Håkanson Lars, Lindgren Dan
Dept. of Earth Sciences, Uppsala Univ., Villav. 16, 752 36 Uppsala, Sweden.
Sci Total Environ. 2009 Jan 1;407(2):899-916. doi: 10.1016/j.scitotenv.2008.09.039. Epub 2008 Nov 12.
In this work a general, process-based mass-balance model for water contaminants for coastal areas at the ecosystem scale (CoastMab) is presented and for the first time tested for radionuclides. The model is dynamic, based on ordinary differential equations and gives monthly predictions. Connected to the core model there is also a sub-model for contaminant concentrations in fish. CoastMab calculates sedimentation, resuspension, diffusion, mixing, burial and retention of the given contaminant. The model contains both general algorithms, which apply to all contaminants, and substance-specific parts (such as algorithms for the particulate fraction, diffusion, biouptake and biological half-life). CoastMab and the sub-model for fish are simple to apply in practice since all driving variables may be readily accessed from maps or regular monitoring programs. The separation between the surface-water layer and the deep-water layer is not done as in most traditional models from water temperature data but from sedimentological criteria. Previous versions of the models for phosphorus and suspended particulate matter (in the Baltic Sea) have been validated and shown to predict well. This work presents modifications of the model and tests using two tracers, radiocesium and radiostrontium (from the Chernobyl fallout) in the Dnieper-Bug estuary (the Black Sea). Good correlations are shown between modeled and empirical data, except for the month directly after the fallout. We have, e.g., shown that: 1. The conditions in the sea outside the bay are important for the concentrations of the substances in water, sediments and fish within the bay, 2. We have demonstrated "biological," "chemical" and "water" dilution, 3. That the water chemical conditions in the bay influence biouptake and concentrations in fish of the radionuclides and 4. That the feeding behaviour of the coastal fish is very important for the biouptake of the radionuclides.
在这项工作中，提出了一个基于过程的、用于生态系统尺度沿海地区水污染物的通用质量平衡模型（CoastMab），并首次对放射性核素进行了测试。该模型是动态的，基于常微分方程，可进行月度预测。与核心模型相连的还有一个鱼类污染物浓度子模型。CoastMab计算给定污染物的沉降、再悬浮、扩散、混合、埋藏和滞留。该模型既包含适用于所有污染物的通用算法，也包含特定物质部分（如颗粒部分、扩散、生物摄取和生物半衰期的算法）。CoastMab和鱼类子模型在实践中易于应用，因为所有驱动变量都可以从地图或常规监测计划中轻松获取。地表水层和深水层的分离不像大多数传统模型那样根据水温数据进行，而是根据沉积学标准进行。之前关于磷和悬浮颗粒物（波罗的海）的模型版本已经经过验证，显示预测效果良好。这项工作展示了模型的改进，并在第聂伯河-布格河河口（黑海）使用两种示踪剂——放射性铯和放射性锶（来自切尔诺贝利核事故沉降物）进行了测试。除沉降后的第一个月外，模型数据与实测数据之间显示出良好的相关性。例如，我们已经表明：1. 海湾外海域的条件对海湾内水体、沉积物和鱼类中物质的浓度很重要；2. 我们证明了“生物”“化学”和“水”稀释；3. 海湾内的水化学条件影响放射性核素在鱼类中的生物摄取和浓度；4. 沿海鱼类的摄食行为对放射性核素的生物摄取非常重要。
