2008-2014年新疆艾比湖流域土壤水分时空分布特征

传统的土壤水分模拟研究难以从土壤水分变化的时空双向出发表达其连续演变的过程，存在时空尺度效应问题。借助SWAT模型模拟的长时间序列优势，结合高分辨率卫星影像和遥感技术，力图在时空尺度效应问题上取得突破。并利用长时间序列的模拟结果分析流域土壤水分的空间格局和不同维度时空异质性。结果表明：（1）2008-2014年间艾比湖流域土壤水分主要受气温、降水及人类活动影响，呈波动变化，总体偏低且具有逐年减小趋势。（2）受降水、地形及土地覆被影响，土壤水分分布呈现出由山区向两侧平原减少的特点，且林地 > 农用地 > 草地 > 稀疏植被。（3）近10年间土壤水分低值区由原来的北部山区及平原向东部、东南部平原区及南部山区迁移，东部减少最为明显。（4）流域四季土壤水分变化差异显著。其中，春季主要受融雪影响；夏季、秋季主要受降雨量和气温影响；冬季主要受固态降雪和气温影响；且不同年份、相同季节、相同子流域土壤水分变化趋势表现一致。

Temporal-spatial dynamic change characteristics of soil moisture in Ebinur Lake Basin from 2008-2014

It is difficult to express the true soil moisture temporal and spatial variation in traditional methods, because it always reflects a certain spatial resolution or discrete temporal pattern, which is not a continuous process. In this paper, we use SWAT (Soil and Water Assessment Tool)model and multi-source remote sensing data to solve the problems caused by the effects of spatial and temporal scales of soil moisture monitoring. Explore the scientific regional scale and long-time-series soil moisture simulation method, and use the simulation results analysis soil moisture in different time and space in study area. The results showed the following:(1) soil moisture over the entire region was continued decline from 2008-2014. The major factors affecting this trend are temperature, precipitation, and human activities. (2) The distribution of soil moisture is affected by precipitation, temperature, and land cover. The distribution of soil moisture is characterized by decreasing from the mountainous area to the plains, and in the following order:woodland > agricultural land > grassland > sparse vegetation. (3) In the past 10 years, the area with low soil moisture shifted from the northern mountainous plains to the eastern part, southeastern plains, and southern mountains, one of the most obvious change was eastern part. (4) The variation in soil moisture in the four seasons was significant. Soil moisture in spring and autumn were affected by rainfall and temperature, and that in winter was affected by the snow melt and temperature. The sub-basin soil moisture change were consistent in same season in different years.