Study On The Planning Of Basic Farmland Based On The Evaluation System Of Farmland Quality And Site Condit-ions

The basic farmland is the essence of farmland and also an important guarantee for stabilizing grain productivity.traditional mechanic of farmland planning depend on the farmland quality conditions, and consider less of the farmland site conditions, which lead the basic farmland frequent adjusted, delimited and destructed frequently, the quantity of the basic fannland is decreasing, the quality is declining and the stability is poor, all these problems seriously distort and violate the national law purport of the basic farmland planning, and touch the authority of land use planning. The paper is based on the analyzing the connotation and the functional properties of the farmland and put forward that farmland quality and site condition are two necessary conditions for fannland planning. On this basis, the paper constructs the evaluating system of farmland quality and site conditions, conducts the evaluation of farmland quality and site conditions, and analyses the characteristics of the farmland quality and site environment conditions. Finally, the comprehensive evaluating system of farmland quality and site conditions are constructed Referencing to American LESA system idea, the criteria is constructed on the basis of the above research, all these guarantee good farmland quality and coordinated site conditions and permanent stability of the planned farmland.(1) The paper defines the basic farmland connotation, puts forward that the basic farmland refer to high-quality, sectors-connecting, pennanent, stable of farmland. On this basis, the functional properties of the basic farmland are analyzed, including six special features, the theory system of the basic farmland planning is constructed on the basis of above functional properties, fannland quality and site conditions are necessary considered and none is dispensable in the basic farmland planning.(2) The paper constructs the system of farmland quality evaluation,the system of farmland site evaluation and the comprehensive evaluation system of farmland quality and site conditions, in which, the fannland quality evaluating system uses ArcGis software as primarily technical means, evaluation units are drawing by superposition method. Referring to agricultural land classifying system, six index constituted of soil conditions as dominant natural elements for fannland quality evaluating are determined by lessons learning and Delphi method, the comprehensive index model is constructed for fannland quality evaluation. In the system of fannland site conditions, it selects the conditions of social economic development, fannland connectivity and Landscape pattern relating with farmland using as evaluating index, and develops the evaluation of above conditions separately. On this basis, the evaluation system of farmland site conditions is constructed by comprehensive index mode. The comprehensive evaluation system are combined the evaluation system of farmland quality with the evaluation system of site conditions, the model of the combined system is Fij=a×Fi+b×Fj, and it’s weight ratio varies with the service of different objects.(3) The pape carries out the empirical study of constructing the comprehensive evaluation system of farmland quality and site conditions in the study are of Lingyuan City, it measures the weight ratio between farmland quality and site conditions in the evaluation system from the object view of promoting the ability of food productivity, the ratio is 3:2. The comprehensive evaluation system of farmland quality and site conditions is constructed based on the weigt ratio. The empirical results show that the natural factors of farmland are predominant in the basic farmland planning.(4) The paper discusses threshold critical point of the planning basic farmland on the result of the comprehensive evaluation, it analyses changing differences in the critical point range, and the farmland zone is divided into realistic basic farmland zone, potential basic farmland zone, reserve zone for construction using, transformation zone for low yield farmland or ecological restoration zone.The pape carries out the empirical study of planning the basic farmland based on the evaluation results of the comprehensive evaluation system of farmland quality and site conditions in the study are of Lingyuan City. The appropriate ratio of planning the basic farmland in the area is 60.35%, which guarantee good quality conditions and coordinating with social economic development, the planning basic farmland is permanent stability.