近50a来青海水文要素变化特征分析

对青海省境内降水、径流、水面蒸发站观测资料的分析,结果显示年降水量在昆仑山、巴颜喀拉山、达板山以北,阿尼玛卿山、日月山以西的地区呈增加的趋势,且以柴达木盆地增幅较大,以东的黄河流域降水略有减少;以南的长江流域变化趋势不明显.年径流量在柴达木盆地南部、昆仑山北麓呈较明显增加的趋势,盆地北部诸河、长江流域、大通河变化趋势不明显,其它地区包括青海湖、黄河及其支流(不含大通河)呈减少的趋势.水面蒸发量除个别站点外,呈明显下降的态势,而且减幅较大,下降的幅度西部地区大于东部地区.与此对应是全省的干旱指数明显变小,湿润程度有所增加.

Hydrological Elements Change of Qinghai Province in Past 50 Years

By use of gauged data series of representative stations, the evolution characteristics of precipitation, runoff and evaporation of Qinghai Province in past 50 years are analyzed and following conclusions are reached: 1) Precipitation in the area to the north of Kunlun Mountain, Bayan Har Mountain and Daban Mountain obtained presents an increased trend, precipitation on the west of A’Nyêmaqên Mountains and Riyue Mountain with Qiadam Basin have the greatest increase, and the result show the changes of precipitation have not the clear trend in other regions except Huanghe Basin which experienced a minute trend of decrease in precipitation; 2) Runoff in the south of Qiadam Basin present a trend of increase, runoff in Qinghai Lake Basin and Huanghe Basin except one of its branch Datong River present a trend of decrease, and no clear trend in other area; 3) Water surface evaporation, besides one station (Qiaotou Station) in Huanghe Basin, almost all increased everywhere in past 50 years; 4) Because of the lack of gauge stations in mountain areas and the violent spatial variance of water balance factors, we should set more gauge stations in mountain areas to get more detail information and make the change characteristic of water balance factors more clear.