TITLE:
Case Study on Identification of Flood Hazard in the Lower Catchment Area of the Attanagalu Oya River Basin
AUTHORS:
Kithulgasmulle Lekamlage Nadeeka Chathurani, Hatanpola Acharilage Sampath Arunashantha, Bamunu Arachchilage Sumanajith Kumara, Pattinaya Marakkala Udara Idunil Thilakarathna, Gargi Arachchilage Anudi Nishika Kaushalya
KEYWORDS:
Flood Hazards, GIS and RS, Attanagalu Oya, Risk Levels
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.10 No.7,
July
29,
2022
ABSTRACT: The present work aims to identify flood hazards and risks, particularly
to the Attanagalu Oya river basin in Gampaha district, the western province in
Sri Lanka. Attanagalu Oya river catchment area periodically faced flood
hazards. The flood is categorized by complex like 2008, 2010, 2016, 2017, and
it chose 2016 as the primary flood event. Study areas have been selected
depending on data availability. Attanagalu Oya river basin is mainly focused as
a study area. However, here selected only four Grama Niladhari Divisions are as a sample area. Those are; Kirindivita, Ambanvita, Thammita West,
Gonagaha1. Furthermore, many flood hazards can be identified when considering
the flood events history. But here selected only two years were 2010 and 2016.
These two years were selected with high flood events. For the study, that flood
series used 1 feet elevation contours used to identify flood levels and used LiDAR
image to identify risk areas in the study site. Due to the blockage of the main waterways that discharge water into the
Negombo Lagoon, limited water transportation, low lying land reclamation
for development, mainly affect paddy lands and roads, and flood as a major
problem identified temporarily and spatially. Eventually, the study could
identify flood-prone areas and map the risk zones within the study area.