A sustainable and allocation model with the integration of remote sensing and GIS - A case study in Dongguan

Urban growth and rural urbanization are an inevitable process in the Pearl River Delta as a result of economic reform. As urban growth and rural urbanization need additional land, which mainly comes from agricultural land, there is a fast agricultural land loss in the rapid growing region. Sustainable land use and land use planning in the Pearl River Delta has become important for the conservation of land resource. The land use problem in the Pearl River Delta is partly due to the lack of updated information and appropriate land use planning. The paper addresses some issues on sustainable land use and provides a sustainable land allocation model with the integration of remote sensing and GIS for Dongguan. The results from the comparison of the actual land loss in 1988-1993 and the optimal land loss predicted by the model highlight some land use problems in Dongguan. It is found that only about the one third of the land loss occurred at the optimal locations. The agricultural land loss in 1988-1993 was 1-2 times higher than the acceptable. Furthermore, there was a strong diffusion process of the 'urban field'. This means that more agricultural land will be swallowed as a faster rate of the land loss has happened in 90s. In 1988-1993, Dongguan converted 10.4% of its total land area into urban land uses. The conversion rate is much higher than the international standard. However, although there was too much agricultural land loss, the urban expansion of the city proper satisfied the principle to maintain the best agricultural land by directing the large proportion of the expansion toward the area of less fertile land. The development pattern was found to be concordant to the optimal result from the sectoral model. A sustainable and allocation model was developed to cope with the conflicts between land demand and land supply.