Change of Cultivated Land Area in Sichuan Province

Change of cultivated land area reflects the development level of society and economy, which has an important impact on security of grain. Based on factor analysis, factors affecting cultivated land change from 1952 to 2000 in Sichuan Province and its 21 cities, regions and prefectures are analyzed. According to the result of principal component analysis, the three driving forces for the changes of cultivated land, i.e. the economic development, the progress of agricultural science and technology, and the development of society including eight factors (i.e. total investment in fixed assets, output value of enterprises, GDP, passenger-kilometers of highway, total population, real estate, per capita grain production, and urbanization are important factors influencing the change of cultivated land area in Sichuan province), are identified. The development of economy gives rise to increasing amount of cultivated land use and brings about the change in the structure of cultivated land as desired, and leads to an increase of nonagricultural land use, especially, increase of farmland. The progress of agricultural science and technology would alleviate the high demand and occupation of farmland by improving the cultivated land and raising the yield. With the increase of population and urbanization level, large amount area of farmland is occupied and used. It is found that since the 1950s, the total area of arable farmland and per capita arable land in Sichuan Province has been reduced. For example, the total area of cultivated land reached 705×10~4 hm~2 in 1965 and declined after year of 1965. Per capita cultivated land decreases sharply year on year, from 0.12985 hm~2 in 1949 to 0.05169 hm~2 in 2000. And the trends will be continued with further development of economy and increase of population. By using multiple regressive mathematical equations and the relationship among the eight factors and decrease of farmland, we have predicted that the cultivated land area in the years of 2010, 2020 and 2030 in the province will be 419.1008×10~4 hm~2, 396.8489×10~4 hm~2 and 374.8162×10~4 hm~2, respectively. The results can provide scientific basis for cultivated land use and safeguard sustainable development in Sichuan Province. Confronting the facts of the shortage of arable land, and land overloading, it is very important for Sichuan province to protect and use cultivated land in a sustainable way. In order to combat the serious and persistent constraints for sustainable use of land resources, and to attain a prosperous, balanced land -food- population system in the province, major strategies have been proposed as follows: agricultural structure needs to be readjusted to make it more comprehensive; And very strict protection and very intensive use of existing cultivated land will be required so that industry land and agricultural land use maintain a right proportion. We must insist on the basic policy of our state of land and protect cultivated land with strict conservation action. With the science and technology, quality and fertility of existing farmland should be sustainable and productively used. Increasing investments is essential to improve the cultivated land. At the same time, population control will be required.