Papers by Samuel Nii Odai
The Role of Science, Technology and Innovative Industries in National Development
Journal of the University of Science and Technology, Apr 12, 2016
The Barekese Reservoir constructed across the Offin River provides 80% of the total public pipe b... more The Barekese Reservoir constructed across the Offin River provides 80% of the total public pipe borne water supplied to the Kumasi metropolis and its environs. The reservoir was designed to produce both potable water and hydropower, however, the hydropower component has not been implemented since its construction in 1971. There is also reported land cover degradation in the catchment area which has the propensity to alter the hydrologic cycle and hence runoff into the reservoir. A 10 year water balance has been assessed for the Barekese Reservoir using an integrated Remote Sensing and GIS approach for estimation of surface runoff based on Soil Conservation Service Curve Number (SCS-CN). The SCS-CN model was calibrated against observed discharges recorded at Offinso located 10.3km upstream from Barekese and the result of the calibration used to simulate runoff into the reservoir. The SCS-CN model produced an R 2 value of 0.84 and an efficiency of 82.68%. Monthly observed reservoir levels were used for the calibration and validation of the water balance model. The water balance model produced an R 2 value of 0.84 and an efficiency of 81.9%. The monthly water budget revealed that total catchment runoff and direct precipitation respectively constituted 94.32% and 5.68% of the inflows while spilled water, water withdrawal and evaporation respectively amounted to 72.19%, 20.85% and 6.96% of the outflows. This result reveals that the reservoir is being underutilized. The current average production of treated water is 109,000m 3 /day but the reservoir can safely yield the design capacity of 220,000m 3 /day and an additional average hydropower of 368.6kW in six months during the rainy season provided the economic analysis for the hydropower generation is found to be justifiable.
Scientific African, Nov 1, 2020
Background: Silent pulmonary thrombi can occur in up to 15-20% of Fontan-corrected adult congenit... more Background: Silent pulmonary thrombi can occur in up to 15-20% of Fontan-corrected adult congenital patients, but the prevalence or effects of pulmonary thrombi in uncorrected cyanotic heart disease is not well defined.
Capacity Estimation of Small Reservoirs Using Remotely Sensed Data---A Case Study of Upper East Region of Ghana
AGU Fall Meeting Abstracts, Dec 1, 2008
Water is a scarce and a valuable resource in semi-arid regions. In areas where water is scarce, e... more Water is a scarce and a valuable resource in semi-arid regions. In areas where water is scarce, every drop of water counts and its efficient use needs to be the primary guideline in water related planning. Small reservoirs therefore represent a strategic tool to manage fresh water storage. Hence the availability of a small reservoir is an important means of
Physics And Chemistry Of The Earth, Parts A/b/c, 2009
Small reservoirs serve many people living in semi-arid environments. Water stored in these reserv... more Small reservoirs serve many people living in semi-arid environments. Water stored in these reservoirs is used to supplement rainfed agriculture, allow for dry season irrigated agriculture and ensure the availability of water for domestic purposes. In order to manage the water effectively for competing uses, the actual storage of these reservoirs needs to be known. Recent attempts to delineate these reservoirs using remote sensing with Landsat imagery have been successful, especially in the upper east region of Ghana, West Africa. This paper shows that radar images (ENVISAT ASAR) can be used to provide similar information all year-round. Radar images have as an important advantage that they are not impaired by cloud cover and thus can be used during the rainy season. Another advantage of radar images is that images taken during night time are usable. The paper compares satellite derived data with field measurements of 21 small reservoirs. Whereas ENVISAT images on the average tend to overestimate the surface areas of small reservoirs, in certain reservoirs these areas are systematically underestimated due to the shallow tail-ends of reservoirs that tend to have reed vegetation. These cannot be readily distinguished from the surrounding vegetation outside the reservoirs. This paper therefore provides a proof of concept of the monitoring of small reservoir volumes by radar imagery.
Journal of the University of Science and Technology, Sep 19, 2012
A study was carried out in the Upper East Region of Ghana to assess the on-site effects and the c... more A study was carried out in the Upper East Region of Ghana to assess the on-site effects and the cost of fertility erosion from five small reservoir catchments (Dua, Doba, Zebilla, Kumpalgogo and Bugri). The catchment soils and reservoir sediments were sampled and analyzed for their bulk density and nutrient content. The mean reduction in soil depth in the various catchments was 3.996±3.806 mm y-1 in the order of Kumpalgogo>Dua>Bugri>Zebilla>Doba. The corresponding decrease in the water holding capacity of the top 20 cm depth of the catchment soils ranged from 0.563 to 4.698 % per year. The percentage loss in the total nutrient stocks in the top 20 cm of the catchments as eroded sediment-bound nutrients ranged from 9.
Man-made lakes in Africa are created primarily to produce hydroelectric power but their fisheries... more Man-made lakes in Africa are created primarily to produce hydroelectric power but their fisheries become an important industry for the economies of riparian communities. The lake and its catchment form a complex hydrological system because of the strong interactions between overland and in-lake physical and biogeochemical processes. While lake productivity is influenced by biogeochemical characteristics of the lake, these characteristics reflect the climate, geomorphology and vegetation-cover of the lake's catchment. Prospects of climate change have implications for the ecosystem of lakes viz. temperature, oxygen and primary production dynamics, which affect fish production. Models can aid in the understanding of potential impacts of climate change, and also serve as scenario tools that may support decision making processing in lake and watershed management. In this study, we set up and validated the one-dimensional GOTM-ERGOM model, to quantify the effects of climate change on the thermal stratification and oxygen dynamics and, primary production in meso-oligotrophic Lake Volta. The validated model was used to evaluate series of future climate change scenarios representing the period 2051-2080. Model simulations under the future scenarios indicated increased water column stability although the lake did not permanently stratify. Simulation further indicated a 1-m upward shift of the thermocline depth, resulted in 8 %-12 % volume loss in the upper mixed layer and reduced oxygen levels below this depth which may be significant in reducing the suitable habitat area for fish. Light limitation on primary production renders the lake somewhat resilient to intensive algae blooms both for present and future climate scenarios. Climate change presents challenges to water resources management therefore, the lake model presented together with catchment models can be informative tools for decision-support in watershed and lake management.
Capacity Estimation of Small Reservoirs Using Remotely Sensed Data: Case Study of a Semi Arid Region of Ghana
ASME Press eBooks, 2011
ABSTRACT Water is a scarce and a valuable resource in semi-arid regions. In areas where water is ... more ABSTRACT Water is a scarce and a valuable resource in semi-arid regions. In areas where water is scarce, every drop of water counts and its efficient use needs to be the primary guideline in water related planning. Small reservoirs therefore represent a strategic tool to manage fresh water storage. Hence the availability of a small reservoir is an important means of overcoming minor droughts. The main drawback in the Upper East Region of Ghana (the study area) is the lack of knowledge on the real-time capacity volume of small reservoirs. Thus this study attempts to use radar images to estimate the volume of water stored in small reservoir for planning and management purposes. A field study of small reservoirs was undertaken in the Upper East Region of Ghana. For each reservoir, a bathymetric survey was carried out and the outline determined. The area and volume of each reservoir were calculated using geographic information system. Remotely sensed data was acquired, processed and reservoir surface areas extracted. The surface areas obtained from fieldwork was compared with that extracted from the satellite images. For the comparison, a regression analysis at 95% confidence interval indicates that the variances of the two surface areas were not significantly different (p
Sustainability, Sep 29, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The paper looks at a prevailing problem in providing water and sanitation in developing countries... more The paper looks at a prevailing problem in providing water and sanitation in developing countries. The number of people in developing countries relying upon untreated groundwater supplies for drinking purposes is rising. Increasing concurrently with the development of groundwater resources is the provision of on-site sanitation facilities. The study assessed the pollution levels of contamination associated with on-site sanitation in forty-five groundwater supplies. Seven hand-dug wells recorded high levels of faecal coliform. Field measurements showed that nearby pit latrines were the courses of polluting these wells.
Evaluating the impact of an agricultural land‐use change adaptation strategy on household crop production in semi‐arid Ghana
Singapore Journal of Tropical Geography
In this study, the Land Use Dynamic Simulator model was applied to investigate the impact of farm... more In this study, the Land Use Dynamic Simulator model was applied to investigate the impact of farm credit as an adaptation strategy to cope with effects of climate variability on agricultural land‐use change and crop production in the Vea watershed in Ghana. The authors identified the determinants of crop choices within the landscape (e.g., farm household and biophysical characteristics of farm plot). The crop choice sub‐model was then linked to the crop yield sub‐model to determine the yields of selected crops. In adapting to the impacts of climate variability, the maize credit adoption sub‐model under the maize cultivation credit scenario was integrated into decision‐making. This was simulated for a 20‐year period, and compared with the business‐as‐usual scenario. Under the simulated maize credit scenario, maize adopters increased from about 20 per cent to about 50 per cent and the area allocated for maize cultivation significantly increased by about 266 per cent. Consequently, the...
Journal of Water and Climate Change
This study aimed to compare the performance of six regional climate models (RCMs) in simulating o... more This study aimed to compare the performance of six regional climate models (RCMs) in simulating observed and projecting future climate in the Savannah zone of Ghana, in order to find suitable methods to improve the accuracy of climate models in the region. The study found that the accuracy of both individual RCMs and their ensemble mean improved with bias correction, but the performance of individual RCMs was dependent on location. The projected change in annual precipitation indicated a general decline in rainfall with variations based on the RCM and location. Projections under representative concentration pathway (RCP) 8.5 were larger than those under RCP 4.5. The changes in mean temperature recorded were 1 °C for the 2020s for both RCPs, 1–4 °C for the 2050s under both RCPs, and 1– 4 °C under RCP 4.5, and from 2 to 8 °C for the 2080s. These findings will aid farmers and governments in the West African subregion in making informed decisions and planning cost-effective climate adap...
Capability of satellite rainfall products in simulating streamflows in the Black Volta Basin
Sustainable Water Resources Management
A Preliminary Investigation of Surface and Groundwater Quality Along the Upper Part of the Ankobra River, Impacted by Illegal Mining Activities
Water Air and Soil Pollution, Feb 25, 2023
Quantifying and analysing water trade-offs in the water-energy-food nexus: The case of Ghana
Water-Energy Nexus
Potentially Toxic Elements (PTEs) contamination and ecological risk of sediment in the upper course of the Ankobra River, Ghana
Environmental Monitoring and Assessment
The likelihood of changing trends in climatic time series over the Pra River Basin in Ghana was e... more The likelihood of changing trends in climatic time series over the Pra River Basin in Ghana was examined. Trend analyses were carried out on monthly, seasonal, and annual timescales for temperature and rainfall from 1950 to 2010. The use of Modified Mann–Kendall, Sen’s slope and Pettit tests revealed warming trends over the Pra River Basin. Maximum and Minimum annual temperature time series revealed a statistically significant increasing trend over 60% of the stations with Sen’s slopes varying from 0.006 to 0.035 oC/yr. Monthly temperature extremes revealed a statistically significant increasing trend over 80% of the stations. Seasonality revealed both increasing and decreasing trends for both dry and wet seasons, while annual rainfall experienced a decreasing trend in four out of the five stations with only one station being statistically significant at a 0.05 level. Both dry and wet season rainfall experienced statistically significant decreasing trends for all stations except one...
Innovative Sustainable Soil Nutrient Management Options for Improving the Resilience of West African Smallholder Farms Livelihoods Under Climate Change Context
Comparing climate change perception of heterogeneous farm households in semi-arid region of Ghana
Soil loss is not limited to change from forest or woodland to other land uses/covers. It may occu... more Soil loss is not limited to change from forest or woodland to other land uses/covers. It may occur when there is agricultural land-use/cover modification or conversion. Soil loss may influence loss of carbon from the soil, hence implication on greenhouse gas emission. Changing land use could be considered actually or potentially successful in adapting to climate change, or may be considered maladaptation if it creates environmental degradation. In semi-arid northern Ghana, changing agricultural practices have been identified amongst other climate variability and climate change adaptation measures. Similarly, some of the policies aimed at improving farm household resilience toward climate change impact might necessitate land use change. The heterogeneity of farm household (agents) cannot be ignored when addressing land use/cover change issues, especially when livelihood is dependent on land. This paper therefore presents an approach for simulating soil loss from an agro-ecosystem using multi-agent simulation (MAS). We adapted a universal soil loss equation as a soil loss sub-model in the Vea-LUDAS model (a MAS model). Furthermore, for a 20-year simulation period, we presented the impact of agricultural land-use adaptation
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Papers by Samuel Nii Odai