摘要
20个世纪60年代以来,鄱阳湖流域径流呈现出增加趋势,特别是1990年代流域径流增加显著,与该时期多次出现洪水灾害事件密切相关.运用Mann-Kendall检验法对1961—2000年流域径流序列进行突变分析,结果显示1992年附近是流域径流突变发生的拐点.基于径流对降雨和潜在蒸散发的敏感关系,以1961—1991年为基准期,定量分析了1992—2000年流域气候变化和人类活动对天然径流的影响分量.结果表明:相对于1961—1991年,1992—2000年多年平均径流量增加211.7mm,其中气候变化引起的增量为282.2mm,人类活动引起径流减小70.6mm,分别占多年平均径流变化量的133%和-33%.不同子流域间,气候变化和人类活动对径流的影响分量相差较大.气候变化因子中,流域降水量的增加,特别是夏季暴雨频率的增加,是引起1990年代鄱阳湖流域径流显著增大的主要原因,其次是蒸发量的长期下降.人类活动对鄱阳湖流域径流起着减流的作用,主要是由于流域内工农业的快速发展,大量水利工程设施的存在提高了水资源的利用程度;另一方面,1990年代流域水土流失状况的有效缓解,有助于增加流域的贮水能力,减小径流.
Runoff in Poyang Lake catchment has presented a long term increasing trend since the 1960s. Especially in the 1990s, runoff increased significantly, which might be responsible for the frequent floods in the catchment. Variation of runoff is resulted from combination of climate change and human activities. Assessing the impact of climate change and human activities on runoff is very important for catchment management and ecological protection. Mann-Kendall rank test is used to detect the change point of annual runoff for the period of 1961-2000, and a change point around 1992 is found. From this point, a method based on a framework of the sensitivity of annual runoff to precipitation and potential evapotranspiration was employed to estimate the impact of climate change and human activities on the change of runoff.Compared to the baseline period of 1961-1991, climate change did a dominant contribution of about 133% to the increase of runoff in 1992- 2000, while human activities account for 33% of the reduction in mean annual runoff. For different subcatchments, climate change and human activities show a significantly different impact on runoff. For climate change, increase of precipitation, especially the increasing frequency of summer storm, was the major reason for the significant increase of runoff in the 1990s; also the long-term decrease of evapotranspiration elevated this effect. Human activities such as construction of reservoirs and irrigation works increase water consumption. Also the implementation of soil conservation and recovery of forest in the catchment in the 1990s had some effects on reduction of annual runoff.
出处
《冰川冻土》
CSCD
北大核心
2009年第5期835-842,共8页
Journal of Glaciology and Geocryology
基金
中国科学院知识创新工程重大项目(KZCX2-YW-337
KZCX1-YW-08-01)
国家自然科学基金项目(40871026)资助
关键词
径流变化
气候变化
人类活动
鄱阳湖流域
runoff variation
climate change
human activities
Poyang Lake catchment
