Xia Li: Plant Stress Physiology and Molecular Genetics 

The Research on Real area of Mountain Arable Land Based on GIS and RS in Lincheng County

Limei Tan, Huitao Liu, Hongjuan Liu and Jintong Liu 

China is currently faced with a growing shortage of arable land; in 2006, there were only 0.095 hm2 of arable land per capita. Much of China is mountain, but few research papers focused on mountain arable land. At the same time, because of the complex topography and dispersed field blocks, so it is hard to get the correct mountain arable land area. But in this paper, we will use an effective method named RS to get the correct mountain arable land area and location. The aim of this research was to find how many arable lands existing in mountain area and compare our estimates with official statistics.

We selected Lincheng County in the mountain North China as our research area. The study involved GIS analysis with resolutions of 90m SRTM DEM, 2.5m panchromatic SPOT5 to identify arable land in the county. The arable land referred in this paper is that being used currently for cropping. The accuracy of our classification was tested by visiting sampled sites and the classification was accurate in 90% of cases. We found considerable differences between estimates of arable lands in mountains of Lincheng County derived from image interpretation results and those from official statistics. The differences were due to conversion of farmland back to forest, difference in definitions of the minimum block size for arable land and infrequent use of the arable land. In the end of the paper, we also give some advice how to use these lands.