DEM-based Grid Data Generation And Potential Land Productivity Evaluation In Datong

How to evaluate the potential land productivity in area with diversified physiognomy types, and how to generate gridded datasets with the objective of establishing a sound-developed evaluation model are important and fundamental work for studying agriculture production, environment protection and the sustainable use of water and soil resources at regional scale..The mountains and hills cover approximately 60% of its total land areas in Datong. The complex terrain conditions characterized by mountainous regions induced high spatio-temporal variations on such eco-environmental variables as sunshine hours, solar radiations, temperatures as well as precipitations. The variations of these variables result in highly differed conditions in heat and water, which will directly determine the potential land productivity in Datong. Quantification of these eco-environment variables in space and time domains, and the generation of griddized datasets with the objective of carrying out potential land productivity evaluations are the main research questions needs addressing in the thesis.The thesis is based on a DEM-derived approach to generate the gridded datasets and perform potential land productivity analysis on agricultural lands in Datong, using GIS as a main research tool. The research started from establishing the distributed spatio-temporal model on eco-environmental variables in mountainous areas in Datong. The gridded datasets of these variables under the conditions of complex terrains such as sunshine hours, solar radiations, temperatures, precipations as well as crop reference evapotranspirations were generated. Proceeding from this, the FAO-AEZ approach is adopted to simulate the potential productivity in crops like spring wheat, maize and sorghum. The results demonstrated the significant constraints imposed by factors like terrains, precipitations as well as land qualities, thus showing the necessity of optimizing cropping patterns, reinforcing agricultural water infrastructure, establishing appropriate irrigation system, and improving soil qualities in the studied areas. Therefore, the results released from the research will not only offer valuable references for landuse evaluations in comparable mountainous and hill regions, but will shed light on the sustainable rural and regional development in Datong.