Chen Wenqian, Ding Jianli, Wang Jingzhe, Zhang Junyong, Zhang Zhe
Key Laboratory of Smart City and Environment Modelling of Higher Education Institute, College of Resources and Environment Sciences, Xinjiang University, Urumqi, Xinjiang, China.
Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, Xinjiang, China.
PeerJ. 2020 Apr 8;8:e8861. doi: 10.7717/peerj.8861. eCollection 2020.
Xinjiang, China, is a typical arid and semi-arid region of Central Asia that significantly lacks freshwater resources, and the surface runoff in this region is mainly supplied by mountain glacier and snow cover meltwater. Based on the above background and issues of transnational water resources between Xinjiang and Central Asia along the Silk Road Economic Belt, which were highlighted in the major strategy of "The Belt and Road", this study analysed the spatial and temporal variations in snow cover and snow cover days in the Xinjiang region from 2001 to 2015. The study area includes four subregions: Northern Xinjiang, Southern Xinjiang, Eastern Xinjiang and the Ili River Valley. Moderate-resolution Imaging Spectroradiometer (MODIS) 8-day snow cover data were used after removing clouds by combining MOD10A2 and MYD10A2. The results showed that seasonal snow cover occurred from October to April in most regions of Xinjiang and that this snow cover consisted of two processes: snow accumulation and snow ablation. The maximum snow cover occurred in January, whereas the minimum snow cover occurred from July to August. During the seasonal snow cover period, the snowfall rates in Northern Xinjiang and the Ili River Valley were higher, while the other regions had a low snowfall probability. To study the relationship between altitude and snow cover, the normalized snow elevation correlation index (NSACI) was calculated. The NSACI showed a significant correlation between snow cover and elevation in most regions of Xinjiang and was classified into five grades. Snow cover days did not fluctuate obviously from 2001 to 2015, and a decreasing trend was observed in the four subregions except for the Ili River Valley (nonsignificant decreasing trend). We also observed a correlation between snow cover and temperature and found that the correlations between monthly snow cover and monthly temperature in the four subregions were strongly related to the underlying land type and global warming background, which also suggests that the special topography of Xinjiang greatly influences both snow cover and climate change.
中国新疆是中亚典型的干旱和半干旱地区，淡水资源严重匮乏，该地区的地表径流主要由山区冰川和积雪融水提供。基于上述背景以及丝绸之路经济带中新疆与中亚跨国水资源问题在“一带一路”重大战略中被凸显出来，本研究分析了2001年至2015年新疆地区积雪和积雪日数的时空变化。研究区域包括四个子区域：北疆、南疆、东疆和伊犁河谷。通过结合MOD10A2和MYD10A2去除云后，使用了中分辨率成像光谱仪（MODIS）的8天积雪数据。结果表明，新疆大部分地区的季节性积雪发生在10月至次年4月，这种积雪由两个过程组成：积雪和融雪。最大积雪量出现在1月，而最小积雪量出现在7月至8月。在季节性积雪期间，北疆和伊犁河谷的降雪率较高，而其他地区降雪概率较低。为了研究海拔与积雪的关系，计算了归一化雪高程相关指数（NSACI）。NSACI显示新疆大部分地区积雪与海拔之间存在显著相关性，并分为五个等级。2001年至2015年积雪日数没有明显波动，除伊犁河谷外（非显著下降趋势），四个子区域均呈现下降趋势。我们还观察到积雪与温度之间的相关性，发现四个子区域月积雪与月温度之间的相关性与下垫土地类型和全球变暖背景密切相关，这也表明新疆特殊的地形对积雪和气候变化都有很大影响。
