气候变化对黄河上游天然径流量影响分析

Analysis on the Effects of Climate Change on Natural Runoff Volume in the Upper Reaches of the Yellow River

根据黄河上游兰州以上地区1959-2002年历年逐月气温、降水量资料,统计分析了近44年区域气候变化的基本特点,同时通过对各站气温、降水量与兰州站年天然径流量相关系数的计算,选取代表站及典型时段,建立天然径流量计算公式,并计算分析了天然径流量对气候变化的敏感性及气候变化对径流的影响程度。结果表明:(1)年径流量随降水的递增而加大,随气温的升高而减小;(2)径流量对降水变化的响应较其对气温变化的响应更显著;(3)20世纪90年代以来,气候变化对天然年径流量的影响较显著,其影响幅度达13.2%。

The catchment area of upper reaches of the Yellow River upstream from Lanzhou is 2.225 5×105 km2, which occupies 28% of the total area of the Yellow River Watershed. The average annual natural runoff volume of the Yellow River at Lanzhou Hydrological Station was 3.32×1010 m3 during the period from 1959 to 2002, which occupied 60% of the total annual runoff volume of the river, so the upper reaches are the main areas of runoff formation and water conservation in the Yellow River Watershed. In this paper, the climate change characteristics in the upper reaches of the Yellow River in recent 44 years are analyzed using the data of monthly temperature and precipitation during the period from 1959 to 2002. The correlation coefficients between the annual air temperature and precipitation at each meteorological station upstream from Lanzhou and the annual natural runoff volume at Lanzhou Hydrological Station are calculated. After selecting the representative stations and the typical periods of time, the equation of calculating the natural runoff volume is developed, and the sensitivity of natural runoff volume to the climate change and the effects of climate change on the runoff volume are analyzed. The results are as follows: (1) Annual runoff volume of the Yellow River is increased with the increase of precipitation but decreased with the increase of temperature; (2) The response of the annual runoff volume to precipitation change is more significant than that to temperature change; (3) The effect of climate change on annual natural runoff volume has been significant since the 1990s, and the affecting scope is 13.2%.