by Deepak Singh, Braj B. Singh and Yogesh Kumar
Original Research
Rivers in any country are important lifeline for the population living around it whose water is used for drinking, agriculture, industrial and commercial purposes. The increasing anthropogenic activities like industrialisation, urbanisation and change in land use pattern, increased use of chemical fertilizer and pesticides in farming have lead to the discharge of the different types of contaminants in the river water. In the present article, the data has been acquired from Central Pollution Control Board, India which continuously monitors different kinds of water quality parameters every year at regular interval. The data analysis of the different biogeochemical water quality parameters of river Ganges has been carried out. In the present study, a total of six cities have been chosen to analyse the water quality of the river Ganges. The chosen six cities are Haridwar, Kanpur, Allahabad, Varanasi, Patna and Kolkata which are situated along the stretch of the river Ganges. The Haridwar is located at a place where the river Ganges enters the Northern Indian Plain from mountainous (Himalayan range) region while Kanpur, Allahabad, Varanasi and Patna are located on Plain and Kolkata is situated on the Deltaic region of river Hooghly which is one of the distributaries of river Ganges. For the analysis purpose, a total of eight water quality parameters which decide the contamination levels of the water bodies have been selected. These parameters are temperature, dissolved oxygen, pH, conductivity, Biological Oxygen Demand, Nitrate + Nitrite, Faecal Coliform and Total Coliform load. The study has been carried out with respect to the data from 2007 to 2016. In this ten years period, the data of four years i.e., 2007, 2010, 2013 and 2016 have been selected having gap of two years. In the spatial analysis of the result, it has been found that the river Ganges in Haridwar is least contaminated and the Kolkata is highly polluted in terms of the eight water quality parameters studied. In the correlation matrix analysis, the population of the city is negatively correlated with the altitude, temperature, dissolved oxygen while positively correlated with conductivity, BOD, Nitrate + Nitrite, Faecal Coliform and Total Coliform load. With regard to the Coliform contamination, except at Haridwar, rest of the river flow through the five cities indicated the Coliform contamination was many time above the standard limits prescribed by theCPCB.
American Journal of Water Resources. 2018, 6(6), 235-245. DOI: 10.12691/ajwr-6-6-4
Pub. Date: December 17, 2018
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by D. Mathieu Maurice Ahouansou, Sampson K. Agodzo, O. Hervé Rodrigue AWOYE, Romaine G. ASSOGBA BALLE and Luc. O. C Sintondji
Original Research
This study assesses groundwater quality in the Dassari watershed, a highly cultivated catchment area in Northern Benin, West Africa. Four sampling campaigns were conducted and the groundwater samples were analyzed using the standardized methods of the American Public Health Association. Descriptive and multivariate statistics were applied to describe and group the water samples into categories. The water samples were also compared to the World Health Organization (WHO) norms and those of the Republic of Benin. Boxplot comparison method and variance analysis were used to analyze the seasonal variation of groundwater parameters in both rainy and dry seasons. The hydro-chemical facies of the sampled groundwater were investigated through Piper and Chadha diagrams, and the general type of groundwater in the catchment was found to be as calcium-rich and magnesium-rich water based on the identification of the dominant cations. The major anion in the samples was Hydro-carbonate HCO3-, thus the groundwater in the study catchment can be considered as carbonate-rich water. Comparing the concentrations of analyzed parameters to WHO and the Republic of Benin guidelines for drinking water, the whole catchment was found to have potable groundwater. Comparing the nitrate concentration in the samples to a natural limit of 10 mg/L, we show that all samples had a nitrate concentration above that limit, thus indicating an anthropogenic pollution due to high fertilizer use. However, these concentrations are still under the permissible limit of WHO (50 mg/L). The analysis of the seasonal change in hydro-chemical parameters revealed no significant change at 5% level of these parameters from rainy season to dry season. In the Dassari catchment, groundwater is still potable although we found a slight sign of pollution due to high fertilizer use.
American Journal of Water Resources. 2018, 6(6), 224-234. DOI: 10.12691/ajwr-6-6-3
Pub. Date: December 14, 2018
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by Homayoon Ganji and Takamitsu Kajisa
Original Research
When real data are unavailable, the standard Penman-Monteith method for estimating reference evapotranspiration can be calculated using alternative input data: wind speed from a nearby station, the default global average wind speed, solar radiation based on temperature and vapour pressure based on the minimum temperature. These alternative data are recommended in FAO paper 56. In this study, we assessed the accuracy achieved when using these alternative data for reference evapotranspiration estimation in a semi-arid region characterised by a strong persistent wind speed. Western Afghanistan was selected as the study site, as it is exposed to strong winds over the 120-day period from June to September. Significant differences were found in the estimates produced using full data and those obtained using wind speed data from a nearby station, the default global average wind speed, and vapour pressure based on the minimum temperature. Root Mean Square Error (RMSE) was found 1.51 mm d-1, 1.27 mm d-1 and 1.07 mm d-1, respectively. Errors were especially significant on days with strong wind. The smallest RMSEof 0.36 mm d-1was found when basing solar radiation on temperature. The assumption that the dew point temperature will be close to the minimum temperature was shown to be unreliable on days of strong wind.
American Journal of Water Resources. 2018, 6(6), 217-223. DOI: 10.12691/ajwr-6-6-2
Pub. Date: December 12, 2018
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by Homayoon Ganji and Takamitsu Kajisa
Original Research
The estimation of reference evapotranspiration (ET0) with the FAO-Penman-Monteith method faces challenges in some places due to its high data demand. To overcome this challenge some methodologies recommended by FAO. However, sharing the nearby station’s data is another way to estimate ET0 more accurate in some cases than that of using the FAO’s recommendation. In this paper, the important matter is the determination of an effective distance (Xc) which is the upper limit of distance for data sharing between the stations. ∆ET0(st)which is the average errors between the two stations given by the measured data is theoretically very small if the distance is zero. ∆ET0(Alt) which is the error produced from the alternative data given by FAO’s recommendation is equal to ∆ET0(st)at Xc. By using the data form 48 metrological stations in Japan, we examined this concept in the case of three kinds of data. The results confirmed, there was Xc exited along the investigated distance at which ∆ET0(st) was smaller than ∆ET0(Alt). This was the case corresponding to the solar radiation and actual vapor pressure. Xc was found smaller than the minimum distance in the case of wind data. It is, therefore, possible to use the FAO’s alternative wind data.
American Journal of Water Resources. 2018, 6(6), 212-216. DOI: 10.12691/ajwr-6-6-1
Pub. Date: December 09, 2018
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