MODIS observed snow cover variations in the Aksu River Basin, Northwest China

A major proportion of discharge in the Aksu River is contributed from snow-and glacier-melt water. It is therefore essential to understand the cryospheric dynamics in this area for water resource management. The MODIS MOD10A2 remotesensing database from March 2000 to December 2012 was selected to analyze snow cover changes. Snow cover varied significantly on a temporal and spatial scale for the basin. The difference of the maximum and minimum Snow Cover Fraction(SCF) in winter exceeded 70%. On average for annual cycle, the characteristic of SCF is that it reached the highest value of 53.2% in January and lowest value of 14.7% in July and the distributions of SCF along with elevation is an obvious difference between the range of 3,000 m below and 3,000 m above. The fluctuation of annual average snow cover is strong which shows that the spring snow cover was on the trend of increasing because of decreasing temperatures for the period of 2000-2012. However, temperature in April increased significantly which lead to more snowmelt and a decrease of snow cover. Thus, more attention is needed for flooding in this region due to strong melting of snow.