基于矢栅混合数据模型的土地适宜性评价研究

土地适宜性评价一般为单独基于栅格数据模型或者单独基于矢量数据模型。单一的数据类型在进行土地适宜性评价时对信息的表达难免存在不足。结合面向对象的思想，以土地评价的对象个体为评价单元，利用矢量数据的评价单元边界来分割各类因子作用分值数据，并将评价单元对象内数据统计分析后的结果通过栅格图斑标号对象的联接，入库作为评价单元该因子的作用分值，再根据确定的各因子权重，计算因子的综合评价分值来建立矢量栅格混合数据模型。在此基础上实现了算法，并以浙江省标准农田建设为例，在标准农田立地条件评价中进行了试验。试验结果表明，提出的矢栅混合数据模型能够较为全面地反映地块的各方面要素信息，保证了土地适宜性评价的准确性，并为土地适宜性评价的数据混合提供了一种新的思路。

LAND ADAPTABILITY EVALUATION BASED ON VECTOR-RASTER MIXED DATA MODEL

Currently,most cases of land adaptability evaluation are based on either raster data model or vector model,boiling down to the incompleteness of information in the evaluation process and costing the assessment accuracy.Therefore,the combination and the full use of the advantages of raster and vector data models together could largely improve the accuracy and efficacy in land adaptability assessment.Based on such idea as object-oriented modeling,this article puts forward vector-raster mixed data model for land adaptability evaluation as well as the approaches of implementation.Firstly,raster data is segmented to raster objects by the linear boundary of land unit in vector data,and then the raster objects are linked to their corresponding vector counterparts with unique raster object labels.Next,statistic features in each raster object are extracted and added to the vector counterparts as attributes.Following this approach,information of each land adaptability index is figured out and stored in the database for future calculations.At last,according to the weights of each index,the comprehensive evaluation is conducted by weighted summation for each land unit.To demonstrate the improvement of this method,the constructions of high quality prime farmland in Zhejiang Province is taken as a case study.