Runoff sensitivity to climate and land-use changes: A case study in the Longtan basin, Southwestern China

• Published in: Journal of water and climate change Vol. 12; no. 4; pp. 1059 - 1070
• Main Authors: Mo, Guiyan, Huang, Ya, Yang, Qing, Wang, Dayang, Mo, Chongxun
• Format: Journal Article
• Language: English
• Published: London IWA Publishing 01.06.2021
• Subjects: Annual rainfall; Annual runoff; Basins; Calibration; Climate; Climate and land use; Climate change; Dams; Evaporation; Evapotranspiration; Forest conservation; Forest management; Grasslands; Hydroelectric power; Hydrologic models; Hydrology; Land use; land-use change; longtan basin; Peak floods; Precipitation; Rain; Runoff; sensitivity; Sensitivity analysis; Simulation; Software; Soil water; Soils; swat model; Temperature; Vegetation; Water conservation; Water consumption; Water resources; Watersheds; Weather; China
• ISSN: 2040-2244; 2408-9354
• DOI: 10.2166/wcc.2020.196

Abstract Based on the scenario hypothesis method, this paper applied a Soil and Water Assessment Tool (SWAT) to analyze the sensitivity of runoff to climate and land-use changes in the Longtan basin, China. Results indicated that (1) for every 1 °C increase in temperature, the average annual runoff decreased by 9.9 mm, and the average annual evaporation increased by 9.3 mm. However, for every 10% increase in rainfall, the average annual runoff and evapotranspiration increased by 96.3 mm and 11.53 mm, respectively. Obviously, runoff was more sensitive to the change in rainfall than temperature in the Longtan basin. Meanwhile, (2) forestland could conserve water resources, but its water consumption was larger. Although grassland played a relatively small role in water conservation, it consumed less water. At the same time, increasing the area of forestland and grassland could weaken peak floods, and the water retention function of vegetation could prevent runoff from increasing and decreasing steeply. Therefore, it is worth improving vegetation coverage.