Ayansina Ayanlade

This paper examines drought characteristics as an evidence of climate change in two agro-climatic zones of Nigeria and farmers' climate change perceptions of impacts and adaptation strategies. The results show high spatial and temporal rainfall variability for the stations. Consequently, there are several anomalies in rainfall in recent years but much more in the locations around the Guinea savanna. The inter-station and seasonality statistics reveal less variable and wetter early growing seasons and late growing seasons in the Rainforest zone, and more variable and drier growing seasons in other stations. The probability (p) of dry spells exceeding 3, 5 and 10 consecutive days is very high with 0.62 ≤ p ≥ 0.8 in all the stations, though, the p-values for 10 day spells drop below 0.6 in Ibadan and Osogbo. The results further show that rainfall is much more reliable from the month of May until July with the coefficient of variance for rainy days <0.30, but less reliable in the months of March, August and October (CV-RD > 0.30), though CV-RD appears higher in the month of August for all the stations. It is apparent that farmers' perceptions of drought fundamentally mirror climatic patterns from historical weather data. The study concludes that the adaptation facilities and equipment, hybrids of crops and animals are to be provided to farmers, at a subsidized price by the government, for them to cope with the current condition of climate change.

This study examined the potential environmental impacts of coastal urban development and the resultant urban thermal changes in Eti-Osa, Lagos between 1984 and 2014. Multi-date Landsat images were used for the spatio-temporal change in the land use over time, while the topographic map and the ASTER image were used to generate the Digital Elevation Model (DEM). Supervised classification method was used to establish rate of urban expansion in the study area. The urban heat pattern variation analysis was performed after the surface temperature data were extracted from the band 6 of each Landsat imageries of the three observed years (1999, 2006 and 2014), using Idrisi Selva 17 software package. The results showed that as built-up areas spread east wards, the riparian forest has been declining from 24.57% area cover in 1984, drastically to 3.75% in 2014. The major reason for this might be because the high density built-up increased from 2.38% in 1984 to 14.19% in 2014 and the light density built-up increased from 5.51% in 1984 to 13.42% over the same period. The implication of increasing built-up areas is obvious on the patterns of heat in the study area. There were observed changes in thermal pattern over time, cutting across both land and the sea surfaces. It was observed that the built-up areas exhibit the highest temperature while the natural vegetation and water body had the lowest temperature.

Selection of appropriate data and methods for environmental change assessment is highly central in any remote sensing research project. This study assessed various land use/land cover change (LUCC) methods and tested the accuracy of prominent classification methods and their implications on land surface temperature (LST) change estimation. Niger Delta of Nigeria was used as a case study. The study concluded that, though no single method can be applied to all cases and regions, there are some factors that determine the remote sensing methods to be used in both LST and LUCC change analysis. Such factors include the spatial, temporal, spectral and radiometric resolutions of satellite image and environmental factors. Therefore, this paper evaluated methods used in earlier studies to assess, monitor and model LUCC impacts on LST. The paper concludes by proposing the use of two or more methods in any LUCC–LST research project. This is because, all remote sensing methods are not totally right, but some are useful, thus, the methods should be viewed as complementary.

This study aims to investigate seasonal and diurnal variations in urban temperature, as well as the contributions of different land uses to land surface temperature (LST). A time series of MODIS data was used in this study. Average seasonal LST differentials between day and night from 2002 to 2014 were estimated. The results reveal substantial changes in land use over the study period; in particular, urban centre and urban fringe surface area increased by 15.93 and 94.49% respectively, while forest land and wetland surface area decreased by approximately 5 and 8% respectively. Average LST increases by nearly 3 degC during the daytime in the dry seasons, compared with the wet season, for all land use/land cover (LULC) classes. In all seasons, the average LST of urban areas is nearly 1.5 degC higher than the LST values for the surrounding rural areas. The explanations for these variations are obvious: the majority of urban centres in Lagos metropolis have dense buildings and slight vegetal cover; thus they appear to have less energy loss due to latent heat by evaporation from the impervious urban surfaces. The study concludes by proposing improved urban planning in Nigeria through implementation of urban planning policies.

The introduction of climate change studies in universities has a fundamental role in helping the general public, especially the next generations, to recognize the global challenges of climate change and to find ways of adapting to the changing climate. This study examined the level of climate change education and perception of Nigerian university graduates. A mixed method approach was used to obtain data relating to perceptions, understanding, and level at which climate change has been taught in Nigerian universities. The results from this study revealed that about 70.7% of university graduates received brief lectures in some special elective courses during their university education, while only 4.1% were taught more than three semesters/terms in some special elective courses. It was also revealed that graduates from departments of environmental sciences have more class experience on climate change than students in the humanities and other faculties. The major finding of this study is that students appear far more informed about climate change, usually from the Internet and international media, than the level of climate change education they were taught in university. These results show the need for the introduction of climate change studies in Nigerian universities, with over 71% of participants believing that climate change studies should be included as a required course in both undergraduate and postgraduate studies.

This study examines environmental change in Tsekelewu, Niger Delta Region. Both remote sensing and social survey methods were used to assess the impacts of oil exploration activities around the Tsekelewu community. Landsat data between 1984 and 2011 were used for spatiotemporal change in the environment around the community while mixed method approaches were used to collect social data. The results show that several mangrove forest areas were degraded around Tsekelewu during the 1980s and 1990s while the vegetation appeared regenerated during the 2000s, although, at a very slow rate. The rate of regeneration noted from 1999 to 2011 has not fully compensated for the mangrove loss that occurred during the 1980s and early 1990s. After 15 years of uncontrolled forest destruction, little vegetation regeneration, the area was taken over by brackish water mangrove.

Purpose
In this study, the spatial and temporal relationship of wind speed, atmospheric particles concentration, and the industrial-induced noise levels during different times of the day were examined, using sawmill industrial location around Ile-Ife in Osun of Nigeria as a case study.

Methods
Mobile devices were used to measure noise level and basic meteorological parameters were examined and their influences on the noise levels distribution were assessed. The maximum and minimum sound levels; Lmax and Lmin, the PM10 and PM1 particle concentrations, wind speeds and directions were measured in the morning (7–9 a.m.), afternoon (12–2) and evening (4–6 p.m.) over 14 consecutive days.

Results
The results revealed that the noise level varies spatiotemporally, much more consistent spatial distribution along the vicinity of sawmill industries. A higher level of noise occurred during the weekday (WD), Leq > 70 dB(A), compared to weekends (WE). Extreme average noise levels are associated with the immediate neighbourhood of sawmill industrial areas during WD compared to streets and road annexes of the study area. The results also show a very weak relationship between noise and PM10 and PMcoarse for both WD and WE with r < 0.35 for PM1 and r < 0.20 for PMcoarse. There appears to be a moderate significant correlation between noise level and PM1 during some meteorological conditions with r > 0.51.

Conclusion
The slight relationship between noise and PM1 is perhaps a result of wind movement that carries particles from the source region since booth noise and particles mostly originate from the sawmill. The study concludes that wind speeds and directions have a significant influence on both noise level and particle concentration within the study sites.

The study evaluated the climatic and societal implications of vegetation
degradation in Okomu and Gilli-Gilli Forest Reserves (OGFRs) of Nigeria. Both remote sensing
and non-remote sensing data and methodologies were used. Landsat data between 1984 and
2011 were used as quantitative data while social survey was carried out for qualitative data
collection and assessment. Both remote sensing classification and Normalized Difference
Vegetation Index (NDVI) methods were used in this study. The results show that deforestation
resulting from farmland encroachment has increased in Okomu Forest Reserves (OFR) but was
relatively low in Gilli-Gilli Forest Reserves (GFR). In 1984, about 17 % of the reserves were
deforested, and this increased to 37 % in 2011 in OFR. These values reveal a massive
deforestation. Forest disturbance within the GFR is much less than OFR possibly because high
rate of illegal oil palm development in OFR. The result shows no significant impacts of
vegetation degradation on local climate, but people in the communities around the reserves
reported several climatic extreme events as a result of vegetation removal. However, the study
could not reveal direct significant impact of vegetation degradation on local climate but there
were rather indirect impacts from climate events. The results from social survey show that over
80 % of local people perceived high rate of heavy erosion and flooding mostly from year 2000 to
2011. It is obvious from the social survey that unrestrained felling of forest in the region has
also rendered the soil vulnerable to erosion and flooding since forests tend to reduce the impact
of erosion and floods. There is a need for proper enforcement of forest conservation laws in order
to reduce the rate of deforestation, not only in OFR and OGR but also in all forest reserves in
the country.

This study examines the spatial extent of coastal urban development and its
potential sensitivity to sea-level rise. The main aim of the study is to critically examine the
extent of growth in Eti-Osa over time, and the potential impacts of sea leve rise. Landsat
Enhanced Thematic Mapper Plus (ETM+) imageries of years 2000 and 2015 were used to
evaluate the different land use type identified. Post-classification change detection method
was used to evaluate the output of the maximum likelihood supervised classification analysis
done. This was also used to estimate the changes induces through urban development on the
environment which accounts for the biodiversity loss. ASTER GDEM 2 imagery of 2011 was
used to generate the elevation data used for the inundation analysis. Thus, both Land use map
of Eti-Osa in 2015 and the down scaled Sea-level rise scenarios (at 0.5 to 15 meters) were
used for the inundation mapping. Results obtained from this research affirms that indeed EtiOsa
has been subjected to gross urban expansion giving room for diverse forms of
environmental degradation among which are huge replacement of natural land cover with
built-up, reclamation of wetlands and sand filling of water bodies. This basically illustrates
growth but also the risk that accompanies the advent of excessive alteration of natural
ecosystem as Sea-level rise projections imply in this research.

Variations in urban land surface temperature (LST) links to the surrounding rural areas result to urban heat island (UHI), which is a global problem challenging both cities in develop and developing countries. Satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS), covering the period between 2002 and 2013 were analysed to examine seasonal variability in the daytime and night-time intensity of urban heat island (UHI), using Lagos metropolitan city of Nigeria as a case study. Contribution index (CI) and landscape index (LI) were used to estimate the LST contributions from non-urban and urban areas to UHI and assess the relationship between the Normalized Difference Vegetation Index (NDVI) and LST. The LI showed that both non-urban and urban areas contribute greatly to strengthen the intensity of LST during the daytime (with LI < 1.0) and much more during the daytime in the dry seasons (LI = 0.13 in the year 2013). The correlation analysis showed seasonal variation in the relationship (R2) between NDVI and the LST for both day and night times. The highest R2 values were recorded for daytime, especially during the wet season (R2 > 0.90), while R2 were very low in the night-time especially during dry season. The study indicates that reduction in vegetal cover in Lagos urban areas altered the terrestrial thermal and aerodynamic processes hence resulted in an intensification of UHI in the metropolitan city.

Removal of vegetation to give space for urban expansion might result in the temperature rise in cities. The present study compares the LSTs derived from Moderate Resolution Imaging Spectroradiometer (MODIS) with observed air temperature from ground weather data. The natures of the materials that are usually found in the urban area are typically concrete and asphalt materials which affect the urban atmospheric system. In this study, variation in urban land surface temperatures (LST) using MODIS and in-situ meteorological data were examined. MODIS data and daily rainfall, minimum (Tm) and maximum (Tmx) temperature from ground weather station were used. The results reveal that average LSTs during the dry season are noticeably higher for both daytime during November: 34.62 °C, December: 33.75 °C, January: 34.68 °C, February: 35.02 °C and March: 34.87 °C. There are notable differences in the LST observed between daytime and nighttime for both MOD11A2 and MYD11A2 and that of maximum and minimum air temperature from in-situ meteorological data. MOD11A2 is a better proxy for daily maximum and minimum air temperature than MYD11A2, though seasonal variations in the extent of LST occurs during the wet and dry season. The study shows that the contribution of the urban LSTs was comparatively smaller at night than the day, perhaps as result of the variations in the amount of solar radiation received by the day and night times.

The Niger Delta, being the most extensive freshwater wetland and aquatic ecosystem in West Africa, provides numerous services both to local people and to the West African economy. Ongoing environmental pressure exerted by large-scale oil extraction and illegal timber logging, however, are suspected to have had a substantial impact on the Delta’s ecosystems over the last decades. Knowledge on impact of these activities on the region’s wetlands now or in the past is scarce and patchy. To address this lack of knowledge, this study assesses spatiotemporal changes in two wetlands in the region by using satellite data from 1984 to 2011 and GIS methods. The results show that both wetlands have experienced substantial degradation, particularly with respect to the area of forest lost. Although comprehensive environmental protection laws were introduced in 1988, ecosystem services of up to US$65 million in value were lost over the study period. The introduction of new legislation in 2007, however, is potentially a first step towards a more ‘wise use’ of wetlands in Nigeria.

This study aimed at using remote sensing methodology to assess the daytime surface urban heat island (SUHI) in Lagos metropolis. Several studies have examined the SUHI, using point data from meteorological stations. However, it has been shown in the literature recently that it is practically impossible to accurately value the intensity of SUHI from ground meteorological measurement due to heterogeneity and complexity of surface temperature over land. Therefore a time series of Landsat data, from 1984 to 2012, were used in the present study to assess spatial and temporal variability in the contribution of source and sink landscape to daytime SUHI in Lagos. This study uses remote sensing methods because Lagos has a strong heterogeneity of land surface characteristics; with several drainage, vegetation, built-up and soil between the coast and mainland, thus the land surface temperature (LST) changes rapidly in space and time. The results from this study show differences in the contribution of source and sink landscape to SUHI. The main findings from the results show that source landscape contributes positively to the intensity of SUHI in Lagos metropolis. The results show a general increase in mean LST during the periods of study from 1984 to 2012. The north-west (NW) zone of Lagos has highest LST compared to other zones. In 1984, the mean LST of NW zone was 300.53 K, but increased to 301.85 K in 2000 and 302.85 K in 2012. Although contributions from the landscapes differ by zones and time, much more intensified LST was noted in the NW zone of the city. The study find out that change in landcover has been the most important driver of intensified SUHI in Lagos metropolis. NW zone recorded the highest increased in built-up area throughout the years: 320.32 km2 in 1984, 535.28 km2 in 2000 and 630.70 km2 in 2012. This study demonstrates therefore that it is possible to assess spatial distribution and long-term temporal evolution of the LST in urban area, using remote sensing data. Also the results shows that remote sensing methods offer possibility for measuring LST over complete spatially averaged rather than point values. The results from this study further our understanding that not only the SUHI is frequent to cities in developed countries, but the effects are also obvious in several urban settlements in tropical countries.

This study aims at examining and mapping the spatiotemporal distribution of meningitis epidemic, in relation to climate variability, using GIS and Remote Sensing techniques. Using the northern part of Nigeria as a case study, data on meningitis epidemic were obtained from the archive of National Bureau of Statistics, Nigeria for the periods between 1998 and 2013. The data were updated with collection from Nigeria Demographic and Health Survey (NDHS). Also, Nigerian Ministry of Health has compiled consistent statistics on meningitis incidence for the periods. A meningitis distribution map was derived from an environmentally-driven form of predicted probability of epidemic experience as it is in International Research Institute for Climate and Society (IRI) Database. The results showed that Meningitis Epidemic is very high during months with low rainfall. Thus, seasonality of rainfall and temperature are important determinants of Meningitis Epidemic incidence in the Northern part of Nigeria. Therefore, it can be confirmed, as cited in some literatures, that the distribution of the epidemics has a strong association with the environment, especially climate variability. Although meningitis surveillance systems in Nigeria have improved, they still fall short of the sensitivity required to demonstrate incidence changes in vaccinated and non-vaccinated cohorts and complementary approaches may be needed to demonstrate the impact of the vaccines. There is however, a need for a new technology and innovation like an integrated GIS, and other environmental modeling system, to allow health practitioners as well as policy makers, for better management, productivity and profitability.

Background

Geoinformatics is a modern technology that provides accurate means of measuring the extent and pattern of changes, and other related information about environment (Boakye et al., 2008). The term “Geoinformation” consists of two main words: “Geo” which means earth’s surface or the environment; and “informatics” stands for fact about something. Thus, Geoinformation is the science and technology of communicating the evidences about the state of the earth’s surface. It is known for technological robustness to assess spatial and temporal change occurring on the earth’s surface (Yang & Liu, 2005; Ehlers, 2008). In the recent years, Geoinformatics has been used to provide electronic representation about earth’s surface and man’s interaction with the earth. Geoinformatics has emerged in the last two decades as an exciting multi-disciplinary endeavour, spanning such areas as Geography, Cartography, Remote Sensing, Image Processing, Environmental Sciences and Computer Aspects of environmental studies.

In general, the science and technology of Geoinformatics encompasses application of remote sensing and GIS data and methodology. GIS is an acronym that stands for Geographic Information Systems while the remote sensing data are those data collected through various devices without human (researcher) contact with field. GIS, in actual sense, is not a new development, it is only recently that it has gained widespread acceptance as a tool to assess both spatial and non-spatial issues. GIS was initially referred to as the management of information with a geographic component primarily stored in vector form with associated attributes. This definition quickly became too limiting with advances in software and recent digital ideas about earth. GIS involves spatiotemporal data analysis using software, hardware, people and approaches to acquire, store, update and manipulate for presenting information about the human environment. GIS could be seen as a digital computing environment and human interactions with the environment. For environmental change analysis, GIS uses both remote sensing and non-remote sensing data. Non-remote sensing data may include field observation, topographic, geological and edaphic data. It may also include terrain data, as well as socio-economic survey data, and reports relating to human environmental relation. Though non-remote sensing data are those data acquired by other means than remote sensing approach, they are sometimes used in Geoinformatics analysis, for identification and interpretation of environmental features and their significant change over time (Campbell 2002). In general, it has been shown in several other recent studies that Geoinformatics is not only good for preparing precise environmental change assessment, but also for observing changes at regular intervals of time, it is cost and time effective (Kreuter et al., 2011; Ahmad, 2012; Aguirre-Gutiérrez et al., 2012; Avitabile et al., 2012).

This study aims at describing and evaluating the relevance of Geographical Information System (GIS) procedures as a standard technique to model atmospheric parameters when there are several data gaps. Generally, high resolution atmospheric parameters are needed to assess the impacts of climate change on crop productivity at the local level, using data at the level of individual farm units. Such high resolution climatic data are non-existent in the West African setting because of the extremely sparse meteorological station network. The problems often arise as to what values to attach to climatic variables at points other than these nodes where there are data gaps. Therefore, GIS interpolation and downscaling methods were used to assess how gaps in climatic parameters could be filled using Nigeria as a case study. Several GIS interpolation methods have been tested for the production of maps in this study. After many attempts of the qualitative and quantitative validations, the last of these- Ordinary Kriging- was chosen for the map productions. A major strength of the method is that measured spatial dependence in the weather parameter of interest and this is used to produce digital maps. Ordinary Kriging was used to interpolate the point observations from a network of rainfall base stations. The results from this study show that GIS interpolation are helpful for downscaling spatial dynamics of climate and also useful in forecasting probable period for farming activities.

Geographic Information Systems (GIS) and Remote Sensing (RS) techniques are increasingly being used
in agricultural management to more efficiently support emergency agro-climatic information needed in
this century. Although several studies have been carried out on application of GIS and remote sensing
for agricultural and rural development in other parts of the world, little research has been done in subSaharan Africa in terms of developing geospatial data infrastructure to enhance agricultural practices
especially agricultural risk management in this age of climate change. This chapter therefore examines
technological aspects of geographic information sharing as a useful platform for sharing information
among agricultural agencies in Nigeria and to formulate relevant prescriptions for the future. The study
shows how an integrated GIS modeling system can allow agricultural producer as well as policy makers to know the impact of variation in climate from one place/region to another for better management,
productivity, and profitability. The study also develops agricultural GDI prototype for agricultural
emergency management. This chapter concludes by suggesting that developing country (i.e. African
countries) should embark on agricultural policy reform to enhance investment in ICT infrastructure in
agricultural production.

This study develops an integrated innovation for malaria early warning systems (MEWS), based on vulnerability monitoring, seasonal climate variability data, and epidemiologic surveillance. The main aim of the study is to examine the relationship between intra-annual climate variability and malaria transmission in Nigeria. For this study, climatic conditions considered suitable for the development of the malaria parasite and its transmission through the mosquito stage of its life cycle are temperatures within the range from 18°C to 32°C. Below 18°C the parasite development decreases significantly, while above 32°C the survival of the mosquito is compromised. Relative humidity greater than 60% is also considered a requirement for the mosquito to survive long enough for the parasite to develop sufficiently to be transmitted to its human host stage. The research findings show that seasonality of climate greatly influences the seasonality of malaria transmission. Specifically, rainfall plays an important role in the distribution and maintenance of breeding sites for the mosquito vector. Rainfall and surface water is required for the egg laying and larval stages of the mosquito life cycle and monthly rainfall above 80 mm is considered a requirement. Also, it is temperature that regulates the development rate of both the mosquito larvae and the malaria parasite (Plasmodium species) within the mosquito host. Relative humidity and temperature play an important role in the survival and longevity of the mosquito vector. This study is in conformity with the findings of the IPCC (2001) that malaria is caused by four distinct species of the Plasmodium parasite, transmitted by mosquitoes of the genus Anopheles, which are most abundant in tropical/subtropical regions, although they are also found in limited numbers in temperate climates.