by Probir Kumar Pal, Afeefa Rahman and Dr. Anika Yunus
Original Research
Dudhkumar River flows from upstream of India Border at Bhurungamari to the confluence with Brahmaputra River at Noonkhawa of Kurigram district having a stretch of 64 km in Bangladesh. Due to onrush of water from upstream in monsoon, erosion in Dudhkumar River takes a serious turn, threatening collapse of Sonahat Bridge in Bhurungamari, embankment on its right bank, dykes and several dwelling houses in recent years establishing the river as a destructive one. Thus study aiming at computing the long and short term bank line shifting along the river is of great significance. In this study, images of Landsat MSS and TM acquired from the year 1973 to 2015 have been used to investigate the riverbank migration pattern, accretion-erosion, rate of change of width, sinuosity and island dynamics of Dudhkumar River. For the short term analysis, migration rates are calculated from one Landsat image to the next. For long term analysis, the migration rates are calculated based on the difference between the 1973 image as the reference and subsequent images. From the short-term analysis, the mean erosion and accretion rate have been estimated as 128 m/y and 194 m/y on the left bank, and 141 and 176 m/y on the right bank indicating the accretion rate as greater than the erosion rate. Erosion rate has been found as greater in right bank rather than left bank and accretion rate is much more in left bank than the right bank. Due to high discharge, maximum erosion and accretion have been found as 349 m/y and 410 m/y respectively at left bank in 2013-2015 indicating the bank protection measures vulnerable. Computations on sinuosity of the river Dudhkumar River show that the sinuosity ranges from 1.36 to 1.53 showing significant increase in year 1989, 1997 and 2011 due to active erosion and deposition induced by monsoon flood. Analyses on island dynamics reveal that the island area started increasing after 1973 and maximum island area found in 2001. The analysis divulged that the Dudhkumar River is a highly meandering river with several critical sections where the river has been suffering enormously with erosion problem and shifting.The present study also identifies steadfast evidence on the dynamic fluvio-geomorphology of Dudhkumar River depicting urge for execution of erosion control schemes.
American Journal of Water Resources. 2017, 5(4), 132-141. DOI: 10.12691/ajwr-5-4-6
Pub. Date: November 15, 2017
18280 Views3858 Downloads
by Jared Okungu, Josiah Adeyemo and Fredrick Otieno
Original Research
The counties traversed by Yala River Catchment in Kenya have been constrained by acute shortages of water resources because of the declining stream flows, which is occasioned by environmental changes, increasing population and changing land uses. This study applied Water Evaluation and Planning (WEAP) model to evaluate past trends and simulate current demand scenarios for the purposes of planning by authorities in regard to future use. The study used historical data (1970-2015) to assess water supply and demand in the catchment for the period 2016 to 2045 by simulation. Calibration and validation were each performed on 10-year streamflow datasets (1991-2000 and 2001-2010 respectively), drawn from 4 gauging stations. Simulations were then conducted for the scenarios namely: Reference (at 2.8% growth rate), High Growth (3.2%), High Growth (3.5%), and Moderated Growth (2.2%). The categories of water demand evaluated in WEAP included: Domestic-Institutional-Municipal, Agriculture, and Industry uses. In a 5-year time-step, WEAP demonstrated resultant increase in water demand for year 2020 by 7.46% from 2016 at Reference Scenario. WEAP further simulated a gradual increase in water demand during subsequent years. This trend would continue for the rest of the scenarios but with variations occasioned by adjustment of variables in WEAP such as population growth rates, monthly variations, annual activity levels, water use rates, water losses and reuse rates, industrial production units, agricultural acreages, and varied demand sites. In conclusion, there were demonstrated substantial increases in water demands within individual scenarios between 2016 to 2045, but these increases were significantly different scenario-by-scenario. The study recommends that supply and demand measures be employed with the aim of regulating activity levels, losses and consumptions so as to meet demands in case any of the studied scenarios would be applicable.
American Journal of Water Resources. 2017, 5(4), 125-131. DOI: 10.12691/ajwr-5-4-5
Pub. Date: November 06, 2017
13074 Views3039 Downloads
by Andriambeloson Onja, Rabenirina Harilanto, Rajoelisoa Andriamalala, Ramaroson Luciano and Rasolomampianina Rado
Original Research
The ability of Actinomycetes strains to degrade pollutant matters and to reduce or eliminate pathogens microorganisms from domestic wastewater of an industrial site (oilfield of Tsimiroro-Madagascar) at the laboratory scale is demonstrated in the present work. Two most active Actinomycetes isolates (Streptomyces albidoflavus strain DSM 40455T and Streptomyces antibioticus strain NBRC 12838T) against test-pathogens were selected for the purification treatment. The analysis of physico-chemical (COD, BOD, pH, conductivity, color, TDS, nitrite, nitrate, phosphate and chloride rates) and microbiological parameters (sulphite reducing anaerobe, fecal coliforms, fecal Streptococcus and Escherichia colirates) allowed to evaluate the quality of the wastewater. Physico-chemical results revealed that purified water is qualitatively improved view that 60.86% of TDS, 71.61% of its color, 25.55% of its chloride rate, 45.32% of its nitrate rate, 99.9% of its nitrite rate, 26.25% of its phosphate rate, 46.53% of its initial COD and 58.11% of its BOD were eliminated at the end of the treatment. Only, the conductivity increased compared with the guideline values for all treatment. The process improved also microbiological quality of the wastewater with total elimination of fecal Streptococcusand diminution of fecal coliforms, sulphite reducing anaerobe and Escherichia coliconcentrations. The experiment proved that biological treatment using Actinomycetes strains is a promising, less expensive and simple technology for wastewater recycling ensuring thus their reuse for other activities.
American Journal of Water Resources. 2017, 5(4), 117-124. DOI: 10.12691/ajwr-5-4-4
Pub. Date: October 28, 2017
12588 Views3016 Downloads
by Emeribe C.N, Isagba E.S and Fasipe O.A
Original Research
The present study examines the possibility of determining supplementary water requirements of selected food Crops per growth stage using the climatic indices alone. Rainfall and temperature datasets on high-resolution (0.5x0.5 degree) grids resolution were assembled from the Climatic Research Unit CRU TS 3.21 of the University of East Anglia, Norwich, United Kingdom for the period 1943-2012. To ascertain the suitability of the datasets for use in the study area the Pearson Product moment correlation was undertaken with measured rainfall data from Yelwa synoptic station, Nigerian Meteorological Agency. Melon, Beans, Millet, Sorghum, Soybean and Cucumber were used for estimating seasonal supplementary irrigation water needs in the Sokoto Rima, River Basin. The observed seasonal patterns of rainfall and PET shows that soil moisture surplus in the basin sets in from June – August while April to May is the soil water recharge periods. From October, water is withdrawn from the basin, paving way for moisture deficit which last from November-March. The study shows that even during the rainy months, supplementary irrigation is needed to compensate for deficit due to increased rate of evapo-transpiration. It is also possible to carry out an all year round cultivation in the basin. For an all-year-round cultivation of crops with greater yields, full scale irrigation is needed for a second cultivation season (from October to February) when the soil moisture storage of the basin is below the basin field capacity. In absence of spatial dataset, the use of CRU proves to be an alternative in climatic response and modelling studies.
American Journal of Water Resources. 2017, 5(4), 106-116. DOI: 10.12691/ajwr-5-4-3
Pub. Date: October 20, 2017
21215 Views2548 Downloads
by Eugine Makaya
Original Research
Different water utilities use different performance indicators to assess their performance. Although these indicators are peculiar to particular situations, it is paramount that each indicator is applied consistently among utilities as this is good for benchmarking purposes. Besides being well documented, performance indicators have not been well reviewed from the perspective of developing countries. Furthermore, there is limited understanding of the application of performance indicators among developing countries. Therefore this paper reviewed performance indicators for physical water loss management. The African Development Bank self-assessment matrix was applied to the City of Gweru, Zimbabwe. Furthermore, the infrastructure leakage index was used to assess the performance of the water utility. The self-assessment approach showed a 62% level of implementation of NRW strategies by the city. This means that the city was poorly managing its non-revenue water. The city had an infrastructure leakage index of 9.7. This index is in Category C of the International Water Association physical loss matrix meaning that the city was managing its non-revenue water poorly. Therefore the city must be proactive in the management of its physical water losses as well as maintain its infrastructure consistently.
American Journal of Water Resources. 2017, 5(4), 100-105. DOI: 10.12691/ajwr-5-4-2
Pub. Date: September 07, 2017
11395 Views2670 Downloads
by Arash YoosefDoost, Mohammad Sadegh Sadeghian, MohammadAli NodeFarahani and Ana Rasekhi
Original Research
According to the importance of climate change, the necessity of develop a fast and accurate tool is undeniable. Although the comparison of a statistical model with specialized models which were designed regard to non-linear complexities of a phenomenon is not common, in this study ARIMA statistical model was analyzed and evaluated with GFDL CM2.1 and CGM3 Atmosphere-Ocean General Circulation Models (AOGCMs) in order to investigate on the effects of climate change on temperature and precipitation in the Taleghan basin. The results showed although GFDL CM2.1 model showed better performance in MAE and R2 validation criteria and the predicted temperature had similar trend with the observational data, the difference between the model results and observations is significant. The CGM 3 model showed better performance in R2 for precipitation, temperature and MAE for long term average of precipitation in addition to having similar trend to the observed data. However, for long term average of both temperature and precipitation, the general predicted trend had a considerable distance with the observational values. In contrast, although the statistical ARIMA model predictions had some fluctuations, they had better conformity to the general trend of observations. These results show that contrary to popular belief, in some cases like this investigated case, even cheap statistical models can likely provide acceptable results.
American Journal of Water Resources. 2017, 5(4), 92-99. DOI: 10.12691/ajwr-5-4-1
Pub. Date: September 07, 2017
15550 Views3718 Downloads