摘要: |
圩区是太湖流域平原区的主要地理单元,其磷素流失是造成平原区水污染的重要原因之一,定量模拟圩区磷素流失过程是非点源磷污染控制的重要环节.以太湖流域的典型圩区——尖圩为研究对象,根据物质守恒原理构建圩区磷素流失过程模型,模型考虑了圩区自然降雨、人工灌溉、洪涝排水、地面渗漏、作物需水、水面蒸发、沟渠磷素拦截等过程,充分体现了圩区系统磷素流失特征;通过已有研究案例、实地监测与野外调研相结合的方法确定模型参数;模拟结果表明:(1) 与太湖流域平原非圩区相比,圩区的年度磷素流失量较低(-0.17~0.54kg/(hm2·a)),并且年度差异显著;(2) 人工灌溉与自然降雨是圩区磷素输入的主要渠道,其磷素输入量分别为0.27~0.69、1.05~1.19kg/(hm2·a);水体下渗和洪涝排水是圩区磷素的输出途径,其磷素输出量分别为1.04~1.06、0.65~0.93kg/(hm2·a). |
关键词: 磷素流失 圩区 模拟 太湖流域 |
DOI:10.18307/2015.0204 |
分类号: |
基金项目:国家自然科学基金项目(41301574)和中国科学院南京地理与湖泊研究所"一三五"战略发展规划项目(NIGLAS2012135005)联合资助. |
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Phosphorus loss simulation of lowland polder system |
HUANG Jiacong, GAO Junfeng
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Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China
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Abstract: |
Polders are widely distributed in the lowland areas of Lake Taihu bsin. Phosphorus loss from these polders is one of the main causes of water pollution in the lowland areas. Modeling the process of phosphorus loss from these polders is a critical step to control non-point phosphorus pollution. A Phosphorus Loss Model for Polder(PLMP) model was developed for Polder Jian, a typical polder system located in Lake Taihu basin. The model is mainly based on mass conservation of the phosphorus in Polder Jian. IIn order to describe phosphorus loss adequately for the polder system, a series of hydrological and phosphorus-transport processes were included in PLMP, such as precipitation, irrigation, flood drainage, infiltration, crop water requirement, evaporation in the water area, phosphorus removal by ditches. Model parameters were determined based on previous case studies and field measurements. The simulation results showed that the phosphorus loss from the polder system was 0.15kg/(ha·a). This value is relatively lower than the phosphorus loss from other lowland areas in Lake Taihu basin. Irrigation and precipitation are the main causes of phosphorus input into the polder, with an input intensity of 0.27-0.69 and 1.05-1.19kg/(ha·a), respectively. Flood drainage and infiltration cause phosphorus output to the surrounding rivers, with an output intensity of 1.04-1.06 and 0.65-0.93kg/(ha·a), respectively. |
Key words: Phosphorus loss polder simulation Lake Taihu basin |