湖泊(水库)沉积物分析在土壤侵蚀研究中的运用

土壤侵蚀研究对于防治自然灾害,实现土地的可持续利用具有重要的现实意义。由于一些地区长期以来水文观测资料较为匮乏,针对过去时间段内的土壤侵蚀研究通常需要寻找替代指标。湖泊(水库)作为流域内侵蚀产物的“汇”,其沉积物可不同程度地记录较长时期土壤侵蚀的具体特征,因此,基于湖泊(水库)沉积物分析的土壤侵蚀研究具有较强的应用价值和发展潜力。本文主要围绕确定土壤侵蚀年代,反演侵蚀过程,探寻沉积物来源的研究主线,详细论述了湖泊(水库)沉积物中放射性同位素、矿物磁性、粒度以及地球化学指标的应用原理和方法,分别总结了国内外学者利用湖泊(水库)沉积物在上述3个领域所取得的研究成果,在此基础上讨论了目前研究中存在的不确定性,并对未来的研究方向进行了展望。

Soil erosion investigation based on sediments in lakes and reservoirs

Soil erosion investigation has important significance for preventing natural hazard-induced disasters and promoting the sustainable use of land. Due to the absence of long-term hydrological observation data in some areas, research on historical soil erosion often needs to use surrogate indicators. As the sink of erosion products in drainage basins, sediments in lakes and reservoirs record the characteristics of soil erosion in a long period of time and have high application value and potential in many fields. Focusing on the questions of determining the age of soil erosion, reconstructing the erosion processes, and searching for sediment sources, this study first reviewed the application theories and methods of radioactive isotopes, mineral magnetism, grain size, and geochemical indicators. Second, we summarized the research in the above fields with the sediments in lakes and reservoirs respectively, thus confirmed the important role of these sediments. Finally, we discussed the uncertainty in soil erosion investigations and identified the potential research directions.