SPATIAL-TEMPORAL ANALYSIS OF CARBONATE OUTCROP IN SOUTH AMERICA WITH RESPOSE OF GLOBAL CO2 SINK

In current research, carbon cycle for global change are mechanically treated. Generally, climate-physics systems and biological processes were usually as short-time scale, fossil fuel-forming were considered as medium-time scale, and all geological processes (including karstification) were treated as long-term scale. As a result, the influences from geological action were neglected in the process of actual observation and test, which is contrary to the theory of earth science system. Therefore, more effort should be focused on improvement of carbon cycle for global change as well as the redivision of scale action. Most carbonate rocks are susceptible to karstification, although not all are well karstified. Thus the area of carbonate rock outcrop provides an upper limit on the area of exposed karst terrain. In this work, ArcGis software was employed to extract the geological data. Furthermore, the global change in South America carbonate outcrop area were analysed according to the temperature, rainfall and forest area from 1989 to 2010. The results show that impact of temperature on the change of carbonate outcrop area is not obvious. As forest area slightly reduced, the less the reduction of rainfall is, the less the increase is for carbonate outcrop area in Venezuela, Argentina and Bolivia. In addition, GEM-CO2 model was used to estimate the CO2 sink of South American carbonate outcrops, which have increased 2.27 million tons.