气候变化和人类活动对洮儿河中上游地区水分适宜性影响分析

摘要

Due to the impact of climate change and human activities, the upper and middle reaches of the Tao’er River have become an ecologicaly sensitive area in Northeast China. It is important to evaluate the contributions of climate change and human activities to water suitability in the Tao’er River area. From the perspective of water and heat balance, the water suitability index (cr) was used to analyze the water suitability of the upper and middle reaches of the river. The nonparametric Mann-Kendall, moving t-test and cumulative anomaly methods were used to detect abrupt changes in Taonan station runoff from 1961 to 2012. Three inflexion years were detected. Thus, the entire time period was divided into four periods: 1961–1974, 1975–1983, 1984–1998, and 1999–2012. In order to estimate the impacts of climate change and human activities on runoff, the slope change ratio of cumulative quan-tity (SCRCQ) was adopted. Finaly, the contribution of climate change and human activity tocr was transformed from the contribution of climate change and human activity to runoff by the sensitivity coefficient method and SCRCQ method. The results showed that the water suitability index (cr) had a decreasing trend 1961–2012. Fac-tors influencing cr, such as net radiation and runoff, also exhibited a decreasing trend, while precipitation exhibited an increasing trend over the past 52 years. The trends of cr, net radiation and runoff were obvious, which passed the Mann-kendal test of significance ata=0.05. Human activities were the main factors that affected runoff, al-though the degree of impact was different at different times. During the past 52 years, the biggest contributor to the change incr was precipitation.%自20世纪60年代以来，由于气候变化和人类活动的影响，洮儿河中上游地区出现了湿地退化、水土流失等严重的生态环境问题，成为我国东北典型的生态敏感地区。本文从水热平衡的角度，利用水分适宜性指数（cr），分析了洮儿河中上游地区1961–2012年的水分适宜性，采用Mann-Kendall法、滑动t检验和累积距平方法检测了径流突变点，以突变点为界，把整个研究时期划分为四个阶段，采用累积量斜率变化率分析法（SCRCQ）分析了不同阶段气候变化和人类活动对径流量的影响，最后利用敏感系数法和SCRCQ方法相结合，把气候变化和人类活动对径流量的影响转化为对cr变化的贡献。研究结果表明：近52年以来，洮儿河中上游地区水分适宜性指数（cr）呈减小趋势，其影响因子净辐射、径流量也呈现减小趋势，降水量呈现增加趋势，其中只有降水量变化趋势不显著，没有通过a=0.05的 Mann-Kendall 显著性检验；1961–2012年间，洮南站径流量发生了三次突变，尽管每个阶段降水量和人类活动对径流量的影响程度不同，但人类活动是影响径流量的主要因子；52年以来，对 cr变化影响最大的因子是降水量，大于人类活动和净辐射对cr变化的贡献。