高寒山区土壤侵蚀时空演变及气候变化响应特征研究

Soil erosion is a severe threat to the global environment and under the impact of climate change. Systematic assessment of soil erosion in response to climate change is of great significance for understanding the erosion process and thus carrying out prevention and control work. However, it is difficult to evaluate the impact of climate change on soil erosion under relatively independent conditions, due to the complexity of soil erosion process and the interaction between controlling factors. Qinghai-Tibet Plateau (TP), which is influenced by human activities limitedly, is a typical eroded vulnerable area and sensitive to climate change. It is an ideal research area to study the relationship between climate change and soil erosion. However, due to the specific climatic conditions and vertical zonality differences in alpine region, the scarcity of measured data poses a great challenge to the estimation and mapping of soil erosion. In addition, it is difficult to simulate the response characteristics of spatio-temporal evolution of soil erosion to climate change under complex ground surface, which makes it difficult to predict future soil erosion changes. In order to solve this problem, this study simulates the key information of soil erosion using the synthesized multi-source information by space-time fusion and collaborative inversion technology over the Sejila Mountain of the TP. Mapping the spatio-temporal distribution characteristics of soil erosion based on data mining and digital soil mapping (DSM) technologies. Predicting the evolution of soil erosion under future climate change scenarios by using the response mechanism of soil erosion to climate change. This study will provide new ideas and methods for the study of soil erosion in alpine region, and provide a reference for the construction of ecological barrier and the formulation of climate change response policies in the TP.

在气候变化的背景下，土壤侵蚀是全球共同面临的严峻问题。系统评价气候要素对土壤侵蚀的影响，对深入理解侵蚀过程并开展防治工作具有重要意义。然而，土壤侵蚀过程复杂、影响因素间存在互作效应，很难在相对独立的条件下评价气候变化对土壤侵蚀的影响。青藏高原受人类活动影响较小，是全球典型的侵蚀脆弱区和气候敏感区，更是研究气候变化与土壤侵蚀关系的理想研究区。但是，受高寒山区特殊气候条件及垂直地带性差异的影响，地面实测数据稀少，区域内侵蚀的估算制图及气候变化响应研究面临着很大的挑战。针对这些问题，本研究以色季拉山为研究区，拟综合利用多源信息时空融合及高精度协同反演技术，对高寒山区土壤侵蚀关键信息进行高精度模拟，并采用数据挖掘技术进行土壤侵蚀数字制图，根据侵蚀对气候变化的响应机制预测未来土壤侵蚀时空演变特征。研究将为高寒山区土壤侵蚀研究提供新的思路与方法，也为青藏高原生态屏障建设及气候变化应对政策制定提供参考。

高寒山区复杂地表环境下土壤侵蚀时空分布特征快速定量模拟，不仅对对区域内的土壤资源和水资源安全具有积极地作用，同时也关系到全球生态安全屏障保护和建设。.本课题针对复杂地表限制下，高精度土壤侵蚀关键信息获取难，未来气候变化驱使下侵蚀是否会加剧的问题，提出采用多源遥感的地表信息时空融合及协同反演技术，利用大数据挖掘技术，结合结构方程模型进行路径分析的方法，进行高寒山区地表信息的快速获取，并定量回答未来土壤侵蚀的演变特征，为土壤侵蚀快速模拟提供了新方法，也为青藏高原土壤侵蚀对气候变化的响应特征研究提供了新思路。.围绕本课题研究任务，共发表了共发表了4篇SCI论文，其中3篇第一标注，授权国家发明专利2项，获得软件著作权2项，全面完成了项目设计的研究目标和相关指标。.主要研究成果包括：（1）综合利用多源遥感及时空数据重构建模，对复杂地表下长时间序列的侵蚀关键信息进行了高精度的模拟。同时，利用线性混合效应模型和路径分析方法，对青藏高原进行植被指数变化趋势归因分析。结合机器学习算法及未来情景模式，在分析当前植被变化的驱动因素及内在机理的基础上，模拟未来全球植被的分布及变化情况。该成果已发表SCI论文2篇，授权国家发明专利1项，获得软件著作权2项。.（2）综合利用土地利用类型及植被覆盖度信息，进行大区域尺度植被覆盖因子的快速定量估算及制图；在前期改进土壤侵蚀模型的基础上，结合土壤有机碳数据，对青藏高原侵蚀碳空间分布特征估算；基于模型分析，对环境变量在土壤侵蚀碳时空分异特征种的贡献程度，以及环境变量作用于侵蚀碳过程中的内部互作机制进行模拟分析；该成果已发表SCI论文2篇，授权国家发明专利1项。.本课题研究为高寒山区土壤侵蚀快速模拟及对其气候变化的响应提供了新的认识，具有积极的科学意义。.