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In many regions both urban expansion and rural development take place simultaneously, and for the purpose of understanding the dynamic process of land use/cover change (LUCC) in such large areas, this study develops a multi-agent based land use model. Taking the Poyang Lake area of China as a typical case, this study applies the mechanism of diffusion-limited aggregation to simulate the behavior of urban agents, while rural land use is illustrated with a bottom-up based model consisting of agent and environment layers. In the agent layer, each household agent makes its own decisions on land use, and at each time interval a government agent takes control of land use by implementing policies. According to incomes and the rate of migrant workers, household agents are divided into six categories, among which different decision rules are followed. For complex LUCC in the Poyang Lake area of China from 1985 to 2005, the artificial society model developed in this study yields results highly consistent with observations. Importantly, it is shown that governmental policies can impose significant effects on the decisions of individual household agents on land use and the multi-agent-based land use model developed in this study provides a robust means for assessing the effectiveness of governmental policies. [ABSTRACT FROM AUTHOR]

Abstract: Environmental threats to wetland ecosystems are increasing, and these ecosystems are becoming increasingly sensitive to human impacts, leading to deterioration of these already fragile ecosystems. Poyang Lake is the largest freshwater lake in China and one of the most important wetlands in the world. However, water pollution and related environmental changes have increasingly drawn the scientific community''s attention. The goal of this paper is to provide insights into the environmental threats to the Poyang Lake region as perceived from the households’ perspective, and to investigate their willingness to pay for conservation of the lake''s environment. We collected both primary and secondary data through a questionnaire delivered to 270 households and analysis of existing water monitoring data. The major threat confronting the Poyang lake region is water pollution; water quality, as represented by the total nitrogen (TN) and total phosphorus (TP) concentrations and by chemical oxygen demand (COD), suggests a moderate to severe degree of eutrophication. The situation has worsened in recent years, particularly due to high TN and TP in agricultural drainage water caused by increasingly intensive use of chemical fertilizers by local farmers. Most households were willing to pay to mitigate these threats, but the magnitude of the payment was related to a farmer''s dependence on the lake for their production and daily life. The results of our analysis will help managers develop more effective environmental management policies. [Copyright &y& Elsevier]