Temporal and Spatial Characteristics Analysis of Relation between Arable Land Non-agriculturalization and Food Productivity based on GIS Technique

With population growth and fast economic development in China,arable land non-agriculturalization process speeds up with the conversion of cultivated land into construction land and thus food security is now attracting more attention than ever before.The three provinces in Northeast China(Heilongjiang,Jilin and Liaoning Province)were selected as the study area to implement the research related to arable land conversion in this paper.We adopted GIS technique to analyze in detail the spatial characteristics of arable land non-agriculturalization,spatial relation of arable land conversion,comprehensive quality index of arable land,high-yield field and the spatial distribution of food production decrease caused by non-agricultural conversion of arable land.The study results indicated that:1)The acreage of non-agricultural arable land reached a total area of 16.599×104hm2 with a conversion rate of 1.012%in the three provinces during 1993～2003.Jilin and Heilongjiang Province are the highest one and lowest one in area of arable land non-agriculturalization respectively.Moreover,arable land non-agriculturalization in Liaoning and Jilin Province were spatially characterized by"cloud flake"and"paralleled strip"respectively.Arable land non-agriculturalization in counties,which are adjacent to sea and have superiority in location,was at a high level;2)Jilin was the province with the largest acreage of arable land non-agriculturalization,but converted arable land was mostly at low and medium quality levels.By contrast,high quality arable land in Liaoning province was mainly converted.The acreage of arable land non-agriculturalization in Heilongjiang province was least and non-agicultural arable land was mainly at low and medium levels;3)High-yield fields concentrate in Songliao Plain and nearly 50%of highly non-agricultural areas of arable land distributed in the high-yield fields,which were most affected by arable lands conversion in Jilin province;4)The total amount of food loss caused by arable land non-agriculturalization in the three provinces during 1993～2003 was up to 9.106×108kg,of which 59%was in Jilin Province and the total loss could feed 5 million people for one year according to the study.It is the relation between economic development and arable land protection that decides the implementation of the policy of"keeping dynamic balance of total arable land area"in the study place.