干旱对地表水体水质的影响研究进展

Progresses on the Study of Drought Impact on Surface Water Quality

干旱的发生不仅对地表水资源数量产生影响,也会对其水质产生影响。干旱期,在温度升高与河道流量减少的共同作用下,地表水体水质呈恶化趋势。不同区域干旱期间的地表水水质受土地利用、区域气候和自然地理属性与人类活动的影响,具有一定的差异。面源污染是当前流域水质恶化的主要因素。面源污染物的入河时间及含量,是干旱影响地表水体水质的关键要素。由于干旱期间面源污染物的积累,旱后的强降水过程,使得面源污染物被大量冲刷进入水体,地表水体的水质急剧恶化,因此,干湿交替的情景对水质的影响更为突出。

As the occurring frequency and intensity of drought is in increase, drought affects both water volume and water quality. Considering from the drought impact to environment, drought events are considered to be more dangerous due to their moderate-term, long-term and large-scale impacts. The joint effect of temperature increase and runoff volume reduction results in a deterioration of water quality, and water quality during drought period is al- so affected by land use change, regional climate change and human activities. Non-point source pollutant is cur- rently the main factor resulting in water pollution in drainage basin, and the entering time and content of non-point source pollutants are the main factors polluting waters during drought period. A lot of non-point source pollutants are eroded into waters due to the accumulation of pollutants during drought period and the increase of precipitation intensity after drought. Therefore, drought-rewetting cycles may impact water quality more significantly.