V.p.i.s. WIJERATNE, Northwest University, China
Gang LI, Northwest University, China
Shuo WANG, Northwest University, China
In recent decades, especially in the second half of the 20th century, EHEs have attracted extensive worldwide attention. The river basin hydrological cycle and the intensification of extreme precipitation events have impacted climate change and humans. As an unsustainable urban expansion, urban sprawl is related to the direct and indirect impact on the river basin hydrological cycle. This study investigated the possible impact of unsustainable urban expansion on the Extreme Hydrological Events (EHEs) in the Kelani River Basin, Sri Lanka. A total of 68 years of satellite-derived precipitation data and land use data were analyzed to assess the relationship between EHEs and urban sprawl. Extreme Precipitation Indices (EPI), Rainfall Anomaly Index (RAI), Shannon Entropy, Geographical relationship were mainly used as analysis methods. The study results revealed that the wet and dry extremes had varied spatially and temporally during the study period (1951-2019). The river basing has experienced an increasing trend of urban sprawl, and unsustainable urban development areas have invaded areas with a high risk of EHEs. The urban areas have recorded a higher number of extreme wet events, and from the beginning of the study period, it has shown a significant increasing trend. A better understanding of the impact of urban sprawl on extreme wet and dry events is essential for taking adequate measures to minimize safety and security issues related to EHEs in the study area.
Mots clés : Urban sprawl|EHEs|extreme rainfall events|Shannon entropy|extreme wet and dry events
A103783VW