Yuan Chengcheng, Liu Liming, Ye Jinwei, Ren Guoping, Zhuo Dong, Qi Xiaoxing
Department of Land Resources Management, China Agricultural University, Beijing, 100193, China.
School of Government, Sun Yat-sen University, Guangzhou, 510275, China.
Environ Sci Pollut Res Int. 2017 May;24(14):12899-12917. doi: 10.1007/s11356-017-8812-0. Epub 2017 Apr 2.
Water pollution caused by anthropogenic activities and driven by changes in rural livelihood strategies in an agricultural system has received increasing attention in recent decades. To simulate the effects of rural household livelihood transition on non-point source (NPS) pollution, a model combining an agent-based model (ABM) and an improved export coefficient model (IECM) was developed. The ABM was adopted to simulate the dynamic process of household livelihood transition, and the IECM was employed to estimate the effects of household livelihood transition on NPS pollution. The coupled model was tested in a small catchment in the Dongting Lake region, China. The simulated results reveal that the transition of household livelihood strategies occurred with the changes in the prices of rice, pig, and labor. Thus, the cropping system, land-use intensity, resident population, and number of pigs changed in the small catchment from 2000 to 2014. As a result of these changes, the total nitrogen load discharged into the river initially increased from 6841.0 kg in 2000 to 8446.3 kg in 2004 and then decreased to 6063.9 kg in 2014. Results also suggest that rural living, livestock, paddy field, and precipitation alternately became the main causes of NPS pollution in the small catchment, and the midstream region of the small catchment was the primary area for NPS pollution from 2000 to 2014. Despite some limitations, the coupled model provides an innovative way to simulate the effects of rural household livelihood transition on NPS pollution with the change of socioeconomic factors, and thereby identify the key factors influencing water pollution to provide valuable suggestions on how agricultural environmental risks can be reduced through the regulation of the behaviors of farming households in the future.
近几十年来，农业系统中由人为活动导致并受农村生计策略变化驱动的水污染问题日益受到关注。为了模拟农村家庭生计转型对非点源（NPS）污染的影响，开发了一种将基于主体的模型（ABM）和改进的输出系数模型（IECM）相结合的模型。采用ABM来模拟家庭生计转型的动态过程，采用IECM来估计家庭生计转型对NPS污染的影响。该耦合模型在中国洞庭湖地区的一个小流域进行了测试。模拟结果表明，家庭生计策略的转变随着水稻、生猪和劳动力价格的变化而发生。因此，2000年至2014年期间，该小流域的种植制度、土地利用强度、常住人口和生猪数量发生了变化。由于这些变化，排入河流的总氮负荷最初从2000年的6841.0千克增加到2004年的8446.3千克，然后在2014年降至6063.9千克。结果还表明，农村生活、牲畜、稻田和降水交替成为该小流域NPS污染的主要原因，2000年至2014年期间，小流域的中游地区是NPS污染的主要区域。尽管存在一些局限性，但该耦合模型提供了一种创新方法，可模拟农村家庭生计转型随社会经济因素变化对NPS污染的影响，从而识别影响水污染的关键因素，为未来如何通过规范农户行为来降低农业环境风险提供有价值的建议。
