锡林河流域积雪时空特征及其对径流的影响

寒旱区草原流域地表水资源极为匮乏,融雪径流是寒旱区草原流域重要的水源,冰雪融化对河川径流有着十分显著的影响。利用锡林河流域水文站2000—2013年逐日径流数据、锡林浩特气象站2000—2015年逐日平均气温、降雨、雪深数据及MOD10A2积雪产品数据,分析了锡林河流域积雪面积、雪深年际变化特征,气象因子与积雪面积、雪深之间的相关性,以及径流的影响因素。结果表明:研究区积雪面积、雪深年内变化呈单峰型,冬季积雪面积、雪深均达到最大值,春秋次之,夏季最小。在年际变化上,积雪面积、雪深总体呈现增加趋势,其中冬季的积雪面积呈显著性增加。通过研究区气象因子与积雪的相关性表明,在积雪期,气温、风速和日照时数是影响雪深和积雪面积的主要因素,而在融雪期,气温与降水是影响雪深和积雪面积的主要因素。对径流影响因素的分析可得,气温对径流的影响最大,并且积雪面积、雪深与径流之间也存在很强的相关性,说明积雪的变化也会对径流产生影响。研究积雪动态变化及其对径流的影响对寒旱区草原流域水资源管理、农牧业发展和灾害防御具有重要的现实意义。

Temporal and Spatial Variations of Snow Cover and Its Impact on Runoff in Xilin River Basin

The snowmelt runoff is an important water resource in the steppe basin in the cold and arid region.The melting of snow and ice has a significant influence on the runoff.We used daily runoff data from 2000 to 2013 for hydrological stations in the Xilin River Basin,average daily temperature,rainfall,snow depth data in Xilinhot Meteorological Station from 2000 to 2015 and MOD10A2 snow product data,to analyze the characteristics of snow cover and snow depth in the Xilin River Basin,the correlation between meteorological factors and snow cover,snow depth,and the influencing factors of runoff.The results show that the snow cover area and snow depth in the study area are single peaks,in winter,snow cover and snow depth all reached the maximum,followed by spring and autumn and minimum in summer.With respect to the interannual changes,the snow area,snow depth showed an overall increasing trend,in which the snow cover area of winter increased significantly.The correlation between the meteorological factors and snow cover in the study area shows that the main factors affecting the snow depth and snow cover are the temperature,wind speed and sunshine duration during the snow cover,in the snowmelt period,the temperature and precipitation are the main factors affecting snow depth and snow cover.The influence of air temperature on runoff is the most significant,and there is also a strong correlation between snow cover,snow depth and runoff,which indicates that the change of snow cover also affects the runoff.It is of great significance to study the dynamic change of snow cover and its influence on the runoff in the grassland drainage area of the cold and arid region,water resources management,agriculture and animal husbandry development and disaster prevention.