黄河中游地区环境脆弱形势

文章以黄河中游地区为对象，研究和分析了其环境的脆弱形势，并编制了１：２００万黄河中游地区环境脆弱形势图。将黄河中游地区的环境脆弱形势分成５类：紧张环境形势（较脆弱）、危急环境形势（脆弱）、危机环境形势（很脆弱）、灾难性环境形势及突发性灾害环境形势。区分上述不同环境形势的指标因子很广泛，结合黄河中游地区的特殊性以及环境主导因子规律，主要选择了污染、地方病、土壤侵蚀、干旱缺水，森林退化、风蚀沙化、土壤盐碱化等因子。所编制的环境脆弱形势图反映了４方面的内容：（１）不同景观类型、地理系统和区域的自然人口承载能力；（２）人类活动对自然环境造成的压力和自然环境发生不可逆变化的起因、特征和程度；（３）自然环境对人类干扰的敏感性及社会经济的弱点；（４）人类活动对自然环境影响的后果及其同自然环境、社会因素相互作用所产生的反响。在制图和分析的基础上，文章总结出了该地区脆弱环境的区域分布规律，并将环境形势、区域分布规律和主导指标因子结合起来，将黄河中游地区划分成８个区，为对整治不同脆弱形式和程度的环境提供科学依据和参考。

CRITICAL ENVIRONMENTAL SITUATION IN MIDDLE REACH AREA OF YELLOW RIVER

This paper researches and analyses the critical environmental situation in middle reacharea of Yellow River and compiles the map of critical environmental situation of this area(1 :2000000)`There are 5 types of environmental situation (ES)divided,namely conflictES,critical ES,crisis ES,disastrous ES and assident ES.7 groups of main factors are usedto identify and class the critical environmental situation after considering the speciality ofthis region and the law of guiding factors.They are pollution,endemic disease,soil erosion,dry and water-shortageforest degeneration,wind-erosion and desertification,and soilsalinization. The situation map contains following contents:(1)the natural popularsustainability in different landscapes,geo-systems and districts,(2)the pressure caused byhuman activities on natural environment and the cause,character,scale and strength ofirreverse changes developing in natural environment;(3 the sensitivity of natural environ-ment to human disturbing and the weakness of social economic;(4)the consequence causedby human activities on natural environment and repercussion of interaction happening inthe consequence,natural environment and social factors.Based on mapping and analysing, the paper also concludes the regional distributionlaw of critical environmental situation of this region and divide it into 8 small districtsthrough combining the critical environmental situation, regional distribution law and guiding factors.This can provide scientific basis and reference for preserving and renovating theenvironments with different fragile types and fragile levels.