Research Of Land Use And Soil Organic Carbon Dynamics In Binhai New Area Of China

The Copenhagen Convention held on December7th in2009mentioned to reducecarbon emission, which raised it to political height. Thought the most effective mea-sures in the present are carbon capture and carbon sequestration technology, with atmo-spheric carbon converted into solid carbon in soil, this is a long and hard innovation,needing a long process to promote in national and global scope. During this process,other reduction measures should be taken to improve carbon loss into the air due to landuse and management, which can be seen as effective and economically viable measuresat present.This paper conducted the research of land use in Binhai New Area from theaspect of soil science, ecological science and geographic information system theory,and an-alyzed the organic soil carbon accumulation and release dynamic because ofland use change from the sight of climate change, then use verification model frompoint sim-ulation to spatial simulation. First of all, within data availability and thesupport of GIS and RS, we did the research of land use change of Binhai New Areafrom1980to2010, according to land use classification standard, land use in BinhaiNew Area can be classified into forest, grass, arable land, urban green land, urbanconstruction land, water body and bared land. Second, the land use evolutionregulation was analyzed by the combination of celluar automata model and multiplelogit regression model according to the regional characteristics from spatial and timedimensions, and then the land use dynamic till2050was predicted and verified by2020and2050land use planning figures. The results showed that land use in BinhaiNew Area has changed a lot from1980to2010, according to the analysis of remotesensing data, the area of arable land has showed a sharp rise from1980to1990, andthen showed a relatively smooth state from2000to2010, and then showed a sharpdecrease after2010; the change of bared land kept decreasing each year, showing anincreased land use efficiency; the change of beach has kept a slow decrease in this timeperiod; the total area of forest is very small in Binhai New Area, and showed littlechange in these years. The whole modeling results showed that the land use change to urban lands in the future will be continued.To study the relationship between land use and soil organic carbon, we collected248soil samples in2010to measure the soil organic carbon in0-30cm soil surface,soil pH, soil texure, soil salt percent and soil bulk density, and analyzed the data nor-mality, dispersion, kurtosis and skewness of each data set. After data transformationof the non-normality data sets, the relationship between each factor was studied andthe regression relationship between soil organic carbon and other factors wasanalyzed. The results showed that the relationship between soil organic carbon, soilbulk density, percent soil clay, percent soil salt and soil pH were significantly high(p=0.01); while due to the strong correlation between soil clay and soil salt, we canconclude that there are high percent salt ions in soil clay. The correlation betweensoil salt and soil pH showed a weak value-0.01, meaning that alkaline ions of the soilbulk density were not high. The correlation between soil bulk density and soil clay,soil pH showed a high value, meaning that the high bulk density was due to alkalineions and percent clay. The correlations between soil environmental factors showedthe impact of these factors and the impact to soil organic carbon accumulation.According to the results of soil samples and the theory of ROTHC andROTHC-salinity, the soil organic carbon is split into5parts, DPM, RPM, HUM, BIOand IOM, each of which has a different soil decomposition rate. The soil organiccarbon dynamic under different land use changes were modeled based on empiricaldecomposition for-mula, and the model results were verified by statistical indicatorsLOFIT, M and r. The results showed that there were several land use changes inBinhai New Area, namely the conversion from grass to forest, grass to arable, grass tourban green, grass to urban land, arable to grass, arable to urban land, bare to arable.Both results of ROTHC and ROTHC-salinity models can be seen as true statistically,however, the results of Rothc-salinity are more compatible to simulate the soil organiccarbon dynamics in Binhai New Area.Combined with soil texure figures, land use classification figures and the modeleddata sets of soil organic carbon, the spatial model to run the whole area was built topredict the soil organic carbon dynamics and green house gas emissions from1979to2050, with running ROTHC-salinity model7848times. The results showed that between1979and2050the soil carbon emission will reach to30-50t/hm~2, at a rate of0.42-0.70t/hm~2each year.