宁夏中部旱区压砂地土壤干燥化特征及驱动机制

项目名称： 宁夏中部旱区压砂地土壤干燥化特征及驱动机制

项目编号： No.41461104

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 王幼奇

作者单位： 宁夏大学

项目金额： 50万元

中文摘要： 针对随压砂地使用年限增加其土壤水分快速下降、土壤干燥化加剧的现象，以宁夏中部旱区压砂土壤为研究对象，结合野外调查、定位监测和室内模拟等手段，借助统计分析、模型分析和GIS方法，深入开展宁夏中部旱区压砂土壤水分时空变化特征研究，探究其变化规律、驱动因子及分布特征。初步建立压砂土壤干燥化量化指标体系，分析压砂地干燥化程度、土壤干层分布深度及广度，阐明压砂土壤干燥化过程中土壤水分时空变化特征以及其与气候、地形、植被类型等响应程度，提出基于土壤水分安全承载下较为合理的压砂粒径和压砂厚度，建立压砂土壤水分指标空间数据库，揭示压砂土壤干燥化演化过程。研究结果一方面有助于防治研究区压砂地老化、延长其利用年限，另一方面有助于科学评价压砂这一特殊耕作方式对西北旱区生态系统水分循环过程的影响，为减缓压砂地土壤干燥化过程提供思路。

中文关键词： 压砂地；土壤水分变化；土壤干燥化；数值模拟；驱动机制

英文摘要： Soil moisture deficit and soil desiccation in the gravel mulched field appeared as the lifetime of service increasing. Field investigation, fixed-site monitoring and laboratory simulation were combined to research spatial-temporal variability of soil moisture in the gravel mulched field of the central arid regions of Ningxia with the statistical analysis, numberical simulation and geographic information system. The project would explore the variation pattern, source and driving factors for the soil moisture, determine quantitative indicator system of soil desiccation, analyze distribution characteristic of dried soil layer. The project would clarify the response of soil moisture variability to climate, topography, vegetation and so on. The suitable size and length of gravel particle would be revealed based on the capacity of soil moisture. Then the spatial databases of soil moisture indexes would be established in the gravel mulched field, and the evolution mechanism of soil desiccation would be revealed. The achievements of the research could contribute to prevent the degradation of gravel mulched field and extend the lifetime of service. Meanwhile, the project could help to scientifically evaluate the impact of gravel mulching on the water cycle process of ecosystems in arid area, and provide the train of thought for the reduction of soil desiccation.

英文关键词： the gravel mulched field;soil moisture variability;soil desication;numberical simulation;driving mechanism