Impacts of climate and land use change on the inflow of water to Songhuaba reservoir

Abstract

[Objective] To quantitatively assess the contribution of climate and land use changes to the inflow of Songhuaba reservoir, [Methods] based on multi-period climate and land-use data since the establishment of Songhuaba water conservation district, the climate change trend is analyzed by the method of Climate Propensity Rate and MK trend test, the spatio-temporal variation characteristics of land use are explored by the GIS spatial overlay tool, and the watershed hydrological processes are simulated by SWAT model, so as to analyze the impacts of climate and land use changes on the reservoir inflow of the study area. [Results] The results show that temperature of the study area increases at a rate of 0.586 ℃/10 a and precipitation decreases at a rate of 12.5 mm/10 a during 1980—2014. The main land use types in the study area include cropland, forest, shrub and grassland. Between 1980 and 2010, the size of cropland increases while forest slightly declines, which result ed in the increase of the reservoir inflow. [Conclusion] Climate change is the main cause of the reservoir inflow variation, and the autumn inflow is the most sensitive in the historical change scenarios. Changes in temperature and precipitation are not linearly related to the inflow amount, either jointly or individually. The average monthly inflow decreases by 0.636 million m³ with the temperature increase of 1℃, and increases by 4.234 million m³ with 10% increase of precipitation.

Keywords

climate change / land use change / reservoir inflow / SWAT model / Songhuaba basin