Flood Hazard Assessment in Madeira (Portugal) – The Case Study of Machico
Andrés Silva,
Leonardo Gonçalves,
André Moura,
Sérgio Lousada,
João Gouveia,
Rafael Camacho
Issue:
Volume 7, Issue 1, March 2021
Pages:
1-13
Received:
18 January 2021
Accepted:
27 January 2021
Published:
4 March 2021
Abstract: This study aims to carry out a proper flood risk assessment in Machico’s main watercourse and purpose at least two different flood mitigation measures to prevent major impacts over the watershed. Furthermore, the assessment addresses the need for structural-measures — i.e. detention basins — towards mitigating flood hazards under high-intensity and short-duration precipitation events. It became possible to morphometrically characterize all the watersheds using empirical equations to gather specific parameters and indexes. A proper articulation between the hydrological and the spatial analysis using geographic information systems was then carried out. According to many parameters calculated the watershed of Machico proved to assume a very large-size and to be highly prone to flash floods. The spatial analysis took into consideration the watershed’s Fill Rate using both Dutch and the Ternary Phase Diagram methods and allowed us to define criteria towards the establishment of detention basins as a valid flood mitigation measure. Finally, it was clear that the watershed corresponding to Machico’s main watercourse induces the need to further implement either a detention basin or to modify the roughness coefficient of its river channel. Moreover, the comparison between the results obtained with DROTA’s Flood Risk Report, allows us to consider this study’s outcome both satisfactory and valid.
Abstract: This study aims to carry out a proper flood risk assessment in Machico’s main watercourse and purpose at least two different flood mitigation measures to prevent major impacts over the watershed. Furthermore, the assessment addresses the need for structural-measures — i.e. detention basins — towards mitigating flood hazards under high-intensity and...
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Assessing the Role of Infiltration Galleries to Enhance Groundwater Recharge in Model Town Lahore
Muhammad Fahim Aslam,
Habib-ur-Rehman,
Noor Muhammad Khan
Issue:
Volume 7, Issue 1, March 2021
Pages:
14-23
Received:
13 November 2020
Accepted:
30 November 2020
Published:
12 March 2021
Abstract: Lahore is the provincial capital of Punjab and second biggest city of Pakistan with respect to the population. Average annual population growth of Lahore is 4.14% from 1998-2018, which is much higher than the average population growth rate of Pakistan which is 2.4%. According to investigations average annual groundwater depletion rate of Lahore is 1.07 m/year. As with the growth of population new housing societies are being built to accommodate the burgeoning population. These societies enhance impermeable areas, moreover, pump huge amount of groundwater from the underground water source. There should be sustainability in water pumping and water recharging. Past studies show that groundwater exploitation in Lahore is not sustainable as abstraction rates are higher as compared to groundwater recharge rates. Therefore it is necessary of find out alternative means to recharge the groundwater aquifer of Lahore. There is a need to investigate the role of infiltration galleries to accelerate the groundwater recharge. In order to complete the research, temporal distribution was plotted on ArcMap. HEC-HMS was used for the calculation of discharges which were verified with analytical methods. Groundwater model prepared on Visual MODFLOW was calibrated and validated. The results indicate that due to groundwater overexploitation water levels continue to decrease with the passage of time. The average simulated water table decline is 1.1 meter per year in the study area. So in order to overcome this crisis, infiltration galleries were proposed and designed in the study area. It was seen that these infiltration galleries allow recharging the groundwater at better rate. As the model results showed that depletion rate of groundwater reduces and the groundwater level is about 0.3m higher when there are infiltration galleries. The study proposes that the Infiltration Galleries have a potential to recharge the groundwater at good rate, therefore its installation must be preferred according to the groundwater hydrological balance in the region.
Abstract: Lahore is the provincial capital of Punjab and second biggest city of Pakistan with respect to the population. Average annual population growth of Lahore is 4.14% from 1998-2018, which is much higher than the average population growth rate of Pakistan which is 2.4%. According to investigations average annual groundwater depletion rate of Lahore is ...
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