Research On The Downsizing Technology Of Land-use Maps In The Third National Land Survey Based On FME

Land use status data is one of the key data of the country in order to grasp the country 's land use characteristics and whether the land use is reasonable.A large-scale land survey will be carried out on the country every ten years.A new round of land survey was just completed last year,Obtained the national land survey results data with a scale of 1: 10000.However,the scale of land use status data required by different levels of land management departments is different,so the original data needs to be synthesized to obtain other land use status data of different scales.The land use map data is the main data in the land use status database.It has the characteristics of full coverage,no overlap and no gap.It is the research object of this paper.It automatically synthesizes the land use map of 1: 10000 scale into The 1: 50000 scale of land-use plots is the goal of this study.Based on the existing research results,this paper proposes a three-level rule system based on scene-category-pattern to control the automatic synthesis of patches,and uses production rule expression method to express the rules in the patches of land-use land.In the way of workflow,make full use of the geoprocessing tools and map synthesis tools provided by the FME platform,and use the most appropriate geoprocessing tools and the best execution order to design solutions for the rules and key issues in the automatic map synthesis process Flow,including patch fusion workflow,patch reduction dimensional workflow,patch enlargement workflow,patch border simplified workflow,category-level synthesis workflow,scene-level synthesis workflow,etc.,Designed a workflow for automatically synthesizing land-use plots,and solved the problem of conversion of plots and scales.Taking the latest land use map data of XX City as experimental data,according to the geographical characteristics,comprehensive purpose and scale requirements of XX City,an automatic synthesis model and process of land maps were designed.Finally,based on the automatic integrated workflow,1: 50,000 square scale map data.Then visually and quantitatively evaluate the results of automatic synthesis.The quantitative indicators select the transfer amount of land type,the distance of the weighted center of the land type in each township,and the layout stability,structural similarity,semantic similarity and other evaluation indicators of various types of land.Before and after the calculation of the maps,the structural similarity index is 0.88,the layout stability index is 0.86,and the semantic similarity index is 0.85.