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.

scholarly journals Detecting land use and climate impacts on water yield ecosystem service in arid and semi-arid areas. A study in Sirvan River Basin-Iran

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jahanbakhsh Balist ◽  
Bahram Malekmohammadi ◽  
Hamid Reza Jafari ◽  
Ahmad Nohegar ◽  
Davide Geneletti
Keyword(s):  
Land Use ◽  
River Basin ◽  
Ecosystem Service ◽  
Climatic Factors ◽  
Land Use Changes ◽  
Climate Impacts ◽  
Water Yield ◽  
Future Evolution ◽  
The Future ◽  
The Impact

AbstractThis study investigates how land use and climate changes affect water yield ecosystem service (ES) in the Sirvan River basin, located in Iran’s Kurdistan and Kermanshah provinces. By detecting land-use and climatic parameter changes in the past, their future evolution were modeled by scenario making. For this purpose, we developed two land-use scenarios (low and high urbanization) and two climatic scenarios (Representative Concentration Pathway 2.6 and RCP 8.5). The implemented scenarios showed how the amount of water yield in the basin and sub-basins changes in the future based on climate and land-use changes. The results showed that, concerning land use, the forest has decreased from 2013 to 2019, and built-up areas have increased. Also, the results showed that precipitation has been declining in the long term, and the temperature has been rising. Finally, the Water yield in 2019 was higher than in 2013 and lower in the future based on forecast scenarios. This trend will continue until 2040. In addition, it was found that the t effects of these factors on water yield ES are a complex process, and based on the results, the impact of climatic factors is more significant than the one of land-use change. We could conclude that this region will face more environmental problems in the future.

scholarly journals Effects of Climate and Land Use/Land Cover Changes on Water Yield Services in the Dongjiang Lake Basin

2021 ◽  
Vol 10 (7) ◽  
pp. 466
Author(s):  
Wenbo Mo ◽  
Yunlin Zhao ◽  
Nan Yang ◽  
Zhenggang Xu ◽  
Weiping Zhao ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Water Resource Management ◽  
Water Source ◽  
Water Yield ◽  
Lake Basin ◽  
Lake Area ◽  
Land Use Land Cover ◽  
Lulc Changes ◽  
Regional Water

Spatial and quantitative assessments of water yield services in watershed ecosystems are necessary for water resource management and improved water ecological protection. In this study, we used the InVEST model to estimate regional water yield in the Dongjiang Lake Basin in China. Moreover, we designed six scenarios to explore the impacts of climate and land use/land cover (LULC) changes on regional water yield and quantitatively determined the dominant mechanisms of water yield services. The results are expected to provide an important theoretical reference for future spatial planning and improvements of ecological service functions at the water source site. We found that (1) under the time series analysis, the water yield changes of the Dongjiang Lake Basin showed an initial decrease followed by an increase. Spatially, water yield also decreased from the lake area to the surrounding region. (2) Climate change exerted a more significant impact on water yield changes, contributing more than 98.26% to the water yield variability in the basin. In contrast, LULC had a much smaller influence, contributing only 1.74 %. (3) The spatial distribution pattern of water yield services in the watershed was more vulnerable to LULC changes. In particular, the expansion of built-up land is expected to increase the depth of regional water yield and alter its distribution, but it also increases the risk of waterlogging. Therefore, future development in the basin must consider the protection of ecological spaces and maintain the stability of the regional water yield function.

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 Impacts of future land use and land cover change on mid-21<sup>st</sup>-century surface ozone air quality: Distinguishing between the biogeophysical and biogeochemical effects

2019 ◽  
Author(s):  
Lang Wang ◽  
Amos P. K. Tai ◽  
Chi-Yung Tam ◽  
Mehliyar Sadiq ◽  
Peng Wang ◽  
...  
Keyword(s):  
Land Use ◽  
Air Quality ◽  
Land Cover ◽  
Dry Deposition ◽  
Surface Ozone ◽  
Boreal Summer ◽  
Ozone Pollution ◽  
Lulc Change ◽  
Lulc Changes ◽  
The Impact

Abstract. Surface ozone (O3) is an important air pollutant and greenhouse gas. Land use and land cover (LULC) is one of the critical factors influencing ozone, in addition to anthropogenic emissions and climate. LULC change can on the one hand affect ozone biogeochemically, i.e., via dry deposition and biogenic emissions of volatile organic compounds (VOCs). LULC change can on the other hand alter regional- to large-scale climate through modifying albedo and evapotranspiration, which can lead to changes in surface temperature, hydrometeorology and atmospheric circulation that can ultimately impact ozone biogeophysically over local and remote areas. Such biogeophysical effects of LULC on ozone are largely understudied. This study investigates the individual and combined biogeophysical and biogeochemical effects of LULC on ozone, and explicitly examines the critical pathway for how LULC change impacts ozone pollution. A global coupled atmosphere–chemistry–land model is driven by projected LULC changes from the present day (2000) to future (2050) under RCP4.5 and RCP8.5 scenarios, focusing on the boreal summer. Results reveal that when considering biogeochemical effects only, surface ozone is predicted to have slight changes by up to 2 ppbv maximum in some areas due to LULC changes. It is primarily driven by changes in isoprene emission and dry deposition counteracting each other in shaping ozone. In contrast, when considering the integrated effect of LULC, ozone is more substantially altered by up to 6 ppbv over several regions, reflecting the importance of biogeophysical effects on ozone changes. Furthermore, large areas of these ozone changes are found over the regions without LULC changes where the biogeophysical effect is the only pathway for such changes. The mechanism is likely that LULC change induces a regional circulation response, in particular the formation of anomalous stationary high-pressure systems, shifting of moisture transport, and near-surface warming over the middle-to-high northern latitudes in boreal summer, owing to associated changes in albedo and surface energy budget. Such temperature changes then alter ozone substantially. We conclude that the biogeophysical effect of LULC is an important pathway for the influence of LULC change on ozone air quality over both local and remote regions, even in locations without significant LULC changes. Overlooking the impact of biogeophysical effect may cause evident underestimation of the impacts of LULC change on ozone pollution.

ANN-SCS-based hybrid model in conjunction with GCM to evaluate the impact of climate change on the flow scenario of the River Subansiri

2019 ◽  
Vol 11 (4) ◽  
pp. 1150-1164
Author(s):  
Swapnali Barman ◽  
Rajib Kumar Bhattacharjya
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Hybrid Model ◽  
Curve Number ◽  
Future Trend ◽  
Land Use Land Cover ◽  
Ann Model ◽  
Non Linear ◽  
The Future ◽  
The Impact

Abstract The River Subansiri, one of the largest tributaries of the Brahmaputra, makes a significant contribution towards the discharge at its confluence with the Brahmaputra. This study aims to investigate an appropriate model to predict the future flow scenario of the river Subansiri. Two models have been developed. The first model is an artificial neural network (ANN)-based rainfall-runoff model where rainfall has been considered as the input. The future rainfall of the basin is calculated using a multiple non-linear regression-based statistical downscaling technique. The proposed second model is a hybrid model developed using ANN and the Soil Conservation Service (SCS) curve number (CN) method. In this model, both rainfall and land use/land cover have been incorporated as the inputs. The ANN models were run using time series analysis and the method selected is the non-linear autoregressive model with exogenous inputs. Using Sen's slope values, the future trend of rainfall and runoff over the basin have been analyzed. The results showed that the hybrid model outperformed the simple ANN model. The ANN-SCS-based hybrid model has been run for different land use/land cover scenarios to study the future flow scenario of the River Subansiri.

scholarly journals Watershed Hydrological Response to Combined Land Use/Land Cover and Climate Change in Highland Ethiopia: Finchaa Catchment

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1801 ◽  
Author(s):  
Wakjira Takala Dibaba ◽  
Tamene Adugna Demissie ◽  
Konrad Miegel
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
Land Cover ◽  
Surface Runoff ◽  
Regional Climate ◽  
Water Yield ◽  
Land Use Land Cover ◽  
Ensemble Mean ◽  
The Future

Land use/land cover (LULC) and climate change affect the availability of water resources by altering the magnitude of surface runoff, aquifer recharge, and river flows. The evaluation helps to identify the level of water resources exposure to the changes that could help to plan for potential adaptive capacity. In this research, Cellular Automata (CA)-Markov in IDRISI software was used to predict the future LULC scenarios and the ensemble mean of four regional climate models (RCMs) in the coordinated regional climate downscaling experiment (CORDEX)-Africa was used for the future climate scenarios. Distribution mapping was used to bias correct the RCMs outputs, with respect to the observed precipitation and temperature. Then, the Soil and Water Assessment Tool (SWAT) model was used to evaluate the watershed hydrological responses of the catchment under separate, and combined, LULC and climate change. The result shows the ensemble mean of the four RCMs reported precipitation decline and increase in future temperature under both representative concentration pathways (RCP4.5 and RCP8.5). The increases in both maximum and minimum temperatures are higher for higher emission scenarios showing that RCP8.5 projection is warmer than RCP4.5. The changes in LULC brings an increase in surface runoff and water yield and a decline in groundwater, while the projected climate change shows a decrease in surface runoff, groundwater and water yield. The combined study of LULC and climate change shows that the effect of the combined scenario is similar to that of climate change only scenario. The overall decline of annual flow is due to the decline in the seasonal flows under combined scenarios. This could bring the reduced availability of water for crop production, which will be a chronic issue of subsistence agriculture. The possibility of surface water and groundwater reduction could also affect the availability of water resources in the catchment and further aggravate water stress in the downstream. The highly rising demands of water, owing to socio-economic progress, population growth and high demand for irrigation water downstream, in addition to the variability temperature and evaporation demands, amplify prolonged water scarcity. Consequently, strong land-use planning and climate-resilient water management policies will be indispensable to manage the risks.

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 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 Assessment of land cover resolution impact on flood modeling uncertainty

2020 ◽  
Author(s):  
Jihui Fan ◽  
Majid Galoie ◽  
Artemis Motamedi ◽  
Jing Huang
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Cell Size ◽  
Hydrological Modeling ◽  
Assessment Tool ◽  
Swat Model ◽  
Flood Modeling ◽  
The Impact ◽  
Scs Cn

Abstract The main objective of this paper is to evaluate the impact of land cover resolution, in comparison with the digital elevation model (DEM) resolution, on hydrological modeling outputs. Three different basins in the various resolutions of DEM (12.5, 25, 50, 100, 500 and 1,000 m) and land-use maps (250, 1,000 and 2,500 m) were collected in this study, and the hydrological modeling process was performed using the Soil and Water Assessment Tool (SWAT) model. The soil type resolution was 1,000 m for all basins, and the runoff modeling was done based on the Soil Conservation Service Curve Number (SCS-CN) method. The final model outputs showed that the DEM cell size variations affect significantly the topographical characteristics of a catchment such as area, mean slope, river network and time to concentration which alter the flood modeling outputs especially in hilly watersheds (mean slope more than 15%) up to 15% for a DEM cell size of 1,000 m in comparison to 12.5 m. Also, the resolution and spatial distribution of land cover maps which directly specify SCS-CN values, can change the output simulated runoff results up to 49% for a land cover cell size of 2,500 m in comparison to 250 m. These results indicated that the quality of the land cover map is more important than the quality of DEM in hydrological modeling. Also, the results showed that for an identical land-use cell size, the differences between model outputs using DEM cell sizes less than 100 m were not very significant. Furthermore, in all models by increasing the DEM cell size, the simulated runoff depth was decreased.

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