1960-2019年鄱阳湖五河流域陆地水储量变化及其对主湖区水量的影响

Spatio-temporal variations of terrestrial water storage in the five rivers of the Lake Poyang Basin and its impact on lake water volume during 1960-2019

流域内地表水、土壤水和地下水等水储量组分相互作用和影响,共同构成了陆地水储量(TWS)的动态变化格局。本文以GRACE卫星数据为基准,利用GLDAS数据解析1960-2019年鄱阳湖“五河”流域TWS的时空变化特征及各组分对其变化的贡献,采用相关分析方法分析TWS对降水的滞后响应关系,并进一步采用多元线性回归分析方法探究了“五河”流域TWS及各组分对鄱阳湖主湖区水量的影响。结果表明:“五河”流域年TWS在1960-2011年(P1)以-0.07 mm/a的下降,而在2012-2019年(P2)以3.37 mm/a的速率上升。相较于P1阶段,P2阶段春、夏季TWS盈余增强,秋、冬季TWS亏损减弱。春、夏季流域西部TWS变化逐渐由地表水转变为地下水储量主导,流域东部TWS变化主要由地下水储量主导;秋、冬季流域TWS变化主要为地下水储量主导,且地表水对TWS变化的贡献减弱。流域TWS对降水变化的响应滞时呈现夏、秋季短(1个月)而冬、春季长(3~6个月)的季节模式。地下水储量和土壤水对TWS变化的贡献增加会延长TWS对降水的响应滞时,而地表水对响应滞时起相反的作用。“五河”流域TWS与鄱阳湖主湖区水量具有显著的正相关性,地表水和地下水储量增加对湖区水体的增长具有正向作用,而土壤水增加对湖区水体的增长具有反向作用。本研究解析了近六十年鄱阳湖“五河”流域陆地水储量的变化及其对主湖区水量的影响,可为流域水安全管理提供参考。

The interactions of water storage components within a basin,such as surface water,soil water,and groundwater storage,determine the dynamic patterns of terrestrial water storage(TWS).Using GRACE satellite data as a reference,this study estimated the spatiotemporal characteristics of TWS variations in the five rivers of the Lake Poyang Basin from 1960 to 2019 using GRACE satellite data.The lagged response of TWS to precipitation was examined through correlation analysis.A multiple linear regression analysis was used to investigate the influence of TWS and its components in the five rivers of the Lake Poyang Basin on the water volume of Lake Poyang.The results showed that annual TWS in the five rivers of the Lake Poyang Basin decreased at a rate of-0.07 mm/a between 1960 and 2011(P1),but increased at a rate of 3.37 mm/a between 2012 and 2019(P2).Compared with P1,P2 had an enhanced TWS surplus in spring and summer,and a weakened TWS deficit in autumn and winter.In spring and summer,changes in TWS in the western basin gradually changed from surface water-dominated changes to groundwater storage-dominated changes.In the eastern basin,TWS changes were primarily dominated by groundwater storage.During autumn and winter,changes in TWS in the basin were mainly driven by groundwater storage,and a reduced contribution of surface water to TWS changes.The response lag of TWS to precipitation in the basin exhibited a seasonal pattern,with short(1 month)in summer and autumn,and longer(3 to 6 months)in winter and spring.Increased contributions of groundwater storage and soil water to TWS changes prolonged the lagged response of TWS to precipitation,while surface water had the opposite effect on the lagged response.The TWS in the five rivers of Lake Poyang Basin showed a significant positive correlation with water volume of the main lake area of Lake Poyang.Concerning the major components of TWS,the increase in surface water and groundwater storage had a positive effect on the growth of the water volume of Lake,while the increase in soil water had a negative effect.This study provided insights into the changing characteristics of terrestrial water storage in the five rivers of the Lake Poyang Basin over the past six decades,offering valuable references for water resource management within the basin.