INTRODUCTION affects humans and their surrounding environment (Leinster, 2009).



Flood is an
extreme naturally occurring weather event that results in an overflowing of large amounts of
surface water over land that is not
always inundated Adeoye; Ayanlande; and Babatimehin (2009 Cited in Mmom and Akpi
2014).  According to Leinster (2009)
flood is an overflow of water that covered the land surfaces that are normally
dry. This includes overflow from water bodies like river, lakes etc.

Floods are
considered to be the worst natural disaster
in the world and are responsible for a third of all natural problems and half of the damages on facilities
around the globe (Mmom and Ayapko, 2014). Alexander;
Viavattene; Faulkner; and Priest (2011) defined flood vulnerability as
“probability of flood occurrences and its potential consequences”. So,
therefore flood vulnerability mapping according to Kaoje and Ishiaku, (2017) is
the presentation or representation of areas that are at risk of flood events on
maps. According to Kaoje (2016) flood vulnerability mapping is very important
for an appropriate urban planning to reduce the likelihood of flood occurrence
and also reduce the consequences of flood disaster when it happen. Flood is the
most common occurring natural disaster that affects humans and their
surrounding environment (Leinster, 2009). This natural disaster is common in
Nigeria, it has been occurring in almost every rainy season (Kaoje and Ishiaku,

In 2012 about
1.3 million Nigerians were displaced and 431 died from various floods
occurrences and over 30 out of 36 states in Nigeria were affected by the flood
(NEMA, 2012; IRIN, 2012). Flood is no doubt is one of
the major environmental problems affecting the livelihood of an area especially
an urban area in which Bayelsa State city and its environs is not in exemption
meaning that Bayelsa State is a typical flood prone area in the Niger Delta
region. According to Cinque; Crowe; and Davies (2003) cited in Kaoje and Ishiaku, (2017) it is understood that flood
is a hazard that can be avoided not only by building dams or constructing more
flood defence systems but also by the use of modern technologies and
appropriate urban planning that will provide accurate information on flood
prone areas on a map. Geographic Information System (GIS) is very important in
generating such maps through rigorous spatial analysis (Eludoyin and Weli, n.d).
 According to Burroughs (1987) cited in
Eludoyin and Weli, (n.d) GIS can be defined as a tool for storing, manipulating
and displaying large quantities of geographic information in a computer. He
stressed further that the geographic data which is stored describes objects
from the real world in terms of their position on the earth with respect to
known coordinate system. According to Atkinson (2008) cited in Kaoje and
Ishiaku, (2017) GIS application have gained a wide acceptability. Mapping has
becomes the keystone for flood risk management and communication in representing
spatial relationships between hazard and vulnerability and resulting risk
(Alexander et al 2011).


Flood is the most common occurring natural disaster that affects
humans and their
surrounding environment (Leinster, 2009). This natural disaster is common in
Nigeria, it has been occurring in almost every raining season (Kaoje and Ishiaku, 2017). In Nigeria,
urban floods are characteristic of cities such as Bayelsa State, resulting
mainly from poor planning and land use, poor drainage network and
indiscriminate dumping of refuse into drains and streams among others (Isong,

Flooding has been a major environmental problem in Bayelsa State,
Nigeria. It has both environmental and socio-economic effects. It has endangered
human lives and property. Some of such effects include damage to economic
activities and surface water pollution than can lead to water-borne diseases. In
Bayelsa State, Nigeria the problem of flooding has been difficult to mitigate
and there seem to be little work on flood risk and vulnerability in Bayelsa
State, Nigeria. The most recent research on flood vulnerability research by
Mmon and Ayapko (2014) examine GIS as a useful and important technique in monitoring
flood in Sabgama area of Bayelsa State, Nigeria using Analytical Hierarchical
Process (AHP) and a flood vulnerability map was produce but  a flood vulnerability map for the entire Bayelsa
State is not available.