Based On GIS Spatial And Temporal Variations Of Arable Land And Its Influence On Grain Production

Arable land is the foundation of human survival, whose quantity and quality directly affect food supply security nationwide. With the acceleration of industrialization and urbanization, construction projects occupied arable land has become fiercer, which resulted in the reduction of high-quality arable land. China’s population will soon peak, the increase of population and the continuous improvement of people’s living standard lead to the increasing demand for food. Thus, massive food needs to be imported every year to balance the lack of domestic demand. Research discussed the impacts of spatio-temporal changes in arable land on the quantity and spatial distribution of grain production, which could provide reference for a reasonable arable land and grain protection strategy.In order to reveal the impacts of spatio-temporal changes in arable land on grain production, the arable land and grain production changes between 1997 and 2012 were analyzed with the use of ArcGIS. Research took the 104 counties (cities/districts) in Shaanxi Province as examples. Results showed as follows:(1) The Guanzhong Plain was the main grain producing area among the 6 areas, whose grain output accounted for 56.99% of the whole province in 2012. Though total outputs and yields have increased from the year 1997 to 2012, grain acreage has declined. Counties of more grain production mainly concentrated in the Guanzhong Plain in 2012. Compared with the year 1997, the number of counties which produced more grain has fallen in the Guanzhong Plain.(2) Arable land was mainly distributed in the Guanzhong Plain, whose cultivate area accounted for 35% of the whole province in 2012. Total area under cultivation presented a declining trend in Shaanxi Province from 1997 to 2012.(3) Causes for the reduction of arable land mainly included four aspects:reforestation, construction occupation, structural adjustment of agriculture and disaster. From the view of reduction amount, reforestation was the first factor, construction occupation was the second factor. After 2008, construction occupation has gradually become the main reason for the reduction of arable land. Causes for the increase of arable land mainly included land development, reclamation, consolidation and structural adjustment of agriculture.(4) Changes in agricultural acreage and grain acreage roughly consistent in counties of Shaanxi Province from 1997 to 2012. Both increase mainly distributed in the Guanzhong Plain and Hanyuan area of Weihe River, while both decrease mainly distributed in Shaanxi hilly-gully region, low level ground mountain area and high mountains area in south Shaanxi. Agricultural acreage decreased but grain acreage increased, this phenomenon could be surveyed in the Guanzhong Plain. Changes in agricultural acreage affected grain output to some extent. Both increase mainly distributed in the Guanzhong Plain, while both decrease mainly distributed in the sandstorm area along the Great Wall.Approval of construction projects occupying arable land must be made strict to ensure the requisition-compensation balance especially in the Guanzhong Plain Area. The land reclamation in the Hanyuan area of north Weihe should be strengthened. In addition, construction of high-standard prime cropland could help to increase the per unit area yield of grain especially in the Guanzhong Plain Area and the low level ground mountain area in south Shaanxi. Meanwhile, the investment in science and technology of agriculture and the subsidies to grain producers should also be enhanced to ensure the grain security.