The use of dual-drainage models has increased in recent decades, mostly because of advances in mathematical methods and geographic information system tools. This type of modelling provides precise diagnoses and can be applied to evaluate stormwater infrastructure and diverse drainage alternatives. Minor and major drainage relations in the Dona Eugênia watershed, Brazil, were analysed in this study. Three alternatives simulated the quasi-two-dimensional hydrodynamic model Modcel. The first alternative considered only the terrain surface layer, representing the current situation. In the second alternative, a layer containing a designed storm sewer was introduced. Considering the previous alternatives as a way to diagnose the main minor and major deficiencies, a third alternative was formulated considering previous projects to solve floods in the watershed, incorporating them in the second alternative with functional minor drainage. The results identified the locations of minor drainage gaps, thus helping to direct efforts to the most critical regions, optimise operations and minimise maintenance costs. The results could also be used to evaluate the effects of storm sewer network discharges in major drainage systems, leading to better design of the drainage infrastructure. The major drainage itself can be optimised, once its responsibility in flooding is identified.

中文翻译：

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多层建模作为洪水诊断和排水系统设计的支持工具

近几十年来，双排水模型的使用有所增加，这主要是由于数学方法和地理信息系统工具的进步。这种类型的建模提供精确的诊断，可用于评估雨水基础设施和各种排水替代方案。本研究分析了巴西多纳尤金尼亚流域的次要和主要排水关系。三种替代方案模拟了准二维流体动力学模型 Modcel。第一种选择仅考虑地形表层，代表当前情况。在第二种选择中，引入了包含设计的雨水管道的层。考虑到以前的替代方案是诊断主要次要和主要缺陷的一种方法，考虑到以前解决流域洪水问题的项目，制定了第三种替代方案，将其纳入具有功能性小型排水系统的第二种替代方案中。结果确定了较小排水缺口的位置，从而有助于将工作重点转向最关键的区域，优化运营并最大限度地降低维护成本。研究结果还可用于评估主要排水系统中雨水管网排放的影响，从而更好地设计排水基础设施。一旦确定了主要排水系统在洪水中的责任，就可以对其本身进行优化。优化运营并最大限度地降低维护成本。研究结果还可用于评估主要排水系统中雨水管网排放的影响，从而更好地设计排水基础设施。一旦确定了主要排水系统在洪水中的责任，就可以对其本身进行优化。优化运营并最大限度地降低维护成本。研究结果还可用于评估主要排水系统中雨水管网排放的影响，从而更好地设计排水基础设施。一旦确定了主要排水系统在洪水中的责任，就可以对其本身进行优化。