利用GRACE重力卫星监测新疆天山山区水储量时空变化

利用经过高斯平滑滤波处理的2003年1月至2010年12月逐月的GRACE卫星时变重力场数据，反演得到新疆天山山区水储量变化,其空间分辨率为1°×1°，结合同时间段该区域31个国家气象台站逐月降水资料，采用趋势分析方法，研究天山山区近8 a来的水储量时空变化特征。结果表明：天山山区水储量变化具有明显的空间差异性，总体表现为东、西部多，中部少的空间分布格局。在时间上，水储量变化与降水具有明显的季节性变化规律，两者变化过程基本一致。天山山区平均水储量变化趋势的年内分布总体上1-12月呈递增变化；1-3月为负增长，最大负增长为21.7 mm•a^-1,出现在2月；4-12月呈正增长，最大月份出现在11月，增长趋势达到29.9 mm•a-¹。水储量变化增加的主要原因是天山山区近几年夏季降水有所增加造成的。2003-2010年天山山区水储量变化总体上呈逐年下降趋势，平均每月下降速度为4.8 mm，8 a间水储量变化减少约13×10⁸ m³，其主要原因是由于气候转暖、冰川消融加速、山前绿洲灌溉及生活用水量增加，导致山区水储量变化减少。

Spatiotemporal Change of Water Reserves in the Tianshan Mountains, Xinjiang Based on GRACE

Change of the volume of water reserves in the Tianshan Mountains was analyzed using the monthly gravity field data derived from GRACE satellite with Gaussian filter during the period from 2003 to 2010, and the spatial resolution was 1°×1°. Trend analysis was used to analyze the spatiotemporal variation trend of water reserves in the Tianshan Mountains in recent 8 years based on the monthly precipitation data observed by 31 state meteorological stations. Results showed that there was a significant spatial variation of water reserves in the Tianshan Mountains, the volume of water reserves in the eastern and western parts of the mountains was higher than that in the central part. Temporally, there was an obvious seasonal variation of water reserves and precipitation, and their change trends were similar. The growth of water reserves in the mountains was negative during the period from January to March, its minimum value, -21.7 mm•a^-1, occurred in February. The growth of water reserves was positive during the period from April to December, and its maximum value, 29.9 mm•a-¹, occurred in November. However, the volume of water reserves in the Tianshan Mountains was holistically in a decrease trend during the period from 2003 to 2010, it was decreased by 13×108 m³ in recent 8 years, and its average monthly decrease was 4.8 mm. Reduction of water reserves in the Tianshan Mountains was mainly caused by climate warming, aggravation of glacier melt and increase of the volume of irrigation water and domestic water in the piedmont oases.