Impact Of Land Use Change On Farmland Potential Productivity In China

In China, food security is threatened by some resource and environmental problems, such as climate change, land use change, population growth and so on. This study focuses on the simulation and analysis of farmland potential productivity in China based on spatial resolution of1km×1km with newly acquired datum which are average of meteorological data, including daily maximum air temperature, minimum air temperature, precipitation, relative humidity, wind speed and sunshine hours during recent30years, terrain elevation data, soil data and land use data in1995,2000and2005. And this research also analyzes the changes of farmland potential productivity in China during the periods from1995to2000and from2000to2005. The results show:The spatial difference of farmland potential productivity in China is pretty evident. The productivity in eastern China is high, but that of in northwest is low. The high productivity is mainly distributed over Northeast China, Yangtze River and Sichuan Basin.There are different changes in the cultivated land areas between two periods from1995to2000and from2000to2005. During the first five years, the trends in the cultivated land areas present decrease in south and increase in north. Net increase in the cultivated land areas is14299.81km2During the next five years, the areas of changes generally decrease in the country, especially in economically developed regions. Net decrease in total farmland areas is5553.16km2.This period saw an obvious change in the potential of farmland productivity as a result of the impact of farmland use. From1995to2000, there was an increase of48.08million tons and a decrease of24.748million tons in the farmland productivity potential, with a net increase of23.34million tons. The increase area was mainly distributed in the northeast China,north China and the loess plateau, while the reduce area was mainly distributed in the Yellow-Huai-Hai region and the Yangtze river delta farmland-town conversion area. From2000to2005, there was an increase of21.21million tons and a decrease of51.00million tons in the farmland productivity potential, with a net decrease of29.75million tons. The increase area was still northeast China, however the net increase was far less than the first five years, while the decrease one was mainly distributed in the Yangtze river delta and the Pearl River Delta. So land use change can be known as the principal cause of change of the farmland productivity potential.