Abstract
Nigeria as a nation suffers the effect of Climate Change majorly through flood events. Recent flood disasters in Nigeria have been of major concern to people, communities and institutions. Floods are the most common in Nigeria during the peak of the rainy season (June-October) and the 2012 flood event in Nigeria is described as the worst in recent times.
Kogi State was the most affected state due to its location at the confluence of the country‘s major rivers (Niger-Benue Rivers). The flood events have pushed rivers to overflow their banks submerging hundreds of kilometers of the urban and rural land in Kogi State which is beyond description and has attracted humanitarian assistance from both national and international organization. Lokoja, the Kogi state capital, is located at the Niger-Benue confluence, hazards erupt when human activities in the confluence area are not properly managed. This study uses the Remote Sensing and GIS technique to assess the flood vulnerability zones of the town using the bench mark minimum and maximum water level from the year 2006 to 2015. Land-use/land-cover and flood vulnerability maps were generated from the digitized satellite imageries and gumbel‘s frequency distribution method. Five districts namely; Sarkin Noma/Galilee, Kabawa-Adankolo, Phase 1 – old poly quarters, Gadumo and Ganaja were directly affected by the flooding and the estimated number of Internally Displaced Person (IDP) yearly is about 5,645 and about 543 house are destroyed, also agricultural lands and farm produce are destroyed, major infrastructures like schools, health centres and transportation routes are fully inundated and destroyed making some communities inaccessible. This study revealed that a total land area of 6681.32Ha was covered by flood excluding the original extent of the river. It further revealed that area of land of 2828.79Ha (13.64%), 3852.53Ha (18.57%) and 14063.26Ha (67.79%) are occupied by high vulnerability, Moderate vulnerability and Low vulnerability respectively. In a bid to mitigate the extent of damage and casualties during a flood disaster, this study aimed at assessing, mapping and analyzing flood disaster in Lokoja Metropolis, Kogi state for an effective flood disaster risk management and proper planning.Â
CHAPTER ONE
INTRODUCTIONÂ
Floods are among the most devastating natural disasters and cost many lives every year (Dilley et al. 2005). Flooding seriously affects people‘s lives and property (Wang, 1999). In a time period of 6 years (1989–1994), 80% of declared disasters in US were related to flooding; flood themselves around the world average four billion dollars annually in property damage alone (Wadsworth 1999). The frequency with which they occur is on the increase in many regions of the world (Drogue et al. 2004). It is reported that flood disasters account for about a third of all natural disasters (by number and economic losses).Â
In Nigeria, aside from droughts, floods cause almost 90 % of damages resulting from natural hazards (Adeoye et al., 2009). Floods that occur in Nigeria are as a result of extensive rainfall, drainage blockages and dam failures (Jeb and Aggarwal, 2008). Flooding are common features in Nigeria during Urban flooding which occurs in towns, on flat or lowlying terrain especially where little or no provision has been made for surface drainage, or where existing drainage has been blocked with municipal waste, refuses and eroded soil sediments (Folorunsho and Awosika 2001). Flooding cannot be completely avoided, but damages from severe flooding can be reduced if effective flood prevention scheme is implemented. Mitigation is hence the cornerstone of emergency management. Flood risk‟ means the combination of the probability of a flood event and of the potential adverse consequences for human health, the environment, cultural heritage and economic activity associated with a flood event‖ (EC, 2007). Recent flood disasters in Nigeria have been of major concern to people, communities and institutions. Flash floods are the most common in Nigeria during the peak of the rainy season (June-October) and the 2012 flood event in Nigeria is described as the worst in recent times. Kogi State was the most affected state due to its location at the confluence of the country‘s major rivers (Niger-Benue Rivers)Â
Kogi state experienced a serious flood disaster in 2012 and the situation is beyond description and it has attracted humanitarian assistance from NEMA, Red Cross and many among others. It has lead most settlements inundated rendering millions of people homeless, destroyed thousands of hectares of farmlands and livestock and also loss of aquatic animals. This flooding came as a result of water release from Ladgo dam into river Benue, Shiroro and Kanji dam also released water into river Niger, as well as climate change itself which led to excess precipitation (NEMA, 2012).
