气候变化对伊逊河流域水资源量的影响

Climate change and its impact on water resources in Yixun River basin

海河流域作为中国水资源最为紧张的流域,其水资源对气候变化非常敏感。以海河流域中受人类活动影响较小的伊逊河流域为对象,基于海河流域未来气候变化研究成果构建了20种气候变化情景,应用具有物理机理的分布式流域水文模型模拟了不同气候变化情景下的流域水循环情景,对气候变化对伊逊河流域水资源量的影响进行了分析,结果表明气温升高1℃将使流域内3.8mm的径流转化为蒸散发,降水的增加将使流域的蒸发和径流都有所增加,其中新增降水50%转化为蒸发,30%转化为径流。同时径流和蒸散发对于高温和强降水更为敏感。未来气候变化的不确定性使未来水资源量的变化也有很大的不确定性,在以升温为主、降水变化存在很大不确定性的情况下,伊逊河流域天然径流量可能进一步衰减。

In recent decades,the global climate has changed markedly characterized by the increasing temperature,and the water resources and the environment are all influenced significantly.Haihe River basin is one of the most intense river basins in water resources in China,and its water resources could be very sensitive to the climate change.In this paper,considering it is less affected by human activities,the Yixun River basin is used as the research region.Based on the previous studies in the context of future climate change in Haihe River,a total of twenty climate change scenarios are constructed.The Spatial Averaging Watershed Hydrological Model is used to simulate hydrological cycling under different climatic change scenarios in the Yixun River basin.The model is characterized as a watershed-scale distributed hydrological model.Climate change impacts on water resources in the basin are analyzed.Results show that the increase in runoff lost to evaporation could be as high 3.8 mm with a temperature rise of 1 ℃.The increase in precipitation could lead to the rise in both evaporation and runoff.Among those two,50% of the precipitation rise would be lost to the evaporation process,and the increase in runoff could be as high as 30% as the result.Both runoff and evaporation could be more sensitive to higher temperature and extreme precipitation.The runoff condition in the Yixun River basin could be further deteriorating under a changing climate that is characterized by rising in temperature and the uncertainty in precipitation trends.