First and second level karst environment zoning for highway engineering

The paper carried on the work of first and second level karst environment zoning for highway engineering from the demands of the construction of highway engineering in karst areas. The purpose of the zoning is to make the karst environment been fully considered during the highway planning and designing. The conditions of geological and natural environment that may influence the highway engineering and environmental geological problems that may be encountered in different zones should be considered so as to provide service for the highway planning, route selecting, designing, construction and maintenance, which also make up for the current natural zoning of highway. In first-level zoning, five zones of tropical and subtropical monsoon humid - semi humid area of South China, temperate monsoon sub arid area of North China, mid-cold temperate monsoon sub arid - sub humid area of the Northeast, mid-temperate continental climate arid area of the Northwest and alpine mountain climate arid area of Qinghai-Xizang plateau are divided using the climate and tectonics as indexes. And 26 zones of mid-mountain area of Qinling-Daba mountain and peak-forest plain area of Guangxi Basin etc are divided using the landform, distribution of karst and karst environmental problems as indexes in second-level zoning based on the result of first-level zoning.