极端干旱条件下河道生态基流研究

A Study on River Ecological Base Flow in Extremely Dry Conditions

近几十年来,随着全球气候的变暖,极端天气气候事件的发生频率在迅速增加,严重影响了人类的生存和社会的可持续发展。极端干旱事件对河流的生态系统健康有着极大的影响。保证极端干旱条件下的生态基流量,对维持物种的生存、保护和生物多样性具有重大的意义。以渭河宝鸡段为例,分别采用湿周法、Tennant和最小日平均流量法,计算了百年一遇的特大干旱年的生态基流量,参考渭河宝鸡林家村断面特大干旱1929年的逐日流量分析,最终得到渭河宝鸡林家村断面的生态基流量为2.51 m^3/s,该基流维持的时间为10 d。开展本次研究,不仅有重要的科学价值,而且为西北干旱地区的河流生态系统健康起到一定的指导意义。

In recent decades, with the global climate wanning, the frequency of extreme weather events is increasing rapidly, which seriously affects the survival of human beings and the sustainable development of society. The extreme drought events have a great impact on the ecosystem health of rivers. It is of great significance that maintaining the survival, conservation and biodiversity of the species to ensure ecological base flow in extremely dry conditions. Taking Weihe river of Baoji Section as an instance, Tennant and minimum daily mean discharge method are adopted to calculate ecological basic flow on the once- in-a-century drought. Referencing the daily flow analysis of Baoji Section in Wei river on the drought year of 1929, it is obtained that the ecological basic flow is 2.51 m^3/s and the duration time is 10 days. This study not only has important scientific value, but also plays a guiding role for the health of river ecosystem in arid areas of Northwest China.