Water and sediment samples were collected along river Ilaje in the Ondo coastal area of Nigeria during the dry and wet season. Water analysis was carried out by using standard methods for the examination of water and waste water, water and sediment samples were digested and analyzed for heavy metals using atomic absorption spectrophotometer. Pour plate technique was employed for the enumeration of bacteria and fungi using nutrient agar and potato dextrose agar respectively, the cultured media was supplemented with 2% oil (petrol, diesel and kerosene) as the only source of carbon and energy. After incubation, biochemical test and morphological features were carried out to identify the microorganisms. The result shows that the physicochemical properties of water varies with the seasons total hardness (620-2,424 mg/l), calcium hardness (130-1,478 mg/l), Alkalinity (120-144 mg/l), phosphate (2.21-2.78 mg/l), nitrate (0.90-22.50 mg/l), sulphate (228-395 mg/l), chloride (1990-3532 mg/l), the concentration of metals in water samples varies with the season having the lowest in Cd (0.01 mg/l) and the highest in Cr (0.66 mg/l). The concentration of metals varies in season with a spatial distribution in the top and bottom sediment samples. Oil tolerating fungi and bacteria were detected from the sampling sites with variation in the dry and wet seasons, E. coli was only detected in the water samples during dry season only. The presence of pathogens and water properties exceeding the WHO standard renders the water unfit for drinking and domestic use.
Over the last three decades, soil erosion phenomenon has grown to be the most serious and significant geo-environmental problem in Morocco as in the whole Mediterranean area. As a matter of fact, it damages both soil functions and quality, not to mention the magnification of the surface waters pollution along with the siltation of Dams and reservoirs.
The Geographic Information System (GIS), in addition to other tools, has shown to be one of the key components used to model and assess potential erosion in a given area by estimating the rate of eroded soils and the amount of sediment carried out by either runoff or through rivers.
The main aim of this paper consists, primly, in producing soil erosion risk map of the Smir Dam watershed (Northwestern Morocco) using the Universal Soil Loss Equation (USLE) adapted to Moroccan conditions and integrated into a GIS platform. The aforesaid equation allows the calculation, spatialization and overlying the five factors controlling water erosion, namely rainfall erosivity, soil erodibility, slope length and steepness, land use and erosion control practices.
As a result, a spatial referenced document has been generated, representing, mostly, high erosion rates with an average loss of 45.45 t/ha/year. Furthermore, the spatial analysis of erosion phenomenon, related with other thematic maps, showed that the vegetation cover is the main factor that controls and affects the erosion in the Smir watershed.
Drainage basin morphometric information is very important in any undertaking to control incidence of flooding in an area. In the present study, morphometrc analysis using remote sensing and GIS techniques have been carried out to examine the flood potentials of the Mayogwoi river basin. The Mayogwoi basin is a small basin. The pattern of this basin is dendritic. The values of bifurcation ratio (2.45), circularity ratio (0.64), elongation ratio (0.66) and form factor (0.35) indicates that the basin is moderately circular and somewhat elongated. The length of overland flow of the basin is 1.25, indicating matured topography and low surface runoff in the study area. The low drainage density (0.4 km/km2) and low stream frequency (0.11) is indicative of low relief, low surface flow, high infiltration and consequently low flood potentials of the basin. The basin has a low relief ratio (0.074) and low relative relief (2.38) indicating low relief and gentle slope. The result of the findings also shows that the basin has a short basin length of 32.2 km indicative of higher chances of the basin been flooded after heavy rainfall of short duration. Consequently, the result shows that there will hardly be enough water supplies to support large scale water resource development prospects particularly irrigation and hydropower project in the basin except with intensive development of land and water resources of the basin. Thus, high intensity of rainfall is required for the generation of flash flood in the drainage basin because of its relatively small basin size. The morphometric parameters of the basin therefore suggest low to moderate flash floods chances and high potential of groundwater aquifers recharge. Thus, heavy rainfall is the most important flash flood - causing factor, followed by morphometric characteristics and land uses in the basin.
Groundwater is one of the natural resource with the potential for domestic, agricultural and industrial consumption. Groundwater quality of bore well water of Baramati city has undergone degradation due to anthropogenic and some natural factors. Groundwater samples were collected from thirty borewells and hand pumps of different areas of Baramati city, District Pune, Maharashtra (India) during the period January 2014 to December 2014 and analyzed for their physico-chemical characteristics. The various physico-chemical parameters such as pH, Electrical conductivity, Ca2+, Mg2+, Na+, K+, total dissolved solids (TDS), total hardness (TH), HCO3-, Cl-, SO42- and DO were determined using standard procedures of APHA. The results of analysis were compared with the drinking water quality standards of Indian Standard Institute (BIS) and World Health Organization (WHO). In study area electrical conductivity and TDS of 80% samples were found above the maximum permissible limit of WHO and BIS. The higher values during summer reflect concentration effect. 30 to 33% groundwater samples shows sodium values above 200 mg/l, which is guideline limit for drinking water by WHO. In the study area 30% water samples were hard water category. The groundwater quality of the study area for drinking purpose has been spoiled by anthropological and other activities. The 30 to 80% borewell and hand pump water samples were found to be unsuitable directly for drinking purposes. Such water can be purified by using suitable purification methods and can be used for drinking purpose.
Groundwater is the main source of drinking water for many small agricultural communities. Nitrate concentration in groundwater is a major problem in Nira River basin area, which is mainly due to the run off or seepage of chemical fertilizers from the agricultural field. A total of 45 water samples were collected in the period of post-monsoon (POM) winter 2013 and pre-monsoon (PRM) summer 2014 seasons from bore wells. The water samples were analysed using standard methods of APHA suggested for analysis of nitrate. Groundwater quality parameter varies spatially in different seasons. In the present study, spatio-temporal variation in nitrate levels in bore wells of Baramati Tahsil area is examined. The results of analysis showed that nitrate concentration in POM and PRM was above the maximum permissible limit of WHO and BIS recommended for drinking purpose. In POM 74% groundwater samples from canal irrigated area and 11% from non-canal-irrigated area were above the standard limit of WHO and BIS. In PRM 66.67% and 11% samples respectively from canal irrigated and non-canal-irrigated area were above the maximum permissible limit of WHO and BIS (45 mg/l). This indicates that peoples especially children using the water from bore wells with higher concentration of nitrate than standard limit, stands a high risk of methemoglobinemia (sometimes referred to as “Blue baby syndrome”). In canal irrigated area concentration of nitrate was found higher than the non-canal-irrigated area. This may due to the use of more nitrogenous fertilizers by farmers in their farms, improper disposal of animal and human wastes in canal irrigated area as compared with non-canal-irrigated area. The groundwater of such bore wells was not suitable for drinking purpose without treatment at the time of analysis. Nitrate containing groundwater is more effective and useful for irrigation purpose. The nitrogen can be removed from drinking water by using treatment such as ion exchange, biological de-nitrification and reverse osmosis.