Land-use and land-cover change (LUCC) projects have inspired researchers to examine complex land-use change systems and develop land-use change models. Various land-use change models have been utilized to simulate land-use change; however, no biophysical approach that can identify material and energy flows in a land-use change system exists. Although spatial system modeling, based on the systems approach, can simulate interactions between natural environments and socio-economic systems, and verify hypotheses and theories regarding land-use change and socio-economic metabolism; it has not received much attention due to its difficulties in dealing with spatial interactions and integrating different software programs. This study presents a procedure that uses Geographical Information System (GIS) in modeling a spatial system to overcome methodological disadvantages of spatial system modeling. To simulate land-use change, an example is utilized to demonstrate the capability of Model Builder in GIS software.

Most prior studies have found that substituting biofuels for gasoline will reduce greenhouse gases because biofuels sequester carbon through the growth of the feedstock. These analyses have failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels. By using a worldwide agricultural model to estimate emissions from land-use change, we found that corn-based ethanol, instead of producing a 20% savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years. Biofuels from switchgrass, if grown on U.S. corn lands, increase emissions by 50%. This result raises concerns about large biofuel mandates and highlights the value of using waste products.