基于SDI校正指数的滨海平原盐渍化生态风险评价

Ecological risk assessment of salinization in coastal plain based on SDI correction index

为了研究滨海平原区土壤盐渍化风险情况,本研究以黄骅市为研究区,将Landsat 8夏季遥感影像获得的SDI(盐渍化植被监测指数)校正指数作为生态终点,采用相关性分析法筛选土壤生产潜力和土壤健康方面指标,最终选取含盐量、电导率及有机质、K^+、Na^+、Mg^2+、SO4^2-、Cl^-含量8个指标,借助SDI指数标准化校正的灰色关联度法构建盐渍化生态风险评价模型,对滨海平原区盐渍化生态风险进行定量评价及空间分析。结果表明:研究区内盐渍化生态风险值介于0.24~0.73,均值高达0.42,其中99.25%的区域处于中度及以上盐渍化生态风险水平,整体上土壤生态风险较高,呈现东部沿海高、西部平原低的趋势;盐渍化生态风险评价在空间上与土壤含盐量、土壤电导率较为相似,因此,土壤含盐量及电导率对盐渍化生态风险评价起主导作用。研究区内盐渍化生态风险及评价因子的空间分布可为生态环境、农业健康持续发展、地下水的限采禁采、土壤改良和盐渍化防治提供参考依据。

Soil salinization is the main ecological problem of land in coastal plain areas.In this study,Huanghua City was chosen as the research area.The soil salinization distance index(SDI)correction index obtained from the Landsat 8 summer remote-sensing image was taken as the ecological endpoint.The soil production potential and soil health indexes were screened by correlation analysis.Finally,eight indexes,salt content,conductivity,organic matter,K^+,Na^+,Mg^2+,SO42^-content,and Cl^- content were selected.Based on the grey correlation degree method of the SDI correction index,the ecological risk assessment model of salinization was constructed.The risk of salinization in coastal plain areas was evaluated quantitatively and spatially.The results showed that the ecological risk value of salinization in the study area varied from 0.24 to 0.73.The average value was as high as 0.42;99.25%of regions had moderate or above salinization ecological risk;and the ecological risk of soil was extremely high,which was generally in the eastern coast.The spatial distribution of the evaluation factors was large,and the salinization ecological risk evaluation conducted was similar in the space with the soil salt content,and soil conductivity.The salt content and the conductivity of the soil play a leading role in the ecological risk evaluation of salinization.In conclusion,the results of soil salinization risk can be used as reference for the ecological environment,sustainable development of agricultural health,limited mining of groundwater,soil improvement,and the prevention and treatment of salinization.