一种基于对象和快照的混合地表覆盖时空数据存储模型

A Mixed Land Cover Spatio-temporal Data Model Based on Object-oriented and Snapshot

时空数据模型是数据库和时空数据分析研究热点之一。由于时空数据变化类型多、分析计算复杂及应用范围广,一种观点认为建立通用的时空数据模型具有高度复杂性。本文针对地表覆盖变化时空数据建库和时空分析应用需求,提出了基于对象和快照的混合时空数据模型。该模型用面向对象描述地表覆盖的斑块对象时空过程,组织管理斑块对象时空事件和空间、属性信息,同时用快照描述地表覆盖整体时空分布,组织管理栅格快照,两者通过基于时间和空间位置的逻辑关联关系形成混合模型。模型在表达对象自身变化的时空事件类型基础上,增加了不同分类对象之间互相转变的时空事件表达。该模型既可以用于对地表覆盖历史观测数据组织存储建库,又可以用于支持时空统计分析、时空演变模拟和时空数据挖掘。通过对黑龙江地区地表覆盖时空数据建库、查询检索、整体格局演变分析和斑块变化时空过程检索与表达的试验,验证了模型的有效性。

Spatio-temporal data model（STDM） is one of the hot topics in the domains of spatio-temporal database and data analysis.There is a common view that a universal STDM is always of high complexity due to the various situation of spatio-temporal data.In this article,a mixed STDM is proposed based on object-oriented and snapshot models for modelling and analyzing landcover change（LCC）,This model uses the object-oriented STDM to describe the spatio-temporal processes of land cover patches and organize their spatial and attributive properties.In the meantime,it uses the snapshot STDM to present the spatiotemporal distribution of LCC on the whole via snapshot images.The two types of models are spatially and temporally combined into a mixed version.In addition to presenting the spatio-temporal events themselves,this model could express the transformation events between different classes of spatio-temporal objects.It can be used to create database for historical data of LCC,do spatio-temporal statistics,simulation and data mining with the data.In this article,the LCC data in Heilongjiang province is used for case study to validate spatio-temporal data management and analysis abilities of mixed STDM,including creating database,spatio-temporal query,global evolution analysis and patches spatio-temporal process expression.