Delineation of parcels in agricultural lands in remote sensing

With advances in agricultural technology and know-how, agricultural fields have increased by twelve percent and agricultural production has almost been doubled over the last fifty years. On the contrary these advances have also caused significant environmental change in many regions despite the increased food production. Hence, accurate information about irrigated lands is crucial in order to make further progress in agricultural production. Updated information about the use of each agricultural parcel is anticipated to be very valuable for diverse agricultural-related agencies and research purposes. Since many applications such as updating cadastral information, land-cover or land-use mapping, estimate of agricultural subsidies require primarily a parcel-based study, a correct delineation of the parcels becomes very crucial. In this paper, we propose an algorithm for automatic delineation of agricultural parcels. We first apply watershed segmentation to high resolution remote sensing imagery. Applying watershed segmentation yields many superpixels which do not correspond to the actual parcels in the scene. We assume that the geometric and texture properties of parcels to be segmented are different from each other, but they are similar for the superpixels that fall into the same parcel. In order to improve segmentation, the superpixels are merged based on two basic assumptions: (a) Superpixels that have similar textural characteristics and which are also within close proximity of each other should be merged. (b) The contraction within a group of merged superpixels should be minimized. In order to evaluate the performance of the proposed method, percentage of correctly segmented parcel areas are computed with respect to the manual ground truth delineation. The experimental results on pilot rural areas in south eastern part of Turkey confirm that the proposed method is quite promising.