scholarly journals Integrated assessment of the impacts of climate variability and anthropogenic activities on river runoff: a case study in the Hutuo River Basin, China

2016 ◽  
Vol 48 (2) ◽  
pp. 416-430 ◽  
Author(s):  
Abubaker Omer ◽  
Weiguang Wang ◽  
Amir K. Basheer ◽  
Bin Yong

Understanding the linear and nonlinear responses of runoff to environmental change is crucial to optimally manage water resources in river basins. This study proposes a generic framework-based hydrological model (Soil and Water Assessment Tool (SWAT)) and two approaches, to comprehensively assess the impacts of anthropogenic activities and climate variability on runoff over the representative Hutuo River Basin (HRB), China. Results showed that SWAT performed well in capturing the runoff trend in HRB; however, it exhibited better performance for the calibration period than for the validation. During 1961–2000, about 26.06% of the catchment area was changed, mainly from forest to farmland and urban, and the climate changed to warmer and drier. The integrated effects of the anthropogenic activities and climate variability decreased annual runoff in HRB by 96.6 mm. Direct human activities were responsible for 52.16% of runoff reduction. Climate (land use) decreased runoff by 45.30% (2.06%), whereas the combined (land use + climate) impact resulted in more runoff decrease, by 47.84%. Land use–climate interactive effect is inherent in HRB and decreased runoff by 1.02%. The proposed framework can be applied to improve the current understanding of runoff variation in river basins, for supporting sustainable water resources management strategies.

2019 ◽  
Vol 11 (4) ◽  
pp. 1072 ◽  
Author(s):  
Xin Jin ◽  
Yanxiang Jin ◽  
Xufeng Mao

Land use/cover change (LUCC) affects canopy interception, soil infiltration, land-surface evapotranspiration (ET), and other hydrological parameters during rainfall, which in turn affects the hydrological regimes and runoff mechanisms of river basins. Physically based distributed (or semi-distributed) models play an important role in interpreting and predicting the effects of LUCC on the hydrological processes of river basins. However, conventional distributed (or semi-distributed) models, such as the soil and water assessment tool (SWAT), generally assume that no LUCC takes place during the simulation period to simplify the computation process. When applying the SWAT, the subject river basin is subdivided into multiple hydrologic response units (HRUs) based on the land use/cover type, soil type, and surface slope. The land use/cover type is assumed to remain constant throughout the simulation period, which limits the ability to interpret and predict the effects of LUCC on hydrological processes in the subject river basin. To overcome this limitation, a modified SWAT (LU-SWAT) was developed that incorporates annual land use/cover data to simulate LUCC effects on hydrological processes under different climatic conditions. To validate this approach, this modified model and two other models (one model based on the 2000 land use map, called SWAT 1; one model based on the 2009 land use map, called SWAT 2) were applied to the middle reaches of the Heihe River in northwest China; this region is most affected by human activity. Study results indicated that from 1990 to 2009, farmland, forest, and urban areas all showed increasing trends, while grassland and bare land areas showed decreasing trends. Primary land use changes in the study area were from grassland to farmland and from bare land to forest. During this same period, surface runoff, groundwater runoff, and total water yield showed decreasing trends, while lateral flow and ET volume showed increasing trends under dry, wet, and normal conditions. Changes in the various hydrological parameters were most evident under dry and normal climatic conditions. Based on the existing research of the middle reaches of the Heihe River, and a comparison of the other two models from this study, the modified LU-SWAT developed in this study outperformed the conventional SWAT when predicting the effects of LUCC on the hydrological processes of river basins.


2019 ◽  
Vol 11 (2) ◽  
pp. 338 ◽  
Author(s):  
Leting Lyu ◽  
Xiaorui Wang ◽  
Caizhi Sun ◽  
Tiantian Ren ◽  
Defeng Zheng

Based on a land use interpretation and distributed hydrological model, soil and water assessment tool (SWAT), this study simulated the hydrological cycle in Xihe River Basin in northern China. In addition, the influence of climate variability and land use change on green water resources in the basin from 1995 to 2015 was analyzed. The results show that (1) The ENS (Nash-Sutcliffe model efficiency coefficient) and R2 (coefficient of determination) were 0.94 and 0.89, respectively, in the calibration period, and 0.89 and 0.88, respectively, in the validation period. These indicate high simulation accuracy; (2) Changes in green water flow and green water storage due to climate variability accounted for increases of 2.07 mm/a and 1.28 mm/a, respectively. The relative change rates were 0.49% and 0.9%, respectively, and the green water coefficient decreased by 1%; (3) Changes in green water flow and green water storage due to land use change accounted for increases of 69.15 mm and 48.82 mm, respectively. The relative change rates were 16.4% and 37.2%, respectively, and the green water coefficient increased by 10%; (4) Affected by both climate variability and land use change, green water resources increased by 121.3 mm and the green water coefficient increased by 9% in the Xihe River Basin. It is noteworthy that the influence of land use change was greater than that of climate variability.


2018 ◽  
Vol 10 (9) ◽  
pp. 3277 ◽  
Author(s):  
Javier Senent-Aparicio ◽  
Sitian Liu ◽  
Julio Pérez-Sánchez ◽  
Adrián López-Ballesteros ◽  
Patricia Jimeno-Sáez

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.


2014 ◽  
Vol 6 (2) ◽  
pp. 325-340 ◽  
Author(s):  
Nuanchan Singkran ◽  
Jaruporn Tosang ◽  
Doungjai Waijaroen ◽  
Naree Intharawichian ◽  
Ornanong Vannarart ◽  
...  

This study was a first attempt to portray the effects of land use and climate changes (CCs) on the hydrologic system in the Lamtakhong Basin in northeastern Thailand, which has been disturbed by various human activities, making it difficult to determine these impacts on hydrologic conditions. The hydrologic Soil and Water Assessment Tool model was set up with land use and soil data of 2002 and observed flow and weather data during 1999–2000. After the model was calibrated and validated against observed flow data during 2001–2009, its land use change scenario with input land use data of 2011 and its CC scenario with input weather data during 2010–2065 were simulated. The results showed that changing land use over the 10-year period had trivial influences on the hydrologic system, whereas changing climate over the 56-year period appeared to affect both water yields and flows. Water scarcity will tend to take place across the Lamtakhong Basin in the near future. Longer periods of severe droughts and floods might occasionally occur, particularly downstream. These findings will be useful for land and water resources managers and policy-makers to manage land and water resources in the river basin.


Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 191 ◽  
Author(s):  
Mohamed Aboelnour ◽  
Margaret W. Gitau ◽  
Bernard A. Engel

Alteration of land use and climate change are among the main variables affecting watershed hydrology. Characterizing the impacts of climate variation and land use alteration on water resources is essential in managing watersheds. Thus, in this research, streamflow and baseflow responses to climate and land use variation were modeled in two watersheds, the Upper West Branch DuPage River (UWBDR) watershed in Illinois and Walzem Creek watershed in Texas. The variations in streamflow and baseflow were evaluated using the Soil and Water Assessment Tool (SWAT) hydrological model. The alteration in land use between 1992 and 2011 was evaluated using transition matrix analysis. The non-parametric Mann–Kendall test was adopted to investigate changes in meteorological data for 1980–2017. Our results indicate that the baseflow accounted for almost 55.3% and 33.3% of the annual streamflow in the UWBDR and Walzem Creek watersheds, respectively. The contribution of both land use alteration and climate variability on the flow variation is higher in the UWBDR watershed. In Walzem Creek, the alteration in streamflow and baseflow appears to be driven by the effect of urbanization more than that of climate variability. The results reported herein are compared with results reported in recent work by the authors in order to provide necessary information for water resources management planning, as well as soil and water conservation, and to broaden the current understanding of hydrological components variation in different climate regions.


Author(s):  
Mohamed Aboelnour ◽  
Margaret W. Gitau ◽  
Bernard Engel

Alteration of land use and climate change are among the main variables affecting watershed hydrology. Characterizing the impacts of climate variation and land use alteration on water resources is essential in managing watersheds. Thus, in this research, streamflow and baseflow responses to climate and land use variation were modeled in two watersheds, the Upper West Branch DuPage River (UWBDR) watershed in Illinois and Walzem Creek watershed in Texas. The variations in streamflow and baseflow were evaluated using the Soil and Water Assessment Tool (SWAT) hydrological model. The alteration in land use between 1992 and 2011 was evaluated using transition matrix analysis. The non-parametric Mann-Kendall test was adopted to investigate changes in meteorological data from 1980-2017. Our results indicated that the baseflow accounted for almost 55.3% and 33.3% of the annual streamflow in the UWBDR and Walzem Creek watersheds, respectively. The contribution of both land use alteration and climate variability on the flow variation is higher in the UWBDR watershed. In Walzem Creek, the alteration in streamflow and baseflow appears to be driven by the effect of urbanization more than that of climate variability. The results reported herein are compared with results reported in recent work by the authors in order to provide necessary information for water resources management planning, as well as soil and water conservation, and to broaden the current understanding of hydrological components variation in different climate regions.


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