中国西北及中亚主要绿洲农区分类

Classification of main oasis agricultural types in the Northwest of China and Central Asia

应用生态学原理以水为主线建立绿洲农区树形分类体系,将中国西北及中亚主要绿洲农区采用五级指标分类并进行区划。一级分类指标为水热配合状况,分水热同期型或不同期型;二级指标为水汽主要来源,分西风环流带来水汽型或太平洋季风带来水汽型;三级指标为灌溉水来源,分为"山地-绿洲-荒漠系统"产生河流灌溉型或由"系统"外来河流灌溉型;四级指标为不同河流类型灌溉形成的土壤,分地面河灌溉形成灌淤土型或地下径流(河)井、泉清水灌溉形成灌耕土型;五级指标为地理位置名称及当地的气候带。将分类结果用亿图图示专家软件绘成树形分类图,再用Arc GIS9.3软件制成分类分布图。经分析比较得出:中国西北水热同期型较中亚水热不同期型绿洲农区的光、温、水资源耦合效应更优越。

The main oasis agricultural area in the Northwest of China and Central Asia locates at the central of Eurasia with the biggest area and the richest type in the world. The oasis agricultural classification is one of the element tasks in oasis research. In the previous studies, the main methods for classification of oasis agriculture were based on either a single indicator or combination indicators. With these methods some valuable results have been found, which have revealed a lot of rules and deserved being followed well by successors. However, these methods couldn＇t cover the entire research field so as to restrict the development of the research field. Therefore an innovation of classification index system is needed. Based on tree classification system for oasis agriculture according to biological and agro-ecology principles, this paper divided the oasis agricultural area in Northwest of China and Central Asia into 5 levels regarding water as the main factor. The first level of the index system is defined according to the condition of water-heat match, in one type water and heat resource meet in the same period and in the other type water and heat resource appears in different time. The second level of the index system is based on the main source of moisture, which includes two types also, one type is precipitation brought by west wind circulation and the other by pacific monsoon. The third class of parameter group is river types for irrigation, which is divided into two types; one is river from mountain--oasis-desert system and the other is coming from the outside. The fourth class of parameter group is the soil type formed by different irrigation river types, including alluvial soil caused by the sediment of Ground River and the other produced by the irrigation with underground runoff, wells and springs. The fifth class of parameter group is geographic location, the corresponding climate and so on. The classification provides fundamental theory basis for deeper understanding of ecological environment and agriculture production in different oasis agricultural areas. Classification indicator system was drawn as a tree classification map by Edraw max software. The classification distribution results were showed by ArcGIS 9.3. From analysis we can get that the oasis agriculture with type of water and heat in West north of China has better resource of light, heat and water coupling effect than the oasis agriculture with Central Asia.