基于GIS与属性识别模型的土壤肥力综合评价

Comprehensive evaluation of soil fertility based on GIS and attribute recognition model

运用基于熵权的属性识别模型,对三江平原试验区100个土壤样品的全氮、有机质、pH值等7项土壤物理和化学指标进行综合评价,在GIS技术的基础上绘制土壤肥力空间分布图。结果表明:试验区的土壤肥力总体水平较高,90%以上的区域属于肥沃、较肥沃水平;土壤氮素和有机质有下降趋势,土壤中的磷、钾元素过低且分布极不均衡,需保持和提高该地区土壤肥力水平,实施平衡施肥;评价方法识别准确、简单稳定,很大程度上减小了主观因素的影响,能为土壤肥力信息系统及专家决策系统提供有力的技术支撑;评价结果直观实用,能够为改良土壤、调节农业产业结构提供直接的科学依据。

Attribute recognition model based on entropy weight was used to evaluate the soil fertility of typical region in Sanjiang Plain, which contained 100 soil samples with 7 physical and chemical indexes, including soil total nitrogen, soil organic matter, pH value etc. Then spatial distribution map of soil fertility was delineated on the basis of GIS techniques. Results indicated that the overall level of soil fertility in typical area was higher, 90% of the soil was in a fertile or relative fertile level, soil nitrogen and organic matter had degressive trend. Soil phosphorus and potassium was lower and had extremely unbalanced distributions. Therefore maintaining and advancing soil fertility and actualizing balance fertilization techniques were necessary measures for the region. Evaluation methods in the study had precise recognition function, simple and steady structure and minished the affection of subjective factors to a great extent, which gave information system of soil fertility and expert decision system a powerful technological support. Evaluation results were intuitive and practical, and can provide immediate scientific basis for soil improvement and agricultural industry adjustment.