一种基于对象和快照的混合地表覆盖时空数据存储模型

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。

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

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 spatio-temporal 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 expressi on.