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一、研究目的水土流失的加剧已是本世纪世界最严重的问题之一。据估计,每年从耕地上流失的肥沃表土达230亿吨。我国丘陵山地占国土3/2,水土流失很普
First, the purpose of the study Soil and water loss has become one of the world’s most serious problems in this century. It is estimated that 23 billion tons of fertile topsoil is lost each year from cultivated land. Hilly and mountainous regions account for 3/2 of China’s territory, soil erosion is very general