Spatiotemporal changes of maize sown area and yieldin Northeast China between 1980 and 2010using spatial production allocation model
TAN Jieyang;LI Zhengguo;YANG Peng;LIU Zhenhuan;LI Zhipeng;ZHANG Li;WU Wenbin;YOU Liangzhi;TANG Huajun;Key Laboratory of Agri-informatics,Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences;Geography and Planning School of Sun Yat-sen University;Environment and Production Technology Division,International Food Policy Research Institute;
Understanding crop patterns and their changes on a large scale is a critical requirement for projecting agro-ecosystem dynamics. However, tools and methods for analyzing crop sown area and yield on spatiotemporal variations are still insufficient currently. By the use of cross-entropy method, a Spatial Production Allocation Model(SPAM)was developed. Combined with geographic spatiotemporal analysis methods, a case study was further presented to analyze the spatial characteristics of maize sown area and yield in Northeast China during 1980-2010 within 5' × 5' grid cells. The results indicated the following:(1) Maize sown area mainly expanded northwards during 1980-2000(located at 44°N-48° N) and then concentrated at central and southern in Northeast China on latitudinal variations in the following years. Also it moved eastwards(located at 123°E to 127°E) and lower elevation(below 100m) as well as higher elevation(mainly from 200 m to 350 m)region on longitudinal and altitudinal variations, respectively.(2) Maize yield which has been improved largely mainly located at 42°N to 48°N and concentrated at the region below the altitude of 350 m on latitudinal and altitudinal variations, respectively, while its increase is relatively homogeneous on longitudinal variations.(3) Additionally, dominant maize proportion on a pixel scale has developed to middle-high proportion gradually during1980-2010, and maize yield located at the pixel of middle-high proportion seems higher,which reflected the trends of agglomeration and large-scale development of maize cultivation driven by market economy.