基于主成分分析及GIS的环渤海区域土壤质量评价

Quality evaluation of soil in land along Bohai Sea Coast by principal component analysis and GIS

以环渤海沿海地区为研究区域,在进行土壤详细调查的基础上,进行具有代表性样点土壤样品（0-30 cm）的采集,并对土壤的养分、盐分和质地等理化性质进行系统测定,选取土壤盐分、p H值、碱解氮、有效磷、速效钾、有机质、全氮、砂粒质量含量、黏粒质量含量为土壤质量评价指标,采用主成分分析综合得分法,结合GIS技术,进行环渤海区域土壤（0-30 cm）质量综合评价.研究结果表明：土壤有机质、全氮和黏粒含量对土壤质量产生正面影响,而土壤全盐含量、p H值及土壤砂粒含量则产生负面影响;获得了土壤质量评价的主成分得分综合模型;土壤质量综合得分在空间分布上具有明显的地带性,根据综合得分划分为6级地力等级,研究区50%以上面积属于五或六级地力水平,土壤质量低下.在此基础上,分析了各土壤质量等级的主要影响要素,可为针对性综合提升环渤海区域土壤质量提供理论依据.

Considering the land along Bohai Sea Coast as the study field,based on a detailed survey on the field,soil samples are collected at representative points across 0-30 cm depth layer,then the physical and chemical properties,such as soil nutrient,salt and texture and so on are measured.The evaluation indexes include soil salt content,p H,nitrogen,phosphorus,potassium,organic matter,total nitrogen,sand content,clay content.Finally,principal component analysis and GIS technique are used to evaluate soil quality comprehensively.The results show that the soil organic matter,total nitrogen and clay content have a positive effect on soil quality,but the soil salt content,p H,and soil sandcontent have a negative impact.The composite score of soil quality is obtained and a soil quality grade is established.The study field can be divided into six fertility levels according to soil quality composite scores.It is turned out the soil quality in the study field is so poor that its more than 50% areas belong to the 5th and 6th grades.The results of the study can provide an important reference for comprehensive improvement in soil quality in the land along Bohai Sea Coast.