旱寒灌区土地利用与土壤盐渍化风险互馈耦合关系研究——以银川平原为例

土壤盐渍化是土地退化的重要诱导因素之一，亦是土地利用变化环境效应研究的重要内容，在干旱、寒冷罐区已成为影响可持续发展的重要因素。课题以银川平原灌区为研究区，以遥感影像和实测土壤光谱为数据源，应用随机森林算法、贝叶斯模型、地统计学和灰色理论及人地关系理论方法，结合遥感和GIS技术，从土地利用与土壤盐渍化空间演化的角度，定量分析土地利用变化与土壤盐渍化的关联关系，研究土地利用与土壤盐渍化变化强度的空间异质性规律，构建土壤盐渍化敏感指数，揭示不同土地利用类型的土壤盐渍化敏感性，探讨土壤盐渍化演变的机制，建立土壤盐渍化生态风险评估模型，评估该区土壤盐渍化生态风险，对黄河上游生态保护和河套灌区土地生态安全具有重要意义。

Soil salinization is one of the most important induction factors for land degradation，it is also an important part of the study of environmental effects of land use change,and has become an important factor affecting sustainable development in drought and cold irrigation area. There has about two thousand years irrigation history in Yinchuan Plain Yellow River water irrigation district, and the soil salinization has become more and more severe especially because of arid and large irrigation from the Yellow River. Also, the area locate in the HU-Bao-Yin-Yu economic zone. In recent years, the land use development intensity have been continuously increasing, hence the spatial distribution, causation, development and succession of soil salinity in Yinchuan Plain irrigation district have been changing greatly. Accurately get the spatial distribution of soil salinization and the spatial location characteristics of its relationship with land use intensity can explain the reason of soil salinization from a perspective of land use intensity, and assess ecological risk of soil salinization, we taking Yinchuan Plain as the research area, based on the remote sensing data, and hyper spectral data and its soil salt content, use support random forest algorithm, Bayesian model, geo-statistics, grey theory, and human-land relationship theory, combined with RS, GIS, the proposed research program attempts to analysis of spatial location distribution characteristics are developed for land use intensity change, soil salinization change, and the respond relationships between each kind of saline soil and land use intensity in Yinchuan plain. Also, we perform to construct the sensitivity index of soil salinization, revealing the sensitivity of soil salinization to different land use types, and discuss the evolution mechanism of soil salinization. The proposed research intends to establish of ecological risk assessment model for soil salinization, and assess ecological risk of soil salinization for the study area. The research outputs are important significance for ecological protection in the Upper Yellow River and land ecological security in Hetao irrigation area.