scholarly journals Fluxes of Nitrogen, Phosphorus, and Dissolved Organic Carbon in the inflow of the Lehnmühle reservoir (Saxony) as compared to streams draining three main land-use types in the catchment

2012 ◽  
Vol 32 ◽  
pp. 1-7 ◽  
Author(s):  
R. Benning ◽  
K. Schua ◽  
K. Schwärzel ◽  
K. H. Feger
Keyword(s):  
Land Use ◽  
Assessment Tool ◽  
Nitrogen And Phosphorus ◽  
Land Use Types ◽  
Doc Concentration ◽  
Change Impact ◽  
Agricultural Areas ◽  
The Impact ◽  
Water Assessment ◽  
Nitrogen Phosphorus

Abstract. The aim of this study was to assess the impact of land-use on inputs of nitrogen, phosphorus, and DOC into the inflow of the Lehnmühle reservoir (drinking water supply). Land-use in the study area is dominated by forest, with smaller proportions of grassland and crops. Water quality was analyzed for the hydrological years 2010 and 2011 at the outlets of three small catchments with homogenous land-use (crops, grassland and forest) and at the outlet of the watershed. The highest nitrogen and phosphorus concentrations were observed in the streams draining the agricultural areas, and the lowest concentrations were found in the forest catchment. The DOC concentration was highest at the outlet of the watershed whereas the concentrations in the small homogeneous catchments were lower. The information collected about the land-use dependent matter exports in these study areas will be used for climate change impact modeling with the Soil and Water Assessment Tool.

scholarly journals The Impact of the Changes in Climate, Land Use and Direct Human Activity on the Discharge in Qingshui River Basin, China

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3147
Author(s):  
Mengxue Zhang ◽  
Radosław Stodolak ◽  
Jianxin Xia
Keyword(s):  
Land Use ◽  
Human Activity ◽  
Assessment Tool ◽  
Mining Industry ◽  
Positive Influence ◽  
Dominant Factor ◽  
Annual Scale ◽  
The Impact ◽  
Water Assessment ◽  
Main Factor

Climate, land use and human activity have an impact on the Qingshui River in Chongli County. The Soil and Water Assessment Tool (SWAT) was used to separately analyze the contributions of climate, land use and direct human activity on the discharge variations. The results indicated that human activity had been the dominant factor for the discharge decrease, while climate and land use change had a positive influence on the discharge increase. The contributions of these three factors were −56.24%, 38.59% and 5.17%, respectively. Moreover, on the seasonal scale, the impact of those factors was consistent with their impact on the annual scale. Human activity was the main factor for discharge decrease in the summer, the contribution accounting for −77.13%. Due to the over-extraction of groundwater for irrigation and use in the mining industry, the discharge showed a decreasing tendency, which has the potential to place stress on sustainable water use in the future. The result of the study may contribute to the optimization of water resource allocation and management.

scholarly journals Assessing Impacts of Climate Variability and Reforestation Activities on Water Resources in the Headwaters of the Segura River Basin (SE Spain)

2018 ◽  
Vol 10 (9) ◽  
pp. 3277 ◽  
Author(s):  
Javier Senent-Aparicio ◽  
Sitian Liu ◽  
Julio Pérez-Sánchez ◽  
Adrián López-Ballesteros ◽  
Patricia Jimeno-Sáez
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
River Basin ◽  
Assessment Tool ◽  
Forest Area ◽  
Se Spain ◽  
Monthly Streamflow ◽  
Agricultural Areas ◽  
Water Assessment

Climate change and the land-use and land-cover changes (LULC) resulting from anthropic activity are important factors in the degradation of an ecosystem and in the availability of a basin’s water resources. To know how these activities affect the quantity of the water resources of basins, such as the Segura River Basin, is of vital importance. In this work, the Soil and Water Assessment Tool (SWAT) was used for the study of the abovementioned impacts. The model was validated by obtaining a Nash–Sutcliffe efficiency (NSE) of 0.88 and a percent bias (PBIAS) of 17.23%, indicating that SWAT accurately replicated monthly streamflow. Next, land-use maps for the years of 1956 and 2007 were used to establish a series of scenarios that allowed us to evaluate the effects of these activities on both joint and individual water resources. A reforestation plan applied in the basin during the 1970s caused that the forest area had almost doubled, whereas the agricultural areas and shrubland had been reduced by one-third. These modifications, together with the effect of climate change, have led to a decrease of 26.3% in the quantity of generated water resources, not only due to climate change but also due to the increase in forest area.

scholarly journals Avaliação de Impactos de Mudanças no Uso e Manejo do Solo Sobre as Vazões da Bacia Hidrográfica do Ribeirão José Pereira, Utilizando o Modelo Swat.

2021 ◽  
Vol 14 (2) ◽  
pp. 619
Author(s):  
Filipe Otávio Passos ◽  
Benedito Cláudio Da Silva ◽  
Fernando Das Graças Braga da Silva
Keyword(s):  
Land Use ◽  
Hydrological Modeling ◽  
Assessment Tool ◽  
Swat Model ◽  
Water Source ◽  
Distributed Model ◽  
Small Scale ◽  
The Impact ◽  
Water Assessment ◽  
Soil And Water

Diversos processos naturais podem causar mudanças nos fluxos hidrológicos dentro de bacias hidrográficas, sendo estas ainda mais afetadas devido a ações antrópicas que mudem as suas características físicas, principalmente, o tipo e o uso do solo. Neste contexto, este trabalho apresenta uma calibração de um modelo de transformação chuva x vazão e posterior simulação para a estimativa das vazões na bacia hidrográfica do ribeirão José Pereira, em Itajubá, sul de Minas Gerais, utilizando o modelo distribuído Soil and Water Assessment Tool (Swat). Foram gerados cinco cenários de uso e ocupação do solo, que foram idealizados a partir de características observadas na bacia ou de tendências futuras de ocupação, a saber, o cenário do estado atual, de manejo do solo, de recuperação das áreas de preservação permanente (APPs) de margens de rios, de substituição total por floresta e de crescimento urbano. Os resultados indicam que o modelo Swat pode ser utilizado na simulação das componentes hidrológicas de bacias hidrográficas de pequeno porte, e ainda que o manejo agrícola e o reflorestamento da bacia são mais eficientes na diminuição do escoamento superficial do que a recuperação das APPs, chegando a uma diminuição de aproximadamente 40% nas vazões máximas simuladas. Impact Assessment of Changes in Land Use and Management on the Losses of the Water Source of the José Pereira Stream, Using the SWAT Model A B S T R A C TSeveral natural processes can cause changes in hydrological flows within hydrographic basins, which are even more affected due to anthropic actions that change their physical characteristics, mainly, the type and use of the soil. In this context, this work carries out an analysis of the impact on the flows of a small-scale hydrographic basin (River José Pereira) due to changes in land use and occupation, using the distributed model Soil and Water Assessment Tool (SWAT). Five land use and occupation scenarios were generated, which were designed based on characteristics observed in the basin or future occupation trends, namely, the current state scenario, soil management, recovery of permanent preservation areas (APPs) of river banks, total replacement by forest and urban growth. The results indicate that the SWAT model can be used in the simulation of the hydrological components of small hydrographic basins, and that agricultural management and reforestation of the basin are more efficient in reducing runoff than the recovery of APPs, reaching a decrease of approximately 40% in the maximum simulated flows.Keywords: hydrological modeling, rainfall, SWAT, land use and occupation.

scholarly journals The Impact Of Tropical Deforestation On River Chemical Pollution

2013 ◽  
Vol 7 (2) ◽  
pp. 180-187
Keyword(s):  
Assessment Tool ◽  
Quantitative Description ◽  
Chemical Pollution ◽  
Nitrogen And Phosphorus ◽  
Pollutant Concentrations ◽  
Run Off ◽  
Percent Area ◽  
The Impact ◽  
Stocking Rates ◽  
Water Assessment

The objective of this study was to provide a quantitative description of the impact of converting tropical forests into pastures for cattle grazing in terms of the sediment, nitrogen and phosphorus concentrations at the outlet of a river basin located in North West Costa Rica. The Soil and Water Assessment Tool (SWAT) was utilized to model the watershed. The graphs for pollutant concentration vs. percent area of the watershed under pasture showed a monotonic increase in concentrations as deforestation increased. Contaminant levels for the entire watershed as grassland were between 3 and 8 times higher than for the total area as forest, which could put at risk the drinking water supply and the tourism-based economy of the region. Keeping the current percentage of area under grassland constant, but restricting pastures to the less fragile and more fertile lands could decrease the sediment, nitrogen and phosphorus concentrations at the main watershed outlet by more than 35%, 12% and 21%, respectively, as compared to the predicted pollutant concentrations for the current land cover distribution. The effect of varying cattle stocking rates resulted in lower sediment and nitrogen run-off for areas with higher animal loads in which confined operations are used part of the year.

scholarly journals Impact of Change in Land Use Land Cover on Water Resources in Gundlakamma Sub Basin

2020 ◽  
pp. 33-46
Author(s):  
N. Hari ◽  
A. Mani ◽  
H. V. Hema Kumar ◽  
V. Srinivasa Rao ◽  
L. Edukondalu
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Field Survey ◽  
Assessment Tool ◽  
Swat Model ◽  
Secondary Data ◽  
Land Use Land Cover ◽  
The Impact ◽  
Water Assessment ◽  
Good Agreement

The present study was conducted to investigate the impact of land use cover change on water resources availability in Gundlakamma Subbasin. The Gundlakamma subbasin is predominantly agricultural based and Gundlakamma is a seasonal river. Hence, a study has been conducted to simulate the availability of water resources in the subbasin using SWAT (Soil and Water Assessment Tool) model. The database was generated like DEM, soil map and land use/cover using the secondary data and field survey. The SWAT model was calibrated three years (2010-2012) and validated with four years (2013-2016) with the observed discharges from reservoir outflow. The values of NSE and R2 was found as 0.79 and 0.87 during calibration, 0.65 and 0.72, respectively during validation. The modelled values showed reasonably good agreement with the observed values of reservoir outflow, both during calibration and validation periods. The reservoir outflow in the subbasin was quantified under the change land use conditions.

Impact of land use/cover change on the relationship between precipitation and runoff in typical area

2018 ◽  
Vol 9 (2) ◽  
pp. 261-274 ◽  
Author(s):  
Bao-qi Li ◽  
Wei-hua Xiao ◽  
Yi-cheng Wang ◽  
Ming-zhi Yang ◽  
Ya Huang
Keyword(s):  
Land Use ◽  
River Basin ◽  
Assessment Tool ◽  
Forest Land ◽  
Runoff Generation ◽  
Dry Land ◽  
Unused Land ◽  
Land Use Types ◽  
The Impact ◽  
The Relationship

Abstract To study the impact of land use/cover change (LUCC), the relationship between precipitation and runoff was investigated. Our main objective was to ensure reasonable development, management, and sustainable utilization of water resources at a watershed scale. To investigate the relationship between precipitation and runoff, a SWAT (Soil and Water Assessment Tool) model was developed by analyzing LUCC in Naoli River basin. Then, runoff response was analyzed under different LUCC conditions. The contribution coefficient of different land use types to runoff was calculated. The results of this research study are as follows. From 1986 to 2014, dry land, forest land, paddy fields, and unused land were the major land use types, accounting for more than 93% of the total catchment. On the other hand, grass land, building land, and water bodies accounted for a small proportion. Among the four main land use types, the contribution coefficient of forest land was 3.10 mm·km−2. This indicates that forest land was suitable for runoff generation. The contribution coefficient of dry land, unused land (fluvial wetland in Naoli River basin), and paddy field are −0.11, −0.37, and −0.83 mm·km−2, respectively. This implies that these three land use types were adverse factors for runoff generation.

scholarly journals The Impacts of Land-Use Input Conditions on Flow and Sediment Discharge in the Dakbla Watershed, Central Highlands of Vietnam

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 627
Author(s):  
Vo Ngoc Quynh Tram ◽  
Hiroaki Somura ◽  
Toshitsugu Moroizumi
Keyword(s):  
Land Use ◽  
Assessment Tool ◽  
Flow Simulation ◽  
Policy Changes ◽  
Simulation Performance ◽  
Short Period ◽  
The Impact ◽  
The Given ◽  
Water Assessment ◽  
Better Than

The main objective of this study was to evaluate various land-use input conditions in terms of the performance improvement found in consequent flow and sediment simulations. The soil and water assessment tool (SWAT) was applied to the Dakbla watershed from 2000 to 2018. After the calibration and validation processes, dissimilar effects between the input conditions on the flow and sediment simulations were confirmed. It was recognized that the impact of the land use on the sediment simulation was more sensitive than with the flow simulation. Additionally, through monthly evaluation, the effects against the flow and sediment in the rainy season were larger than those in the dry season, especially for sediment simulation in the last three months from October to December. Changing land-use conditions could improve flow and sediment simulation performance better than the performance found with static land-use conditions. Updated land-use inputs should be considered in simulations if the given land-use condition changes in a relatively short period because of frequent land-use policy changes by a local government.

scholarly journals Hydrological Response of the Wami–Ruvu Basin to Land-Use and Land-Cover Changes and Its Impacts for the Future

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 184
Author(s):  
Jamila Ngondo ◽  
Joseph Mango ◽  
Joel Nobert ◽  
Alfonse Dubi ◽  
Xiang Li ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Assessment Tool ◽  
Climatic Factors ◽  
Water Yield ◽  
Warm Up ◽  
Lulc Changes ◽  
The Future ◽  
The Impact ◽  
Water Assessment

The evaluation of the hydrological responses of river basins to land-use and land-cover (LULC) changes is crucial for sustaining water resources. We assessed the impact of LULC changes (1990–2018) on three hydrological components (water yield (WYLD), evapotranspiration (ET), and sediment yield (SYLD)) of the Wami–Ruvu Basin (WRB) in Tanzania, using the Soil and Water Assessment Tool (SWAT). The 1990 LULC imagery was used for SWAT simulation, and imagery from 2000, 2010, and 2018 was used for comparison with modelled hydrological parameters. The model was calibrated (1993–2008) and validated (2009–2018) in the SWAT-CUP after allowing three years (1990–1992) for the warm-up period. The results showed a decrease in WYLD (3.11 mm) and an increase in ET (29.71 mm) and SYLD (from 0.12 t/h to 1.5 t/h). The impact of LULC changes on WYLD, ET, and SYLD showed that the increase in agriculture and built-up areas and bushland, and the contraction of forest led to the hydrological instability of the WRB. These results were further assessed with climatic factors, which revealed a decrease in precipitation and an increase in temperature by 1°C. This situation seems to look more adverse in the future, based on the LULC of the year 2036 as predicted by the CA–Markov model. Our study calls for urgent intervention by re-planning LULC and re-assessing hydrological changes timely.

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