Study On Rapid Estimating Wide Range Of Cultivated Land Area Using High-Medium-Low Resolution Of Remote Sensing Images

Grasping the information of cultivated land area in time is extremely important to agricultural production. However, China is a country with a vast territory, and the cultivated land is widely distributed, complex, and variable, which makes it extremely hard to monitor the cultivated land. The use of remote sensing images technology to extract cultivated land is time-limited, reduces the workload greatly, and is also with great advantages. It is realistic significance to have a scientific judgment simply and fast on cultivated land use status and provide timely information services for relevant decision-making departments.At home and abroad, low-resolution remote sensing images are used to estimate cultivated land area in a wide range. It makes the result low-precision. While we using high-resolution remote sensing images could have a result with high-precision, the study area is much huge, much more workload is needed. It is not economic or efficiency. It’s extremely hard to estimate a wide range of cultivated land with high-precision. To solve this problem, this paper provides the solution of estimating a wide range of cultivated land with high-precision, which is sampling the high-resolution, mid-resolution, and low-resolution of remote sensing images step by step, and using farming division as homogeneous area.Take Shandong Province for example, we take the use of MODIS images, CBERS-2B CCD and HR images to sample, calculate the accuracy among different images, and correct accuracy step by step. At last the cultivated area of Shandong Province is calculated. Compared with the statistical data in the same year, the results show that:(1) High-resolution, mid-resolution, and low-resolution of remote sensing images are used to sample, calculate, and estimate the area of cultivated land in Shandong Province. The result is only8.07%higher than statistical data in the same year. It indicates that the method is in good operation, raised the accuracy, and also satisfies the demand of monitoring a wide range of cultivated land. Therefore, it can be well used in agriculture production and research.(2) After the analysis of the information in study area extracted from CBERS-02B satellite HR image, the value difference between area of the cultivated land and that of the CCD image shows that mainly of the differences are caused by the mixed pixel in CCD image between small features (such like path, drain) and cultivated land around. In study area,10%-20%extracted area of cultivated land is these small features. The percentage does not alter with the change of topography factor and cultivation index.(3) After the analysis of the information in study area extracted from CBERS-02B satellite CCD image, the value difference between area of the cultivated land and that of the MODIS image shows that mainly of the differences are caused by the mixed pixel in MODIS image between the features less than25hectares (such like road, river, pond) and cultivated land around. These features occupied20%-40%in the cultivated land area extracted by using MODIS image within the same study area. In contrast, the percentage will be different with the alternation of topography factor and cultivation index, and they are negative related.