关键词: 天津, 淡水养殖, 适宜性评价, 地理信息系统（GIS）

Abstract: The evaluation index system of the land for freshwater aquaculture in Tianjin was built based on the analytical hierarchy process (AHP) method with 22 evaluation factors selected from natural resources, conditions for basic development, and prospects of market. In the system, the weights of different layers were determined by Delphi method combined with AHP. Using large quantity of field investigation and collecting relevant statics and maps, a basic map was developed as the evaluation model consists of standardized data. The land used for freshwater aquaculture in Tianjin was divided into 4 grades for different suitabilities: unsuitable, moderately suitable, suitable and very suitable. Results of evaluation indicated that 63 142 hm2 area could be used for freshwater aquaculture in Tianjin. They were mainly moderately suitable and suitable, accounting for 56.56% and 42.38%, respectively. Very suitable area accounted for 0.62%, mainly distributed in southern of Baodi District. Not suitable areas were the least, accounting for 0.44%, mainly distributed in southern of Dongli District. By comparing the present status of aquaculture area with the available areas, the following counties with great potential were found to develop freshwater aquaculture: Ninghe Country, Binhai New Region, Xiqing District and Jinghai Country. Wuqing, Baodi and Beichen Districts were relatively developed, but there was still room for further development. On this basis, the paper analyzed the prospects of aquaculture in various districts and counties were in terms of natural resources and conditions for basic development, and then put forward suggestions for future development. In order to expand the application areas of this suitability evaluation and share the research results, a system were developed for planning and management of aquaculture-the desktop and network version based on ArcGIS. This system has been running on line.

Key words: Tianjin, freshwater aquaculture, suitability assessment, GIS