Study On The Suitability Evaluation Of Farmland Fallow Of Maoli Lake Basin Based On Bayesian Network Model

Maoli Lake,as the largest stream water lake and the second largest natural high-quality freshwater lake in Hunan Province.It officially became a national wetland park in August 2016,with important ecological functions such as water conservation,water purification,biodiversity maintenance,flood storage and drought prevention,climate regulation,and carbon sequestration.In recent years,due to excessive development of agricultural land and fishing for all,water quality has deteriorated significantly,making local ecological and environmental issues increasingly prominent.Therefore,conducting the suitability assessment of agricultural farmland fallow in the Maoli Lake region is an important means to optimize agricultural production layout,scientifically select fallow areas,achieve rational resource allocation,and protect the ecological environment of water sources.In this paper,based on Bayesian network model,combined with the geographical environment of Maoli Lake Basin,the current situation of farmland and ecological characteristics,firstly from the cultivation suitability,and protection suitability of two aspects of a comprehensive balance,the construction of farmland fallow suitability evaluation index system.Secondly,the ArcGIS10.8 was used to extract the layer list information and process the index layer data by combining spatial analysis and attribute database linkage.Dry land(14.09%)and paddy field(35.53%)were evaluated areas in this paper.Then,based on the conditional probability table of experts’ evaluation of filling target layer and criterion layer,the Bayesian network model was established to calculate the posterior probability of fallow suitability,and the probability of different states of cultivation,protection and fallow suitability in Maoli Lake Basin was evaluated.Finally,GIS was used to determine the spatial distribution of fallow suitability,and the farmland fallow suitability in the study area was divided into three levels,and the policy suggestions were put forward.