土地变更调查数据库质量评价及其错误空间自相关分析——以河北省为例

Quality Evaluation and Error Spatial Autocorrelation Analysis of Land Change Survey Database: A Case Study of Hebei Province

评价土地变更调查数据库质量,研究数据库错误产生的原因是变更调查工作中的关键问题。本文采用对比分析法定量分析3年间数据库质量变化,并运用全局Moran's I系数、局部Moran's I系数,从县域尺度分析数据库错误的空间自相关格局,揭示数据库错误空间分布变化和局部异常特征。研究结果表明:(1)从错误数量、缺陷等级、错误分布图层和空间分布方面进行评估,河北省2012年数据库质量相较于2010年和2011年得到明显改善;(2)河北省各区县错误分布保持高度自相关,聚集程度波动变化,而局部显著性异常区域的出现主要源于人为误操作。通过研究数据库质量3年间变化情况及空间分布格局,能客观地评价数据库质量状况,有效地分析错误产生的原因,为新一轮土地变更调查工作提供建设性意见。

Land change survey is an important survey for investigating national conditions and national strength. The purpose of land change survey are： identify the nationwide land use status and changes in the year of con- cern; maintain the accuracy and timeliness of national land survey data and the basic information of the compre- hensive land and resource supervision platform; and meet the requirements of land and resource management as well as economic and social development. Officially released land change survey results are the basis for the im- plementation of planning, management, protection and reasonable utilization of land and resources, the strategic planning of national economic and social development, and other relevant special-purpose plans. There still are problems that need to be solved, such as how to ensure the authenticity and accuracy of land change survey re- sults, how to improve the work efficiency of land change survey with new technology, and how to shorten the er- ror modification time. The purpose of this paper is to evaluate the quality of land change survey database and an- alyze the causes of database errors. For a quantitative analysis of the changes of database quality in 2010, 2011 and 2012, comparative methods were employed. Methods known as Moran＇s I and local Moran＇s I were adopted to analyze the spatial dependence in observations of database errors among administrative units, and to reveal the change of spatial distribution and the anomaly characteristics of database errors in local areas. To be specific, five steps are required for quality evaluation and pattern analysis. Firstly, the descriptive chart of original errors at the county level is processed in batch transaction by software, and then is aggregated into database tables. Sec- ondly, since the quality inspection rules were found inconsistent among 2010, 2011 and 2012, it is impossible to use a comparison analysis method, thus we preprocessed the data and acquired the common quality inspection rules for the three-year period. The third step is to use the comparison analysis method to assess the database quality from different aspects, including the defect levels, the main check items of errors and the spatial distribu- tion. The fourth step is to define the database errors by observing through the global autocorrelation method in analyzing the land change survey of Hebei province, and obtaining the spatial distribution characteristics and the influential factors of database errors. Finally, the spatial pattern of the phenomenon was reflected and the causes of database errors were explained. The results showed that the quality of the database of Hebei province in 2012 have been improved significantly according to the number of errors, the defect levels and the spatial distributions in assessment. In addition, the distribution of Hebei＇ s database errors were high autocorrelated with the fluctua- tion of aggregation level, while the generation of local anomaly was usually derived from artificial error. It is concluded that throughout the quality analysis of the research database and its space distribution pattern in three years, we can evaluate the changes of database quality objectively and identify the causes of database errors ef- fectively, therefore provide a forecasting and monitoring approach to new land change surveys.