Abstract:
Flood is a major natural hazard in Sri Lanka. Even though flooding is a natural
phenomenon, anthropogenic factors have intensified the hazard in recent time. Objective of
this study is to identify and analyze anthropogenic factors that give rise to flood hazard.
Akuressa area is some times vulnerable to over flow due to over bank flow of Niiwala
river during rainy seasons was selected for this study. Over flow usually drains back within
two or three days and the process could not be considered as major flood. The area
consists of major tributaries and six sub catchments. For the study, 46 Grama Niladari
divisions that covers 149 km2 were selected. The population of the area is 49752
consisting of 12170 families. A questionnaire was submitted to cover 35% of the families.
In addition to the primary data, information from secondary sources such as reports of the
RSO, Grama Niladari Office, was gathered.
The results show that the flood preventive program which carried out since 1986 has
adversely affected to intensify the flood hazard in the area. The other adverse affects are
the changing land use pattern and less attention on agriculture by farmers of the area, the
indirect effects are the crocodile intrusion in to villages and salinity intrusion in to wells.
Forest clearing and construction activities and improper land use pattern, in the upper
catchment, sand mining, structures constructed along the river banks have affected to
intensify flood hazard. The removal of sand from river at the Akuressa area amounts to
2000m2 and it leads to bank erosion and widening of the river channel.
Enforcement of the existing laws against sand mining, and organizing people’s awareness
programmes will help to manage the situation. In addition, proper utilization of land under
suitable methods and protection of forest reserves may help to control the flood hazard of
the area.
