The Impact Of Urban Sprawl On Carbon Stocks Based On The InVEST Model

Global warming has become one of important environmental issues affectinghuman existence and life, and global climate change directly affects human societyand natural ecosystems. In many years, Earth’s carbon cycle is regarded as the focalcontent of global climate change studies. Carbon stock change of terrestrialecosystem plays a key role in changes of atmospheric greenhouse gas and globalcarbon cycle, so it is the basic problem of the global carbon storage. Human activitieshave great impact on carbon stocks of terrestrial ecosystem through changing landuse/land cover or management measures in agriculture. In the process of China’sdevelopment for the decades, urbanization has become an important impact factor ofland use change. With the urbanization accelerating, urban space expansion isinevitable, and the urbanization process will inevitably lead to changes in surroundingland use patterns and land cover types, thereby affect carbon stocks of terrestrialecosystems.In this paper, Landsat ETM+images are used as the basic data, urbanagglomerations of Liaoning Southern and Central as the study area. Land use in theyear of2000,2005and2010are extracted from these remote sensing images usingobject-orient classification methods. Based on existing methods of global or regionalcarbon stock estimation, the InVEST model is chose to calculate the carbon stock ofthe study area. The superiority of the model and the data accessibility are alsoanalyzed. The values of aboveground and underground carbon density of terrestrialecosystem and soil carbon density are collected from many related literatures. Theappropriate data are used to calculate and analyze. According to the requirements ofthe InVEST model and existing data, the re-classification system is determined. There-classification land use/cover data in the study area are exported and appropriateraster dataset is established. Then the InVEST model is adopted to estimate theterrestrial ecosystem carbon stock of the urban agglomerations of Liaoning Southernand Central of the year2000,2005and2010. The ArcGIS software is used to analyzethe urban sprawl of the study area. Finally the impact of urban sprawl on carbonstocks is analyzed qualitatively and quantitatively.In summary, the InVEST model is an effective method of regional carbon stockestimation. Urban sprawl leads to land use and land cover change, which may causethe carbon sequestration capacity of terrestrial ecosystem reduce, eventually leading to decrease in carbon stocks of terrestrial ecosystems.