关键词: 复种指数, 遥感反演, 时空变化, 影响因素

Abstract:

Using SPOTNDVI data, the multiple cropping indexes were inversed by remote sensing in 2000, 2004 and 2008 around Bohai in China. Meanwhile, the influencing factors for the changes of the multiple cropping indexes were detected by geographical detection method. The results showed: 1) The Spatial differences of the multiple cropping index were significant. The latitude zonal laws were obvious for the multiple cropping index spatial distribution, which was changed from 280% in the south plain to 70% in the north mountainous region. It was lower to 40%-50% in hills and the plateau mountain region than in the plain of the same latitude, showed a certain vertical zones law. The multiple cropping index was higher than 150% in traditional agricultural areas of plains, including the southern of Hebei Province, the southwest and north of Shandong Province. The lower value regions of the multiple cropping index were located at Shandong Hilly Areas, Bashang Plateau in Hebei Province and Changbai Mountains in Liaoning Province. 2) The regional differences of the dynamic change for the multiple cropping index were obvious in 2000-2008. The multiple cropping index was increased in the traditional agricultural areas of the plains. The regions where the dynamic degree was more than 10% were located in the southwest, northwest and east in Shandong Province, Haihe river plain in Hebei Province. On the contrary, the negative value regions of the dynamic degree were located in the Hilly Areas of Shandong Province, Bashang Plateau of Hebei Province and the Liaohe River plain in Liaoning Province in 2000-2004. There were rebound in declined areas, and remained stable in increase areas in 2004-2008. 3) The level of grain production was an important factor affecting changes of the multiple cropping indexes. There were many factors affecting changes of the multiple cropping index, including the per capita cultivated land area, transfer degree for rural labor force, the basic conditions of agricultural production, the level of agricultural modernization, location conditions etc. In order to improve cultivated land use efficiency and agriculture development, a reasonable and order land transfer should be actively pursued in the plain. Meanwhile, large of new agricultural cooperative organizations should be developed, so that the regional agricultural modernization is improved. On the other hand, the comprehensive consolidation of land should be actively implemented including cultivated land, water, roads, forests, and villages, which promoted the construction of high-standard farmland, to protect regional food security and rural-urban development transition healthily. Developing specialized agriculture in the hills and mountains and highland areas, the quality fruits are developed to enhance industrial competitiveness of specialty agriculture.

Key words: multiple cropping index, remote sensing inversion, spatial and temporal change, influencing factors