Earth Science

Climate change is attributed directly or indirectly to human activities rhesulting in the alteration of the composition of global atmosphere in addition to natural climate variability observed over a comparable time periods. Climate change has adversely affected agriculture and food security in Nigeria and other West African Countries. It is estimated that by 2100 Nigeria and other West African Countries would have agriculture losses of up to 4% Gross Domestic Product (GDP) due to climate change. Agricultural experts has also observed that parts of the Country that experience soil erosion and operate rain-fed agriculture would have decline in agriculture yield of up to 5% between 2000 and 2020. In 2012, most states (Balyasae, Rivers, Bauchi, Kogi, Adamawa and Imo) in Nigeria witnessed serious floodind which affected adversely humans, farm lands and livestocks. Te flood which resulted from excessive rainfall attributed to climate change constituted a threat to agriculture and food security in all the geo-political zones of the Country. Desertification in the Northern part of Nigeria has also dealt a great blow to agriculture. The ravaging impacts of climate change on agriculture and food security calls for coping or adaptable measures such as construction of gas re-injection plants, public awareness campaigns, forest conservation, Taungaya and agrosiliviculture. However, the ultimate remediation is drastic reduction of the release of greenhouse gases into the atmosphere.

This study aimed to assess how markets affect smallholders’ decision-making about their arecanut, pepper and banana smallholders cropping systems in Sri Lanka. An economic assessment of the markets available for different crops was made using data obtained from a market survey and village study. Study found that farmers selected different crops based on market accessibility. Majority of farmers reluctant to grow banana as smallholdings in Pannila, whilst it was a popular choice on smallholdings in Pallekiruwa . Farmers faced high risk with perishables as their price variation was higher than that of storable crops. Study recommend to improve the market infrastructure for enabling farmers’ income.

The present study deals about to assess the rainfall variation during 1999 to 2014 in Salem district, South India, which makes to understand the rainfall fluctuation over a period of 16 years differences. Precipitation pattern analysis is very essential for the forecasting of any regions like agriculture or hazards. The analysis results shows that the mean winter season has contributed only 1%, summer season 19%, SW season 41% and NE season 39% of rainfall. The average rainfall in the study area is 829mm from 1999 to 2014. IDW has been used for prepare the spatial distribution maps.

This study was designed to evaluate the facies and petrophysical models of a reservoir interval, R700, within the Sigma Field, Onshore Niger Delta with a view to understanding the reservoir property distribution which could help in in-fill well placement. Well tops from well logs were interpreted by variations in depositional characteristics and were tied to seismic surfaces in order to construct the stratigraphic framework. Well data including facies, porosity, volume of shale and hydrocarbon saturation were scaled-up to geological grids. The pixel-based facies model was built based on normal distribution of the facies using Sequential Indicator Simulation algorithm. Petrophysical models were constrained to the facies models using Sequential Gaussian simulation algorithm. The average petrophysical parameters of the three reservoir intervals penetrated by the wells revealed the reservoirs to be of good quality with porosity ranging from 22.2-32.4%, net-to-gross; 51.9-80.3% and water saturation; 23.3-27.1%. The generated fault model of the field showed a dominant East-West trend with good connectivity/linkage. From the analysis of the structural maps and positions of existing wells, the faults can be said to play a major role in aiding accumulation and as such can be used as a guide/control in delineating other areas where accumulation can be favoured. The facies interpretation from well log and analysis of the isochore maps helped in delineating the direction of sand development and helped in constraining the facies model. The facies model captured the heterogeneity in the reservoir interval. Cross section drawn across positions of existing wells showed the location of the wells on structural highs while those drawn across other areas of the field away from existing wells but through areas of structural high revealed areas of good reservoir quality for sitting new wells for optimum recovery of hydrocarbon from the field.

Ground water is an important resource of water. However, over exploitation has affected the groundwater quality and quantity. Assessing the ground water potential zone is very important for the protection of water and management of groundwater system. Recent trends are showing the systematic planning to stop the over exploitation of groundwater and shrinking natural resources. Geo-spatial technology is very useful to study about the groundwater in detail. In the present study delineate the possible groundwater potential zones in the Salem district using geo-spatial technology. The thematic layers considered in this present study, which are geomorphology, drainage density, lineament density. These thematic layers are integrated for identify the groundwater potential zone. Therefore, five different groundwater potential zones were identified, which are very good, good, moderate, poor and very poor. Finally, it concluded that the Geo-spatial technology is very efficient and useful for the identification of groundwater potential zones.

The release of chlorophenolics in pulp bleaching wastewater is a threat to the aquatic ecosystems. The chlorophenolics can migrate throughout the biosphere and pose serious health hazard. The work is aimed to detect chlorophenolics using GC-MS and evaluate the effectiveness of TiO2 photocatalysis for their degradation in the paper mill wastewaters. Four type of chlorophenolics i.e. chlorophenols (CP), chloroguaiacols (CG), chlorocatechols (CC), and chlorosyringaldehyde (CSA) are detected in the wastewaters. The wastewaters are subjected to photocatalysis with UV radiation under optimum conditions (TiO2 = 0.50 g/L, pH = 7.0, time = 4 hr, and H2O2 = 15 mM/L). UV/TiO2/H2O2 process has been found to be more efficient for the degradation of chlorophenolics with 68% and 75% removal of chlorophenolics for primary clarified (PC) and biotreated (BT) wastewaters, respectively, as compared to UV/TiO2 process. The Monochlorophenols (MCP) are removed to the maximum extent followed by di- (DCP) and trichlorophenols (TCP).

Desertification is considered as an important problem facing arid and semi-arid regions, as Iran. These processes are resulted either from human activities or adverse natural conditions. However, the combination of both is often applicable. The aim of this study is the identification of areas sensitive to desertification in the southeastern coast of Iran. In this study we used from IMDPA model for quantitative of this problem and we used from GIS for mapping of desertification. Three main benchmarks of desertification, including: soil, wind erosion and climate were considered. The results show that the weight of soil is 1.7 that it is the most effective benchmark in region. On the other hand with analysis of indicators we know that the most important is annual precipitation. After obtain each weigh of benchmarks we understand that the weight of desertification intensity (DS) in region is 1.61 and located in very high class. We know more that 1321.74 (Ha) is in medium class and 2639.30(Ha) of area is in very high class. After soli benchmark, wind erosion with 1.64 value and climate with 1.51 value are effective in desertification.

A regional geoelectrical study was embarked upon covering some major towns within the Niger Delta and Anambra basin. Some of the towns include; Owerri, Umuahia, Ohafia, Aba, Umuosu, Ngwa, Mbaise, Okigwe, Lekwesi, etc. About 100 Vertical Electrical Sounding points were established along two long profiles running perpendicularly to each other at North-South and East-West directions covering a distance of about 110km in each traverse. The maximum electrode spread was 500metres, AB/2. The schlumberger array was adopted on the field. The ABEM Terrameter SAS 4000 was used for the data acquisition. The purpose of the study is to examine the variability in lithological units both vertically and horizontally from the North to South and East to West along these profiles because there have been reported cases about land degradation like; gully erosion, landslide, minor subsidence, road failure, etc within the study area. The field data were processed with computer softwares. Iso-resistivity values at AB/2 equals 1m, 4m, 8m, 15m, 50m, 150m, 250m and 350m at surface electrode spacings were plotted and processed for each VES point in order to reveal the variation in resistivity with depth and variability changes in lithological units with depth. This procedure was repeated for all the VES stations on the East-West profile and North-South profile. Results show that the top soil contour has resistivities between 200?m and 9000?m while at AB/2 = 4m, resistivities are 500 - 1000?m (Aba), 1000 - 5000?m (Owerri), 2000 - 2500?m (Afikpo). Results were also obtained for AB/2 = 8m, 15m, 50m up to 250m. These resistivity values were interpreted as clay, shale, sand, etc, accordingly. From the correlation of the VES points, other geologic structures like faults, boundaries, flood plains, landsides are identified. Other environmental implications are highlighted.

The present study was carried out in order to study about the textural characteristics of sediments, trace metal concentration (Cu, Zn), and their seasonal changes along with the influence of organic matter and physico-chemical parameter like pH, temperature, salinity and rainfall. Samplings were done at 3 different stations during 4 seasons starting from premonsoon-2009 to summer-2010. The changes in the phi mean grain size are due to selective winnowing of the finer grain size population by waves and currents acting in that environment. The sediments were well sorted to moderately well sorted in nature, skewness of the sediment samples were nearly symmetrical to coarse skewed and kurtosis ranged from mesokurtic to extremely leptokurtic in nature. The organic matter concentration range from 3.2% to 9.7% as minimum and maximum respectively. Concentration of reactive copper ranged from12.8ppm to 34.16ppm and the zinc concentration ranged from 39.3ppm to 228.2ppm.Thus in the present study the concentration of trace metals (copper & zinc), organic matter, grain size distribution and the interaction of Physico chemical parameters during different seasons were discussed.

The aim of the study is to determine the morphodynamic changes based on beach profile, and grain size distribution of sediments along the beaches between Mandapam to Valinokkam of Ramanathapuram district southern Tamilnadu. Morphodynamic condition and changes along the coastal length of 50km are recorded, and the granulometric study is done by dry sieving methods. Two seasonal both summer and winter sediment's samples were collected from the four main geomorphologic units (water level, slope, berm, and dune) during field observation periods. Grain characteristics are estimated by using GRADISTAT software, and the results are revealed. The sediments are mainly of course to fine grained, moderately sorted to poorly sorted, nearly-symmetrical skewed to find skewed, and leptokurtic to mesokurtic in nature. The majority of the sediment shows the bimodal nature of the interrelation ship of various parameters in sediment having the dominance of course to fine sand. Grain size characteristics varied from beach orientation foreshore, slope and wave action. The study area shows that sediment environment in high wave action compared to Ramanathapuram district in Mandapam to Valinokkam beaches were under erosion or deposition with a strong winnowing process.