珠江流域氮、磷营养盐入河量估算及预测

针对日益严重的流域营养盐污染问题,以珠江流域为例,采用系统动力学模型与多主体农户和农村环境管理模型耦合构建反映农户生产决策实际污染过程的流域氮、磷营养盐排放仿真系统,模拟2000—2030年不同污染源的营养盐产生、排放和进入河流的污染过程,分析其污染特征、影响因素和演变趋势.结果表明:在基准情境下,珠江流域总氮(TN)入河量从2000年的5.79×10~5t增加到2030年9.45×10~5t,在2027年达到峰值(9.53×10~5t);总磷(TP)入河量逐年递增,年均增长率为2.0%,从2000年的7.9×10~4t增加到2030年1.4×10~5t.在TN入河量中,种植业贡献最多,其次是城镇污水、养殖业和农村污水,2000—2030年期间年均贡献率相应为43.5%、32.5%、19.2%和4.9%.在TP入河量中,2000—2030年种植业、养殖业、城镇污水和农村污水的年均贡献比例分别为35.6%、28.8%、21.5%和14.1%;2000—2010年,养殖业为第一污染源,其次是种植业、城镇污水和农村污水;2011年种植业的贡献比例(31.6%)开始超过养殖业(30.8%)成为首要污染.研究显示,流域营养盐排放仿真系统可为营养盐控制提供技术支持和理论依据.

Input load to river and future projection for nitrogen and phosphorous nutrient controlling of Pearl River Basin

In view of the increasing serious watershed nutrient pollution, simulation system of watershed nutrient pollution with coupling System Dynamic model with Multi-agent Agricultural household model for Rural Environmental Management model was established to reflect the practical pollution process of farmers'' production decision;The nitrogen and phosphorus nutrient generation, emission and pollution process of arriving rivers from various emission sources were simulated from 2000 to 2030, and the pollution characteristics, influencing factors and evolution trends were analyzed. This research took Pearl River Basin as the research object. Under the business as usual scenario, the results indicated that the total nitrogen (TN) input to Pearl River Basin fluctuated with one peak in 2027 (9.53×10⁵ t), and increased from 5.79×10⁵ to 9.45×10⁵ t during the period of 2000-2030. Total phosphorus (TP) input to Pearl River Basin increased from 7.9×10⁴ to 1.4×10⁵ t at an average annual rate of 2.0% during the period of 2000-2030. Among the various sources of TN input, planting industry was the largest contributor, followed by municipal sewage, livestock and poultry breeding, and rural domestic wastewater;Their average annual contributions were approximately 43.5%, 32.5%, 19.2% and 4.9%, respectively. Among the various sources of TP input, the average annual contributions of planting industry, livestock and poultry breeding, municipal sewage and rural domestic wastewater were approximately 35.6%, 28.8%, 21.5% and 14.1% over the period of 2000-2030, respectively;The livestock and poultry breeding was the largest emitter, followed by planting industry, municipal sewage and rural domestic wastewater from 2000 to 2010;In 2011, the contribution of planting industry (31.6%) has begun to exceed livestock and poultry breeding (30.8%), and planting industry became as primary pollution source. Research showed that the simulation system of watershed nutrient pollution can provide technical support and theoretical basis for controlling nutrients.