【摘要】 以三江平原挠力河上游流域为研究对象,选择年均流量和洪峰流量两个水文参变量,对流域降水、耕地面积和各水文参变量的统计回归分析,分别建立水文过程的单因素模型,用于分析气候变化、土地利用变化对水文过程的影响。在定量区分土地利用变化和气候变化的水文效应基础上,利用最小二乘法建立基于降雨量和耕地面积两种因素的流域水文过程驱动力模型。研究结果表明:(1)1956-1975年间降雨量对水文过程的影响非常显著,之后影响逐渐降低,总体上为气候模型对年均流量的模拟能力高于洪峰流量;(2)流域耕地面积,自1954年以来不断扩张,但未对水文过程产生显著影响,对洪峰流量的影响高于对年均径流的影响;(3)研究区的水文过程驱动力模型的模拟效果较好,相比单因素模型,年均流量和洪峰流量的模拟精度均得到较大提高,RMSE分别为0.5和1.04;对年均流量的模拟精度更高一些,决定性系数为0.933;(4)总体上,研究区水文过程受气候变化的影响程度高于土地利用变化,但土地利用变化对水文过程的影响不容忽视,尤其是对洪峰流量的影响呈增大趋势。更多还原

【Abstract】 During past five decades,land use and climate changed substantially in upstream basin of the Naoli River,Sanjiang Plain,resulting in huge hydrological changes accordingly.However,quantitatively distinguishing the hydrological responses to each factor-land use change and climate change,is not an easy issue.In this paper,the impacts of land use and climate change to hydrology in this region were assessed.First,based on the hypothesis of one factor changes slightly,we built the functions that hydrological processes responses to land use and climate change separately and forecasted the hydrological change resulting from cropland change and climate change respectively.Second,the impact of each factor to hydrologic change was quantitatively distinguished and then the hydrological processes driving force model was built based on precipitation and cropland area through least square arithmetic.Last,we gave a forecast model of hydrological processes with both natural and anthropogenic factors.The results showed that between 1956 and 1975,climate had a strong effect on hydrological processes.However,after 1975 the influence decreased gradually.Taking one with another,climate model behaved better to simulate annual average discharge than to simulate the peak discharge.Furthermore,cropland expansion that has being done since 1954 did not bring on significant change to hydrological processes.But comparing with annual average discharge,land use change impacted peak discharge more.Hydrological processes driving force model in this study was fairly ideal and it gave the modeling errors of 0.5 and 1.04,indicating the precision improved highly,which,was in contrast to a single factor model.In addition,the dynamic model performed more suitable for annual average discharge whose precision improved more with the R2 of 0.933.As a whole,hydrologic processes in the basin were mainly affected by climate change,while the effect of land use change was weaker relatively but unneglectable,especially,effect to peak discharge is increasing.更多还原