Measurement of Rapid Agricultural Land Loss in the Pearl River Delta with the Integration of Remote Sensing and GIS

Rapid land-use change has taken place in China since economic reform. A significant amount of agricultural land has been encroached on by urban development in many coastal cities, especially in the Pearl River Delta. This has caused severe land-use problems because China is among the nations with the lowest per capita land resources in the world. In this paper, measurement of agricultural land loss with the integration of remote sensing and GIS is presented. Such measurement consists of land-development monitoring, land evaluation, and GIS overlay analysis. The concept of suitability loss is addressed to measure the degree of encroachment on the agricultural land of good quality as well as the amount of land loss. The approach demonstrates that the simple indicator AREA (total amount of land loss) is inadequate to identify completely the influences of agricultural land loss. It is illustrated that the proposed indicator I_loss, which integrates quantity of land loss, spatial integrity of land development, and quality of land, is more useful than AREA in highlighting land-use problems. The indicator AREA may lead to a false perception of agricultural land loss owing to the negligence of land quality.