The area of cropland has decreased

Carbon emissions from land use and LUCC.
2.3.2. Assignment of carbon emissions to different land use types
2.3.3. Total carbon emissions change caused by land use change
Carbon emission intensity varies significantly among different land use types, and land use transition will cause carbon emissions change. Therefore, carbon emissions here, not only includes carbon change in terrestrial ecosystems caused by LUCC, as discussed above, but also includes anthropogenic carbon emissions, for which land AC 187 its carrier (Equation (10)):equation(10)C=∑ijn(Vi−Vj)×Stransfer−ijwhere C represents the total carbon emissions change caused by land use change, Vi and Vj are carbon emission intensities of land use type i and j, and Stransfer−ij represents the area of land use transition from type j to i.
To determine the type of land transition discontinuous variation has a decisive effect on total carbon emissions, we created a transition matrix of land use using intersect analysis in ArcGIS9.3, and we used the mean values of carbon intensities for the different land use types of the five typical years to describe the carbon intensities between 1985 and 2010. According to the land use transition matrix and the mean values of carbon emission intensity for the different land use types, the average annual carbon emissions transfer between 1985 and 2010 can be calculated.