地球是人类共同的家园 .水是生命之源 ,土是生存之本 ,洁净的淡水和可耕作的土壤 ,已成为 2 1世纪人类最为重要的战略资源 .在人类物质文化生活水平不断提高的同时 ,全球面临的资源、环境问题也日益突出 .近几十年来 ,气候变化、森林减少和植被破坏 ,水土流失加剧 ,沙漠化扩展 Earth is the common homeland of mankind.Water is the source of life, and the soil is the basis of existence, clean freshwater and arable land, and it has become the most important strategic resource for mankind in the 21st century.While mankind’s material and cultural life is constantly improving , The global resources and environmental problems are also becoming increasingly prominent.In recent decades, climate change, forest reduction and vegetation damage, soil erosion increased, desertification expansion