Open Access Original Research Article

Implication of Land Use Change on Flood Vulnerability in an Urban Watershed of Ibadan, Southwest, Nigeria

Olusola O. Ige-Olumide, Ayobami T. Salami

Journal of Geography, Environment and Earth Science International, Page 1-17
DOI: 10.9734/JGEESI/2018/36574

This study identified the relationship between land use land cover changes (LULC) and flood vulnerability (FV) in a watershed using geospatial data. Using the supervised classification method and post classification change detection technique, nature, extent and rate of land use land cover change were examined from 1972 -2013 with a view of assessing flood vulnerability on land use changes. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model (DEM) and Landsat multispectral medium resolution satellite image (Landsat) (30 m) covering Ibadan for the years 1972, 1984, 2000 and 2013 were acquired. The AsterDEM was used to delineate the urban watershed of Ibadan while the Landsat imageries were used to evaluate spectral and spatial changes in the LULC of the study area within the 41 years’ period under consideration. Analytical hierarchical process was used to standardize and integrate identified factors (slope, soil, drainage, LULC, elevation) contributing to flood which were assigned weight and overplayed in the principle of pairwise comparison. The flood vulnerability (FV) sensitivity index was developed using the multi criteria decision analysis model. The study also examined the relationship between LULC and FV. The results showed that LULC in the watershed experienced increase in built up areas by 9.4% (1972), 14.1% (1984), 15.3% (2000) and 40.2% (2013) while waterbody experienced decrease of 2.8% (1972), 0.2 (1984), 0.1% (2000) and 0.1% (2013). Highest flood vulnerability was recorded in 2013, followed by 1984; while 1972 had the least flood vulnerability. The flood vulnerability on built up, light vegetation, bare soil and water body increased by 15.66%, 12.56%, 21.24%, 34.42% for 1984 and 57.16%, 9.16%, 83.68%, 0.78% for 2013 respectively. Results revealed that rapid changes in land use play a significant role in intensifying flood risk in the urban watershed. This study concluded that change in LULC is increasing drastically in the watershed. Implication of this is that if human activities are not properly controlled and if a well-planned and effective land use policy is not put in place within the watershed, vulnerability of the area to flood disaster may assume an unprecedented dimension.

Open Access Original Research Article

Geographic Foci of Industries: A Suitability Analysis

Abia Moses, Eja Iwara, Njoku Chukwudi Gbadebo, Okeniyi Oluwafemi Olubukola, Itu Prince-Charles Omin

Journal of Geography, Environment and Earth Science International, Page 1-14
DOI: 10.9734/JGEESI/2018/39994

Industrial development in the world, especially in developing countries is a prevailing issue with serious emphases on the location of these industries. Finding suitable geographic foci for industries is very important for administrators of firms, investors as well as the government. This geared this study which proffered the most suitable foci for industrial location in Calabar metropolis of Cross River State, Nigeria. In all, data obtained include locations of existing tertiary industries, airport and dumpsite. Also were population figures, pipe-borne water network, topographic, land use and cadastral data (boundaries, roads and rivers). The data analysis was done majorly with Geographic Information System operations (topographic, proximity, overlay and structured queries). Standard physical suitability criteria for siting an industry were considered. The analysis recommended the most suitable geographic foci for industries in the city. The best site deducted from the                    analysis covers a land area of 2.23sq km, situated at the far eastern corner of the metropolis, by the boundary of the metropolis and Akpabuyo Local Government Area. It was thus recommended                  that a multi-criteria site selection analysis must be executed for a more precise, effective and sustainable selection of the best site for locating industries in Calabar and elsewhere.

Open Access Original Research Article

Effect of Inter-annual Rainfall Variability on Precipitation Effectiveness in Nasarawa State, Nigeria

V. A. Agidi, S. M. Hassan, T. G. Baleri, J. G. Yilgak

Journal of Geography, Environment and Earth Science International, Page 1-21
DOI: 10.9734/JGEESI/2018/40005

The study investigated inter-annual rainfall variability effect on precipitation effectiveness in Nasarawa State. Tropical Rainfall Monitoring Mission (TRMM) remote sensing rainfall data was used for the study. The daily rainfall record from 1998-2015 was collected for the study. Onset, Cessation and Length of Growing season are the only precipitation effectiveness indices examined. The pentad method of calculating onset, cessation and length of rainy season was adopted for the study across the entire Local Government Areas of the state. The summary of the findings show that, the averages of Onset dates, Cessation Dates and Length of rainy season dates across the state are not uniform. Rainfall starts early in the Southern zone of the state on 12th April, followed by Western zone 6th May then the Northern zone 12th May. The cessation dates of rainfall are almost the same in all zones with the North and South having cessation dates at 16th October while the West has its cessation date as 18th October. This finding reveals that the dates of cessation are more reliable and predictable than onset dates. Onset date that run between April and May in the state is good because it has not moved far from the expected pattern.

Open Access Original Research Article

Structural Analysis Using Upwards Continuation / Lineaments Trends Analysis on Aeromagnetic Data: A Case Study of Southern Nigeria Basins

D. A. Obi, A. M. George

Journal of Geography, Environment and Earth Science International, Page 1-9
DOI: 10.9734/JGEESI/2018/39331

Twenty aeromagnetic maps were used for this study, which covers parts of Southern Sedimentary basins and their adjourning basement flanks in Nigeria. The aeromagnetic maps were acquired from the Nigeria Geological Survey Agency on a scale of 1: 100,000. The data was digitized manually along flight lines and a total of 16,689 data points obtained. The information was processed using computer techniques such as map merging, reduction to pole, polynomial filtering, upwards continuation, manual trend analysis and depth estimates. The results from upwards continuation reveals five major deep-seated anomalous fracture trends which could characterize major depositional centers. Lineaments trend results indicate dominant NE –SW trends within the Niger Delta, Mamfe basin, Lower Benue Trough, and Anambra basins, while the Calabar Flank area has a NW –SE Lineaments trends. Manual depth estimates indicate grater sediments thickness within the deeply seated anomalies ranging between 2.5km -10.0km, and within the shallow anomalous structures depth to source of anomalies varies between 1.0km – 2.0 km .The identified five major deep-seated anomalies  characterize good prospecting sites for possible hydrocarbon deposits accumulation.

Open Access Original Research Article

Effects of Inner Shelf Environment on the Distribution of Recent Ostracoda from the Southern Part of Gulf of Mannar, SE Coast of India

V. Kumar, B. Satish

Journal of Geography, Environment and Earth Science International, Page 1-12
DOI: 10.9734/JGEESI/2018/40549

To understand the impact on temporal variation of inner shelf environments of the southern part of Gulf of Mannar on the distribution of Ostracoda, a systematic collection of sediment and bottom water samples were made at 28 stations. Seven samples each were collected along four traverses, from off the coast of Tuticorin, Sippikulam, Mookaiyur and Volinokkam, for three seasons, representing Pre-monsoon, Post monsoon/winter and Summer. Thus the collections amounted to a total of 84 samples. A total of 48 species belonging to 36 genera, 18 families, 5 super families and 2 suborders of Podocopida have been identified. The bottom water parameters viz. temperature, salinity, dissolved oxygen and sediment parameters viz. calcium carbonate, organic matter content and sand, silt & clay ratio have been studied for three different seasonal collections along with the population distribution of the Ostracoda.  Temporal variation of temperature, salinity and dissolved oxygen content of the bottom water shows a positive correlation with the distribution of Ostracoda. Spatially, higher CaCO3 content and moderate organic matter content are associated with a higher population of Ostracoda. Temporally, the conditions prevailed during April (summer) accounts for higher population.  The siltysand type of substrate is found to be an accommodative substrate for higher population.