Desertification Control and Sandstorm Mitigation in the Area Encircling Beijing - with a Discussion on the Application of Bayesian Network and Hydrological Modeling

摘要

Desertification has drawn much concern in China amid a string of strong sandstorms hitting Beijing in recent years. Returning farmland to forests and grasslands around Beijing has been taken as a key measure to tackle the problem. This paper examines the causes of desertification and favored measures in dealing with the problem from the perspective of locals using a case study for three counties in northern Beijing. The results suggest that returning farmland to forests and grassland has received a wide support in the areas concerned. Such a support, however, is partly backed by the economic benefits the locals have received or expected to receive from the central government. The effectiveness of the measure in mitigating Beijing's sandstorms may, however, be limited. Meanwhile, hydrological and environmental impacts of the measure on the downstream areas, notably Beijing, are also not clear. In order to clarify these ambiguities, this paper proposes to apply a Bayesian network to estimate the risk of desertification and a model approach to quantify the effects of land use changes on hydrological systems and the environment for the entire watershed.