洮河红旗站年平均流量长期演变趋势分析

Analysis of Long-term Change Tendency of Average Annual Discharge at Hongqi Station on Taohe River

通过对洮河红旗站径流资料的分析得出:径流的补给来源主要是大气降水,径流与降水相应,主要集中在5～10月;由于流域下垫面条件不同,其产流模数在面上的分布有很大差异,岷县站以上流域植被条件好,其产水量随流域面积的增大而增大,岷县站以下流域植被条件差,水土流失严重,产水量随着流域面积的增大而减小。该站年平均流量持续减少,其原因既有降水量减少和气温升高的影响,又有流域内用水量不断增加的影响。预计该站年平均流量未来的演变趋势在近期均值112m3/s的上下摆动,2015～2020年在近期均值上可能出现丰水年组,2021～2027年可能出现枯水年组。

The analysis of the runoff at the Hongqi Station on the Taohe River has made the results as that the runoff supply source is mainly the atmospheric precipitation, the runoff and the precipitation is corresponding, mainly concentrates in the period from May to October. As the condition of underlying surface in the basin is different, the runoff yield modulus have very big difference on the surface distribution. There is a good vegetation above the Minxian Station, with the water yield increasing along with the basin area increase. There are bad vegetation and serious soil and water loss below the Minxian Station, with the water yield decreasing along with basin area increase. There is continuous reduction of average annual discharge at the station, of which the reasons are the influence of the precipitation reduction, air temperature rise, and water consumption increasing in the basin. It is estimated the change tendency of average annual discharge in future will swing around the value of 112 m^3/s in the short-term, wet year group may appear during the years from 2015 to 2020, and dry year group may appear during the years from 2021 to 2027.