Authors:Noshin Anjum, Md. Motaleb Hossain Pages: 1 - 16 Abstract: Estimating the discharge from a rainfall event is a challenging task because of a number of affecting elements. A multitude of physiographic factors are essential for both channel and surface flow. In a developing nation like Bangladesh, discharge measurement is critical for forecasting floods, managing land, measuring sediment, nutrients and promoting sustainable development. It is possible to measure the discharge and physiographic parameter using a hydrological model. Using a semi-distributed model Soil and water Assessment Tool (SWAT), the discharge of the Teesta River Basin, one of the most significant basins of Bangladesh, is simulated for the years 2003 to 2020. Sequential Uncertainty Fitting version2 (SUFI-2) technique within SWAT-CUP (SWAT Calibration Uncertainty Program) is used to accomplish model calibration and validation for daily time periods utilizing physiographic parameters. The simulation period of this study spans from 2003 to 2020, and the meteorological data utilized includes temperature, wind speed, relative humidity and rainfall. With and , our calibration results for the time period 2003–2011 demonstrated a strong correlation between observed and simulated discharge. Reasonable values are obtained for the and , which are 0.65 and 0.70 for the validation period 2012-2020. Sensitivity analysis is an integral part of model development and involves analytical examination of input parameters to aid in model validation and provide guidance for future research and sustainable development. Sensitivities of physiographic parameters have been analyzed using SUFI-2 algorithm in SWAT-CUP. It is done by global and one-at-a-time sensitivity procedures. For the Teesta river basin parameters coefficient curve number CN2.mgt, saturated hydraulic conductivity of the soil lair SOL_K ().sol and soil bulk density SOL_BD ().sol show most sensitivity for both of global and one-at-a-time sensitivity procedures. The findings contribute to predict the discharge in period of no observe data as well as to enhance the understanding and informing decision-making processes for sustainable water resource management. PubDate: 2024-07-19 DOI: 10.9734/ajgr/2024/v7i3238 Issue No:Vol. 7, No. 3 (2024)
Authors:Nzemeka Christopher Olisah, Nkechi Theresea Obiekezie Pages: 17 - 35 Abstract: Solid waste landfill management has been a significant issue for Nigerian urban areas and other developing countries across the globe.Similar to most other cities, Nsukka also generates waste on a daily basis, much of which is dumped in poorly designed and positioned dumping sites. The majority of the disposal sites are found on roadsides, at marketplaces, on farms, and in residential neighborhoods, among other places. The road infrastructure and groundwater are under danger, and the beauty of the impacted communities are not spared. Undoubtedly, the unchecked citation of boreholes as the source of potable water in the majority of our rural and urban communities—given that the government doesn't seem to be providing water to the people—has become a significant challenge. An investigation using electrical resistivity method was conducted around a solid waste dumpsite at Nsukka in Nsukka L.G.A of Enugu State, Nigeria with an aim to investigate the level of groundwater contamination and the objectives to determine the subsurface geoelectric layers, depth to water table, lithology delineation and map out the contamination zones. The scope of this study provides an overview of some of the approaches used to assess the aquifer vulnerability and aquifer potential using Vertical Electrical Sounding (Schlumberger array) and 2D resistivity imaging (Wenner array) in different locations around Nsukka municipality dumpsite. Both methods were used for this study in order to provide a geophysical database for exploration of the study area’s groundwater resources and also they are less expensive and less time consuming. VES has proved to be effective in solving groundwater problems in most places in Nigeria (Ezeh and Ugwu, 2010; Ugwu and Ezeh, 2012; Nzemeka et al. [1,2]. Electrical Sounding (VES) and 2D resistivity imaging were carried out with a digital read out resistivity meter (ABEM SAS 1000) to acquire data in the area and were interpreted using the Schlumberger automatic INTERPEX analysis software and the RES2DINV software respectively, which generates model curves using initial layer parameters and display the variations of electrical resistivities respectively. A total of eight (8) sounding and six (6) 2D resistivity imagings were carried out in the area. A contaminant leachate plume was delineated in 2D resistivity sections as low resistivity zones while the VES shows the depth of aquifer. In 2D pseudosections where bluish colours with low resistivities (less than 20.80\(\Omega\)m) with the depth ranging from 1.28m to 17.1m in the Line 1 and 2 are seen as contaminated zones. The rest of the lines are not contaminated because of their high resistivities (greater than 20.80\(\Omega\)m). The result of the electrical resistivity survey also showed 4 - 5 layers geo-electric sections and an AA and AK type sounding curves. The VES result shows that VES 1A, 1B, 2A and 2B which are carried out on line 1 & 2 of the wenner lines showed signs of contamination with low resistivity values less than 20.80\(\Omega\)m complementing the wenner results. The contamination has not yet got to where the aquifer is located on the lines. Since the depth to the aquifer ranges from 30.26m to 155.43m while maximum depth of contamination is 17.1m. It is believed that the leachate has not percolated down to the aquiferous zones as such aquifers are presumed to be free. As such, it is recommended that boreholes around the study area should not be less than 30m deep to avoid exploiting polluted water. PubDate: 2024-07-22 DOI: 10.9734/ajgr/2024/v7i3240 Issue No:Vol. 7, No. 3 (2024)
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