A framework for assessing flood risk responses of a densely urbanized watershed, to support urban planning decisions

Figures & data

Figure 1. Location of the Acari River Basin, along with slums, protected areas and main watercourses of the region.

Figure 2. Photographs show the current state of degradation of rivers.

Source: Google StreetView (2021).

Figure 3. General steps of the proposed framework.

Figure 4. Proposed simulation scenarios.

Figure 5. Results of the calibration process on the river gauges.

Table 1. Manning coefficient base values and adjustments based on the channel condition.

Channel conditions	Coefficient of Manning adjustment
Material	Concrete 0.015	Firm soil 0.020	Fine gravel 0.024	Gravel 0.028
Degree of irregularity	Smooth +0.000	Minor +0.005	Moderate +0.010	Severe +0.020
Variation in channel cross section	Gradual +0.000	Alternating occasionally +0.005	Alternating frequently +0.010
Effect of obstruction	Negligible +0.000	Minor +0.010	Appreciable +0.020	Severe +0.040
Amount of vegetation	Small +0.005	Medium +0.010	Large +0.025	Very Large +0.050
Degree of meandering	Minor ×1.00	Appreciable ×1.15	Severe ×1.30

Figure 6. Flood maps obtained for each of the considered scenarios.

Figure 7. Overflow volumes of each scenario considered.

Data availability statement

The data that support the findings of the study are available from the corresponding author, Antonio Krishnamurti Beleño de Oliveira, upon reasonable request.