| The Arid region of China (includes xinjiang province, Hexi Corridor of Gansu province, Qaidam basin and the west of Helan Mountain), with drought climate and strong wind, is the most rigorous region of eco-environmental problems. Vegetation succession and oasis development are controlled by water resource within the region. However, in recent decades, the unprecedented magnitude and rates of water cycle change, along with other environmental changes, lead to serious imbalance between human and natural. In order to balance the water requirements between human and natural, and accomplish sustainable development in inland basin, an integration of regional climate model, basin-scale hydrological model, ecosystem model and economic system model is needed.In this research, I chose Qilian Mountain in arid region of China as study area to analyze the 40 years (1960-2000) temporal trend of temperature, precipitation and runoff, related works mainly conducted at upper reaches of three inland river, which are Shule river, Heihe river and Shiyang river. After that, I studied the relationship between runoff variation and climate change. Subsequently, the SWAT model was employed to simulate the water balance at upper reach of Heihe river basin. Finally, I tried to coupling climate model with hydrological model, output data of regional climate model (RegCM3) was used as input data of SWAT during this procedure. Since the integration of regional climate model and regional hydrological model is a key issue in studies related to eco-hydrology synthetical research, so this study can provide useful reference for concerned problems.Some conclusions can be draw from this research:1) An increasing trend of annual precipitation can be detected at north-facing slopes of all the three basins, but the significances and variation periods are different. In general, mean annual temperature displays a significant increasing trend at three basins. Also, a good consistence of heating can be found. Variation trends and periods of mountainous runoff in these basins are different. Grey relation analysis showed that relationship between changes of runoff and temperature-precipitation are different among basins.2) SWAT model have high sensitivity for base flow coefficient (Alpha_Bf), the temperature laps rate (Tlaps), SCS runoff curve number (CN2), threshold water level in shallow aquifer for base flow (Gwqmn), the maximum canopy storage capacity (Canmx) and soil evaporation compensation coefficient (Esco). After calibrating the model parameters use observed data, the Nash-Suttcliffe coefficient reached 0.75 and coefficient of determination reaches 0.86 during calibration stage. The Nash-Suttcliffe coefficient and determination coefficient reached 0.64 and 0.87 in validation stage.3) Comparison between output of regional climate model and observed data showed that, for simulation of temperature, RegCM3 displayed the best performance, following with precipitation and relative humidity, the worst is for the wind speed. Output of RegCM3 was inputted to SWAT model for the simulation of runoff, related Nash-Suttcliffe coefficient and determination coefficient are 0.29 and 0.69, indicated failure of coupling between RegCM3 and SWAT. In future works, improvement of RegCM3 results is needed, meteorological station observed data would still be the better input for SWAT. Keywords:climate change Qilian Mountain upper Heihe River runoff simulation SWAT RegCM3... |
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