生态风险分析用于苏北滩涂土壤盐渍化风险评估研究

APPLICATION OF ECOLOGICAL RISK ANALYSIS TO SOIL SALINIZATION RISK ASSESSMENT OF COASTAL TIDAL FLAT IN NORTH JIANGSU PROVINCE

针对制约苏北滩涂土壤资源开发利用的盐渍障碍因素,将生态风险理论引进该区域农田生态系统的盐渍化风险评价中,探讨了生态风险分析的方法与过程,建立了土壤盐渍化风险评价指标体系,构建了风险评价模型,并对区域土壤盐渍化风险状况进行了定量评估与分级。结果表明:研究区土壤盐渍化风险总体较高且不同部位风险差异较大,其综合风险值介于0.26～0.91之间,平均值达0.53;盐渍化风险分布表现出与土壤盐分、地下水矿化度较为相似的空间规律,受种植制度与耕作措施的影响,研究区东部水稻地盐渍化风险总体高于西部棉花地。研究区内风险较大的区域占总面积比例为63.54%,风险一般的占30.53%,风险很大的占5.01%,风险较小的仅占0.92%;其中较大风险和一般风险区分布面积最大,是土壤改良治理的重点区域。该结果可为滩涂区中、低产地改造、障碍土壤的科学管理提供参考依据。

Aiming at the restraints in exploiting and utilizing the soil resource of tidal flat in the coastal region of North Jiangsu Province,the theory of ecological risk was introduced into soil salinization risk assessment of the agro-ecosystem of this area;methodology and procedure of ecological risk analysis was discussed;and an index system for soil salinization risk assessment was established and risk assessment models were constructed.Then the soil salinization risk of the region was quantitatively assessed and graded.Results show that the integrated risk value of the region ranged from 0.26 to 0.91 with an average of 0.53,indicating its soil salinization risk was generally high and varied significantly from place to place in the study area.The spatial pattern of the soil salinization risk was similar to that of soil salinity and groundwater mineralization.As affected by the farming system and field practices,the salinization risk was generally higher in the rice-growing eastern part than the cotton-growing western part of the study zone.The area very high,high,medium,and low in risk accounted for 5.01%,63.54%,30.53%,and 0.92%,respectively,of the total study area.The two grades of high risk and medium risk were the largest in area and hence are the critical area for soil amelioration.The findings may be cited as reference for amelioration of moderate-and-low-yield farmlands and for scientific management of problem soils in the coastal region.