流域宏观尺度降雨-景观-径流变化的相互作用  

The Changes and Their Interactions of Precipitation-Landscape-Runoff in Jinghe Watershed

作　　者：谢高地[1] 甄霖[1] 陈操操[1] 杨丽[1] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101

出　　处：《资源科学》2007年第2期156-163,共8页Resources Science

基　　金：国家973项目:"西部典型区域森林植被对农业生态环境的调控机理"(编号:2002CB111506);国家自然科学基金项目:"北方小麦-玉米农田生态系统服务功能研究"(编号:30570303)

摘　　要：大流域宏观尺度上长时间序列的降雨变化、景观变化、径流变化及其相互作用是近年来研究全球变化的一个重要问题。本文研究泾河流域降雨-景观-径流变化的相互作用,结果表明:①泾河流域中上游主流域40多年来的降水具有微弱下降趋势,降雨倾向率为-4.9mm/10^-11.3mm/10年;泾河流域马莲河分流域,年降雨量表现为不变或微弱下降;②泾河流域1986年~2000年15年之间,景观结构变化不大,一直以草地景观和耕地景观为主。草地景观和农耕地景观二者始终占流域总面积的85%以上,林地景观始终占流域总面积的10%左右,其他景观类型一直占流域总面积的5%左右。在宏观景观格局的变化中,泾河流域中上游主流域,农耕地景观所占比例有所上升,而泾河流域马莲河分流域农耕地景观所占比例维持稳定;③泾河流域中上游主流域年径流量逐年较大幅度地减少,下降速度达到每10年减少1.78m3/s。在泾河流域马莲河分流域,年径流和径流模数在过去30年中基本维持稳定,整个泾河流域年径流量逐年下降;④相应年份内对应的径流和降雨相关性极为显著(P<0.01)。在泾河主流域中上游地区降水每减少10mm,径流可能相应减少70×108m3,在马莲河分流域地区每减少10mm,径流可能减少110×108m3。在泾河流域,若维持景观结构的稳定,则径流的变化趋势会与降雨的变化趋势保持一致。景观结构的微弱变化会改变径流对降雨响应的变化幅度。在景观组成中,耕地景观比例的增加会显著减少径流。The variation of precipitation, landscape patterns and stream runoff together with their interaction is an important issue in global change research in recent years. The paper investigates the interaction between variation of precipitation landscape patterns and runoff, and results show that： 1 ） Precipitation in upper-middle main Jinghe watershed over 40 years descends little, and the isograms of inclination rate of precipitation are between -4.9mm/10a to - 11.3mm/10a. However, precipitation in Malian river sub-watershed remains no change or drops weekly; 2 ） The landscape structure in the watershed does not change very much during 1986 to 2000, and grass land and arable land occupy more than 85% of the total watershed area. Forest and other land use occupy 10% and 5%. In the transformation of macro landscape structure, proportion of arable land in the upper-middle main Jinghe watershed increases, but arable land in the upper-middle Jinghe watershed of Malian river maintains stable; 3 ）Annual stream runoff in the upper-middle main Jinghe watershed declines obviously. The decreasing rate is 1.78m^3/s every ten years. In the upper-middle Jinghe watershed of Malian river, annual stream runoff and runoff modulus almost have no change during the last 30 years. But in the whole watershed the stream runoff decreases; 4 ）Correlation between the corresponding stream runoff and precipitation each year is significant （ P 〈 0.01）. In the upper-middle main Jinghe watershed, when precipitation reduces 10mm, relevant stream runoff may decline 70 × 10^8m^3. And in Malian river sub- watershed, the value is 110 × 10^8m^3. Therefore, if the structure of landscape patterns maintain unchanged, the trend of stream runoff and precipitation will be the same. Tiny variation in landscape pattern may lead to change extent of stream runoff which is in answer to precipitation. Furthermore, proportion of arable land increases in landscape patterns will reduce the stream runoff obviously.

关 键 词：泾河流域 景观变化 气候变化 径流变化 相互作用 

分 类 号：P426.6[天文地球—大气科学及气象学] P331[天文地球—水文科学]