关于统万城遗址周围自然环境的变迁 ,学者们进行了很多研究和讨论 ,笔者是外行 ,本无权置喙。但有幸实地考察 ,又翻阅史书 ,发现有一些材料尚待进一步研究利用 ,故作如下陈述。统万城的荒废、毛乌素沙漠的形成和发展 ,其主导性因素是什么 ,许多研究者认为 ,人类的过度开发是罪 As for the changes of the natural environment around the site of Tongwan City, scholars have conducted many researches and discussions. The author is a layman and has no right to set his beak. But fortunate enough to field visits, but also read the history books and found that some of the materials yet to be further studied and utilized, so made the following statement. The ruination of Tongwan City and the formation and development of the Mu Us Desert have led to many of the leading factors. Many researchers believe that the over-exploitation of human beings is sin