The Effects Of Rapid Urbanization On The Distribution Paterns Of Organic Carbon In Multimedia

The level of organic carbon can indicate the influence of human activities on the environment to a certain extent,It has a profound impact on the ecosystem carbon cycle and carbon storage.It is significant for us to understand and predict the dynamic changes of land ecosystem.Based on the three kinds such as environmental media of soil,road dust and lake sediments which were collected on the trunk road in Nanchang,we set up a database of environmental multi-media organic carbon in Nanchang.Based on the remote sensing image data of Nanchang in the past 30 years,We use RS and GIS techniques and related models to analyze the temporal and spatial patterns of urbanization in Nanchang,and to explore the impact of the rapid urbanization process on the distribution of environmental organic carbon in the past30 years.The main conclusions are as follows:(1)From 1983 to 2014,the overall trend of land use in Nanchang was significant,urban and rural residential areas and mining land increased greatly,cultivated land resources reduced,urbanization trend of land use structure is obvious,land use change has significant changes of time and space differences.In the period from 1983-2014,the expansion of the urban and rural residential areas and mining mainly along the old city and center area to the surrounding radiation,it is a significant margin expansion mode;In time,urban shows two slow growth stage,which is from 1983 to 2000 and from 2005 to 2014,and a high growth stage,which is from 2000 to 2005.(2)It is proven that the average content of organic carbon of soil,dust,and soil organic carbon of lake sediment in Nanchang is as followed: soil > lake> sediments,its value were 25.21 g·kg-1,28.7 g·kg-1,and 14.90 g·kg-1.There are more spatial heterogeneity of organic carbon in soil and lake sediments,and the mean values??of organic carbon in each medium are much higher than those in Jiangxi Province,and the environmental media(soil,dust and lake sediments)of Nanchang are organic Carbon content is at a high level,respectively,10 times the background value,11 times,more than 6 times,indicating that the environment in Nanchang,organic carbon in a large extent by the impact of human activities,and withShanghai,Hangzhou,Kaifeng and Urumqi Compared with other cities,soil organic carbon in Nanchang is at a moderate level.In addition,organic carbon in soil and lake sediments has more obvious spatial heterogeneity.(3)The rapid urbanization process has a significant impact on environmental multi-media(dust,soil and lake sediments).The distribution pattern of organic carbon in Nanchang has a significant effect on the distribution of organic carbon in Nanchang.The distribution of organic carbon in environment has obvious accumulation and spatial heterogeneity,and the distribution shows a gradual decrease from urban area to suburb.The accumulation of organic carbon in each medium is coupled with the phenomenon of rapid urbanization,indicating that environmental organic carbon can be used as a valid indicator,reflecting the urbanization process and the impact of human activities on the environment.