Methodology for the construction of an urban flood hazard chart

Abstract

Flood events are one of the major causes of economic loss and the loss of life worldwide. Unfortunately, their occurrence has become increasingly more frequent and of greater magnitude. In order to minimize the population’s exposure to danger, it is necessary to invest in tools that aid in the decision-making process related to urban drainage management. The present work proposes a methodology for the construction of a Flood Hazard Chart for urban watersheds. The Storm Water Management Model (SWMM) was applied to the Cachoeirinha Watershed (Belo Horizonte, Brazil). The model was calibrated and validated using precipitation data and water levels recorded in monitoring stations located in the study area. The Nash-Sutcliffe Coefficients for the calibration and validation were 0.72 and 0.70, respectively. The performance of the model was satisfactory, although the model was not able to represent the more intense rain events that led to emergency and overflow warnings. Modeling results allowed the construction of the hazard chart, which defined hazard ranges or warning levels of hazard as a function of accumulated rainfall and duration. The constructed graph was assessed from real precipitation events and proved to be valid, since most events corresponded with the defined warning levels in the chart. The Flood Hazard Chart proposed in this research is a valuable tool for flood risk management as it has the potential to reduce exposure to flood disasters.

Thermal functioning of a tropical reservoir assessed through three-dimensional modelling and high-frequency monitoring

“…Concerning the lake water inflow, since 2011 monitoring stations integrate a Hydrological Monitoring System (Figure 1) operated by PBH (Siqueira et al, 2019). Monitoring stations are present only on the two main tributaries, Sarandi stream (station SAR18F, 2.8 km upstream the lake), located at 19º 52' 01" south and 44º 0' 33" west and Ressaca stream (station RES17F, 2,0 km upstream the lake), located at 19º 52' 11" south and 43º 59' 57" west.…”