青海地表水资源的变化及影响因子

通过分析近３８年青海省主要河流径流量及其流域降水、气温的变化趋势，着重研究了干旱气候对青海地表水资源的影响。结果表明，内陆河多为高山冰雪融水和雨水混合补给型河流，外流河多为以雨水补给为主的河流；青海地表水资源呈减少趋势，其减少趋势进入９０年代后尤为明显；气温和降水是影响青海地表水资源的主要气候因子，其中气温升高加剧了流域蒸发量的增大和干旱影响，减少了地表径流量；而９０年代以来降水量的减少特别是汛期降水量的减少直接影响到径流量的减少。

Variation of Surface Water Resource in Qinghai Province and Its Influent Factors

The variation tendency of river runoff,precipitation and temperature over drainage areas of the major rivers in Qinghai province was analysed by using nearly 38 years observative data.The Influence of dry climate on the surface water resource in Qinghai was mainly discussed.The results show that the inland rivers are mainly supplied by mountain snowmelt and precipitation,and the outflow rivers are mainly supplied by precipitation.The surface water resource in Qinghai tends to decrease and the tendency is more obvious after the 1990s.The temperature and precipitation are primary influent factors on the surface water resource of Qinghai province.Temperature increasing causes evaporation enhancement,drought aggravation and surface runoff reduction.Precipition decrease after the 1990s,especially during flood season,and it leads to a direct reduction of surface runoff.