The Runoff Evolution and the Differences Analysis of the Causes of Runoff Change in Different Regions: A Case of the Weihe River Basin, Northern China

Abstract

The runoff levels of the major hydrological stations in the Weihe river basin (WRB) have been found to present decreasing trends. However, the conspicuous spatial differences in the hydro-meteorological conditions have led to variations in the rainfall–runoff pattern in each of the sub-basin areas. The aims of this research study were to reveal the main factors contributing to the runoff changes in the different regions—and it has significance in the water resources rational allocation and protection in the different regions. Three statistical methods were used to analyze the law of precipitation and runoffs of five hydrological stations. The SWAT (Soil and Water Assessment Tool) model was used to reconstruct the runoff in the impact period. The effects of climate change and human activity on runoff were separated by comparing measured runoff and reconstructed runoff. The results show that the closer the proximity to the downstream hydrological station, the more the runoff decreased. In the tributaries and upstream hydrological stations (Zhuanhtou (ZT), Zhangjiashan (ZJS), and Linjiacun (LJC)), from 1970 to 2016, the dominant factor of the runoff reduction was determined to be climate change, and accounted for 148.2%, 98.9%, and 90.5%, respectively. In the hydrological stations of middle and lower reaches (Xianyang (XY) and Huaxian (HX)), the contributions of the climate change to the runoff reduction were 49.7% and 44.3%, respectively, and the impacts of human activity accounted for 50.3% and 55.7%. The impacts of human activity on the runoff reduction were slightly greater than that of the climate change. Due to the different leading factors affecting runoff change in the basin, in response to future climate change, for tributaries and upstream areas, land use should be rationally planned to achieve the optimal balance of water volume in each part of the basin, which is of great significance to the protection and utilization of water resources. As for the middle and downstream regions, reasonable planning should also be focused on the amount of water withdraw, water resource allocations, and water conservancy project construction. According to the factors affecting runoff, corresponding strategies are proposed for different regions, which have important research significance for the protection and sustainable development of watershed water resources.

Base Flow Variation and Attribution Analysis Based on the Budyko Theory in the Weihe River Basin

“…The two effects on total stream flow were mainly attributed to human activities at Linjiacuan and Xianyang stations, accounting for 64% and 60%, respectively, while the effect at Huaxian station was 49%. The effects of climate change and human activities on stream flow in WRB have been computed in several studies, and the results of this study are consistent with those of Zuo [32], Zhan [33], and Jiang [34]. Therefore, in the change process of total stream flow, except for the variation at Huaxian Station that was greatly affected by climate change, the other two stations were heavily influenced by human activities.…”

“…The Weihe River Basin (WRB), an important river in Shaanxi Province, known to the Shaanxi people as their mother river, is the largest tributary of the Yellow River in northern China and is a main river for Ningxia and Gansu Provinces in northwestern China that provides the surface water for irrigation and water supplies for several major cities in the arid region. The stream flow in the WRB has significantly declined in the 20th century [31,32]. Based on 13 stream flow gauges in the WRB, the monthly stream flow depth has declined 0.1-2.1 mm during the period from 1960 to 2009, and the main driving factors for the declined stream flow are believed to be related to reservoir operation, vegetation change, surface water consumption, and water and soil conservation [33].…”

Comprehensive Evaluation of the Level of Water Ecological Civilization Construction in the Min River Basin, China

“…In 2015, the southeastern section of Sanming was affected by a severe drought, and the region's WECC level was very poor. This should relate to the arrangement of water infrastructure in the Min River Basin [36]. The first terraced hydropower plant in New China was constructed at Ningde [37].…”

Streamflow Response to Climate and Land-Use Changes in a Tropical Island Basin

“…Various methods are currently used to evaluate the effects of climate change and LUCC on streamflow, which is at the forefront of the research on global environmental change. This includes the elastic coefficient method [7], the precipitation-runoff regression relationship method [8], the method of reconstructing runoff by using or combining hydrological models [9], etc. The SWAT (Soil and Water Assessment Tool) model was developed for basin management by the USDA (United States Department of Agriculture) and ARS (Agricultural Research Service) [10] because it is relatively simple to operate and, due to its favorable performance in simulating hydrological and water-quality processes, it is widely used to capture the hydrological response to climate change and LUCC [11][12][13].…”