An alternative flood model calibration strategy for urban watersheds: the case study of Riohacha, Colombia.

The city of Riohacha (Colombia) has a complex urban setting that, under the pressure of recurring intense rains, experiences increasing flood damage. With the aim of identifying a systemic solution to flood problems, a hydrodynamic mathematical modelling exercise was conducted. Within the modelling process, calibration and validation are two fundamental actions that must precede the use of the model. However, most of the river basins around the world lack hydrometeorological information, which is indispensable for the calibration process. This paper presents an original approach to collecting such information for the calibration process, based on interviewing inhabitants. The results of this effort were surprisingly good, when considering the kind of approximations involved in using people's answers as hard data. This encouraged us to promote it as a working solution for many other similar cases, which all suffer from lack of suitable data.

Use of detention basin for flood mitigation and urban requalification in Mesquita, Brazil.

Unplanned urbanization is one of the main factors responsible for worsening flood-related problems in cities, increasing the frequency of flooding and flooding depths, consequently degrading both the natural and built environment. Considering this, the use of engineering techniques that reduce runoff and promote urban requalification are an efficient option for managing rainwater. This paper presents a case study of a flood control project using a storm water detention pond, designed to allow multiple uses of an urban space. The operation of the system is evaluated by an urban flow-cell model, known as MODCEL. This application seeks the best configuration for the layout of 'Celso Peçanha' Detention Basin, considering the local restrictions imposed by the City of Mesquita - Brazil, and optimized to damp storm flows resulting from rainfall events with return periods up to 50 years. The solution proposed considers the possibility of social urban space uses in flood control projects, revitalizing degraded areas and giving them multiple functions.