基于GIS的典型黑土区海伦市耕地地力评价研究

Assessment of cropland productivity based on GIS for typical blacksoil region at Hailun County

以海伦市农田耕层0~20 cm采集的577个样点数据、土地利用现状图、区划图、土壤图和地貌图为基础数据,利用GIS空间分析、数学和土壤学等多学科交叉的方法,以多项重要指标为依据,对海伦市耕地地力进行了定量化的分析和评价。评价结果表明海伦市耕地地力整体水平为:一级地面积占总耕地面积的32.1%,二级地面积占52.9%,三级地面积占16.0%。结果表明实现了对典型黑土区海伦市耕地地力分等定级,明确了不同等级耕地的面积、空间分布格局,为探讨制定科学的培肥政策、提高作物产量和土壤基础地力,保护生态环境提供了定量化的分析依据。

The assessment of cropland productivity was conducted based on GIS,combined with fuzzy mathematics and soil sciences in Hailun County in black soil region,northeast China.In the study,the 577 soil samples with 0-20 cm layer were collected from the field in all the Hailun County,and the geostatistics and Kriging method were used in the study in order to analysis the spatial heterogeneity of soil nutrients and built a soil nutrients map.Other maps such as the soil map,land-use map and regional map with village boundary also were collected and treated using ArcGIS.The database was established by the collecting data,and prepared for the analysis.Then the assessment unit was created by overlay the maps of landuse actuality map,soil map and regional map.The 12 essential factors,which were decided from the aspects of the soil nutrients,soil physic-chemistry character,site condition and land management,including Som(soil organic matter);Ap(available phosphors);Ak(available potassium);soil texture;pH;≥10 ℃ accumulated temperature;landforms;gradient;slope aspect;plough layer thickness;type of soil obstacle and position of soil obstacle were selected as evaluation indices by using Delphi model.Linking with the AHP(Analytical Hierarchy Progress),and with GIS flatform,the cropland productivity was evaluated.Finally the evaluation results were obtained by counting and analyzing the assessment outcomes: The results indicat that the area of 1st,2nd,3rd grade cultivated land are 98 839 hm2,159 817.9 hm2,49 093.4 hm2,which constitute the rates of 32.1%,52.9%,16.1% of the total area of the cultivated land respectively.The research has achieved quantitative evaluation on cropland productivity level in Hailun County,and has verified the area of cultivated land of different level and the space distributing pattern.So this research can provide scientific and quantification foundation for making scientific fertilizer policy,improving crop production and the soil fundamental fertility,and protecting ecological environment.