安康水库蓄水前后上游气候变化特征

Characteristics of Climate Change in Ankang Reservoir Upstream Basin before and after Impoundment

利用陕西省安康水库上游气象站点的月及日降水、气温、蒸发等气候资料,分析了安康水库蓄水前后上游流域气候变化特征。分析结果表明,年降水量呈逐年代减少趋势,年平均温度呈增暖趋势,年蒸散量呈减少趋势;蓄水后年及主汛期降水量、雨日、暴雨日数、极端强降水概率、蒸散量均比蓄水前减少,平均气温比蓄水前升高,其中冬季升温幅度最大;主汛期和年降水量、平均气温蓄水前后差异显著,冬季蒸散量蓄水前后差异显著。近45年来汉江径流量呈下降趋势,降水对径流影响显著。

Based on the data of precipitation, temperature, evaporation, etc., from meteorological stations over the drainage areas of the Shaanxi Ankang Reservoir, an analysis is made of the characteristics of climate change over in the drainage areas of the reservoir. The results indicate that annual preeipitation reduced year by year; annual average temperature was increasing year by year; annual evapotranspiration had a negative trend; annual and main flood season precipitation, rainy days, heavy rain days, the probability of extreme heavy precipitation and evapotranspiration appeared much less after reservoir impoundment than before. The extent of warming in winter was most obvious. The main flood season and annual precipitation, average temperature, and evapotranspiration in winter before and after impoundment show significant differences. The natural runoff of the Hanjiang River had a negative trend in the past 45 years and rainfall influenced runoff significantly.