发生分类半淋溶土在中国土壤系统分类中的归属特征

利用最新建立的1∶100万中国土壤数据库，研究了我国发生分类半淋溶土在中国土壤系统分类的归属及其在中国土壤系统分类下的空间和数量特征.结果表明，我国发生分类半淋溶土总面积为427 843.1 km²,可参比归属于中国土壤系统分类中的4个土纲，即淋溶土、雏形土、均腐土、人为土，分别占发生分类半淋溶土总面积的51.3%、35.2%、10.7%和2.8%，其中包含了系统分类的22个土类和38个亚类.对发生分类某一类型土壤分属于系统分类不同类型的面积比例及其标准偏差的分析表明，土壤参比归属的单元级别越低，越易于参比和把握.研究结果对于土壤类型的正确参比、中国土壤系统分类的应用具有很好的参考价值.

Evaluation system of urban ecological environmental quality in Nanjing city

From the viewpoint of ecology,this paper analyzed the principal part and major points of urban ecological environmental system in Nanjing,and established the evaluation indices related to the ecological environment.By layered processing the evaluation indices,the indiecs system of urban ecological environmental quality was established,and the significance and function of this system was explained.Analytic Hierarchy Process(AHP) was applied to judge the weight of each evaluation index,and to calculate the comprehensive assessment values of evaluation indices system.The urban ecological environmental quality level was graded according to the comprehensive assessment values,and the results were actually coincided with the situation of Nanjing.Overall,the ecological environmental quality of Nanjing was improved step-by-step,the environmental pollution was obviously lessened,but the natural environment was gradually worsened,especially under the influence of natural disasters.This study established an effective method for the ecological evaluation of urban environment,which would benefit to the establishment of ecological cities in China.