[关键词]
[摘要]
径流变化归因分析对流域水资源管理与可持续利用具有重要参考价值。利用1964-2015年汉江流域气温、降雨和径流等资料,采用线性倾向估计与滑动平均法分析白河和沙洋站水文气象要素的变化趋势,通过Mann-Kendall检验和Pettitt检验确定2个站径流序列的突变年份,基于Budyko水热耦合平衡理论,计算径流量对各影响因子的弹性系数,并采用互补关系法进行归因分析。结果表明:(1)白河与沙洋站年径流量均呈现下降趋势,变化速率分别为-1.653亿m3/a和-2.702亿m3/a,并在1991年发生突变;(2)白河与沙洋站变化期(1992-2015年)降雨、潜在蒸散发和下垫面的弹性系数分别为1.79、-0.79、-0.64和2.07、-1.07、-0.71,表明2个站的径流量均对降雨最为敏感,对下垫面最不敏感;(3)下垫面变化是汉江流域径流量减少的主要因素,其对白河、沙洋站径流量变化的贡献量分别为74.67%、76.37%;(4)变化期的NDVI较基准期整体增加,植被变化是导致汉江流域径流量整体下降的重要原因。
[Key word]
[Abstract]
The analysis of the attribution of runoff changes has important reference value for the management and sustainable utilization of water resources in the basin. Using the data of temperature, rainfall and runoff in the Han River Basin from 1964 to 2015, the linear trend estimation and the moving average method were used to analyze the change trends of hydrometeorological elements at Baihe and Shayang stations. Mann-Kendall test and Pettitt test were used to determine the abrupt change years of runoff series at the two stations. Based on water-energy balance equation within the Budyko hypothesis, the elastic coefficient of runoff on each influencing factor were calculated, and the complementary method is used for attribution analysis. The results showed that: (1) The annual runoff from Baihe and Shayang stations showed a decreasing trend with a rate of -165.3 million m3/a and -270.2 million m3/a, respectively, and a abrupt change occurred in 1991; (2) During the change period of Baihe and Shayang stations (1992-2015), the elastic coefficients of rainfall, potential evapotranspiration and underlying surface were 1.79, -0.79, -0.64 and 2.07, -1.07, -0.71, respectively, indicating that the runoff of the two stations were both the most sensitive to rainfall, the least sensitive to the underlying surface; (3) The underlying surface change was the main factor of runoff reduction in the Hanjiang River basin, and its contribution to the runoff change of Baihe and Shayang stations was 74.67% and 76.37% respectively; (4) The NDVI of the change period increased as a whole compared with that of the base period, indicating that vegetation change was an important reason for the overall decrease of runoff in the Hanjiang River Basin.
[中图分类号]
[基金项目]
国家重点研发计划项目 (2016YFA0601703, 2017YFC0405603) ; 国家自然科学(51709151); 宜昌市自然科学研究项目 (A21-3-004)