气候变暖情景下黄河上游径流的可能变化

Possible Change of Runoff over the Upper Yellow RiverBasin under Global-Warming Scenarios

根据水文气象台站观测资料,分析了全球变暖情景下黄河上游唐乃亥以上流域温度、降水和径流的变化状况,并采用假定气候组合对未来数十年黄河上游唐乃亥以上流域的径流变化进行了预测.结果表明:黄河上游的温度与全球变暖有着明显的对应关系,近几十年来,流域各个地方的温度有不同程度的上升.降水变化因流域各地所处位置、地势、地形的不同而差异较大,受温度上升和主要产流区域降水大幅减少的影响,近10余年来黄河上游的径流量呈持续递减的态势.在未来几十年,如果遭遇到气温升幅与降水减幅较大的"暖 干"气候组合时,流域产水量将有较大的减幅;当气温变化不大而降水增幅较大时,流域产水量将有明显的增加,同时由于冰雪及冻土融水的补给,此气候情景下黄河上游唐乃亥以上流域径流量的增幅还将略大于降水量的增幅.

Characteristics, possible causes and trends of variations of temperature, precipitation and runoff in the upper Yellow River basin above Tangnag were analyzed, based on the hydrological and meteorological data for about 50-year at some observation stations. The results indicate that the variations of temperature in the basin possess an obvious relationship corresponding with global warming and temperature. Runoff in the upper Yellow River has been decreasing continually since the end of 1980s due to the rising temperature and the decreasing precipitation in the main areas of runoff formation. In the future decades, the runoff in the basin will largely decrease under the conditions of temperature rising obviously and precipitation decreasing greatly, whereas it will increase under the condition of temperature immovability and a great increase in precipitation, and the increase range of runoff may be more than that of precipitation because of the synchronously increasing supply of meltwater from snow, glacier and frozen soils.