Geography

SOCIAL ECOLOGY AND GREEN SPACES OF THE IBADAN METROPOLIS, NIGERIA

2022-03-04T10:44:15Z

SOCIAL ECOLOGY AND GREEN SPACES OF THE IBADAN METROPOLIS, NIGERIA AREOLA, ABIODUN AYOOLUWA Green spaces (GS) are vegetation areas in urban landscapes, including forests, parks, gardens, wetlands and street trees. Their loss has great consequences for the aesthetic, recreational, economic and human health value and sustainability of urban environments. The literature on urban GS hasfocused on locations and effects on human well-being with limited attention to the impact of the existing social ecology (SE) on GS patterns. SE considers spatio-temporal patterns, socio-cultural variables, and underlying environmental patterns. Ibadan is Africa’s largest traditional city with a long history of GS which has reduced over the years, thus providing a suitable environment for examining SE. This study was, therefore, designed to analyse the spatio-temporal patterns of GS,relationship between SE and GS, the perception on greening culture and government greening interventions in the Ibadan metropolis. The concept of Social Ecology guided the study, while a survey research method was adopted. Cloud free Landsat Imageries (LI) of 1972, 1984, 2000 and 2015 were obtained from www.Glovis.com. Normalised Difference Vegetation Index threshold of 0.2-0.8 was used in identifying GS from the processed LI. The Oyo State map sourced from the State Valuation Department was superimposed on the LI to identify a total of 104 localities. The stratified proportional sampling technique was used to categorise the localities into four population range groups using sample percentages – A: 0.1%, B: 0.2%, C: 0.4% and D: 0.8%. The systematic technique was used to draw a total sample of 3,410 from the localities. Area of GS in each locality was thereafter computed for all the years. The change detection method was used to map the changes in GS, while Global Moran’s-I was used to analyse its temporal pattern. Geographically Weighted Regression (GWR) was used to identify the SE predictors of GS in different localities. Analyses were done at p<0.05. The age of residents was 33±6.01 years, and the estimated monthly income was ₦42,055±13, 934. About 46.1% had secondary education. The GS declined by -62.0%, -37.8% and -38.4% between 1972-1984, 1984-2000, and 2000-2015, respectively. In 1972 (I: 0.348091), the GS were principally clustered in Bodija, Elewura and Academy. In 1984 (I: 0.452642), 2000 (I: 0.313010) and 2015 (I: 0.229712) the GS were principally clustered around UCH, Jericho GRA, Alalubosa, Iyaganku and along Ogunpa river channels indicating unequal spatial distribution. Occupation, income and housing were the SE determinants of GS distribution (Bandwidth: 0.02: AICc: 3043.3; R2: 0.52) while SE effects were very strong in some localities in group A (Sango, Jericho, University of Ibadan) and group B (Ring road, Molete, Apata), which are the non-traditional areas of Ibadan.The major perceived cause of GS depletion in groups A, B and C is building construction and poor development control in group D. More than 64% favoured government greening intervention, but doubted their implementation competence. The social ecology in Ibadan has resulted in uneven spatial distribution of green spaces in the city. There is a need for policy intervention to reduce the adverse loss of green spaces and consequent effect on the environment

SPATIOTEMPORAL PATTERNS OF ADOPTION OF CASSAVA IN SOUTHEASTERN COTE D’IVOIRE, 1951-2017

2022-03-04T10:38:07Z

SPATIOTEMPORAL PATTERNS OF ADOPTION OF CASSAVA IN SOUTHEASTERN COTE D’IVOIRE, 1951-2017 KOUAME, KOFFI JEAN MARIUS BORIS Cassava is one of the world's leading staple root crops whose adoption for food security varies over space and time in the West African sub-region. Research on cassava has focused on production, processing, post-harvest systems, and diseases with little or no attention paid to spatial variation of its adoption. This study was therefore, designed to analysed spatiotemporal patterns of adoption, factors influencing adoption, and impediments to adoption of cassava in South Eastern Côte D'Ivoire during the period 1951 to 2017. Available information showed that cassava was first cultivated in South Eastern Côte D'Ivoire in 1951. Adoption of Innovation, Reasoned Action and Planned Behaviour provided the framework, while survey design was adopted. Based on the information provided by the Ministry of Agriculture and Rural Development, the entire 154 villages cultivating cassava in the three districts (Comoé, Lacs and Lagunes) in South Eastern Côte D'Ivoire were purposive selected. Information on cassava growers’ associations were provided by Directors of the Ministry of Agriculture and Rural Development in, while the number of farmers in the cassava growers association was provided by officials of each association in villages. A structured questionnaire which focused on socio-economic characteristics, adoption of cassava, factors influencing, and impediments to its adoption was administered to all the 4000 members of the cassava growers’ associations in the three districts. Descriptive statistics, Global Moran’s I, Trend Analysis, Chi square and Analysis of Variance were used to analyse the data at 0.05. Female cassava farmers were 53.3%, 25.6% were aged between 31 and 40 years, 53.3% were married, 37.7% had primary education, 32.9% had more than five children, and 39.1% earned <121.000 FCFA (220 USD) annually. There was significant clustering of villages adopting cassava in 1951-1960 (I=0.26;z=5.9); 1961-1970 (I=0.25;z=5.8); 1971-1980 (I=0.28;z=6.4); 2001- 2010 (I=0.08;z=2.1) and the entire period 1951-2017 (I=0.05;z=1.3). The number of individuals who have adopted cassava was only 53 before1951 but increased to 1422 in 2017. The number of adopters increased significantly from 1951 to 2017 (R2= 0.72; F=6.2). Adoption of cassava in the districts was significantly influenced by: age (X²=483.061), sex (X²=14.861), marital status (X²=351.361) annual income (X²=772.924), educational level(X²=413.270) and number of children (X²=218.604). In Comoé district, annual income (X²=313.499); educational level (X²=237.131) and number of children (X²=71.012) were significantly related to cassava adoption, whereas in Lacs district, annual income (X²=302.581); educational level (X²=299.157) and number of children (X²=256.511) were the significant variables. In Lagunes district, annual income (X²=525.926); educational level (X²=105.192) and number of children (X²=151.538) significantly influenced cassava adoption. Financial return (73.1%) was the major reason for cassava adoption by farmers. The impediments to adoption of cassava in the districts were inadequate rainfall, no training on cassava cultivation, difficulty in getting stems, lack of capital and lack of labour. The pattern of adoption of cassava cultivation in South Eastern Côte D’Ivoire from 1951-2017 was mostly random. Financial gain was the major reason for its adoption. Therefore, more farmers should be encouraged to adopt and cultivate cassava given its contribution to income generation in the country.

TOPOGRAPHICAL AND SEASONAL EFFECTS OF DECOMPOSED CASSAVA PEELS ON BIOREMEDIATION OF HYDROCARBON POLLUTED SOILS IN OBIO/AKPOR LOCAL GOVERNMENT AREA OF RIVERS STATE, NIGERIA

2022-02-14T13:37:03Z

TOPOGRAPHICAL AND SEASONAL EFFECTS OF DECOMPOSED CASSAVA PEELS ON BIOREMEDIATION OF HYDROCARBON POLLUTED SOILS IN OBIO/AKPOR LOCAL GOVERNMENT AREA OF RIVERS STATE, NIGERIA DEEKOR, TORNUBARI NIIENI Oil exploitation in the Niger Delta has resulted in widespread hydrocarbon pollution. Despite vast research on bioremediation using organic amendments for restoring hydrocarbon contaminated land, the potential of decomposed cassava peels has attracted little attention in the literature. This study was therefore designed to examine the seasonal effect of decomposed cassava peels for bioremediation of hydrocarbon polluted soils of different topographical surfaces in Obio/Akpor Local Government Area(LGA), Rivers State, Nigeria. Ecosystem concept was adopted while experimental research design was used. A well-drained and waterlogged sites were purposively selected for the study. Each site was divided into 18 plots, each measuring 2m by 2m and was contaminated with Bonny light crude oil at three levels of 2.0, 4.0 and 6.0% concentrations. The experiment was undertaken in both dry and wet seasons. The baseline soil without contamination served as control. Decomposed cassava peels were introduced into the soil to a depth of 10cm seven days after contamination. Seventy two soil samples were collected from 0-15cm and 15-30cm depth. Soils in the experimental sites were analysed before and after contamination, and after three months of bioremediation for physical (sand, silt and clay, bulk density, total porosity) and chemical (Total Organic Carbon-TOC, Total Nitrogen-TN, Phosphorus-P, pH, Total Hydrocarbon Content-THC, and Total Petroleum Hydrocarbon-TPH) properties respectively. The properties of polluted soils before and after remediation were compared using descriptive statistics and independent t-test at p<0.05. The TOC, TN, P and pH of soils before and after contamination, and after remediation were: 0.37%, 0.08%, 0.67mg/kg and 6.39; 0.72%, 0.21%, 0.82mg/kg and 6.4; and 0.58%, 0.16%, 0.51mg/kg and 6.22, respectively. These indicated an increase in the parameters after contamination and decrease after remediation. Percentage reduction in TPH was 58.2% in dry season and 24.8% in wet season. The THC in dry seasonbefore contamination were 40.63mg/kg, 32.5mg/kg and 36.67mg/kg in well drained site and 35mg/kg, 30mg/kg and 40mg/kg in waterlogged site for 2.0, 4.0 and 6.0% levels of contamination. After contamination, THC increased to 740.8mg/kg, 755mg/kg and 787mg/kg in well drained site and 882.5mg/kg, 912.5mg/kg and 935mg/kg in waterlogged site. After remediation THC decreased to 339.2mg/kg, 317.5mg/kg and 436.7mg/kg in well drained site and 525.1mg/kg, 462.6mg/kg and 558.2mg/kg respectively in waterlogged site. In the wet season THC results before and after contamination, and after remediation were 85.8mg/kg, 100.8mg/kg and 121.7mg/kg; 470mg/kg, 598.3mg/kg and 827mg/kg; and 238.2mg/kg, 350mg/kg and 486.7mg/kg respectively. The THC was significantly lower in remediated soils t(5)=15.12. The TPH reduced from 69.7ppm to 29.1ppm in dry season, while in wet season TPH declined from 58.9ppm to 44.3ppm. Bioremediation was influenced by seasons and topographical locations in Obio/Akpor Local Government Area, Rivers State. Remediation was more effective in well-drained soil than in waterlogged soil but proceeded faster in the dry season than in the wetseason. Application of decomposed cassava peels for hydrocarbon remediation on well-drained soil in dry season is recommended.

URBAN GROWTH PATTERNS AND PROCESSES IN LAGOS ISLAND LOCAL GOVERNMENT AREA, NIGERIA

2022-02-14T08:41:11Z

URBAN GROWTH PATTERNS AND PROCESSES IN LAGOS ISLAND LOCAL GOVERNMENT AREA, NIGERIA OLANIRAN, HEZEKIAH DARAMOLA Unplanned urban growth is one of the major challenges in developing countries. The literature on urban growth has focused more on horizontal growth, without a corresponding emphasis on vertical growth. Even within the urban horizontal growth analysis, greater attention has been on the dynamic patterns rather than processes of growth. This study was, therefore, designed to analyse the spatiotemporal dynamics, patterns, and processes of horizontal and vertical urban growth in Lagos Island Local Government Area (LGA), Nigeria. Urban Morphology and Complexity theories provided the framework, while a survey research design was adopted. Lagos Island LGA was purposively selected given the concentration of high rise buildings. A total of 1,200, out of 47,447 households were systematically selected using Neumann (2014) probability method. Socio-economic and building related data were collected through questionnaire survey. Landsat (1984, 2000, and 2015) and IKONOS (2013) images provided information on growth patterns and processes. Spatiotemporal dynamics of urban growth were analysed using change detection and ANOVA. Moran’s Index (I), spatial metrics (Clumpiness index) and spatial regression were used to analyse horizontal growth patterns and processes. Three-Dimensional Spatial Index (3DSI), Nearest Neighbour Index (𝑅𝑛), vertical entropy (𝐻𝑛) and standard regression were used to analyse patterns and processes of vertical growth. Cellular Automata Markov model (CA-Markov) and binary logistic regression were used to predict future urban growth. Analyses were conducted at p≤0.05. Age of household heads was 39.92±12.48 years, while 65.5% were male. Household size was 4.92±2.38 and income was N66,468.43±N33,798.96 per month. Urban land area increased from 4.20km² in 1984 to 5.40km² in 2015. Net and gross changes in the built-up area were ±0.77km² and 1.45km² respectively. There were significant spatial variations in urban horizontal growth in 1984 (F(1;18)=3.79), 2000 (F(1;18)=5.71) and 2015 (F(1;18)=11.75), but no significant temporal variation. Horizontal temporal growth patterns were significantly clustered (I=0.28(1984), 0.53(2000) and 0.29(2015)). Fragmentation and aggregation were the major processes of urban horizontal growth (Clumpiness index=0.87(1984), 0.84(2000) and 0.87(2015)). Population growth (β=0.98), building lot size (β=0.04), demand for space (β=0.22) and housing stock (β=0.0003) were major drivers of urban horizontal growth. Vertical growth increased between 2000 and 2015 (3DSI=6914.45) more than between 1984 and 2000 (3DSI=6601.82). Vertical growth pattern was significantly clustered (𝑅𝑛=0.52), while aggregation (𝐻𝑛=0.1) was the major temporal process of vertical growth. Number of financial institutions (β=0.68), rental value (β=0.46) and proximity to water bodies (β=0.63) were the major drivers of vertical growth. By 2031, about 71.5% of Lagos Island would have been built-up. Proximity to water bodies through land reclamation (β=4.11, Exp(β)=60.74) would be the most significant predictor of future urban growth. Lagos Island Local Government Area, Nigeria has witnessed both horizontal and vertical urban growth due to fragmentation and aggregation of urban patches between 1984 and 2015. Urban horizontal growth will decrease with the increasing vertical expansion, hence the need for effective urban planning.