Abstract: The spatiality and attribute database of double cropping rice in Fujian Province were established based on the GIS technology, and the productivity potentials of sunlight and temperature, climate, and climatesoil of double cropping rice in each county of Fujian Province were calculated by using modified Kassam-Wageningen method. In terms of grading statistics and mapping, the numerical distribution of the productivity potentials as well as the spatial distribution and potentially predominant development regions of double cropping rice in this province were analyzed. The results showed that the productivity potential of climate would be increased by 1 800 kg·hm^-2 when irrigation was appropriate, and that of climatesoil would be increased by 4 000 kg·hm^-2 when fertilization was at an optimal level. Therefore, there existed great productivity potential for double cropping rice. Moreover, the productivity potential of climatesoil for double cropping rice was greater in south Fujian than in north Fujian, and the greatest potential was in southwest Fujian. According to the variation characteristics of the productivity potentials and ensuring the directions of agricultural input, the countermeasures of keeping food security of Fujian were brought forward: (1) to strictly restrict nonagricultural land and to keep the planting area of double cropping rice in stable, (2) to adopt appropriate planting ratio of different double cropping rice cultivars and to use the agricultural and climatic resources adequately, (3) to construct stable yielding cropland regardless drought or flooding, (4) to improve soil fertility by increasing organic fertilizer application and planting green manure, and (5) to increase input to the potentially predominant regions of developing double cropping rice step by step.

Key words: Landscape pattern, Urbanization, Beijing, Remote sensing