近期黄河来水特点与历史典型枯水时段对比

Comparison on the Characteristics of the Yellow River Water Amount in Recent Period and the Historical Typical Dry Periods

20世纪90年代以来,黄河来水量总体呈偏枯态势。自1990年至2011年的22 a花园口水文站多为偏枯与枯水年份,间有平水年,多数年份与上游龙羊峡水文站枯与偏枯性质同步,但有个别年份下游偏枯而上游偏丰,这有利于上游大型水库蓄水进行多年调节,以丰补欠,满足全河工农业及生态用水。1994—2002年为连续9 a枯水与偏枯时段,与历史上1922—1932年连续11 a枯水时段相比较,在枯的程度与年数上1922—1932年更为严重,因此应作好遭遇更长连续枯水段的水量调度预案。

Since 1990s,the Yellow River water amount has shown partial dry trend in general. Dry years and partial dry years mostly occurred at Huayuankou Hydrological Station within the 22 years from 1990 to 2011,sometimes normal years occurred. The characteristics of day years and partial dry years in most years were synchronized with Longyangxia Hydrological Station in upper reaches,but in specific years partial dry years oc-curred in lower reaches,meanwhile wet years occurred in upper reaches,which was propitious to multi-year regulation of large-scale reservoirs in upper reaches to supplement water shortage and satisfy agricultural and ecological water demand. Dry period and partial dry period of continuous 9 years from 1994 to 2002 occurred. Compared with the historical continuous dry period of 11 years from 1922 to 1932,the dry degree and duration of the latter was more severe. Therefore water regulation pre-arranged plan should be prepared to prevent longer continuous dry period.