Impacts of Agricultural Wastes on Groundwater Pollution in Lipakala Farms, Ondo Southwest Nigeria

The impact of Agricultural wastes on ground water pollution was investigated in Lipakala Farms, Ondo Southwest, Nigeria. Physical, chemical and microbial parameters of the water samples of the only water source in the farm were analysed. This was to determine the level of pollution and the suitability of the water source for domestic and animal consumption. Results showed that minute traces of ions were present in water, lead ranges between 0.4 and 0.6mg/l, Nitrate 64 – 65mg/l; pH value of 7.8; Iron, 56.3-57.8mg/l. For the physical characteristics, while temperature ranges between 31.50c and 330c, samples were odourless, colourless but tasty with turbidity value of I0NTU and electrical conductivity of 690mho/cm, indicating high presence of salt deposits as a result of the location of precambium basement rock near the farm. The average bacterial count of 4cfu/ml and total coliform count of 10MPN/100N were indication of microbial contamination of the water source. Hence, it is recommended that wells should be located at upland to croplands to prevent inflow through runoff of fertilizers and chemicals from farmlands. Also, modern waste disposal methods should be adopted, phasing out open dumpsites to avoid microbial contamination of well and safeguard public health. In addition, public health enlightment and awareness campaign should be conducted in the farm to sensitize the inhabitants of the farm of the dangers inherent in haphazard waste disposal. Keywords: Agricultural wastes, Pollution, Well, Microbial contaminant

Analysis of meteorological and hydrological droughts in the Niger-South Basin, Nigeria

Information gained from drought analysis can serve as the basis for water resources planning and management under the prevailing climate change condition especially at the basin scale. The aim of this work is to apply two meteorological drought indices - Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI) and a hydrological drought index - Standardized Runoff Index (SRI) to investigate the occurrence of drought in the Niger-South Basin (NSB), a sub-catchment of the Niger River Basin in Nigeria, during the period 1970–2008. The results showed that the period between 1970 and 1981 was dominated by wet conditions; second, from 1982 to 1998, a period of droughts ranging from moderate dry to extreme dry alternated with moderate wet conditions, while the third period beginning from 1999 to 2008 displayed another round of severe droughts sparingly intercepted by occasional moderate wet conditions. High correlation values of between 0.66 (at 3-month scale) and 0.56 (at 12-month scale) show comparativeness in the performance of the two drought indices. For the hydrological drought, a severe drought was observed in 1982 and near normal and moderately wet since 1997. The higher agreement between the SRI and SPEI, suggests that hydrological droughts are more affected by temperature (warming) than precipitation (drying) in the basin. Further analysis of the frequency of the various conditions shows that it has been more of near normal conditions (> 60%), while extremely dry and wet conditions (2% each) have been very rare. However, given the projected global warming conditions, a reversal of the present normal condition might be witnessed in the nearest future, hence, the results of this study can serve as a basis for effective water resources planning and management in the basin

Empirical model for the assessment of climate change impacts on spatial pattern of water availability in Nigeria

Rising temperatures and changing rainfall patterns due to global warming would affect sustainability in water resources in many regions. This change would impact several sectors, particularly the agricultural and water resources. The major objective of the present study is to model the impacts of climate change on spatial variability in water sustainability of Nigeria. Gauge based gridded rainfall data of global precipitation climatology centre (GPCC) and temperature data of climate research unit (CRU) for the period 1901–2010 and total water storage (TWS) anomaly data of Gravity Recovery and Climate Experiment (GRACE) for the period 2002–2016 were used for this purpose. The concept of reliability-resiliency-vulnerability was used for the assessment of sustainability in water resources. Machine learning models were used for the development of empirical models for the simulation of TWS from GPCC rainfall and CRU temperature. Finally, the multi-model ensemble mean projections of rainfall and temperature of four GCMs namely MRI-CGCM3, HadGEM2-ES, CSIRO-Mk3-6-0 and CESM1-CAM5 were used in the model for the assessment of climate change impact on water sustainability. The results revealed the declination of TWS in Nigeria up to -12 m during the rainy periods in some parts. Spatial assessment of the changes in TWS for the future shows the northeast, southeast and south-south parts would mostly experience decreases in TWS. Water sustainability will be low in these areas and some other parts of the country for the future