Cultivated Land Productivity Distribution And Basic Farmland Demarcation Based On Productivity Calculation

China is currently in a period of rapid economic development. Due to the sharp contradiction between human and land and inevitable decreasing trend on land resources, crop productivity is largely restricted. At such circumstances, Conducting cultivated land productivity calculation which reveals the distribution of cultivated land productivity in certain areas, shows a significant meaning to achieve cultivated land management both in quantity and quality, and it greatly guarantees the comprehensive productivity of cultivated land. With a fully review on basic theories and methods of cultivated land quality evaluation and cultivated land productivity, this study takes Enshi City, Hubei Province as an example, mainly discusses the cultivated land productivity distribution and basic farmland demarcation based on productivity calculation as below:1) Cultivated land productivity and result analysis. Based on agricultural land classification results, the theoretical and achievable productivity calculation model is firstly built. Combining the latest land use survey data and outdoor supplementary investigation data, the theoretical, achievable, and actual cultivated land productivity are finally obtained. It is figured out that in2010, the total area of the cultivated land in Enshi is81392.09ha, the theoretical, achievable, and actual cultivated land productivity is respectively11599.20kg/ha,10347.19kg/ha,9600.08kg/ha; while the average theoretical, achievable, while the actual cultivated land productivity is respectively94.4082,84.2184and78.1433thousand tons. Regardless of the differences among the3levels productivity, there exists an overall cultivated land productivity distribution feature that central plains higher than eastern and western mountainous areas in Enshi.2) Cultivated land productivity usage intensity and usage potentiality evaluation. By evaluating the cultivated land productivity usage intensity and potentiality of each town from different levels, it shows some unreasonable phenomenon in cultivated land management and operation still exist. Some towns’ cultivated land productivity usage intensity and potentiality are even unbalanced, and measures to enhance those towns’ productivity is promoted.3) Cultivated land productivity distribution pattern and variation. Globe spatial autocorrelations analysis indicates the3levels productivity, as well as the theoretical productivity usage intensity and theoretical usage potentiality, they all show some sort of autocorrelations, the spatial aggregation order of these3levels productivity above is: theoretical productivity>achievable productivity>actual productivity; while no autocorrelations are found in theoretical productivity usage intensity and theoretical usage potentiality. On the other hand, those towns whose local spatial autocorrelations type of the3levels productivity, the theoretical productivity usage intensity and theoretical usage potentiality represent H-H, all gather around central downtown areas, such as WuYangba and XiaoDuchuan, which reflects a positive development trend.4) Basic farmland demarcation based on productivity calculation. Based on the results of cultivated land productivity calculation, a basic farmland demarcation indicators system is built to emphasize the bottom quality and site conditions of basic farmland, while GIS techniques are used to acquire the attribute data of each indicator. According to the latest land use planning, this study finally demarcates50322.64ha of cultivated land as basic farmland. Compared to the currently demarcated basic farmland, the basic farmland demarcation method based on productivity calculation is proved to be a practicable approach, it shows a more reasonable result that largely excluded human interference, providing a new idea to traditional basic farmland demarcation.