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本研究は、奈良教育大学附属中学校における「１・２年合同奈良めぐり」において、菩提川（率川）流域から学ぶ ESD 実践を構想し、実践の結果生じた生徒の変容からその効果を明らかにすることを目的としている。また、ESD で重視されるシステム思考を、中学校の実践に落とし込み、そのあり方や有効性についても考察する。本実践のねらいは、多様な視点から川の役割や人との関わりについて読み解き、持続可能な川のあり方や関わりについて自分事に引き 寄せて考えることで、流域の社会変容にせまる自己変容を促すことにある。実践の結果、生徒の流域に対する価値観の変容が引き起こされ、流域の持つ地域課題について自分事に引き寄せて思考することができた。

地理の技能として中村和郎は二つのアプローチがあることを指摘した。それは，自然と人間活動の諸要素が複雑に関係し合うシステムを統合的にとらえるアプローチと，場所や地域の特性から他の場所や地域との関係をとらえるアプローチである。地理教育では，地域の生態系についての空間秩序を示す手法を学習に取り入れることが課題として挙げられる。そこで，高校地理の授業において，アムール川流域と親潮海域を生態学的に関係づけた白岩孝行らの研究をもとに，要素間の関係を示す生態的関係と場所の関係を示す空間的関係を認識させ，その図式を地図上に描かせた。さらに，流域の開発が生じた場合にそれらのシステムがどのように変化するのかを予測させた。学習者には，流域と海域の要素間の関係を生態的に示すだけでなく，その要素が分布する実際の空間的な位置と関係を示させた。本稿ではその図式を「生態・空間関係図」とした。学習者による「生態・空間関係図」とシステムの変化を予測した説明を分析した結果，「生態・空間関係図」の評価が高いと，「予測の説明」の評価も高くなる傾向にあった。「生態・空間関係図」を描けていない学習者は，「予測の説明」に困難を生じていると考えられる。漁業資源の増減に影響するという可能性について，多くの要素からなる多構造で説明できた学習者は，流域と海域の「生態・空間関係図」を綿密に描いていた。「生態・空間関係図」は，地理空間情報を認識するツールとしての効果が期待され，地理歴史科・地理探究に設けられた「生態系」の学習などでの活用が考えられる。

Soil erosion is one of the most common types of land degradation. To provide useful information for proper management, quantitative soil erosion evaluation and identification of effective factors are needed. However, rare studies have been reported on spatial modeling of soil erosion in connection with affective factors to prioritize the locality and the type of erosion control measures Hence, the aim of this study was to (1) assess erosion-prone areas in the Talar Watershed, Iran, using the Revised Universal Soil Loss Equation (RUSLE) model, and (2) investigate the relationship between soil erosion variability and land-use changes. Toward that, the ordinary least squares (OLS), geographically weighted regression (GWR) models, and Principal Component Analysis (PCA) were used to analyze spatial relationships between soil erosion, and land-use, and the RUSLE factors. The results of the OLS and GWR models indicated these relationships are spatially non-stationary and GWR models had a good predictive performance rather than OLS with lower Akaike's Information Criterion (from 254.31 to 276.81 in OLS, and from 247.87 to 269.42 in GWR) and higher adjusted R2 values (from 0.12 to 0.54 in OLS, and from 0.36 to 0.66 in GWR). Among the aforementioned variables, LS factor, P factor, forest, and irrigated land were the most effective variables in GWR models. The results of PCA showed PC1 and PC2 explained 66.2 % of the variation in soil erosion concerning land-use and the RUSLE factors. These results provided appropriate references for managers and experts in the proper planning of the study watershed.

The Brazilian Cerrado biome provides relevant ecosystem services for Brazil and South America, being strategic for the planning and management of water resources as well as for agribusiness. The objective was to evaluate the water quality along the course of the Córrego da Formiga in a virgin portion of the Brazilian Cerrado, the relationship of land use with physical-chemical and biological parameters of the water, and the inflow of the tributary. Five water collection points were defined (between the source and mouth) and observed on a quarterly scale in 2015, water samples were collected and analyzed for physical-chemical and biological parameters in the laboratory, and flow measurements were performed at the same point and day of water collection. To identify and quantify land use and land cover (LULC) in the watershed, an image from the Landsat8-OLI satellite was obtained, and other geomorphological data from hypsometry (Topodata-INPE) were obtained to generate the slope, basin delimitation, and contribution area for each water collection point. The LULC percentages for each area of contribution to the water collection points were correlated with the physical-chemical and biological parameters of the water and submitted to multivariate analysis (PLS-DA) for analysis and grouping among the five analyzed points. Changes in water-quality patterns were more pronounced concerning the time when the first and last sampling was performed (rainy period) and may be influenced by the increase in the volume of water in these periods. The stream flow is highly variable over time and between points, with the lowest recorded flow being 0.1 L s−1 (P1) and the highest being 947.80 L s−1 (P5). Córrego da Formiga has class III water quality (CONAMA resolution 357), which characterizes small restrictions on the use of water for multiple uses. The soil cover with native vegetation is just over 12%, while the predominance was of the classes of sugar cane (62.42%) and pasture (19.33%). The PLS-DA analysis allowed separating the water analysis points between P1, P2, P3, and P5, while P4 was superimposed on others. It was also possible to verify that the parameters that weighed the most for this separation of water quality were pH, alkalinity_T, alkalinity_h, calcium, and hardness, all with a tendency to increase concentration from the source (P1) to the mouth (P5). As for water quality, it was also possible to verify that points P2 and P5 presented better water-quality conditions.

Ephemeral gullies are widely distributed in the hilly and gully region of the Loess Plateau and play a unique role in the slope gully erosion system. Rapid and accurate identification of ephemeral gullies impacts the distribution law and development trend of soil erosion on the Loess Plateau. Deep learning algorithms can quickly and accurately process large data samples that recognize ephemeral gullies from remote sensing images. Here, we investigated ephemeral gullies in the Zhoutungou watershed in the hilly and gully region of the Loess Plateau in China using satellite and unmanned aerial vehicle images and combined a deep learning image semantic segmentation model to realize automatic recognition and feature extraction. Using Accuracy, Precision, Recall, F1value, and AUC, we compared the ephemeral gully recognition results and accuracy evaluation of U-Net, R2U-Net, and SegNet image semantic segmentation models. The SegNet model was ranked first, followed by the R2U-Net and U-Net models, for ephemeral gully recognition in the hilly and gully region of the Loess Plateau. The ephemeral gully length and width between predicted and measured values had RMSE values of 6.78 m and 0.50 m, respectively, indicating that the model has an excellent recognition effect. This study identified a fast and accurate method for ephemeral gully recognition in the hilly and gully region of the Loess Plateau based on remote sensing images to provide an academic reference and practical guidance for soil erosion monitoring and slope and gully management in the Loess Plateau region.

Landscape and quality attributes are major ecosystem characteristics closely associated with soil conservation service (SCS). However, the intrinsic mechanisms by which these two attributes influence SCS are still unclear. Therefore, this study quantitatively analyzed the landscape pattern, ecological quality, and SCS in the Lianshui River watershed (a typical soil and water loss area of red soil in southern China) and its sub-watersheds in 2019. The boosted regression tree model was used to explore the influence of 15 factors (i.e., landscape and quality attributes) on SCS at the sub-watershed scale. According to the results, compared with the landscape attribute, the quality attribute of the watershed ecosystem could better explain the spatial heterogeneity of SCS across 66 sub-watersheds. The overall degree of influence of five quality factors on SCS reached 57.81%, with the highest being the normalized differential build-up and bare soil index (NDBSI), at 25.11%. Among 10 landscape factors, aggregation had the greatest influence on SCS, at 28.64%. The relationships between key influencing factors and SCS were non-monotonic and non-linear, with threshold effects. For example, NDBSI values of 0.18–0.41 had a positive influence on SCS, while NDBSI values of 0.41–0.65 had a negative influence on SCS. The findings broaden our understanding of the response of SCS to changes in landscape and quality attributes at the sub-watershed scale, and could offer comprehensive support for soil erosion management in the watershed ecosystem.

China’s forest ecological problems are becoming increasingly serious, especially in the Yangtze River Basin (YRB) area. The basin has rich species resources and a well-developed natural forest management and conservation policy. Taking the YRB as the object, we combine the DPSIRM model to build a forest evaluation system containing 6 criterion layers and 24 indicator layers. The entropy weight method-TOPSIS and ArcGIS were combined to assess the forest state and the distribution characteristics of the 11 regions. Furthermore, grey relational analysis (GRA) was used to study the influencing factors of forest status. The results are as follows: (1) the comprehensive index of the YRB forests increased by 192.66% during the study period. The forest status showed the stage characteristics of small climb, basic flatness, and significant improvement. (2) The forest status varied significantly among provinces (cities), with Tibet (0.483) in the best condition and Qinghai (0.103) in a worse condition. (3) Except for Tibet, the rest of the regions are more influenced by the extent of development of the economy. (4) The factor most strongly correlated with the YRB is the forest response (R) indicator.

The Paraiba do Sul River Basin (PSRB) is a vital source of water resources in Brazil, providing water for human consumption, industry, agriculture, and hydroelectric energy generation. As part of one of the most developed areas of the country, in the Southeast of Brazil, the region is vulnerable to the impacts of climate change, with evidence of extreme events such as droughts and floods affecting the availability and quality of water. Hence, this study analyzes precipitation and streamflow rates data from the PSRB between 1939–2020 to investigate the spatial variability of average patterns and extreme events, trends, and their relationship with urban growth and socioeconomic development. The analysis reveals significant spatial variations in precipitation and runoff rates, with higher altitude areas, such as the Serra da Mantiqueira, exhibiting higher average values. Moreover, the Mann–Kendall trend results showed in most of the sites no significant trend regarding precipitation data; however, about 50% of the sites in the PSRB presented a decreasing trend of runoff rates. Since the precipitation does not explain identified changes in the hydrological patterns, the evaluation of the area’s urban growth and socioeconomic development throughout the decades suggested that human activities, such as those associated with urbanization, have played a significant role in altering the runoff patterns in the basin. These findings highlight the importance of sustainable land-use planning and water resource-management practices in the PSRB to mitigate the negative impacts of urbanization on the hydrological cycle and to enhance the resilience of the region’s water resources.

En este proyecto de investigación se realizó una estimación de las pérdidas anuales de suelo por erosión hídrica potencial (EHP) y efectiva (EHE) (expresada en t/ha/año) en la cuenca del río Cravo Sur. Se pretende dar respuesta a los siguientes interrogantes: ¿A cuánto equivale las pérdidas anuales de suelo por erosión hídrica potencial y efectiva en la cuenca del río Cravo Sur? y, ¿cuál es la distribución o zonificación del grado de erosión hídrica de la cuenca en estudio? Dicha estimación se realizó con base en la Ecuación Universal de la Pérdida de Suelo Revisada (RUSLE) empleando Sistemas de Información Geográfica (ArcGIS Pro–ESRI®). En un primer momento se hizo el cálculo del factor de erosividad de la lluvia (R), erosionabilidad del suelo (K), relieve (LS) y cobertura vegetal (C) para luego, mediante álgebra de ráster calcular la EHP y EHE. Como resultado se destaca el papel clave que desempeña la cobertura vegetal en la protección del suelo frente al fenómeno de la erosión ya que, la EHP (sin cobertura vegetal) en la categoría de severa a catastrófica sumaría 55.141 ha afectadas (el 10,6% del área de la cuenca) mientras que la EHE (con cobertura vegetal) en el mismo rango cubriría 1.685 ha (el 0,3% del área total de la cuenca). Identificar y cuantificar aquellas zonas más susceptibles o vulnerables a la erosión hídrica es necesario para priorizar acciones de intervención que mitiguen y contrarresten la aceleración y aumento del fenómeno. In this research project, an estimate of the annual soil losses due to potential (EHP) and effective (EHE) water erosion (expressed in t/ha/year) in the Cravo Sur River watershed was made. It is intended to answer the following questions: How much is the annual loss of soil due to potential and effective water erosion in the Cravo Sur River watershed? And, what is the distribution or zoning of the degree of water erosion in the watershed under study? Said estimation was made based on the Revised Universal Soil Loss Equation (RUSLE) using Geographic Information Systems (ArcGIS Pro–ESRI®). At first, the calculation of the rain erosivity factor (R), soil erodibility (K), relief (LS) and vegetation cover (C) was made and then, using raster algebra, calculated the EHP and EHE. As a result, the key role played by vegetation cover in soil protection against the phenomenon of erosion is highlighted, since the EHP (without vegetation cover) in the severe to catastrophic category would add 55,141 hectares affected (10.6% of the basin area) while the EHE (with vegetation cover) in the same range would cover 1,685 hectares (0.3% of the total area of the basin). Identifying and quantifying those areas that are most susceptible or vulnerable to water erosion is necessary to prioritize intervention actions that mitigate and counteract the acceleration and increase of the phenomenon. Especialista en Ordenamiento y Gestión Integral de Cuencas Hidrográficas Especialización

This paper presents an innovative digital twin dam and watershed management platform, K-Twin SJ, that utilizes real-time data and simulation models to support decision-making for flood response and water resource management. The platform includes a GIS-based geospatial digital twin of the entire Sumjin dam and river water system in Korea, with high-precision geospatial topography and facility information for dams and rivers (watershed area 4913 km2, river length 173 km, and 91 water infrastructures). The platform synchronizes real-time data such as rainfall, dam and river water levels, flow rate, and closed-circuit television (CCTV), and incorporates three hydraulic and hydrological simulation models for efficient dam operation considering the river conditions. AI technology is also used to predict the river water level and suggest optimal dam discharge scenarios. Additionally, the platform includes a geotechnical safety evaluation module for river levees, advanced drone monitoring for dams and rivers, and an AI CCTV video surveillance function. The digital-twin-based platform supports efficient decision-making for smart flood responses and contributes to reducing flooding damage and optimal operation through better smart water management.

Funding Information: We thank the organizers and funders of the ILTER Nitrogen Initiative Training Course and Workshop in Hokkaido, Japan in June 2016, which brought together many of the participants in this project. Templer was supported by a US National Science Foundation LTER grant NSF DEB 1637685. McDowell was supported by US National Science Foundation LTER grant NSF DEB 1831592. We are grateful to the EU Horizon 2020 funded eLTER PLUS project (Grand Agreement No. 871128) for financial support to Haase and Dirnböck. Dirnböck was also funded by the LTER-CWN project (FFG project number 858024). This study was partly supported by the Research Initiative Grants of the ILTER, Grants-in-Aid for Scientific Research (17H03833), and Research Institute for Humanity and Nature (RIHN; a constituent member of NIHU) Project No. 14200156. Sharif was supported by NRT-INFEWS: UMD Global STEWARDS (STEM Training at the Nexus of Energy, WAter Reuse and FooD Systems) that was awarded to the University of Maryland School of Public Health by the National Science Foundation National Research Traineeship Program, Grant number 1828910. The monitoring of the Svartberget site in Sweden was funded by the SITES program from the Swedish Research Council. The monitoring of the Volbu Nyhaga site in Norway was part of JOVA—The Norwegian Agricultural Environmental Monitoring Programme, financed by the Ministry of Agriculture and Food. Lajtha was supported by NSF grants DEB-1257032 and DEB-1440409 to the H. J. Andrews Long Term Ecological Research program. The data collection in the Wüstebach catchment was supported by TERENO (Terrestrial Environmental Observatories) funded by the Helmholtz-Gemeinschaft. We thank the “Hessisches Landesamt für Naturschutz, Umwelt und Geologie” for providing data from the Rhine-Main-Observatory. I.Kokorīte was supported by the University of Latvia grant No. AAp2016/B041//Zd2016/AZ03. We thank the Latvian Environment, Geology and Meteorology Center for providing the monitoring data for Latvian site. Anna Avila was supported by Spanish Ministry of Science projects CGL2017-84687-C2-2-R and CGL2009-13188-C03-01. We thank the Tyrolean Alps Long-Term Sociological Ecological and Research (LTSER, Austria) and R. Psenner and S. Morales for helping with data for Piburger See. Data from Hubbard Brook were supported by the National Science Foundation (DEB-1907683) and US Forest Service, Northern Research Station. A. Robison was supported by US National Science Foundation LTER grant NSF OCE 1637630. W. Dodds was supported by NSF DEB 2025849. Observations at Lange Bramke site were funded by the Ministry of Nutrition, Agriculture and Consumer Protection of Lower Saxony under the Permanent Soil Monitoring Programme. The Krofdorf site was funded by the Hessian Ministry of Environment, Climate Protection, Agriculture and Consumer Protection under the “Waldökosystemstudie Hessen”. SRM Lins was supported by the São Paulo Research Foundation—FAPESP, grant number 2012/20377-9. Long-term monitoring at Lake Maggiore (LTER site EU-IT08-001-A) was funded by the International Commission for the Protection of Swiss-Italian waters (CIPAIS). We thank Emma Conrad-Rooney for help with Fig. . Publisher Copyright: © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG. Previous studies have evaluated how changes in atmospheric nitrogen (N) inputs and climate affect stream N concentrations and fluxes, but none have synthesized data from sites around the globe. We identified variables controlling stream inorganic N concentrations and fluxes, and how they have changed, by synthesizing 20 time series ranging from 5 to 51 years of data collected from forest and grassland dominated watersheds across Europe, North America, and East Asia and across four climate types (tropical, temperate, Mediterranean, and boreal) using the International Long-Term Ecological Research Network. We hypothesized that sites with greater atmospheric N deposition have greater stream N export rates, but that climate has taken a stronger role as atmospheric deposition declines in many regions of the globe. We found declining trends in bulk ammonium and nitrate deposition, especially in the longest time-series, with ammonium contributing relatively more to atmospheric N deposition over time. Among sites, there were statistically significant positive relationships between (1) annual rates of precipitation and stream ammonium and nitrate fluxes and (2) annual rates of atmospheric N inputs and stream nitrate concentrations and fluxes. There were no significant relationships between air temperature and stream N export. Our long-term data shows that although N deposition is declining over time, atmospheric N inputs and precipitation remain important predictors for inorganic N exported from forested and grassland watersheds. Overall, we also demonstrate that long-term monitoring provides understanding of ecosystems and biogeochemical cycling that would not be possible with short-term studies alone.

Resumen El análisis de la variabilidad espacial y temporal de la precipitación es un componente trascendental para la toma de decisiones en las cuencas hidrográficas debido a que influye en las actividades de las personas que habitan dichas cuencas; sin embargo, en Colombia este tipo de investigaciones se desarrollan principalmente a nivel nacional y departamental, dejando a un lado los estudios a nivel de cuenca hidrográfica. Razón por la cual, en este estudio, se realizó un análisis de la influencia del fenòmeno El Niño Oscilación del Sur sobre la distribución espacial y temporal de la precipitación en la Cuenca Hidrográfica del rio Cali. La metodologia consistió en la estimación de datos faltantes, estimación de anomalias de precipitación y comparación de diversos índices como ONI, SOI y EMI y el análisis espacial y temporal de la precipitación. Durante los años de estudio 1972 a 2016 se observó una disminución del 10% de las lluvias en la zona alta de la cuenca del rio Cali, con una tendencia negativa, además, se comprobó que los meses de mayo y agosto son más susceptibles a eventos de precipitación extremos en periodos del fenómeno ENOS. Entre las causas probables de la disminución de las precipitaciones en la zona de estudio, se ha encontrado que el cambio en el estado medio de las precipitaciones en el pacifico tropical (región andina) tienden a mostrar un patrón similar a El Niño. Abstract The analysis of the spatial and temporal variability of precipitation is a transcendental component for decision making in watersheds because it influences the activities of the people who inhabit them; however, in Colombia this type of research is carried out mainly at national and departmental levels, leaving aside studies at watershed scale. For this reason, in this study, an analysis of the influence of the El Niño Southern Oscillation phenomenon on the spatial and temporal distribution of precipitation in the Cali River Basin was carried out. The methodology consisted of the estimation of missing data, precipitation anomalies, comparison of various indices such as ONI, SOI and EMI and the spatial and temporal analysis of precipitation. During the study years 1972 to 2016, a 10% decrease in rainfall was observed in the upper area of the Cali River basin, with a negative trend, in addition, it was found that the months of May and August are more susceptible to events of extreme precipitation in periods of the ENSO phenomenon. Among the probable causes of the decrease in rainfall in the study area, it has been found that the change in the average state of rainfall in the tropical Pacific (Andean region) tends to show a pattern similar to El Niño.

Our work focuses on the assessment of trends, erosion states and causal risk factors for soil erosion of the Asfalou watershed through the use of the Priority Actions Program/Regional Activity Center (PAP/RAC). This qualitative study model for water erosion makes it possible to assess susceptibility and determine potential fragile areas in order to diagnose the state of soil degradation. We adopted the PAP/RAC crossed matrices, the geographic information system (GIS) and remote sensing (RS) to develop the classical modelling. This method is based on three main approaches: predictive, descriptive and integration. Introducing soil types, slope length (LS) and climatic factors into our model, including rainfall erosivity (R), slope exposure, soil moisture index (SMI) and land surface temperature (LST), improved the reliability of our model. The correlation analysis identified these factors that explain erosion states and the risk of soil erosion. The coefficients of determination (R2) of the various erosive states resulting from the modified PAP/RAC approach explain respectively 98.30%, 77% and 49.3% of the observed variability of the erosive states. These factors provide information on the current state of soil degradation depending on the degree of influence of the different factors that control erosion. The descriptive approach has shown that soil loss manifests itself in different forms, whether for sheet erosion (L) and ravines (C1) successively affecting 79.95% and 17.84% of the land. The integration approach identifies factors and areas requiring intervention to counter the effects of soil erosion in the Asfalou watershed effectively and sustainably.

Hydrologic response in a watershed is driven by precipitation. Multi-site rainfall generators can be used to model watersheds using spatially varied rainfall inputs to better analyze how the rainfall variability affects runoff generation. This study adopted both a single-site rainfall generator (CLIGEN) and a multi-site rainfall generator to generate two rainfall data sequences, which were then used to drive the Soil and Water Assessment Tool (SWAT) for runoff simulation. The 148-km2 Walnut Gulch Experimental Watershed and its two sub-watersheds were selected to evaluate the hydrologic response. Runoff calibration was done against measured runoff in the watershed. Statistics showed that the single-site and multi-site rainfall generators gave similar results regarding annual precipitation. However, the multi-site generator performed much better than the single-site generator in both mean summer flow and for the different return period flows. The runoff derived from the single-site generator was significantly over-estimated in all three watersheds. As for the multi-site generator, the derived runoff was satisfactorily predicted in the smaller watersheds but only overestimated in the largest watershed. This indicated that in small to medium sized watersheds, the spatial variability of rainfall could play an important role for hydrologic response because of the heterogeneity of convective rainfall in this semi-arid region, which makes the application of multi-site rainfall generator a better option than the single-site generator.

Identifying the response of runoff changes to extreme climate evolution was of great scientific significance for the rational regulation of watershed water resources and the prevention of hydrological disasters. However, the time–frequency response relationships were not clear. The Yinjiang River watershed, a typical watershed with karst trough valley areas, was chosen to identify the impact of different climatic driving factors on runoff changes from 1984 to 2015. Continuous wavelet transform (CWT), cross-wavelet transform (XWT), and wavelet coherence transform (WTC) were performed to study the response relationship and time–frequency effect between runoff changes and extreme climate change at different time scales. The main results showed that: (1) Twelve extreme climate indices (ECIs) were detected to have a significant impact on runoff changes, mainly on a 6-year time scale; (2) The R10 and Rx1day in extreme precipitation index and SU34.4 and TNx in the extreme temperature index were the main driving factors of runoff changes, which had relatively large impacts on runoff changes in high and low energy vibration regions. However, the remaining eight ECIs that passed the 0.05 confidence level showed relatively large impacts on runoff changes only in low energy vibration regions; (3) The transition of the interaction between ECIs and runoff changes in high and low time–frequency scales was related to the abrupt change characteristics of the ECIs. The correlation of abrupt change was an important reason for the emergence of highly correlated regions that trigger high and low energy vibrations; (4) As a whole, the extreme precipitation events were ahead of runoff changes at the high time–frequency scale and exhibited small lag effects at the low time–frequency scale, while extreme temperature events were mainly ahead of runoff changes. This study has effectively revealed the impact of climate factors at different scales on runoff changes, and provides a theoretical understanding for regulating and managing water resources in karst basins.

North of the Maghreb, the flow of the wadis is generated by the rains. The hydro-climatic network is not dense enough to reasonably estimate the flow in any watershed where the wadis are not gauged. There is a need to develop methods for the acceptable estimation of river flow. The average flow of wadis is conditioned by a combination of climatic factors and local physicogeographic and hydrogeological factors. The influence of these local factors is dominant on the small and medium watersheds through the subterranean supply, where the climatic factors determine the superficial flow. The mean interannual flow (MIF) is composed of a regional climatic flow and a potential local flow. Regional climate flow differs from the actual climate flow in a watershed. The objective of this research is the genetic determination of the main components of the average interannual flow of wadis in the semi-arid climate of the Maghreb.

V Sloveniji se zaradi edinstvene geografske lege na izredno majhnem prostoru prepletajo najrazličnejši dejavniki in vplivi sosednjih naravnih enot, ki puščajo sledi na geomorfometričnih, podnebnih in hidroloških lastnostih ter značilnostih pokrovnosti in rabe tal po posameznih hidrografskih območjih. S pomočjo zelo dobro razvitega in strukturiranega sistema šifriranja padavinskih/hidrografskih območij in uvozom pred pripravljenih prostorskih baz podatkov je določevanje iskanih značilnosti porečij z uporabo geografskih informacijskih sistemov razmeroma enostavno. V diplomski nalogi so izračunane in predstavljene osnovne morfometrične lastnosti in značilne rabe tal, povprečna letna količina prejetih padavin (1980-2010), numerična organiziranost rečnih sistemov ter erozijska faktorja LS in R za hidrografska območja v Sloveniji na 3. nivoju. Tako pripravljeni podatki so podlaga za nadaljnje primerjalne analize, hidrološke študije ter hidrološko modeliranje. V nadaljevanju smo naredili primerjavo rezultatov lastnosti med posameznimi območji, ki pripadajo istemu glavnemu porečju. Narejena je tudi analiza medsebojne odvisnosti izbranih lastnosti porečij s pomočjo Pearsonovega koeficienta korelacije. Rezultati oz. lastnosti hidrografskih območij so v veliki večini pokazali veliko odvisnost od geografske lege. Višje ležeča območja, ki se nahajajo na severnem in zahodnem delu Slovenije (Julijske Alpe), izkazujejo sorazmeroma precej višje povprečne vrednosti geomorfometričnih lastnosti kot območja, ki segajo v panonsko ravnino. Obenem pa po rezultatih erozijskih faktorjev RUSLE (LS, R) sodijo med območja v Evropski Uniji z najvišjimi vrednostmi faktorjev za določevanje stopnje letne erozije. Due to its unique geographical location and extremely small area, various factors and influencing factors of neighbouring geographical landscapes are intertwined in Slovenia. This in turn, affects the geomorphometric, climatic and hydrological features, as well as the land cover and land use on each hydrographic unit/area. In favour of a very well developed and structured Slovenian watershed coding system and with the use pre-prepared spatial databases in geographic information systems, the determination of watershed characteristics is relatively simple. In the diploma thesis, the basic morphometric characteristics and typical land uses, average annual precipitation (1980-2010), stream order and erosion factors LS and R are calculated and presented for each Slovenian hydrographic unit on the 3rd level. So prepared data are the basis for further comparative analyses and hydrological studies and modelling. Furthermore, we compared the results of characteristics between individual hydrographic areas belonging to the same main watershed. Additionally, an analysis of the dependence of individual watershed characteristics using the Pearson correlation coefficient was conducted. The results of the characteristics of the hydrographic areas showed, in the vast majority, a high dependence on the geographical location and a large influence of the geographical landscape to which they belong. Higher areas located in the northern and western part of Slovenia (Julian Alps) showed relatively higher average values of geomorphometric characteristics than areas belonging to the Pannonian plain. According to the results of erosion factors RUSLE (LS, R), the Alps are also one of the areas in the European Union with the highest values of factors for determining the soil erosion rate.

Multi-scalar climate hazards in watersheds and growing consideration regarding equity call for innovation in how agencies evaluate and prioritize mitigation and adaptation projects. Benefit–Cost Analysis (BCA) is one approach that is increasingly being applied to decision-making (i.e., FEMA BCA toolkit), but that has not been applied to watershed and equity-based flood management initiatives. This paper addresses this topic and presents a case study evaluating projects for watershed flood and climate mitigation projects by the Louisiana Watershed Initiative (Louisiana, USA). Through semi-structured interviews with stakeholders and practitioners, we found that BCA tool design must be embedded in the program and policy in order to be successfully applied and that equity has not traditionally been a core value of mitigation practice. Even though many stakeholders understand the need for incorporating environmental and social project consequences at a watershed scale, challenges to doing so include inequitable barriers to project design in competitive processes, the complexity of integrating modeling and environmental outcomes data, jurisdictional interests, and the need for better science communication with local decision-makers.

This paper presents the results of one of the hydrological models, the InVEST “Annual Water Yield” (InVEST–AWY), applied to the Meta River basin in Colombia, which covers an area of 113,981 km². The study evaluates the performance of the model in different subbasins of the Meta River basin. The model’s accuracy was assessed using different statistical measures, including Nash–Sutcliffe Efficiency (NSE) coefficient, Root Mean Square Error (RMSE), correlation coefficients for the calibration (rcal) and validation (rval) periods. The overall performance of the model in the Meta River basin is relatively poor as indicated by the low NSE value of 0.07 and high RMSE value of 1071.61. In addition, the model explains only a 7% of the variance in the observed data. The sensitivity analysis revealed that a 30% reduction in crop coefficient (Kc) values would result in a 10.7% decrease in water yield. The model estimated, for example, the annual average water yield of the river in 2018 as 1.98 × 1011 m3/year or 6273.4 m3/s, which is 1.3% lower than the reported value. The upper Meta River subbasin shows the highest NSE value (0.49), indicating a good result between observed and simulated water discharge. In contrast, the South Cravo River subbasin shows a negative NSE value of −1.29, indicating poor model performance. The Yucao River subbasin and the upper Casanare River subbasin also show lower NSE values compared to the upper Meta River subbasin, indicating less accurate model performance in these subbasins. The correlation coefficients in calibration (rcal) and validation (rval) for the upper Meta River, Yucao River, South Cravo River, and upper Casanare River subbasins were 0.79 and 0.83, 0.4 and 0.22, 0.5 and −0.25, and 0 and 0.18, respectively. These results provide useful insights into the limitations for the proper use of the InVEST–AWY model in Colombia. This study is the first to use the InVEST–AWY model on a large scale in the territory of Colombia, allowing to evaluate its effectiveness in hydrological modeling for water management.

The GeoWEPP model has estimated water and soil losses caused by erosion at the watershed level in different parts of the world. However, this model was developed and its parameters have been adjusted for temperate climates, which are different from tropical climates such as those found in Brazil. Our study evaluated the performance of the GeoWEPP model in estimating soil erosion in three micro-watersheds in the Cerrado (i.e., savannah) of southeastern Mato Grosso state, Brazil. Major land uses modeled were soybean and corn cultivation, traditional pasture, and native vegetation. Input parameters for the GeoWEPP model involved climate, soil, land use and management, and topography. GeoWEPP was calibrated with input parameters for soil erodibility specified as interrill and rill soil erosion, soil critical shear stress, and saturated hydraulic conductivity obtained experimentally and estimated by internal routine equations of the GeoWEPP model. Soil losses observed in micro-watersheds with agriculture, pasture, and native vegetation were 0.11, 0.06, and 0.10 metric tons per hectare per year, respectively. GeoWEPP best modeled soil erosion for native vegetation and pasture, while over-estimating that for crops. Surface runoff was best modeled for crops versus native vegetation and pasture. The GeoWEPP model performed better when using soil erodibility input parameters.

Sin duda alguna la responsabilidad civil que existe cuando se tienen herramientas y/o conocimiento que puedan contribuir al bien común, debería ser obligatoria. Por lo tanto, el enfoque que pretende dar a este ensayo investigativo, es el de detectar zonas de alta vulnerabilidad por medio de imágenes satelitales, combinando los diferentes campos involucrados como son: ambientales, geográficos, hidrológicos, topográficos y distribución territorial, representando en un plano los puntos críticos que se consideren importantes a evaluar, con la premisa de una posible eventualidad de índole natural generada por las altas lluvias. Sin duda alguna la pretensión de este documento radica en que la población Quindiana y en general, es merecedora de controles o de vigilancia del comportamiento de su territorio, donde la población ubicada en el municipio de Salento Quindío en esta oportunidad sea estudiada. Tabla de contenido Introducción 10 1. Planteamiento del Problema 13 2. Justificación 14 3. Objetivos 16 3.1. Objetivo general 16 3.2. Objetivos específicos 16 4. Marco de referencial 17 4.1. Desastres naturales 17 4.2. Cuenca hidrográfica 17 4.3. La precipitación como responsable de amenazas naturales 18 4.4. ¿Qué son los sistemas 18 4.5. Integración de herramientas SIG con modelos hidrológicos e hidráulicos para la generación de mapas de áreas susceptibles de inundación 19 4.6. Clasificación de movimientos 19 4.7. Estudio de vulnerabilidad ante 20 4.8. Documento metodológico 20 4.9. Predicción de la susceptibilidad 21 4.10. Guía metodológica para 21 5. Diseño metodológico 22 5.1. Gestión de información base 23 5.1.1. Área de estudio 23 5.1.2. Modelo digital de elevación (DEM) 24 5.1.3. Precipitación media Mensual 24 5.2. Carpeta raíz, almacenamiento de la información 24 5.3. Cuenca hidrográfica de Salento 25 5.4. Conexión con carpeta de trabajo 25 5.4.1. Delimitación de la zona de estudio 26 5.4.2. Delimitación de la zona de estudio 26 5.4.3. Configuración sistema de referencia espacial 27 5.4.4. Rellenar campos de Raster 29 5.4.5. Calculo de la dirección de flujo 30 5.4.6. Identificación de imperfecciones sobre el modelo de dirección de Flujo. 31 5.4.7. Cálculo de la acumulación de flujo 31 5.4.8. Clasificación de las corrientes de flujo 32 5.4.9. Realizar un filtrado al raster de clasificación de Arroyos 33 5.4.10. Crear la red hidrográfica de la cuenca 34 5.4.11. Punto de Cierre 35 5.4.12. Delimitación de la cuenca hidrográfica 36 5.5. Parámetros morfometricos de la cuenca de Salento Quindío 38 5.5.1. Área de la cuenca 38 5.5.2. Perímetro de cuenca 38 5.5.3. Longitud del rio principal 38 5.5.4. Coeficiente de Compacidad 39 5.5.5. Densidad de drenaje 40 5.5.6. Curva hipsométrica 40 5.5.7. Red hidrográfica de Salento Quindío 41 5.6. Procedimiento paso a paso para realizar un modelo de pendientes y reclasificarlo a datos cualitativos 42 5.6.1. Delimitar el área de estudio 43 5.6.2. Crear modelo de pendientes 44 5.6.3. Reclasificación modelo de pendientes 45 5.7. Modelo de Isoyetas de Precipitación 50 5.7.1. Archivo de Puntos 50 5.7.2. Obtención Modelo de Isoyetas mediante el método IDW 51 5.8. Obtención Modelo de pendientes Reclasificado 54 5.9. Modelo de Susceptibilidad, Matriz ponderada. 56 5.9.1. Proyectar modelos raster a datos vectoriales de tipo polígono 57 5.9.2. Unión espacial Modelo de Pendientes y Precipitación. 58 5.9.3. Agregar atributos cualitativos al modelo de susceptibilidad 60 5.10. Geoproceso Disolver capa 63 5.11. Validación del modelo de susceptibilidad de deslizamientos de masa en base al tipo de relieve y la precipitacion 65 6. Resultados 67 6.1. Cuenca hidrográfica Salento Quindío 67 6.2. Modelo de pendientes y tipos de relieve cuenca Salento Quindío 68 6.3. Modelo de isoyetas de precipitación método IDW 69 6.4. Modelo de susceptibilidad de deslizamientos en masa Salento Quindío 70 7. Impacto 71 8. Conclusiones 73 9. Referencias Bibliográficas 76 Without a doubt, the civil liability that exists when you have tools and/or knowledge that can contribute to the common good should be mandatory. Therefore, the approach that this investigative essay intends to give is to detect areas of high vulnerability through satellite images, combining the different fields involved such as: environmental, geographic, hydrological, topographic and territorial distribution, representing in a plan the critical points that are considered important to evaluate, with the premise of a possible eventuality of a natural nature generated by high rainfall. Undoubtedly, the claim of this document is that the Quindian population and in general, is deserving of controls or surveillance of the behavior of its territory, where the population located in the municipality of Salento Quindío on this occasion is studied. Pregrado Sans aucun doute, la responsabilité civile qui existe lorsque vous disposez d'outils et/ou de connaissances pouvant contribuer au bien commun devrait être obligatoire. Par conséquent, l'approche que cet essai d'investigation entend donner est de détecter les zones de grande vulnérabilité à travers des images satellites, combinant les différents domaines impliqués tels que: la distribution environnementale, géographique, hydrologique, topographique et territoriale, représentant dans un plan les points critiques qui sont considérés comme importants à évaluer, avec comme prémisse une possible éventualité de nature naturelle générée par de fortes précipitations. Sans aucun doute, l'affirmation de ce document est que la population quindienne et en général mérite des contrôles ou une surveillance du comportement de son territoire, où la population située dans la municipalité de Salento Quindío à cette occasion est étudiée.

Water bodies refer to natural or artificial bodies of water, such as lakes, rivers, oceans, and wetlands. Water management refers to the process of managing the use, distribution, and conservation of water resources to meet the needs of society and the environment. That have been important themes in tamil literature for centuries, with ancient texts emphasizing their cultural and societal significance, and more recent literature highlighting the need for sustainable water management practices. This article examines the ability of the Tamil peoples to save water and bring the idea of water management to the world.

In the floodplains of Bolivia’s western highlands, or Altiplano, farmers, herders, and fishers maintain their livelihoods at water-land interfaces that are riddled with disaster risk. This paper draws on 13 months of fieldwork in the region as well as contemporary press accounts to explore water-land disasters in the Desaguadero River floodplain and Lake Poopo watershed. My analysis builds on Henri Lefebvre’s notion of rhythm to articulate a “politics of cyclic dissonance” – struggles and negotiations surrounding cyclical relationships like rainfall and annual flooding that break apart and leave dangerous consequences in their wake. I analyze two recent cases in Bolivia related to climate change taken from opposite extremes of the water cycle. The first case is the drying of Lake Poopo in 2015, an event that garnered headlines around the world as a representation of a drastic impact from climate change. The second case is the struggle of farmers in a community in the Lake Poopo watershed to manage flood irrigation in their canal systems without becoming victims of flooding themselves. Both cases illustrate how managing cyclic dissonance is a matter of negotiation, both between people representing different communities, between political constituencies and political leaders, and even between people and the environment, but such politics also works to obscure solutions to environmental problems that emerge from desynchronized cycles.

A compound perspective on hydrological extreme events is of paramount significance as it may lead to damages with larger losses. In this study, an integrated framework, based on downscaled climate variables and hydrological model, i.e. the Soil and Water Assessment Tool, was applied to generate extreme precipitation (Rx1day) and extreme streamflow (Sx1day) series under historical and future climate conditions. Then the potential impacts of climate change for univariate and bivariate joint frequency of extreme precipitation and flood in Xitiaoxi River Basin (XRB), a representative watershed of the Yangtze River Delta, is detected. The compound risk of extreme precipitation and flood under different levels of joint return period for historical and projected periods are estimated by copula‐based two-dimensional approaches. Major findings can be summarized: (1) The Rx1day and Sx1day under future scenarios increased by -0.4 ~ 11.7% and 0.7 ~ 20.4%, respectively, compared to historical period based on univariate frequency analysis, indicating the increasing magnitude of the flood in the future. (2) Climate change with different emission scenarios all have a driving effect on the rising coactivity of extreme precipitation and flood under compound flooding frequency analysis. In addition, the enhancement of climate change to extreme events is more apparent for extremes with higher return period and under the periods of 2080s. (3) Moreover, the flood frequency designs are deduced by bivariate joint distribution are safer than that by univariate distribution. This study may provide actionable insights to formulate the planning scheme of flood control and disaster reduction under the changing environment.

A split-window algorithm has been used in the Ilam dam watershed to determine the relationship between land surface temperature (LST) and types of land use. Landsat satellite images of the TM sensor for 1990, 1995, 2000, 2005 and 2010 and Landsat 8 (OLI Sensor) for 2015 and 2018 are used. After geometric and radiometric corrections of satellite images, land use maps are extracted by using the fuzzy ARTMAP method. An accuracy assessment showed that the highest value of the kappa coefficient was 94% with a total accuracy of 0.95 for 2015, and the lowest kappa coefficient value was 87% with a total accuracy of 0.9 for 1990. The high values of these coefficients indicate the acceptable accuracy of using Landsat’s remote sensing data for land use detection. The most important land use change is related to dense forest and sparse forest land uses, with decreases of 20.07 and 17.04%, respectively. The minimum LST measures in 1990, 2010, and 2018 in dense forest are 21.27, 30.55 and 33.82 ºC, respectively. The maximum LSTs for the sparse forest land use in 1990 and 2010 are 52.48 and 56.09, and 56.10 ºC for the dense forest land use in 2018. As a result, the average LST in agricultural lands was lower than in sparse forest and rangeland;, which is mainly due to the high moisture content and the greater evapotranspiration rate. Land use/land cover variations from 1990 to 2018 show that all land uses have experienced an increase in LST.

Watershed soil erosion is an important cause of soil degradation. The impact of land use change on erosion is an important aspect of human activity affecting soil resources. In this study, the resp...

Microlitter is a widespread contaminant with implications for aquatic health; however, knowledge of its distribution in fresh waters is limited. We examined microlitter in surface water, sediment, and mussels within the Saint John River and four major tributaries. Microlitter was present at all 89 sites, with concentrations in water equivalent to other Canadian watersheds. Microlitter concentrations likely reflected differences in land use and development. Comparisons between rivers generally revealed distinct water microlitter particle compositions, suggesting that input sources were specific to each river, while microlitter in sediments and mussels was largely homogeneous among rivers. There was little similarity in concentration and composition of microlitter among the three matrices sampled. Microlitter in sediments and mussels may not reliably track concentration and composition in aquatic environments. Microlitter concentration was not significantly greater downstream of wastewater treatment plants. Airborne microlitter transportation was evident, as remote sites in two tributary rivers demonstrated the highest concentrations of microlitter. Our data highlights the prevalence of microlitter in rural rivers, underscoring the ubiquity of this emerging contaminant and its integration into food webs.

In watershed modeling research, it is practical to subdivide a watershed into smaller units or sub-watersheds for modeling purposes. The ability of a model to simulate the watershed system depends on how well watershed processes are represented by the model and how well the watershed system is described by model input. This study is conducted to evaluate the impact of watershed subdivision and different weather input datasets on streamflow simulations using the soil and water assessment tool model. For this purpose, Cuhai-Bakonyér watershed was chosen as a study area. Two climate databases and four subdivision variations levels were evaluated. The model streamflow predictions slightly effected by subdivision impact. The climate datasets showed significant differences in streamflow predictions.

Soil erosion is a serious environmental problem arising from agricultural intensification and landscape changes. Improper land management coupled with intense rainfall has intricated the problem in most parts of the Ethiopian highlands. Soil loss costs a profound amount of the national GDP. Thus, quantifying soil loss and prioritizing areas for conservation is imperative for proper planning and resource conservation. Therefore, this study has modeled the mean soil loss and annual sediment yield of the Gumara watershed. Landsat 5 TM, Landsat 7ETM+, and Landsat 8 OLI were used for land use land cover (LULC) change analysis. Besides these, other datasets related to rainfall, digital soil map, Digital Elevation Model, reference land use, and cover (LULC) ground truth points were used to generate parameters for modeling soil loss. The watershed was classified into five major land-use classes (water body, cultivated land, grazing land, built-up and forest and plantation) using a maximum likelihood algorithm covering a period of the last 30 years (1988–2019). The mean annual soil loss and sediment yield were quantified using RUSLE, Sediment delivery ratio (SDR), and Sediment Yields models (SY). The analysis result unveils that within the past 30 years, the watershed has undergone significant LULC changes from forest & plantation (46.33%) and grazing land to cultivated land (31.59%) with the rate of −1.42km2yr-1 and -2.80km2yr-1 respectively. In the same vein, the built-up area has expanded to cultivated and grazing land. Subsequently, nearly 15% (207 km2) of the watershed suffered from moderate to very severe soil loss. On average, the watershed losses 24.2 t ha−1 yr−1 of soil and yields 2807.02 t ha−1 yr−1 sediment. Annually, the watershed losses 385,157 t ha−1 yr−1 soil from the whole study area. Among the admirative districts, Farta (Askuma, Giribi, Mahidere Mariam and Arigo kebeles), Fogera (Gazen Aridafofota and Gura Amba kebeles), East Este (Witimera kebele), and Dera (Gedame Eyesus and Deriana Wechit kebeles) districts which cover 50% of the watershed were found severely affected by soil erosion. Thus, to curve back this scenario, soil and water conservation practices should prioritize in the aforementioned districts of the watersheds.

Lack of appropriate agronomic practices is one of the major causes for soil erosion and low yields in teff (Eragrostis tef [Zucc.]) production in Ethiopia. A 3-yr study was conducted at the Aba Gerima watershed in northwestern Ethiopia, to investigate the effects of two tillage practices (reduced tillage [RT] and conventional tillage [CT]), two planting methods (row planting [RP] and broadcast planting [BP]), and two compaction options (with [+T] and without [–T] trampling) on soil loss and teff yields in a split-split plot arrangement. Sediment concentration ranged from 0.01 to 5.37 g L⁻¹ (mean, 0.25 g L⁻¹) in our study. Accordingly, the estimated total (August–October) soil loss ranged from 0.2 to 0.5 t ha–¹ (mean, 0.3 t ha–¹). The sediment concentration and total soil loss were significantly influenced (P

More frequent extreme rainfall events associated with global climate change cause greater challenges for soil conservation. Severe erosion occurs on many unpaved roads since these structures create important water flow paths during heavy storms. The present research aimed to investigate the intensity and influencing factors of unpaved road erosion under varied land use and management conditions (sloping cropland, terraced cropland, forest & grass). The erosion occurred in the watersheds contributing runoff water to roads after the greatest rainfall event recorded in the mountain area of northern China caused by Typhon Lekima. The research was conducted in an agricultural-forest-dominated watershed based on field investigation and UAV-based image analysis. A road erosion level classification standard was given according to the occurrence of rills, ephemeral gullies, and gullies. Significant erosion happened on 67% of the unpaved roads; 42% of them suffered moderate to severe erosion in which ephemeral gullies or gullies developed. The average erosion amount from these roads was 2280.75 t ha-1 and was significantly influenced by the watershed land use type and management. The dominant factor governing unpaved road erosion associated with terraced cropland was vegetation coverage on roads. Drainage area was the most important factor for road erosion in sloping cropland and forest & grass land, and road gradient was also a critical factor. Terraces, and forest & grass in drainage areas significantly reduced unpaved road erosion by 85% and, 47%, respectively, compared to sloping cropland. More integrated measures should be used to prevent unpaved road erosion. The results of this research can be applied to road protection against erosion in heavy storms.

As an important soil and water conservation engineering measure, more than 100,000 check dams are constructed across the Loess Plateau; these dams play a vital role in reducing floods and sediment in the region. However, the effects of check dams on hydrologic process are still unclear, particularly when they are deployed as a system for watershed soil and water management. This study examined the watershed hydrologic process modulated by the check dam system in a typical Loess Plateau catchment. By simulating scenarios with various numbers of check dams using a distributed physically-based hydrological model, the effects of the number of check dams on runoff generation and concentration were analyzed for the study catchment. The results showed that the presence of check dams reduced the peak discharge and the flood volume and extended the flood duration; the reduction effect on peak discharge was most significant among the three factors. The system of check dams substantially decreased the runoff coefficient, and the runoff coefficient reduction rate was greater for rainstorms with shorter return periods than for rainstorms with longer return periods. The check dams increased the capacity of the catchment regulating and storing floods and extended the average runoff concentration time in the catchment that flattened the instantaneous unit hydrograph. This study reveals the influencing mechanism of check dam system on the watershed hydrological process under heavy rainstorm conditions and provides a theoretical basis for evaluating the effects of numerous check dams on regional hydrology and water resources on the Loess Plateau.

The upstream of the Bedadung watershed is a catchment area. Now Bedadung watershed does not function optimally because of illegal logging and the change in function of protected forest to production forest. There was an increase in erosion, landslide, and flood. This research aims to identify conservation activities and Identify the roles of stakeholders in governance upstream Bedadung watershed. The result of the first purpose is conservation activities in the fourth Sub-watershed with exploratory, descriptive analysis: (1) Jompo Sub-watershed (coffee plants, teak plants, and terraces), cover crops, DAM controller, (2) Antrokan Sub-watershed such as durian terracing, use of organic mulch, sengon plants with elephant grass, (3) Rempangan Sub-watershed, such as planting cover crops, coffee, and lamtoro terracing, (sengon, coffee, and terrace), reforestation with matoah, sengon, durian, avocado, petai, guava, (4) Rembangan Sub-watershed, such as grass strips, cover crops, (lamtoro, coffee, and terrace). The results of the second purpose are to identify roles, relationships, influence, and strength of stakeholders in the implementation of conservation governance using The Four Rs analysis and stakeholder strength analysis. The position and function of each stakeholder managing the upstream Bedadung Watershed, namely (1) LMDH and KTH as (Subject), (2) Branch of the Jember Regional Forestry Service, Perum Perhutani, and BPDAS Brantas Sampean as (Key Player), (3) Dinas Environment of Jember Regency, Bappeda Jember, Department of Public Works Bina Marga of Jember Regency, and Department of Agriculture of Jember as (Context Setters), (4) Brantas Sampean Watershed Forum as (Crowd).

The Büyük Menderes watershed is the largest drainage watershed in Western Anatolia with an area of approximately 26000 km2. In the study area, almost 863 landslides occurred, extending over 222 km2 with a mean landslide area of 0.21 km2. In this study, landslide susceptibility assessment was carried out using Artificial Neural Network method which is one of the data driven methods. Geology, digital elevation model, slope, topographic wetness index, roughness index, plan, profile curvatures, and proximity to the active faults and rivers were used as landslide conditioning factors. In susceptibility assessments, landslides were separated by 70 % analysis, 15 % test and validation data sets by random selection method. The performance of the landslide susceptibility map was assessed by the area under the receiver operating characteristic curves, error histogram, and confusion matrix, respectively. The area under the receiver operating characteristic curves, analysis, testing, validation, landslides and study ares was found 0.82, 0.84, 0.86, 0.82. The susceptibility map had a high perediction rate in which high and very high susceptible zones corresponded to 26 % of the study area including 82 % of the recorded landslides.

Extensive efforts are underway to reduce phosphorus (P) export from the Lake Erie watershed. On the Canadian side, the Thames River is the largest tributary source of P to Lake Erie’s western basin. However, the role of dams in retaining and modifying riverine P loading to the lake has not been comprehensively evaluated. We assessed whether Fanshawe Reservoir, the largest dam reservoir on the Thames River, acts as a source or sink of P, using year-round discharge and water chemistry data collected in 2018 and 2019. We also determined how in-reservoir processes alter P speciation by comparing the dissolved reactive P to total P ratio (DRP:TP) in upstream and downstream loads. Annually, Fanshawe Reservoir was a net sink for P, retaining 25% (36 tonnes) and 47% (91 tonnes) of TP in 2018 and 2019, respectively. Seasonally, the reservoir oscillated between a source and sink of P. Net P release occurred during the spring of 2018 and the summers of 2018 and 2019, driven by internal P loading and hypolimnetic discharge from the dam. The reservoir did not exert a strong influence on DRP:TP annually, but ratio increases occurred during both summers, concurrent with water column stratification. Our analysis demonstrates that Fanshawe Reservoir is not only an important P sink on the Thames River, but also modulates the timing and speciation of P loads. We therefore propose that the potential of using existing dam reservoirs to attenuate downstream P loads should be more thoroughly explored alongside source based P mitigation strategies.

The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide. This study investigated the environmental behaviors and risks of heavy metals in the aquatic environment of a typical system composed of main watersheds in Suzhou and Jinze Reservoir in Shanghai. Results shown that Mn, Zn and Cu were the dominant metals detected in multiple phases. Cd, Mn and Zn were mainly presented in exchangeable fraction and exhibited high bioavailability. Great proportion and high mobility of metals were found in suspended particulate matter (SPM), suggesting that SPM can greatly affect metal multi-phase distribution process. Spatially, city system (CiS) exhibited more serious metal pollution and higher ecological risk than river system (RiS) and reservoir system (ReS) owing to the diverse emission sources. CiS and ReS were regarded as critical pollution source and sink, respectively, while RiS was a vital transportation aisle. Microbial community in sediments exhibited evident spatial variation and obviously modified by exchangeable metals and nutrients. In particular, Bacteroidetes and Firmicutes presented significant positive correlations with most exchangeable metals. Risk assessment implied that As, Sb and Ni in water may pose potential carcinogenic risk to human health. Nevertheless, ReS was in a fairly safe state. Hg was the main risk contributor in SPM, while Cu, Zn, Ni and Sb showed moderate risk in sediments. Overall, Hg, Sb and CiS were screened out as priority metals and system, respectively. More attention should be paid to these priority issues to promote the sustainable development of the watershed.

Modelling the hydrological characteristics of watershed is a method of understanding behavior and simulating the water balance components of watershed for planning and development of integrated water resources management. The soil and water assessment tool (SWAT) physically based hydrological modelling was used for modelling hydrologic characteristics of the Hangar watershed. The data used for this study were digital elevation model (DEM), land use land cover data, soil map, climatological and hydrological data. The model calibrated and validated using measured streamflow data of 13 years (1990-2002) and 9 years (2003-2011) respectively including warm-up period. The SWAT model performs well for both calibration (R2 = 0.87, NSE = 0.82 and PBIAS = +1.4) and validation (R2 = 0.89, NSE = 0.88 and PBIAS = +1.2). The sensitivity analysis, which was carried out using 18 SWAT parameters, identified the 13 most sensitive parameters controlling the output variable and with which goodness-of-fit was reached. The analysis results indicated that the watershed receives around, 9.6%, 59.9%, and 30.5% precipitation during dry, wet and short rainy seasons respectively. The received precipitation was lost by 9.6 %, 40.5%, and 41.3% in the form of evapotranspiration for each seasons correspondingly. The surface runoff contribution to the Watershed were 3.8%, and 79.2% during dry and wet seasons respectively, whereas, it contributes by 17.0% during short rainy seasons.

In the context of climate variability resulting in a decrease in rainfall with a severe drought, a spatio-temporal study of this phenomenon remains imperative for the efficient management of water resources. This paper aims to assess the long-term rainfall drought trend and breakpoints within the Comoe River watershed. From monthly rainfall data series (1960-2000), Standardized Precipitation Index (SPI) values were calculated for a time scale of 3 months (SPI.3). Statistical tests for breaks (CUSUM, and t-Student) and trends (Man-Kendall and Linear Regression) as well as the Sen’ slope method for estimating the magnitude of trends was applied. The breaks dates observed are mostly located after the 1970s. Based on SPI.3 values below the threshold of 0.84 chosen as an indicator of drought, rarely has more than half of the catchment area been affected by drought. The average watershed affected is about 20% over the study period (1960-2000). The most representative years, in terms of spatial expansion of the drought, in decreasing order of importance are: 1983, 1992, 1972 and 1982. The years 1982 and 1983 stand out for their exceptional condition, as the drought-affected 50% to 90% of the total catchment area. SPI.3 series from 1960 to the various break dates recorded slopes between -0.01 and 0.00 with a slight drought trend for most of the catchment. After the break periods, almost the entire northern part of the basin is characterized by slight moisture with Sen’s slopes between 0.000 and 0.005. The southern part will remain slightly subject to normal rainfall conditions.

Environmental flows are unanimously considered to be one of the most comprehensive indicators of the rivers health and their capacities to provide ecosystem goods and services. In this study, the objective was to predict the response of environmental flow components in a typical North African rivers network to future climate change. The study watershed is Bouregreg watershed (BW) in Morocco. To achieve this objective, a hybrid approach was build based on the semi-distributed model Soil and Water Assessment Tool (SWAT) and the Indicators of Hydrologic Alteration program (IHA). Data of two emissions scenarios (RCP4.5 and RCP8.5) from a downscaled Global Circulation Model were used to force the hybrid SWAT-IHA to calculate modifications of BW's environmental flow components in 2085-2100 period. Results showed that BW will experience climatic changes under both scenarios. Most of the environmental flow attributes will be modified within the study period: loss of natural flow variability due to shift in exceedance probability of low flows (up to 40%), decrease of monthly low flows, forward shift in high flow timing (up to 50%), and alteration of both the duration and the rise rates of floods. BW's streams responded unequally to the simulated changes in terms of the altered attributes as well as the degree of the alteration. This study confirmed the ability of the developed modeling approach to monitor environmental flow parameters for the first time in Morocco, and contributed in highlighting the necessity of proactive long term strategies to protect riverine ecosystems in North Africa watersheds.

Rare Earth Elements, including the lanthanide series and Y (REYs), are important tracers and paleo-proxies of biogeochemical processes, water mass transport and oceanic mixing. At the interface between the continents and oceans, the geochemical behaviour of REYs in estuarine environments is generally described as being non-conservative, with large-scale removal by particle scavenging. This conventional interpretation stems from observations carried out in tropical or sub-tropical estuaries. However, major river systems in the mid- and high latitude regions are subjected to winter conditions when a frozen watershed and an ice cover may affect the continental input of particles and the REY geochemistry. Here, we investigate the geochemical behaviour of REYs in the Estuary and Gulf of St. Lawrence (EGSL) in spring 2003 as well as winter and summer 2020. In contrast to the ice-free seasons, REYs and Fe behave conservatively in the estuary during the winter. In addition, we observed a higher REY affinity toward particles and fractionation in the REE patterns in the hypoxic deep waters of the estuary. The latter observation may reflect enhanced REY sorption to mineral-carrier surfaces exposed upon the remineralization of settling organic particles and to manganese oxides of benthic origin. Computed partition coefficient (Kd) values and strong correlations between Y/Ho, Er/Nd and Ce anomalies with dissolved oxygen concentrations support this hypothesis. The estimated annual dissolved load of REYs from the EGSL to the ocean ranges from 0.4 to 75 tons per year, thus contributing significantly to the global marine budget. The global river loading of dissolved Nd to the ocean was also revised to 4,000 tons per year based on data available for 21 river systems.

A proposed dam is to be built at a North Core watershed of the Federal University of Agriculture Makurdi. Reservoir capacity based on the mean inflow from the catchment yield into the proposed dam was assessed. The hydrological soil group of the area was studied. Mean annual rainfall for a period of 31 years (1987 to2017) was used to determine the runoff from catchment areas. Reservoir capacity was estimated using an analytical, mass curve, and residual mass curve methods. The area of the catchment was 8.82km2. The mean annual runoff from catchment areas was 1222.59mm. The mean annual catchment yield (inflow) was 10,783,243.8m3. Cumulative inflow was used to prepare mass curve inflow into the reservoir at drafts 60% and 80% on the cumulative draft line, superimposed on the cumulative mass curve. At draft 60%, reservoir capacity of 9,513,000m3 resulted; at draft 80%, 10,549,000m3. The residual mass curve of the inflow from the catchment area at a draft of 60%, gave a reservoir capacity of 3,632,000m3, while 80%, gave 4,426,000m3. An annual sediment discharge of 1302.02 tons was expected. A reservoir capacity of 11,000,000m3 was recommended for the proposed dam. Installment of an upstream sedimentation basin, soil conservation systems, vegetative screenings are recommended to reduce sediment load into the reservoir.

This research aimed to prepare for spatial hydrological modeling using the Hydrologic Modeling System (HEC-HMS) by integrating different spatial technologies to study the Beht catchment area, which covers 4560 km2 and also has a perimeter of 414 km. Firstly, the approach was to extract automatically the sub-basins and the drainage network. Then, these data were edited using the HEC-GEO-HMS extension, whereas the land use and land cover data were prepared for the generation of a Curve Number (CN) map of Beht watershed; lastly, the basin model was imported into the Hydrologic Modeling System (HEC-HMS) to simulate the surface runoff. The findings indicated a good match between the calculated and measured values and revealed also that the model is valid, good and performed well in terms of assessment criterion, with average values of Relative Error in peak: REP=9.6%, Relative Error in volume: REV=1.69%, Nash-Sutcliffe Efficiency: NSE=0.63, coefficient of determination: R2=0.870, and Ratio of standard deviation of observations to root mean square error: RSR=0.36.

Lakes act as both ecosystems for numerous life forms, and in many cases, tourist destinations. In order to sustain lakes as tourist destinations and protect them as ecosystems, municipalities need to understand the tourist, their demographics, motivations, satisfaction levels and the tourists’ desire for sustainability initiatives. To this end, the purpose of this study was to examine lake tourists, their demographics, motivational drivers and their relation to each other. Using a sample of 475 surveys, cross-tabulations, t-tests, and ANOVA’s were executed to understand differences and relationships. The results show varying differences with three key findings. First, motivations drive visitors based on their age and gender. Second, income has an influence on the importance visitors put on businesses promoting sustainability, such that the greater the income-level the lower the importance visitors placed on businesses promoting sustainability. This research builds upon past segmentation studies to show the link between sustainable types of tourism and the importance of sustainability. This adds a third key finding to the area of inquiry, demonstrating that increased awareness not only strengthens the relationship between demand and nature-based offerings, but that it can also increase satisfaction levels.

Impervious surfaces are the greatest contributors to degradation of water quality and large volumes of stormwater runoff. Green infrastructure is the holistic solution to this problem which not only reduces flooding but also actively moves towards achievement of larger environmental goals. Green infrastructure has the co-benefits of reducing the heat island effect, traffic calming, beautifying the neighbourhood, improving the canopy within the city, the creation of parks and even supports economic development. The City of Falls Church is deeply concerned with the pressing matter of flood control due to the threats to human life and property in recent flooding events. The polluted waters of Falls Church also contribute to a highly impaired watershed- the Chesapeake Bay. This thesis recognizes the environmental crisis caused by polluted runoff and places equal emphasis upon reducing runoff as well as improving water quality. In order to mitigate the effects of inundation, it is most critical to intervene at the source of locations which create the most runoff and pollution. The thesis provides a systematic methodology of identifying such areas and intervening in them. The watershed which contains the downtown area of Falls Church has the greatest amount of impervious surfaces and the highest rate of stormwater runoff. The two intersecting streets of S. Maple Avenue and Annandale Road are identified as the location of intervention after tabulating a confluence of stormwater and public realm factors. S. Maple Avenue is a part of the Falls Church bike network and is also designated to become a civic great street. Meanwhile, Annandale Road has the potential to play an active role in collection and management of stormwater. Annandale Road runs along the watershed boundary as well as crosses several tributaries which are low points in the watershed. Furthermore, there is a dynamic urban character to the street as it transitions from a residential zone to the commercial zone. Both streets present excellent possibilities for road diets, pedestrianization and traffic calming which bolsters the implementation of stormwater management in the public realm. Master of Science Impervious surfaces are the greatest contributors to degradation of water quality and large volumes of stormwater runoff. Green infrastructure is the holistic solution to this problem which not only reduces flooding but also actively moves towards achievement of larger environmental goals. There is a growing recognition that gray stormwater infrastructure has no benefits other than the conveyance of water away from the site. Green infrastructure has the co-benefits of reducing the heat island effect, traffic calming, beautifying the neighbourhood, improving the canopy within the city, the creation of parks and even supports economic development. There are many cities today which have had positive results by implementing a green approach towards the management of runoff. The City of Falls Church is deeply concerned with the pressing matter of flood control due to the threats to human life and property in recent flooding events. This thesis recognizes the environmental crisis caused by polluted runoff and places equal emphasis upon reducing runoff as well as improving water quality. In order to mitigate the effects of inundation, it is most critical to intervene at the source of locations which create the most runoff and pollution.The two intersecting streets of S. Maple Avenue and Annandale Road are identified as the location of intervention after tabulating a confluence of stormwater and public realm factors. Both streets present excellent possibilities for road diets, pedestrianization and traffic calming which bolsters the implementation of stormwater management in the public realm.

In this study, we aimed to map and characterize the choroidal thickness over a wide area from the posterior pole to the vortex vein in normal eyes. This observational study included 146 healthy eyes (63 male). Three-dimensional volume data were acquired to create a choroidal thickness map using swept-source optical coherence tomography. The map was classified as type A if an area with a choroidal thickness >250 µm in the vertical direction from the optic disc, and the area corresponding to the watershed was not observed, or as type B if such an area was observed. The relationship between the ratio of groups A to B and age was compared by classifying the age for three age groups: 60 years in men and women. In men and women, 69.8% and 49.4% were classified as type A, respectively, with significant sex differences (p = 0.013). The proportion of type B decreased with increasing age in both the sexes. There was a significant difference between ≤60 and >60 years in men and between ≤40 and >40 years in women (p < 0.05). To conclude, the wide-area choroidal thickness and the age-dependent changes in healthy eyes differed between the sexes.

Advances have been made in water resource investigation due to the implementation of mathematical models, the development of theoretical frameworks, and the evaluation of sustainability indices. Together, they improve and make integrated water resource management more efficient. In this paper, in the study area of the Duero River Basin, located in Michoacan, Mexico, we schematize a series of numerical indices of the Watershed Governance Prism to determine the quantitative status of water governance in a watershed. The results, presented as axes, perspectives, and prisms in the Axis Index, Water Governance Index, and Watershed Governance Prism Index, provide the conclusion that it is possible to establish and evaluate the Watershed Governance Prism Index using our numerical implementation of the Watershed Governance Prism theoretical framework. Thus, it is possible to define a quantitative status and evoke how water governance is being designed and implemented in a watershed.

The particle size of pellets is an important parameter in steel big data, and the high density and high overlap rate of pellets bring a great challenge to particle size detection. To address this problem, a particle size intelligent detection algorithm with an improved watershed and a Gaussian mixture model (GMM) is proposed. First, the initial segmentation of the pellets and background is achieved by using adaptive binary segmentation, and then the secondary fine segmentation of the pellets and background is achieved by combining morphological operations such as skeleton extraction and marked watershed segmentation; then, the contour of the connected domain of pellets is calculated, and the non-overlapping pellets in the foreground and the overlapping pellets are filtered according to the roundness of their contours. Finally, the number of overlapping pellets is predicted by Gaussian reconstruction of the grayscale image of the overlapping pellets, and the number and granularity of the overlapping pellets are predicted by the Gaussian reconstruction of the overlapping pellets. The experimental results showed that the algorithm achieved a 91.98% segmentation accuracy in the experimental images. Compared with other algorithms, the algorithm can also effectively suppress the over-segmentation and under-segmentation problems, and it can effectively realize the pellet size detection of dense, overlapping pellets such as those on a pelletizing disk, which provides an effective technical means for the metallurgical performance analysis of pellet ore and intelligent pellet-making driven by big data.

Wetlands are recognized as hotspots of biodiversity and providers of several ecosystem services, including water purification, sediment stabilization, and flood, erosion, and climate regulation. This article aims to investigate the floristic diversity of the wetlands the Haho River watershed in southern Togo. Spatial data from Astrium service and Google Earth were collected, and phytosociological data were classified following the Braun–Blanquet approach. The findings indicate that 72 families in total have evolved in this environment, with Poaceae (14.95%) and Fabaceae (11.98%) dominating. The number of species was estimated to be 323; the three species that were most prevalent in the wetland’s habitats were Elaeis guineensis Jacq (2.44%), Panicum maximum Jacq (2.29%), and Lonchocarpus sericeus (Poir) H. B. K. (1.71%). The most prevalent and abundant life forms in these moist habitats were micro-phanerophytes (34.70%) and therophytes (23.50%). However, the most common and abundant chorological categories included pantropical (31.05%) and Guinean-Congolese species (21.46%). Principal Component Analysis (PCA) was used to examine how abiotic parameters, including depth/degree of immersion, influence the distribution of plant species in a wetland landscape. This research has the potential to be developed into a more robust action study for wetland classification and recognition.