历史纪录的西北环境变化与农业开发

 由中国西北地区的现代气候状况和古气候记录来回溯过去时期的气候变化，并依据历史文献记载论述过去时期农业开发活动的规模、效益与温度、湿度背景之关联。文中指出：西汉和唐前期气候适宜，河西地区大规模农田开垦成功；唐后期和明朝中叶的气候转寒导致河西屯垦凋敝；公元初塔里木盆地的繁荣和后来的衰落与水资源变化有关。历史上的垦后抛荒行为加速了土地的沙化进程，乌兰布和沙漠的形成和较温暖的13世纪降尘事件频繁发生即为此类不良后果的两个典型例子。

Historical Records of Environmental Changes and Agricultural Development in Northwest China

A review of historical evolution of climate conditions in Northwest China is demonstrated. Based upon rich historical documentary records regarding wasteland reclamations for cultivation, the relationship of sizes and benefits of agricultural development with the conditions of temperature and moisture at that time is indicated. In the west Han Dynasty and the early Tang Dynasty suitable climate provided sufficient heat and moisture for large-scale reclamation of wasteland in the Hexi region, resulting in swiftly booming economy, while economy fell in the target region in late Tang Dynasty and mid-Ming Dynasty mainly because climate got cold. And agricultural development or decline in Tarim Basin from the 1st to the 4th century was caused by change of water source. In historical time, frequent over-reclaiming and subsequent leaving the land alone were responsible for the acceleration of land desertification, there were two cases of Wulanbuhe desert's formation and the high frequency of sandstorm during the warmer 13th century as such adverse consequences caused by above actions.