根河流域1980-2017年气候和径流的变化特征分析

根河流域处于我国寒温带地区,气候和自然环境较为特殊,分布着大面积冻土,对于气候变化非常敏感。【目的】通过分析根河流域气象要素和径流的变化,探讨气候和水文之间的相互关系,为该流域的水资源科学管理提供理论依据。【方法】以额尔古纳水系根河流域为研究对象,利用M-K检验和Hurst指数等方法,分析根河流域1980-2017年气象要素和径流的变化趋势及相互作用关系。【结果】①根河流域年平均气温在1980―2017年,共上升了1.10℃,在α=0.01的水平上呈上升趋势,且上升趋势有较强的持续性(H=0.75)。其中,生长季的气温变化最为强烈(Z=4.63)。②根河流域生长季降水量占年降水量的85%,趋于下降趋势,下降幅度为1.68 mm/a。③根河流域始冻期和完全冻结期的空气相对湿度分别α=0.001和α=0.01的水平上显著下降,且下降趋势有很强的持续性(H=1.0),变化幅度为0.05%/a。④根河流域径流量趋于下降趋势,在1997年和1999年发生突变,不年降水量发生突变的时间基本吻合,且降雨不径流的变化趋势一致,相关性分析表明,降雨不径流的相关系数为0.91。⑤根河流域径流量不年均气温相关系数为0.50,气温主要以增加流域各因子的蒸散发以及土壤和河流冻结、融化的时间或面积来影响流域径流量。【结论】根河流域降水量和径流在1980―2017年没有很大的变化趋势,气温呈猛烈的上升趋势,流域气候整体上趋于夏季越来越干冷,冬季干热的趋势。

Analysis of Climate and Runoff Variation Characteristics in the Genhe River Basin from 1980-2017

Climate change has a major impact on human life and economy, such as melting glaciers, changing vegetation, ocean acidification, and forest line backwardness. Water resource is the basic natural resource of a country, which can maintain the ecological balance and is an important factor to measure the comprehensive national strength. River runoff is an important part of hydrological cycle and water resources system. Under the background of global warming, the change of gas phase factor and runoff in the root river basin is studied to reveal the change law of climate and runoff in the basin and its interaction mechanism, which can provide a basis for the study of permafrost change, vegetation change and evapotranspiration in the basin. Located in the cold temperate zone of China, Genhe River basin has a special climate and natural environment, with a large area of frozen soil, which is very sensitive to climate change.【Objective】The relationship between climate and hydrology is discussed by analyzing the change of meteorological elements and runoff in the Genhe River basin, which will provide a theoretical basis for the scientific management of water resources in the basin.【Method】In this paper, the Erguna River basin was taken as the research object, and m-k test and Hurst index were used to analyze the change trend and interaction relationship between meteorological factors and runoff in the Erguna River basin from 1980-2017.【Result】①The average annual temperature in the Genhe River basin increased by 1.10 ℃ between 1980 and 2017, and tended to rise at the level of alpha α=0.01, with a strong persistence(H=0.75). In the growing season, the temperature variation was the strongest(Z=4.63). ②The precipitation in the growing season of the Genhe River basin accounts for 85% of the annual precipitation, and tends to decline, with a decreasing range of 1.68 mm/a. ③ The air relative humidity in the initial freezing period and the complete freezing period in the Genhe River basin decreased significantly at the levels of alpha α=0.001 and 0.01, and the trend of decrease was very persistent(H=1.0), with a range of 0.05 %/a. ④The runoff in the Genhe River basin tended to decrease, and the abrupt change occurred in 1997 and 1999, which was basically consistent with the abrupt change of annual precipitation, and the variation trend of rainfall and runoff was consistent. According to the correlation analysis, the correlation coefficient between rainfall and runoff was 0.91. ⑤The correlation coefficient between the runoff in the Genhe River basin and the average annual temperature was 0.50. The runoff in the river basin was mainly affected by the increase of evapotranspiration of various factors in the basin, as well as the freezing and thawing time or area of soil and river.【Conclusion】The precipitation and runoff in the Genhe river basin did not change significantly from 1980―2017, while the temperature showed a violent rising trend. The overall climate in the basin tended to be drier and colder in summer and drier and hotter in winter.