摘要
河川径流量和水位变化是反应气候变化和人类活动的重要表征,对其长期变化规律的研究结果可为该区域的水资源管理与洪水灾害风险研究提供重要的参考.本文选择频受洪水严重威胁的湘江流域为研究对象,利用近30年的径流量和水位观测的日资料及派生出的月、季和年资料,采用Mann-Kendall趋势检验法对湘江流域主要水文站的径流和水位进行了趋势分析和突变检验,并从气候变化和人类活动两方面分析其造成洪水危险性增大的原因.结果表明:(1)近30年来,湘江流域中下游的年径流量表现出增大趋势,而多数站点年最大径流量变化不大;(2)湘江流域径流的季节变化明显,多数站点春、冬季径流量没有明显变化趋势,但夏、秋季径流量呈显著上升趋势,这与夏季降水量的增大有关;(3)湘江流域7月和8月径流量呈增大趋势,5月份径流量呈减少趋势,7、8月径流量的突变点与夏季降水突变时间基本吻合,由降水变化导致径流增加的贡献率达57%以上;(4)湘江流域多数站点年平均水位和年最高水位均呈现显著的上升趋势.对比湘江流域年径流量,年平均水位的增长趋势更为明显,这可能是由于植被破坏,水土流失严重造成的淤积所致.
Trends of runoff and water level are significant indicators reflecting climate change and human activities.Therefore study on trends of these hydrologic variables can provide references for water resource management and flood risk analysis.Based on the site data of daily runoff and water level as well as the derived annual,seasonal and monthly time series data over the past thirty years,a non-parametric statistical method（Mann-Kendall trend test） is employed to detect trends and change-point of runoff and water level in the Xiang River basin where the threat of flood hazard is often high.The results shows that：（1） Annual runoff in the middle-lower reaches of Xiang River demonstrated an increasing trend,while a general absence of clear trend is noted for annual maximum runoff at most stations;（2） Seasonal runoff in Xiang River basin is changing.Although there is no clear trend for runoff in spring and winter at most stations,runoff in summer and autumn exhibits strong increasing trends,which is caused by the increasing precipitation in summer;（3） For monthly flows,runoff in July and August exhibits increasing trends,while in May exhibits decreasing trends.The change point of runoff in July and August almost coincide with the sudden change in summer precipitation,and precipitation has contributed about 57% of increase in runoff;（4） Both Annual water level and annual maximum water level at most gauging stations in the Xiang River basin demonstrate strong increasing trends.Comparing to annual runoff,the trend of annual mean water level is more pronounced,which may have resulted from the destruction of vegetation cover,and the deposition of mud and sand in river channels.
出处
《应用基础与工程科学学报》
EI
CSCD
2010年第3期369-378,共10页
Journal of Basic Science and Engineering
基金
国家自然科学基金重点项目(40535024)
高等学校学科创新引智计划资助(B08008)
