2 research outputs found
Comprehensive analysis of design storm formulation across Newfoundland and under climate change with scarce data
Urban and rural watersheds are becoming increasingly vulnerable to extreme weather events
and their consequences. One such consequence is flooding. Stormwater management systems
need to be efficiently designed to handle both the quantity and quality of floodwaters.
Efficient stormwater systems can be achieved when design parameters are set to their
optimum. The design parameters for proper sizing of stormwater infrastructure are obtained
from design storms, a combination of Intensity-Duration-Frequency (IDF) curves
and a rainfall temporal distribution. IDF curves are developed using rainfall data; as such,
changes to the climate will affect these curves. There is a need to re-evaluate the current
design storms to determine how they will be affected by the changing climate. Evaluating a
design storm from a chaotic variable such as precipitation is complex, and the variation in
climate makes it more complicated.
Information on IDF curves is challenging to obtain, especially at locations where precipitation
data is lacking or for which there is little data. The focus of this study is the
use of models for data generation and analysis of data for appropriate temporal distribution
identification. The application of the work in this thesis provides information to guide engineering
design and other hydrological studies under climate change. This thesis presents
a series of studies that: assess the impact of climate variations on temporal distributions
used in design storm analysis; analyzes how these temporal distribution patterns - when
combined with other hydrologic factors - can impact mapping for risk of floods, especially
under climate change projections, and develops a precipitation disaggregation model.
The assessment of temporal distribution variation with climate shows that current temporal
distributions being used may result in under- or over-design based on the location
of interest and climate condition used, either current climate or future climate projections.
It highlights the importance of using the appropriate temporal distribution to justify the
conservative design. The temporal distributions identified are taken a step further to determine
their interplay with hydrologic loss methods and their impact on mapping for the risk
of floods. The outcome shows that the extent of a flooded area is highly sensitive to the
temporal distribution and loss method used. A precipitation disaggregation model is also
developed by coupling a method-of-fragments model with a crossover operator and applied
to meteorological stations at Ruby Line, St. John’s and Corner Brook to generate hourly
data from daily data. These stations were chosen to mainly draw attention to the lack of
precipitation data across most locations in the province. The results show that the model
can generate hourly data statistics similar to that observed
Implications of Climatic Variations in Temporal Precipitation Patterns for the Development of Design Storms in Newfoundland and Labrador
The distribution of precipitation in time is an important aspect for the development of design storms for storm water infrastructure design. The current set of mass curves used throughout the province of Newfoundland and Labrador (NL) may not be justified. In order to identify variation in mass curves across NL, and compare results with existing mass curves, hourly precipitation data from 10 stations were used. Bayesian k-means clustering was used to identify dimensionless mass curves to represent precipitation patterns. Eight distinct temporal patterns of precipitation were identified and further regrouped into four, useful for making recommendations on the choice of mass curve. Crosstabulation applied to the patterns were found to be significantly influenced by event duration, depth and climate zone. Results support the conclusion that climate was an important determinant of temporal distribution of precipitation, and it is important to determine which pattern is dominant in a given region.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author