaluating the effect of small reservoirs on TDN fluxes over seasonal and annual timescales. With dam removal becoming a common solution to aging, unsafe dams, their ability to retain or produce N must be scrutinized at longer time scales while accounting for the complete N pool to better comprehend the effect their reservoirs have on downstream waters. Plain Language Summary: Excess nitrogen in the environment can negatively impact both freshwater and coastal ecosystems. However, water bodies such as reservoirs have been shown to reduce the amount of nitrogen flowing downstream. This has led to the idea that if reservoirs are removed, there will be more nitrogen exported downstream. Many studies on reservoir influence on nitrogen flowing downstream have not explicitly included small reservoirs, transformations between forms of nitrogen, or seasonal variability of nitrogen processing. We found that while small reservoirs do decrease inorganic nitrogen during the warm season, organic nitrogen is also produced, leading to a lesser impact on total nitrogen. Dissolved inorganic nitrogen retention is highest during low flows. When flows are higher and nitrogen transport is greater, small reservoirs are not as biologically active, leading to very little nitrogen being transformed. We conclude that small reservoirs are not a nitrogen sink when accounting for transformations between nitrogen forms and accounting for nitrogen processing across all seasons. Removal of small reservoirs will likely not lead to increased annual nitrogen exports to coastal areas. Key Points: Small reservoirs were not a significant nitrogen sink over annual timescales when considering both inorganic and organic forms of NSeasonal variability in nitrogen processing led to small reservoirs acting as temporary sinks or sources for different forms of nitrogenIn contrast to previous predictions, small dam removals do not always lead to greater nitrogen exports to coastal ecosystems [ABSTRACT FROM AUTHOR]

The Midwest of the USA is a highly productive agricultural region, in part due to the installation of perforated subsurface pipes, known as tile drains that remove excess water from wet soils. Tile drains rapidly move water to nearby streams, influencing how quickly streamflow rises and falls (i.e., streamflow "flashiness"). Currently, there are no comprehensive studies that compare the extent to which tile drainage influences flashiness across large and diverse agricultural regions. We address this knowledge gap by examining growing‐season (April–October) flashiness using the Richards‐Baker Index (RBI) in 139 watersheds located throughout the Midwest. Using a spatial tile‐drainage dataset, watersheds were split into low, medium, and high tile‐drainage classes. We found no significant differences between the flashiness of these three classes using a one‐way Kruskal–Wallis test. When watersheds were separated into infiltration groups to help control for different soil types, the high tile‐drainage class RBI was significantly higher than the low tile‐drainage class RBI in the high infiltration group. To further understand the causes of flashiness, additional environmental variables and their relationship to flashiness were examined using multivariate regression. In the low infiltration group, tile drainage significantly reduced flashiness, with watershed area and average depth to water table being the largest influences on flashiness. Tile drainage produced a larger reduction in flashiness in the high infiltration watersheds, with the largest influences being percent clay in the watershed and watershed area. These results indicate that the influence of tile drainage on flashiness emerges only after other watershed variables are accounted for. Given that tile drainage may increase in the future as precipitation patterns and extremes change, flashiness will likely continue to be modified. These results lead to an improved understanding of flood‐generating and nutrient transport mechanisms that are relevant to stakeholders across a wide range of sectors. [ABSTRACT FROM AUTHOR]

The upstream of the Cisadane Watershed is included in the Mount Halimun Salak National Park area as the water catchment area. Water resource conservation is important because of land use change. Rainfall analysis was carried out to determine the rain intensity amount. Then, infiltration observations were also carried out in Ecosystem Restoration (ER) areas. ER is an area in the rehabilitation zone that requires improvement, especially in biophysical improvement. Several ER areas are in Cibunian Village and Purwabakti Village. The analysis determined the infiltration rates in the ER areas. Field surveys carried out data collection on infiltration sample measurements. Sample points were selected using Stratified Random Sampling. The results show the average rainfall in the study area is around 3950 mm/year. The results show the infiltration ability in the ER area is relatively slow. However, there are still results of rapid infiltration at several sample points. Due to limited water absorption capacity, soil characteristics with clay texture influence slow infiltration conditions. Even though the rainfall is high, surface water runoff is quickly formed. The rainfall in the Cisadane watershed should be stored to reserve water supply, especially during the dry season. In detail, water storage can be an infiltration pit, artificial water storage tanks, reservoirs, or ponds. The limited availability of water resources challenges water uses in the Cisadane Watershed. This research is essential as an initial study to find out more about the watershed hydrological system and the water demand level. [ABSTRACT FROM AUTHOR]

Integrated watershed management is the method of overseeing human exercises and characteristic assets on a water shed basis, taking into consideration social and financial concerns. It is an ever-evolving hone including the administration of arrive, water, biota, and other assets and it requires involvement of strong institutions at the grass root level. Most watershed projects were not successful due to a lack of effective community participation. The objective of this study was to evaluate the contribution of community participation in integrated watershed management schemes in the Dandi lake watershed (Ethiopia) for long-term water resource conservation initiatives and short-term livelihood activities that enables the communities of the study area to meet their needs. Questionnaires, FGD, key informant interviews, personal observation were used as data collection tools. The collected data were organized and categorized according to the intended objectives and analyzed in qualitative and quantitative methods. The result of the study showed that role of community participation in participatory watershed management was examined by involvement in different management phases, 65.1% were involved only in the implementation stage, only 27.6% of respondents confirmed as they involve in all stages, 5.9 and 1.3% of sampled respondents witnessed as they are only involved in planning and mapping stage of watershed management. This study revealed that community participation in water shade management was hindered due to shortage of resources, interest, and previous experience, as well as peer pressure. In the meantime some successful efforts have been made on different land uses meant to reduce natural resource degradation and food security problems. These efforts include, contribution of delivered extension service, infrastructure provision and maintenance. The study also realized and proved the existence of unused development potential to improve the livelihood situation of the watershed community. This study came up with a good managerial implication, typically, it enhances Community engagement status by increasing its visibility and understanding of issues and empowers communities to have a say in decisions that affect their lives, cities and neighborhoods. The watershed management guidelines have to be clear to the community. [ABSTRACT FROM AUTHOR]

The water level fluctuates continuously at local, continental, and global levels. Consequently, remote sensing offers extensive data for assessing the location, extent, and variability of change, including the causes and changes that occur and the reactions and repercussions of change. Considering the significance of the water level, this research focuses on describing the methodology and process to determine the water level in the Al-Zab River. This study offers a straightforward and cost-effective approach and procedure for precisely delineating flood danger regions in the Al-Zab River basin utilizing a geographic information system and the existing database. The proposed strategy for regionally dispersing flood risks combines the size of prior flood events and the geographical distribution of their causes. This approach allows for the calculation of a weighted score for each participant's causative component. The regional distribution of the flood hazard intensity level is obtained by categorizing the spatial patterns of the flood hazard index. The 30-m digital elevation model with a high resolution was utilized to evaluate the water level in this river. Furthermore, this work is considered the first step towards enhancing information management in the studied area. This study mainly aims to explain how to outline and define watersheds using ArcGIS for flood mapping. [ABSTRACT FROM AUTHOR]

Regional hydraulic geometry curves, which relate drainage area to channel morphology, are powerful tools for river restoration and watershed management. While there is a strong correlation between channel morphology and drainage area, the importance of watershed slope and relief on channel-forming flow, especially in mountainous regions, cannot be ignored. This research used single variable power functions along with multiple regression to determine which network- and or local-scale variables are influencing channel morphology in the Southern Blue Ridge Mountains. Within this region, watershed topography (i.e. relief and slope) and or local-scale characteristics (e.g. channel slope and sinuosity) are better predictors of channel morphology than drainage area. Additionally, the importance of local-scale characteristics in the multiple regression models provide strong evidence that site-specific conditions can be just as important as watershed characteristics in determining channel morphology. While multiple regression has been used to create hydraulic geometry equations in other regions, this is the first study that determined whether non-drainage area multiple regression models perform better than models that include drainage area. With the increasing ease with which network- and local-scale characteristics can be calculated, this research shows a clear need to incorporate additional network- and or site-specific characteristics into hydraulic geometry equations. [ABSTRACT FROM AUTHOR]

In this study, three lakes, Cibi Hu, Haixi Hai, and Xi Hu, in the upper reaches of the main inflow rivers in the northern part of Erhai Lake were selected as the research objects. Based on the water environment monitoring indicators, land cover data, and lake macrobenthic community observation data, the non-parametric Kruskal-Wallis test, spatial analysis and community structure analysis were used to quantitatively assess the water environment and ecological status of the lakes. Using the Pollution Tolerance Index (PTI), the potential utility of macroinvertebrate communities as indicators of water ecological quality was investigated. The results showed that Cibi Hu and Haixi Hai have similar characteristics on water environmental quality. The physical and chemical indexes of water quality, the land cover of the lake catchment area, and the PTI index of the benthic community showed that Xi Hu was the most affected by human disturbance; the water ecological condition was the worst; and the environmental protection pressure was the greatest. In general, PTI analysis based on benthic fauna is convenient and can reflect the basic conditions of the aquatic benthic environment keenly, which is worthy of promotion. [ABSTRACT FROM AUTHOR]

In the early 2000s, harmful algal blooms and hypoxia returned to Lake Erie following a period of ecosystem recovery from the late 1980s through the 1990s. This corresponds to a drastic increase in dissolved reactive phosphorus loads and flow-weighted mean concentrations in the major tributaries to the Western Lake Erie Basin. However, there is substantial variability in suspended sediment and nutrient yields across Lake Erie tributaries. It is well known that agricultural and urban land uses lead to increased watershed sediment and nutrient yields, especially in the absence of proper management practices. Yet attributes such as watershed soil types and slope can also affect yields. We examined the influence of watershed land use, hydrology, soil type, and slope on annual nutrient and sediment yields from tributaries to Lake Erie monitored as part of the Heidelberg Tributary Loading Program. A minimum of one sample and, during storm runoff, up to three samples a day are analyzed for all major nutrients and suspended sediments. The 5-year average annual yields across these watersheds exhibited distinct geographic patterns from west to east, with high suspended sediment but lower nutrient yields from the eastern most tributaries (Cuyahoga, Old Woman Creek, Huron) and the lowest sediment along with lower nutrient yields from the western most tributaries (Raisin, Tiffin, Lost). The Maumee, Portage, Sandusky, along with select subwatersheds tended to have intermediate sediment yields with high nutrient yields. Altogether, the % cultivated crops and poorly drained soil in the watershed increased nutrient yields whereas a higher % slope and lower % pasture increased sediment yields. These patterns highlighted unique regional differences that can help guide management decisions for these watersheds that ultimately would improve the health of Lake Erie. [ABSTRACT FROM AUTHOR]

We developed a Parsimonious Multi-dimensional Moving Window (PMMW) algorithm that only requires Digital Elevation Model (DEM) data of a watershed to efficiently locate potentially optimal hydropower sites. The methodology requires only open source DEM data; therefore, it can be used even in remotest watersheds of the world where in situ measurements are scarce or not available at all. We used three parameters in this algorithm, and tested the method using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Shuttle Radar Topography Mission (SRTM) derived DEMs. Our case study on the Morony Watershed, Montana, USA shows that (1) along with 6 out of the 7 existing hydropower plants being successfully located, 12 new potential hydropower sites were also identified, using a clearance of 1 km, diversion of 90 m, and Hydropower Index (HI) threshold of 109 m as the criteria. For the 12 new potential hydropower sites, 737.86 Megawatts (MW) ± 84.56 MW untapped hydropower potential in the Morony Watershed was also derived; (2) SRTM DEM is more suitable for determining the potential hydropower sites; (3) although the ASTER and SRTM DEMs provide elevation data with high accuracy, micro-scale elevation differences between them at some locations may have a profound impact on the HI. [ABSTRACT FROM AUTHOR]

Eutrophication, harmful algal blooms, and human health impacts are critical environmental challenges resulting from excess nitrogen and phosphorus in surface waters. Yet we have limited information regarding how wetland characteristics mediate water quality across watershed scales. We developed a large, novel set of spatial variables characterizing hydrological flowpaths from wetlands to streams, that is, "wetland hydrological transport variables," to explore how wetlands statistically explain the variability in total nitrogen (TN) and total phosphorus (TP) concentrations across the Upper Mississippi River Basin (UMRB) in the United States. We found that wetland flowpath variables improved landscape‐to‐aquatic nutrient multilinear regression models (from R2 = 0.89 to 0.91 for TN; R2 = 0.53 to 0.84 for TP) and provided insights into potential processes governing how wetlands influence watershed‐scale TN and TP concentrations. Specifically, flowpath variables describing flow‐attenuating environments, for example, subsurface transport compared to overland flowpaths, were related to lower TN and TP concentrations. Frequent hydrological connections from wetlands to streams were also linked to low TP concentrations, which likely suggests a nutrient source limitation in some areas of the UMRB. Consideration of wetland flowpaths could inform management and conservation activities designed to reduce nutrient export to downstream waters. [ABSTRACT FROM AUTHOR]

Grasslands (pastures and hayfields) can be seen as the main natural resources of rural territories, considering the predominantly agricultural profile of these areas. In this context, the present study has as its main purpose the inventory of grassland areas in the Crișul Alb river basin and their relationship with certain components of the natural environment (altitude, slope, relief unit and so on). The Corine Land Cover database, 2018 edition, was used to identify and locate the grassland areas, and the data and spatial analyzes were carried out in the GIS environment. The analyzed area has a total surface of 422798 ha, and grasslands were identified on 61250 ha, which represents 14.49% of the total. In terms of territorial distribution, the areas used as grasslands can be found in all relief forms and units, in different proportions, but a greater concentration of them was observed in the Crișurilor Plain, in the Cigherului Hills and in the Zarandului Depression. In terms of altitude, the study area falls between 82 - 1587 m, with significant grassland areas being concentrated, for the most part, in the lower altitudinal levels. In the case of areas used as grasslands, the slope of the land, one of the most important limiting factors, has different values, depending on the sub-area and the relief conditions. Overall, in the study area, grasslands are well "represented", especially in its western half, the eastern half being dominated by forest areas. [ABSTRACT FROM AUTHOR]

After seven years in the making, a state‐of‐the‐art microfiltration membrane facility and new source water intake is being celebrated by the City of Sitka, Alaska. [ABSTRACT FROM AUTHOR]

Morphometric analysis is essential for determining soil erosion-prone areas in drainage basins. In the present study, identification and prioritization of 19 watersheds in the Upper Bhima basin was done using areal, shape, and landscape parameters of watersheds. Some uncertainty was observed with morphometric variables of watersheds in previous prioritization methods. A geographic information system was used to identify critical sub-watersheds in the study area. A newly developed weighted sum approach technique was used to rank each sub-watershed based on weightages derived from morphometric parameters. The 19 watersheds were classified into five categories based on their final priority ranking: very high, high, medium, low, and very low. According to the findings of this analysis, 30.00% of the total area was highly vulnerable with sub-watersheds (4D7H4, 4D7H5, 4D7H7, 4D7G4, 4D7G7) require immediate attention to provide soil and water conservation measures. This study proposed morphometric analysis with a geographic information system and the novel weighted sum approach technique to help decision-makers make technically and economically effective decisions for proper water resource planning and management. [ABSTRACT FROM AUTHOR]

Urbanization introduces new and alters the existing hydrological processes. Projecting the direction and magnitude of change of evapotranspiration (ET), often a large existing process, in humid subtropical climates is difficult due to the lack of land‐cover specific estimates of ET. This research aims to improve our fundamental understanding of ET in urban areas by focusing on ET specific to land‐cover classes of the National Land Cover Database (NLCD). Using multiple physically based models along with ET from reference watersheds, this study estimates ET—within the Atlanta, GA, USA region—for NLCD classes. ET also is estimated for urban watersheds—both in the Atlanta region and in areas with humid subtropical climate types—for which published ET estimates exist. There are major differences in land cover among the four developed classes: high‐intensity developed land is 92% impervious surfaces, while open‐space developed land—the least intensively developed land—is only 8% impervious surfaces. Consequently, open‐space developed land has an ET total that is over four times that of high‐intensity developed land. Due to a high percentage of impervious cover and substantial evaporation of water from impervious surfaces throughout the year, there is little intra‐annual variation in ET for the high‐intensity developed class. The land‐cover ET totals aggregate to reliable estimates for urban watersheds. The largest source of uncertainty for ET estimates in urban areas is likely the evaporation magnitude associated with impervious surfaces; therefore, more work is needed in determining those magnitudes for humid subtropical climates. Key Points: Evapotranspiration (ET) varies greatly among developed land‐cover classes in a humid subtropical climateET totals specific to land‐cover classes aggregate to reliable estimates for urban watershedsThe largest source of uncertainty for urban ET estimates is likely the magnitude of evaporation from impervious surfaces [ABSTRACT FROM AUTHOR]

Introduction and Objective Due to droughts occurred in recent years, available water resources in southern basins and watersheds of Iran especially those are in Hormozgan Province has been drastically decreased which may not only change their ecosystem but also make serious problem for the country’s food security. In addition to find new water resources, effective use of available water is the best choice to tackle water deficit which in turn, requires accurate estimation of evapotranspiration or water needs of plants. Crop evapotranspiration is usually calculated using the two-step FAO method. In this method, first the reference crop evapotranspiration (ET0), representing effect of weather on crop evapotranspiration is estimated by models using weather variables and then, multiplied by crop coefficient (Kc) which reflects crop characteristics on evapotranspiration. A review on the research conducted around the world revealed that each model may have different accuracies and performances at different watersheds or locations. Subsequently, using these models without testing their accuracy and relevance at each watershed may increase error in estimating (ET0) and hence crop water requirements which may complicate any planning for the watershed in the future. Therefore, this research was conducted to evaluate the accuracy and performance of the FAO proposed models at Haji Abad watershed of Hormozgan Province.Materials and Methods In this research which was conducted in Haji Abad watershed of Hormozgan for four years, reference crop(grass) evapotranspiration was measured weekly using a drainable lysimeter. In the first year, a large square drainable lysimeter (3 m wide ×3 m long × 1.9 m tall) was installed in the center of a 2-ha agricultural field which was representative of the watershed. In the next third years, grass (Cynodon dactylon L.) was grown inside the lysimeter and in the 900 m2 surrounding field. At full cover and when grass height reached 8 cm, evapotranspiration from grass inside the lysimeter was measured weekly by the water balance method. Reference crop evapotranspiration was also estimated using the FAO models: Adjusted penman and Blaney- Criddle, Radiation, Evaporation pan and Penman-Monteith. The estimated (ET0) values from the FAO models were compared with the data measured from lysimeter using linear regression, root mean square error and error percentage in estimating seasonal (ET0) and subsequently, the most appropriate models were recommended for the watershed.Results and Discussion Seasonal grass evapotranspiration measured from the lysimeter was 2729.8 mm and estimated by Adjusted penman and Blaney- Criddle, Penman-Monteith, Radiation and Evaporation pan 3405, 2695.2, 2868, 2789.2 and 2054.6 mm, respectively. The FAO adjusted Penman, Penman-Monteith and Radiation models overestimated ETo by as much as 24.7, 5.1 and 2.2% respectively, whereas, the FAO evaporation pan and Blaney- Criddle underestimated it by as much as 24.7 and 1.3%, respectively. Comparing weekly (ET0) data showed that adjusted penman model overestimated (ET0) but the FAO evaporation pan model underestimated it for most of the periods. FAO radiation model had tendency to overestimate at ETo10 mmday-1 (normally in Summer).Conclusion and Suggestions According to the results, the FAO Blaney-Criddle and Penman-Monteith models had respectively higher accordance and homogeneity with the real data measured from lysimeter and can predict (ET0) with higher accuracy than the other tested models. Therefore, these models are recommended, respectively as the most appropriate models to estimate (ET0) in Haji Abad Watershed and the areas having the same climate. Furthermore, the FAO Blaney-Criddle model needs fewer weather parameters and hence, may be used in the areas with limited climatic data.

Introducing reliable regional models to predict the maximum discharge of floods using characteristics of sub-basins has special importance in terms of flood management and designing hydraulic structures in basins that have no hydrometric station. The present study has tried to provide appropriate regional flood models using generalized linear models (GLMs) to estimate 2-, 10-, 50-, and 100-year maximum daily discharges of 62 sub-basins in Great-Karoon and Karkhe basins. According to the results, the sub-basins were categorized into four sub-regions based on some physiographic and climatic characteristics of the study sub-basins. The results showed that regional flood modeling was successful in all sub-regions except sub-region II, which includes very large basins (A̅≈17300 km2). The adjusted R2 of the best models in sub-regions I, III, and IV were estimated at around 82.4, 91.3, and 90.6 percent, and these models have a relative error (RRMSE) of around 9.5, 9.23, and 6.7 percent, respectively. Also, it was found that more frequent floods with 2- and 10-year return periods are influenced by properties such as basin’s length, perimeter, and area, while rare floods with 50- and 100-year return periods are mostly influenced by the river systems characteristics such as the main river length, total lengths of the river system, and slope of the main river. According to the research, it can be stated that the behavior of maximum daily discharges in the study area is extremely influenced by the different climatic and physiographic characteristics of the watersheds. Therefore, the maximum daily discharges can be estimated accurately at ungauged sites by appropriate modeling in gauged catchments.

This paper examines groundwater potential zones with the help of remote sensing and GIS methods for controlling and investigating the geospatial data of each parameter. Because of several conditions such as rapid population growth, urbanization, industrialization and agricultural development, groundwater sources are under severe threat. Climate change plays an important role in the quality and quantity of groundwater potential. Unreliable exploitation, poor quality of surface water resources tend to increase the decline in groundwater levels. This study was conducted in the Abbay River Basin, where groundwater serves as the main source for agricultural purposes rather than surface water. Seven selected parameters—lineament density, precipitation, geology, drainage density, land use, slope and soil data—were collected, processed, resampled, projected and reclassified for hydrological analysis. For generation of groundwater zones, weightage was calculated using an analytical hierarchy method. The consistency ratio estimated for this study was 0.089, which was acceptable for further analysis. Based on the integration of all thematic layers and the generated groundwater potential zones, the map was reclassified into five different classes, namely very good, good, moderate, poor and very poor. The results of this study reveal that 1295.33 km2 of the study area can be considered very poor, 58,913.1 km2 is poor, 131,323 km2 is moderate, 18,557 km2 is good and 311.5 km2 is very good. Any groundwater management project performed in the better regions would offer the greatest value. A similar study would be valuable before planning any water resource development activity to save comprehensive field investigations.

The analysis of the spatial interrelationship between soil properties and slope aspect is vital for understanding the range of influence on soil depth, moisture, and stone content distribution. This study aimed to investigate the spatial interrelationship of topsoil moisture and stone content in different slope aspects and soil depth. The 53.7 km2 watershed was divided into a 500m by 500m grid using ArcGIS and 230 soil samples were collected. In each sampling point, the soil was taken at three soil depth classes (0–25cm, 25–60cm, and 60–100cm) using a cylindrical auger, then soil samples were tested to determine the percentage of topsoil moisture, and stone content. The spatial interrelationship between aspect, soil depth, topsoil moisture, and stone content was analyzed using the R and GS+ software. The study had shown non-significant effects of aspect on topsoil moisture, stone content, and soil depth. However, topsoil moisture tends to be higher on the north-facing slope, while stone content tends to be higher on the southeast-facing slope. The analysis of Local Moran’s I revealed that topsoil moisture, stone content, and soil depth were significantly autocorrelated. The cross-semivariogram analysis of soil depth with topsoil stone content depicted a negative spatial correlation. The experimental cross-semivariogram of soil depth versus topsoil moisture was positively fitted to the exponential function, whereas soil depth with topsoil stone content was best fitted to the Gaussian model. Overall, soil depth is the more influential factor than the slope aspect regarding topsoil moisture depletion and stone content distribution in the study watershed.