Spatio-Temporal Analysis of the Change of the Cultivated Land and Food Production in Shaanxi Province based on Index Method
基于指数法的陕西省耕地和粮食时空变化分析

The cultivated land transformation intensity index,which was put forward by LI Xiao-wen et al,could reflect the change degree of the cultivated land in a region in a year.Considering such specific condition as the physical situation,the soil attributes,the input of the agriculture,it is more reasonable to assess the food security by using the index of food rather than the index of the cultivated land.So this paper tentatively put forward the concept of the relative food carrying capacity index.Using these two indexes we worked out the cultivated land transformation intensity index and the relative food carrying capacity index in 101 counties from 2000 to 2004 and analyzed the difference in the spatio-temporal scale with GIS.All the data were derived from the statistics yearbooks of the Shaanxi Province and some cites in the province.The results were as follows: 1) In the recent 5 years,the population increased from 35,721,700 to 36,744,400,the cultivated land decreased from 3,103,700 hm~2 to 2,786,200 hm~2,and the amount of the food fluctuated obviously,11,644,700 t in 2000,10,782,500 t in 2001,11,230,500 t in 2002,10,721,400 t in 2003 and 12,366,800 t in 2004.2) According to the standard we made in this paper,17 counties belonged to the quick-decreased type of the cultivated land,70 counties belonged to the moderate-decreased type of the cultivated land,13 counties belonged to the moderateincreased type of the cultivated land.Wu Qi County's area of the cultivated land kept balanced and there was no county belonging to the quick-increased type of the cultivated land in all 101 counties.3) From 2000 to 2004,the amount of food per capita was 325.98kg,300.39kg,311.04kg,294.34kg and 336.56kg,respectively.According to the food quantity standard of the well-off society,the province as a whole is in a very insufficient situation of food production.Of which,66 counties is in insufficiency and 34 in richness.Based on the present situation of the cultivated land and the food,it's very imperative to improve the food carrying capacity by protecting and using reasonably the cultivated land,constructing the agricultural infrastructure,taking advantage of advanced technology and rectifying the structure of the agriculture.