基于微波遥感的喀斯特小流域土壤水分时空变异研究

Soil moisture is the foundational water resource for the vegetation in karst area,hence, study of the spatial-temporal variation of soil moisture is essential forecological reconstruction. Although it is accurate, conventional soil moisture monitoring methods have some obvious disadvantages, especially in monitoring soil moisture for large areas. Microwave remote sensing technology has demonstrated aquantitative, economical and time saving advantage in measuring soil moisture under a variety of topography and vegetation cover conditions and large space scale, particularly for bad weather conditions. Inversing soil moisture using remote sensing has been applied and studied widely, however, the relevant studies in karst region are still rare. The main objectives of this project are to establish applicable models (RADARSAT-2) for soil moisture inversion, and to investigate the spatial-temporal variation of soil moisture and the influencing factors in typical karst catchment. This project would provide the knowledge for reasonablely managing water resources and deep understanding of the soil water distribution and movement, and would also be helpful for ecological restoration.

土壤水分是喀斯特地区植被生长重要的水分来源，研究土壤水分时空变化对当地石漠化治理和生态重建具有重要意义，而其中土壤水分的测定又是关键环节。传统土壤水分测定方法虽然精确，但在大尺度上却有明显不足。而卫星遥感则能快速、大面积地获取地面信息，已成为土壤水分测定最有效的手段之一，应用十分广泛。然而，目前在喀斯特地区土壤水分遥感反演方面的研究仍处于起步阶段。针对这一问题，本研究以定位观测和地面调查为基础，以期建立适用于喀斯特地区的微波遥感（RADARSAT-2）土壤水分反演模型，并用其揭示喀斯特地区土壤水分时空变化规律及其影响因素，为喀斯特地区水资源管理和石漠化治理提供支撑。

土壤水分是喀斯特地区植被生长重要的水分来源，研究土壤水分时空变化对当地石漠化治理和生态重建具有重要意义。传统土壤水分测定方法虽然精确，但在大尺度上却有明显不足。卫星遥感则能快速、大面积地获取地面信息，已成为土壤水分测定最有效的手段之一。然而，目前利用遥感反演土壤水分在喀斯特地区的研究仍然不足。本研究以野外调查和遥感数据为基础，确定了喀斯特土壤水分空间分布的主控因子（植被类型35.7%）；筛选出了适用于喀斯特地区的土壤水分遥感估算参数（坡位指数HI和Landsat 8 B5波段）；建立了土壤水分估算模型（SM=9.37*E^(-2)*HI-1.82*E^(-5)*B5+0.519）并获得了小流域土壤水分空间分布图；明确了表层土壤水分与深层土壤水分时间格局的显著相似性特征（r=0.50~0.99），本研究为喀斯特地区水资源管理和生态重建提供支撑。该项目共计发表第一标注SCI论文3篇（一二区），中文核心期刊文章1篇，培养硕士生3名。