沱江流域水文对全球气候变化的响应

本文研究了全球气候变化对沱江流域水文的影响。根据流域水量平衡模型和未来气候情景对水量平衡各分量的可能变化进行了计算。结果表明；径流对气温变化不敏感，但对降水变化十分敏感；降水变化±１０％将引起径流量±３５％左右的变化；此外，径流年内分配亦发生了明显的变化。这将对沱江流域未来水资源计划与管理带来一定程度的影响。

IMPACTS OF CLIMATIC CHANGES ON HYDROLOGIC BALANCE IN TUOJIANG BASIN, SICHUAN PROVINCE, CHINA

Impacts of climatic changes due to CO 2 doubling on hydrologic balance in Tuojiang Basin, Sichuan Province are studied in this paper. A monthly water balance model is developed. Based on the recent study about relationships between flux and profiles over rough vegetated surfaces, Penman Monteith equations is rededuced in order to analyze the error when it is used to calculate evapotranspiration of high vegetation covered area. With the water balance model, monthly evapotranspiration, soil water content, surface runoff, ground runoff are calculated. Scenario based on NCAR CCM Outputs is selected. For the sensitive study, hypothetical scenarios based on OSU, GISS, GFDL and UKMO GCMS outputs are also selected. Impacts of climate changes on magnitude and timing of hydrological elements are estimated. Sensitive studies with the hypothetical scenarios show that runoff is not sensitive to temperature changes but sensitive to precipitation changes. Temperature increases 2~4 degrees, runoff only decreases 5%~10%. While precipitation changes 20%, runoff changes about 35%~40%. With the NCAR CCM Scenario, seasonal distributions of hydrologic elements changes obviously.