河西走廊水资源变化与生态环境时空关联分析

[目的]对河西走廊地区2003—2015年水资源和生态环境的时空变化规律以及时空关联关系进行分析,为该区水资源合理开发利用及实现生产、生活和生态可持续发展提供科学依据。[方法]利用GRACE重力卫星数据、TRMM降水数据与MODIS的植被指数数据,通过线性回归与相关性分析等方法,分别对河西走廊整体、3个流域分区和像元尺度的水资源变化与生态环境时空变化规律及其相互作用机制进行分析。[结果]年尺度上河西走廊及3个流域分区的水储量均呈现下降趋势,黑河流域与石羊河流域下降速度最大。研究区历年降水趋势稳定无明显变化,植被呈正增长趋势。月尺度上水储量变化与降水量和植被指数呈正相关,年尺度上水储量变化量与降水量不存在相关关系,与植被指数年均值存在高度负相关,并表现出明显的空间异质性和尺度效应。[结论]研究区人工植被尤其是耕地的快速、持续上升,加大了水资源的消耗,造成水储量逐年下降。

Analysis on Spatiotemporal Correlation Between Water Resource Change and Ecological Environment in Hexi Corridor

[Objective] The temporal and spatial variation of water resources and ecological environment in Hexi Corridor as well as their spatial and temporal correlation from 2003 to 2015 were analyzed in order to provide scientific basis for promoting reasonable development and utilization of water resources and realizing sustainable development of production, life, and ecology in the study area.[Methods] Based on the GRACE gravity satellite, TRMM precipitation, and MODIS vegetation index data, this study investigated the spatiotemporal variations of water resources and ecological environment as well as their interaction mechanisms in the pixel, watershed, and region levels, using the linear regression and correlation analysis.[Results] The annual water storage in the Hexi Corridor and its three watershed areas presented a downward trend with the highest decline rate in the Heihe and Shiyang basins. There had nonsignificant trend in the precipitation in the study area, and the vegetation presented an increasing trend. The monthly water storage was positively correlated with monthly precipitation and NDVI. The annual water storage was independent of annual precipitation, while it was highly negatively correlated with annual averaged NDVI, and this relationship presented apparent spatial heterogeneity and scale dependent.[Conclusion] The rapid and continuous increase in the artificial vegetation, especially in the cultivated land, accelerated the water resources consumption and caused the decrease in annual water reserves in study area.