American Journal of Water Resources

An estimated 96 percent of deaths related to natural disasters in the past decade occurred in developing countries. Flooding is one of the greatest water-related environmental disasters and is the major concern in West Bengal state in India. The number of people vulnerable to devastating floods is expected to rise due to large-scale urbanization, population growth in flood-prone areas, land use changes, climate change and rising sea levels apart from its contributions to the biodiversity and sustainability of ecosystems and to many human activities. New disaster risk reduction approaches are needed to build the necessary capacity to address these challenges. Based on this context, an investigation is made in the state of West Bengal in India over six years of extreme rainfall event highlighting the flooding situation interlinked with the structural and non-structural measures and its management strategy. West Bengal State experience heavy precipitation particularly in the months of September and October consequently upon low pressure/depressions developed in the Bay of Bengal during the years 1956, 1959, 1978, 1995, 1999 and 2000, which faced such worst type of rainfall and the year 2000 may be designated as the year of the worst precipitation in terms of quantum, intensity and duration. Lack of control structures coupled with very high discharge in the rivers during the year 2000 resulted in prolonged agony for a large number of people within the state. It is also attempted to develop a neuro-genetic models to identify the relationship between return period and extreme rainfall event.

American Journal of Water Resources. 2014, 2(2), 41-53. DOI: 10.12691/ajwr-2-2-3
Pub. Date: June 05, 2014

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Geoelectric Characterization of Aquiferous Units and its Implication on Groundwater Potential of Owo, Southwestern Nigeria

by Ogundana A. K and Talabi A. O.

Original Research

Geophysical study of the North-eastern part of Owo was conducted to investigate the geoelectric characteristics of its aquiferous units and its implication on groundwater potential of the area. Vertical electrical sounding method was employed and Schlumberger configuration was adopted. Thirty-two points were sounded along three different sections of the town namely; Idasen, Okedogbon and Express (Figure 1). Six different subsurface lithologic units were established namely; lateritic topsoil, clay, sand, quartzite, weathered/fractured basement and, basement. The curve types range between simple H, K, HA, HK, KH to complex, HKH, KHA and KHK. The topsoil, clay, sand and weathered basement materials are characterised with relatively low resistivity values while the quartzite ridge materials are characterized with high resistivity values. The average resistivity and thickness values for the topsoil are 220 Ωm and 2.0 m respectively. Clay was encountered across Okedogbon and Express area of the town and the average resistivity and thickness values of 34 Ωm and 6.0 m respectively. Sand was encountered across the entire study area with average resistivity and thickness values of 115 Ωm and 11.0 m respectively. Quartzite was encountered in all the locations with average resistivity and thickness values of 611 Ωm and 11.0 m respectively. Weathered/fractured basement was encountered across the three sections with average resistivity and thickness values of 86 Ωm and 12.0 m respectively. Basement is relatively deep in the study area and the average resistivity and depth values to the top of basement are 878 Ωm, and 24 m respectively. Overburden thickness was established across the area with an average value of 20 m. The overburden materials with the fractured basement constitutes aquiferous units within the study area though the sand and weathered basement units are largely responsible for the groundwater potential. The groundwater potential of the area is moderate with Express area having the highest potential.

American Journal of Water Resources. 2014, 2(2), 37-40. DOI: 10.12691/ajwr-2-2-2
Pub. Date: May 22, 2014

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Access to Potable Water Supply in Nigerian Cities Evidence from Yenagoa Metropolis

by Odafivwotu Ohwo and Abel Abotutu

Original Research

The importance of safe water supply to human health cannot be over emphasized. However, potable water supply to most Nigerian cities is still inadequate. This study was designed to determine households’ access to potable water supply in Yenagoa, in terms of quality and quantity. To achieve this aim, 15 borehole water samples were collected from 15 neighbourhoods, which the metropolis was structured. 375 questionnaires were randomly distributed in these neighbourhoods using the systematic sampling technique. The analyses revealed that both the quality and quantity of water supply in Yenagoa were inadequate. For instance, turbidity values (20.70-41.20 NTU) in all the sampled water were above the WHO 5 NTU threshold; while 7 (46.67%) samples have pH values below the WHO minimum value of 6.5, indicating acidity. Similarly, iron and lead also have 4 (26.67%) and 3 (20%) samples above the WHO thresholds of 0.3mg/l and 0.01mg/l respectively. The analyses of the quantity of water supply in Yenagoa also show that in spite of the proliferations of wells and boreholes, and the short distances to sources of major water supply, 29.28% of sampled respondents used below 20 litres of water per capita per day. This is mainly attributed to the high cost of water supply (average of N4, 500 per month) in relation to the monthly minimum national wage of N18, 000. It is therefore recommended that the State Government should as a matter of urgency revive and increase the capacity of the state water corporation to deliver potable water supply to the people at reasonable cost.

American Journal of Water Resources. 2014, 2(2), 31-36. DOI: 10.12691/ajwr-2-2-1
Pub. Date: May 10, 2014

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