Aplicabilidade de medidas de controle do escoamento superficial: distribuição espacial na bacia hidrográfica do Rio Reginaldo, Maceió-AL

Abstract

The basin of the Reginaldo River in the city of Maceió suffers from flooding and flooding problems due to increased runoff. The increase in surface runoff occurs due to soil sealing, which usually originates in unplanned urbanization and when associated with lack of urban drainage planning, problems tend to be intensified. Among the solutions currently available for the mitigation of the excess surface flow and consequently of the peak flow, we have the compensatory techniques and the specific restriction flow. Compensatory techniques are structures that aim to compensate for the effect of urbanization on the hydrological cycle; And the specific flow restriction is that which approaches the natural conditions of the basin or pre - urbanization, is also known as the maximum flow that each lot can release in the city 's river gallery. The objective of this work is to map the propitious areas for the applicability of control devices in the source by infiltration (biorretention, permeable pavement, infiltration well and infiltration trench) and to calculate and spatialize the specific restriction flow by the rational method. For the delimitation of the propitious areas and not propitious the installation of the devices was necessary to create a restriction matrix with the criteria and restrictions that were previously. The restrictions were codified in order to represent and identify the occurrence of restrictions in the case of areas with specific restrictions and to identify the propitious and non-propitious areas. The restriction matrix after being coded was programmed in the python language to be used in the ArcGIS Geographic Information System (GIS), aiming the spatialization of the results. The scenario used for the calculation of the specific restriction flow was the year of 1960, aiming to approach the maximum of the pre urbanization flow rate. For the calculation of the flow, it was used a simplification of the kinematic method (simplification of the manning equation) and the rational method. The calculation and spatialization constraint-specific flow were also programmed in python language and operated within the Arcgis software. From the results obtained it was possible to verify that even in the current scenario of urbanization of the basin it is possible to find suitable areas for the installation of the proposed devices. The result of the mapping of the propitious areas for the installation of the compensatory techniques revealed that the slope is a parameter that significantly influenced the choice of areas, in addition, no device obtained a propitious area greater than 22.64% of the area of the basin. However, the areas of special restrictions may be incentive areas, increasing the possibilities of applying the techniques. The result of the calculation and the spatialisation of the restriction flow identified that the rational method applied to the kinematic method presented some limitations with respect to the size of the study area. Among the durations used the best result found was for the duration equal to 4 hours.