Spatiotemporal Variation of Snow Cover in Tianshan Mountains, Central Asia, Based on Cloud-Free MODIS Fractional Snow Cover Product, 2001–2015

Zhiguang Tang,Xin Wang,Xiaoru Wang,Hongyi Li,Jian Wang,Zongli Jiang

doi:10.3390/rs9101045

Abstract

The change in snow cover under climate change is poorly understood in Tianshan Mountains. Here, we investigate the spatiotemporal characteristics and trends of snow-covered area (SCA) and snow-covered days (SCD) in the Tianshan Mountains by using the cloud-removed MODIS fractional snow cover datasets from 2001–2015. The possible linkage between the snow cover and temperature and precipitation changes over the Tianshan Mountains is also investigated. The results are as follows: (1) The distribution of snow cover over the Tianshan Mountains exhibits a large spatiotemporal heterogeneity. The areas with SCD greater than 120 days are distributed in the principal mountains with elevations of above 3000 m. (2) In total, 26.39% (5.09% with a significant decline) and 34.26% (2.81% with a significant increase) of the study area show declining and increasing trend in SCD, respectively. The SCD mainly decreases in Central and Eastern Tianshan (decreased by 11.88% and 8.03%, respectively), while it increases in Northern and Western Tianshan (increased by 9.36% and 7.47%). (3) The snow cover variations are linked to the temperature and precipitation changes. Temperature tends to be the major factor effecting the snow cover changes in the Tianshan Mountains during 2001–2015.

Highlights

Snow cover, as an important component of land cover, is one of the natural materials on the Earth’s surface with wide distribution, obvious seasonal variation, and high sensitivity to climate change [1]
At the entire Tianshan Mountains scale, the snow-covered area (SCA) from the end of November to the middle of March are greater than 20%, with relatively large standard deviations reflecting the high interannual variability, whereas, in the June–September period, the SCAs are less than 5% and with a relatively small interannual variability (Figure 4c)
We find decreasing trends of snow cover in Central and Eastern Tianshan, and slight increasing trends in Northern and Western Tianshan during the 15 years

Summary

Introduction

As an important component of land cover, is one of the natural materials on the Earth’s surface with wide distribution, obvious seasonal variation, and high sensitivity to climate change [1]. In arid and semi-arid regions of Western China, snow cover is a very important water resource, since water from melted snow forms the headwaters for several of the largest rivers in Asia. In these regions, the snowmelt water is dominant among all water sources [6]. More than one sixth of the global population relies on water from mountainous snowmelt [9]

Methods

Results

Discussion

Conclusion