渔塘坝微地域高Se环境中土壤Se的分布规律及其影响因素

Distribution and Affecting Factors of Selenium in Soil in the High Se Environment of Yutangba Mini landscape

选取迄今世界上唯一发生过人群Ｓｅ中毒的湖北恩施市双河乡渔塘坝为研究区．在渔塘坝０．０１ｋｍ２的微地域内，土壤Ｓｅ的分布存在着显著的不均一性．控制渔塘坝土壤Ｓｅ分布的３个主要因素是地形，土壤粒度和成土母质的含Ｓｅ量及出露情况，其中地形是最重要的控制因素．土壤Ｓｅ的分布规律表明，在表生的中强化学风化环境中Ｓｅ是一种极为活泼的元素，易于积累Ｓｅ的负地形是最易于Ｓｅ中毒发生的地貌位置．

Yutangba was selected as the research area,which is located at Shuanghe of En'shi city in southwest of Hubei province,and is a well known area for people suffered from selenosis.At Yutangba mini landscape of 0 01km 2,distribution of Se in soil is significantly uneven,and obviously controlled by three factors,which are topographic condition,soil grain size and Se contents in soil forming parent material and its outcrop condition.Of them,topographic condition is the most important factor.The distribution of Se in soil indicates that Se is an active element in the supergene moderate strong chemical weathering environment,and that lower area where Se accumulates easily are such sites where selenosis is ready to occur.