岷江镇江关流域分布式水文及泥沙侵蚀模型研究

Distributed hydrological and sediment erosion model with its application to Zhenjiangguan watershed in Minjiang River basin

基于空间地理信息系统的流域分布式水文泥沙模型为研究流域产流产沙及在河道中的汇流、输移过程提供了科学有效的手段。针对岷江上游镇江关流域土壤易受降雨侵蚀的问题,采用水沙耦合的流域分布式水文综合模型,对该流域1990年后典型年的径流及泥沙侵蚀输移过程进行了数值模拟,并结合镇江关水文站的实测资料对模型进行了验证,计算成果令人满意。分析表明,近年来岷江上游地区的年径流和输沙量均呈现出下降的趋势,且后者下降速率更快,说明泥沙侵蚀输移与径流相比对流域环境变化的反应更为敏感,今后水土保持工作应注重坡面治理。

Distributed hydrological model based on spatial geographic information system provides an effective way of simulating flow/sediment yield on the slope and runoff/suspended-load transport in a channel.The integrated model,coupled with a sediment simulating module,was established and applied to Zhenjiangguan watershed in the upper Minjiang River basin, focusing on the erodible soil there.Measured data of runoff hydrograph and soil erosion from five typical years were used to calibrate and verify the model.Verification showed that the simulation result was reliable.Analysis also indicated that during the past decade the annual runoff and sediment delivery both decreased,and that the latter dropped more sharply because of its sensitiveness to soil and water conservation practice in the watershed.Regional work on soil and water conservation should lay more stress on slope control.