大渡河流域积雪特征及其与气候要素和径流的关系

Characteristics of Snow Cover and Impact on Streamflow in the Dadu River Basin

利用MOD10A2遥感影像提取大渡河流域2010~2014年积雪覆盖数据,结合水文气象站点数据分析了大渡河流域积雪时空分布特征及气象因子-积雪面积-径流之间的关系。结果表明:年平均积雪面积最大的是康定,最小的是泸定。积雪在冬季最大,夏季积雪最少。积雪面积变化随月份起伏明显,积雪过程集中在10月到次年4月。降水和气温变化较一致,其峰值滞后于积雪面积峰值。积雪和气温、降水的相关性表明,积雪面积与气温、降水呈负相关,且气温与积雪面积相关性更大。径流的变化具有周期性,5月开始迅速增大,7月达到最大值。径流和积雪以及气象因子的相关性分析表明,径流与积雪面积呈负相关,与气温和降水都是正相关,且径流与降水相关性更大。

By using the snow cover data in the Dadu River Basin during 2010 ？2014 extracted by MOD10A2,and hydrog-raphic weather station data, the temporal and spatial distribution characteristics of snow cover in the Dadu River Basin as well as relationships among meteorological factors, snow cover, and streamflow were analyzed. The results showed that the largest annual average snow cover was Kangding, the smallest was Luding. The largest snow cover was in winter, and smallest in sum-mer. Snow cover changed obviously with the ups and downs of the month. The snow cover was concentrated from October to next April. Precipitation changed coincident with temperature, and the peak value lagged behind the peak of snow cover. The correlation between snow cover, temperature and precipitation indicated that the negative correlation with temperature and pre-cipitation. And the correlation between temperature and snow cover was larger. The streamflow changes were cyclical, in-creased rapidly in May and reached maximum in July. The correlation between streamflow, snow cover and meteorological fac-tors indicated that the negative correlation with snow cover, and the positive correlation with temperature and precipitation. And the streamflow was more sensitive to precipitation.