贵州威宁麻窝山地区近五万年来土壤侵蚀速率研究

摘要定量研究喀斯特地区土壤侵蚀速率对了解石漠化过程具有重要意义.本文以重度石漠化贵州威宁麻窝山地区岩溶洼地堆积土壤为研究对象,采用了钻探取样、土壤有机质14C测年方法、137Cs含量测定并结合历史文献,定量研究了麻窝山地区近5万年来的土壤侵蚀速率变化.结果表明,距今4.69～3.08万年(Bp)间的侵蚀模数与距今3.0...

Soil Erosion Rates on the Guizhou Mawo Hill in the Past 50000 Years

The quantitative investigation of erosion rates in a karst area is of great significance in understanding the desertification process.This paper takes a typical karst basin's sedimentary soil as an example,which is located on the Mawo hill of Guizhou.The 14C age measurements are used to quantify the variation of erosion rates on the Mawo Hill for about fifty thousand years.The results showed that the erosion modulus at 4.69～3.08 million years(Bp) ago was 10.81 t/km2·a,it is similar to 12.05 t/km2·a at 3.08～1.50 million years(Bp) ago.While the erosion modulus at during 1.50 million years(Bp) ago and was dropped to 8.10 t/km2·a.From the late 70s of the last century,the erosion modulus has increased to 2902.73 t/km2·a.The variation of soil erosion rate could be impacted by climate change before the late 70s of the last century,while the rapid increase of soil erosion rate should be attributed to anthropogenic activities(e.g.deforestation).Based on the quantitative investigation of karst soil erosion rate,it is suggested that the karst desertification is caused by human activities.