| dc.description.abstract | Urban drainage systems are experiencing a decline in their performance, which is compounded by various
global change pressures such as urbanization, climate change, and population growth. The more frequent
occurrence of intense rainfall and the growing informal settlements in the catchment has had a direct impact
on flooding with in Nalukolongo catchment. This is the challenge my thesis addresses through evaluating
the suitability of sustainable urban drainage systems mitigate flooding.
This thesis addresses this problem through the different objectives, determining the impacts of climate and
land use change on the hydrology patterns in the catchment in terms of runoff volumes generated and
carrying out a suitability analysis for sustainable drainage systems for flood control. Prediction of future
rainfall (2022-2060) and the future land use (2030, 2040, and 2060) and their impacts on the generated
flood volumes were carried out.
The methodology includes how the different objectives were achieved. The future land use and land cover
scenarios were projected using Geographical information software programs and remote sensing (GIS,
IDRISI Selva) as they are appropriate tools for exploring spatial changes. The CORDEX repository for
Africa domain (AFR-44) Regional Climate Model (RCM) was used to obtain future records of rainfall and
other climatic data .The different IDF curves for the past rainfall data and projected rainfall were established
for the different intensities from the acquired rainfall data. The runoff quantity was obtained using SCNCN method and EPA SWMM model for the hydrological analysis and this was used to determine the
impacts of climate change and land use land cover scenarios in the catchment.
Simulating using EPA SWMM gave a peak discharge of 252.86 m3
/s and a total flood volume of 1,643,700
m3
throughout the entire catchment using the baseline conditions (past rainfall data and existing land use
land cover). A multi-criteria analysis using the projected land use land cover conditions and rainfall showed
that the peak discharge increased to 419.47m3
/s and the total flood volume increased to 2,410,170m3
. The
study also focused on four specific SUDs: rain barrels, infiltration trenches, permeable pavements, and bioretention ponds. Compared to the scenario without SUDs, the peak discharge was reduced across all SUDs,
with permeable pavements exhibiting the highest reduction at 55% of the initial peak discharge. Similarly,
the flood volumes generated in the catchment were decreased for all SUDs, with permeable pavements
demonstrating the most substantial reduction.
The conclusions provide an in-depth overview of our findings, while the recommendations offer guidance
on how to move forward based on the discoveries made in our project | en_US |
