森林资源空间数据更新模型

Updating Technology of Spatial Data of Forest Resource Based On Temporal-GIS

森林资源小班是森林资源二类调查、统计和经营、管理的基本单位,通过研究其变化的形式和影响其变化的因素,得到的结果可以适用于整个森林资源空间数据。本文依据小班对象的空间变化和属性变化,将其变化归纳为8种基本变化类型。对传统基态修正模型查询速率低下的问题予以解决:使用动态多级索引的方法进行模型的改进,同时,用面向对象的方法对小班空间数据更新的时空信息进行描述,构建了基于版本的多基态修正扩展时空数据模型(VBMBSEA-STDM),很大程度上提高了二类调查数据的准确性和更新速率,更加有利于实现历史查询和分析。在研究的基础上,通过GIS分析凉水实验林场1999年和2009年小班调查数据,得出小班数据的具体变化形式,构建森林资源空间数据更新时空模型,实现历史比较和回溯。

Spatial data of forest resource is that related data which has characteristic of space geometry.It mainly comes from the forest resources survey,including the national forest resource continuous inventory and the local annual survey.It often lost information of time among the surveys.It causes difficult to achieve the characteristics of historical inquiry.Therefore,temporal-GIS was introduced in this paper.The sub-compartment is the basic unit of forest resource investigation and management.Taking it as the main research object,as the same time,introducing the time factor,we have established a data update model based on temporal-GIS.The object of this model is to improve the update rate realize the historical query of forest resources spatial data.In this paper we have analyzed the changes of forest resources spatial data and has understood those changes are due to reasons such as natural growth of trees,disasters,legal and illegal human activities and the survey error.According to the variation of space and attribute,the variation type of sub-compartment is divided into eight basic ones.Through described temporal and spatial information of sub-compartment updating we have improved the traditional base-state with amendments by the way of dynamic classification indexes.At the same time,we have extended model through object-oriented and version management.On this basis,we structured a new spatio-temporal data model named version-based multi-base state extended spatio-temporal data model with amendments which is short for VBMBSEA-STDM.The article has a systematic description of model mainly about the three aspects： data structure of sub-compartment object,basic spatial operation of sub-compartment object and data storage of sub-compartment.According to the study,by analyzing the data of Liangshui experimental forest in 1999 and 2009,it reaches the specific changes form of sub-compartment data.It has constructed a spatio-temporal data update model of forest resource to realize the historical comparison and backtracking.