Prediction of water table in an alluvial aquifer using modflow

Groundwater is the main source of water in the Kingdom of Saudi Arabia (KSA). A larger part of groundwater is founded in alluvial (unconfined) aquifers. Prediction of water table elevations in unconfined aquifers is very useful in water resources planning and management. During the last two decades, many aquifers in different regions of the KSA experienced significant groundwater decline. The declines in these aquifers raised concerns over the quantity and quality of groundwater, as well as concerns over the planning and management policies used in KSA. The main objective of this study was to predict water table fluctuations and to estimate the annual change in water table at an alluvial aquifer at wadi Hada Al Sham near Makkah, KSA. The methodology was achieved using numerical groundwater model (MODFLOW). The model was calibrated and then used to predict water table elevations due to pumping for a period of 5 years. The output of the model was found to be in agreement with the previous records. Moreover, the simulation results also show reasonable declination of water table elevations in the study area during the study period

Hazardous effect of raw sewage disposal from indigenous housing settlement on natural water bodies

One of the problems that are causing a threat to public health is a sanitation system of indigenous houses built on water. The traditional way of life of indigenous society living in housing settlements over rivers or the sea is becoming a source of environmental pollution. These houses did not actually have a proper sanitation system for disposing wastes from toilets. The sanitation systems for these houses unfortunately dispose wastes directly into natural water bodies. The centralization of the waste disposal may cause problem to the public due to technical and financial different faced by the authorities. This research requires gathering relevant data source based on direct observation and indirect observations. Also this project will utilize on qualitative data collection tools, but is rooted in a qualitative epistemological position that recognizes the importance of locating the research within a particular social, cultural, and house settlement. This paper surveys the literature on problems that arise from raw sewerage disposed into natural water bodies before any sanitation is proposal to solve the problem. Also the potential solutions to the problem were discussed too

A Laboratory Based Study of Hydraulic Simulation of Leakage in Water Distribution Networks

It is obvious to all people the importance of water as an essential element for life, hence, water loss is a life-threatening and alarming predictor of the future. Leakage problem is one of the most important causes of water loss in water systems; therefore, it was and is still a matter of attention of many researchers, who are in search of the most effective methods to solve this problem using many techniques. These techniques vary with one another in terms of accuracy, cost and speed of obtaining results. This research paper presents a part of an extensive research work, which aims to develop a geospatial approach for solving the leakage detection problem in water systems using an integrated geospatial system. This paper will show a sample of the results that has been obtained through a lab experiment, which explains the changes in hydraulic behavior of the network due to the change in leakage size and leakage location as a step for validating the mentioned approach. Keywords: Leakage detection, water distribution networks, GIS, Hydraulic modeling

Proposed sanitation for a timber house constructed on water

One of the problems causing a threat to public health is the sanitation system of timber houses built in water. The sanitation systems of these houses unfortunately dispose wastes directly into the natural water bodies, since the houses are not actually equipped with the proper sanitation system for disposing wastes from the toilets. The centralization of the waste disposal system is not used widely at tourist areas constructed on water due to technical and financial difficulties. This research requires gathering relevant data from various sources. Moreover, this project will utilize qualitative data collection tools, but is rooted in a qualitative epistemological position that signifies the importance of locating the research within a particular social and cultural house settlement. This paper surveys the literature on problems that arise from raw sewerage disposed into natural water bodies before any sanitation is proposed to solve the problem and how an individual sewage treatment plant can be installed and solve this problem. A sustainable potential solution through making use of a new individual sewage treatment plant for Timber houses is presented in this proposal. The results would lead to the development of affordable waste management systems, as well as, improvement of water quality surrounding the Timber houses while maintaining the social and cultural values of indigenous people living in them. In this study, a sanitation system is proposed to be used in the timber houses constructed in water and the system was tested and showed that it is effective in wastewater treatment

Modelling of groundwater pumping scenarios and their impact on saline water intrusion in a Tripoli coastal aquifer, Libya

Tripoli coastal aquifer, Libya, which is located in a densely urbanised area, is the primary source of water supply in Tripoli city. In the last few decades and due to population growth, more than 100 wells have been drilled in Tripoli aquifer for the purpose of increasing pumping to meet demand on groundwater. The urbanisation at the Tripoli upper aquifer system has reduced the recharge rates and affected the groundwater storage. In this study, changes in groundwater dynamics in Tripoli's unconfined aquifers were simulated using MODFLOW-2005 code. The model was calibrated and validated using measured and simulated values. Statistical tests such as coefficient of determination, R2 mean error, mean absolute error, and the root mean square error were computed and found to be 0.97, 0.31, 1.70 and 2.32 respectively. The simulation will assist in the assessment of the long term saline water intrusion. Calibrated transient groundwater flow models for the years 2020 – 2100 indicated that this case is likely to occur along pumping profiles with high pumping rates. Simulation results show that the groundwater levels will decline and exceed 12 m in the Southern area while in the Northern area near the coastal line, depletion is continuous and more than 70 wells will face saline water intrusion by the year 2100. Doubling the pumping rate from the wells will accelerate the drop in the groundwater levels and about 98% of the wells will be subjected to high salinity level by 2100. The salinity levels in these wells will make the groundwater unfit for human consumption

Review for the management of vitamin B12 deficiency in diabetic patients on metformin

Long-term usage of Metformin is associated with lower serum vitamin B12 levels. The lower than normal levels could worsen neurological complications of diabetes, including diabetic neuropathy and poor cognition. Guidelines advise periodic monitoring of vitamin B12 but do not specify frequency, treatment targets or treatment modality. This commentary aims to review the prevalence and the severity of the presentation and to provide evidence-based answers to those clinical questions not answered by current guidelines

Generalized regression neural network for prediction of peak outflow from dam breach

Several techniques have been used for estimation of peak outflow from breach when dam failure occurs. This study proposes using a generalized regression artificial neural network (GRNN) model as a new technique for peak outflow from the dam breach estimation and compare the results of GRNN with the results of the existing methods. Six models have been built using different dam and reservoir characteristics, including depth, volume of water in the reservoir at the time of failure, the dam height and the storage capacity of the reservoir. To get the best results from GRNN model, optimized for smoothing control factor values has been done and found to be ranged from 0.03 to 0.10. Also, different scenarios for dividing data were considered for model training and testing. The recommended scenario used 90% and 10% of the total data for training and testing, respectively, and this scenario shows good performance for peak outflow prediction compared to other studied scenarios. GRNN models were assessed using three statistical indices: Mean Relative Error (MRE), Root Mean Square Error (RMSE) and Nash – Sutcliffe Efficiency (NSE). The results indicate that MRE could be reduced by using GRNN models from 20% to more than 85% compared with the existing empirical methods

SIMULATION OF DIFFERENT PUMPING SCENARIOS ON THE GROUNDWATER - SEA WATER INTRUSION INTO THE TRIPOLI AQUIFER, LIBYA

In arid and semi-arid regions; increasing groundwater salinity is one of the significant signs of groundwater quality degradation. This is a particularly serious environmental problem in coastal cities where the groundwater resources are being contaminated by sea water intrusion in coastal aquifers. In the coastal aquifer of the Tripoli region, the sea water intrusion continues to expand and the salinity of many wells has increased drastically in the last decades. The volume of groundwater being abstracted from this aquifer has exceeded the safe yield of the aquifer, causing a very significant drop in the water table, thus drying some of the wells. This issue of increased salinity in many parts of the aquifer has become a major cause of the deterioration of the aquifer structure. To address this issue, numerical modelling has been used to effectively manage groundwater resources to predict future responses, particularly in complex aquifer systems and heterogeneous formations. The ModelMuse model has been used as an indicator tool of this serious problem in the Tripoli aquifer. In this paper, three suggested pumping scenarios with varying abstraction rates for the next 80 years(from 2020 to 2100) were suggested. The impact of each scenario on groundwater level were investigated by using MODFLOW 2005 under ModelMuse software. The pumping scenarios; include: firstly, maintaining the fixed pumping rate of 70×106 m3 /yr for the study period, then increasing pumping rates due to population growth and in the third scenario, maintaining the pumping rate by using the sustainable abstraction of 19×106 m3 /yr for the period from 2020 to 2100. Results indicate that the first and second scenarios have a negative effect on the groundwater level, where these scenarios will lead to a significant decrease in the groundwater level. It is predicted that most of the wells will be dry by the year 2100 and sea water intrusion will extend to the boundary of the Tripoli aquifer in the South. However, when a sustainable quantity will be pumped from the aquifer (third scenario), a clear recovery of the aquifer will occur (increase in groundwater levels with reverse movement of the sea water from the aquifer towards the sea)

Assessment of chemical properties of tropical peatland soil in Malaysia oil palm plantation

The chemical assessment of the peatland in oil palm plantation in South Selangor Peatland Swamp in Malaysia were evaluated in this study. Soil samples were obtained from fifteen (15) different locations within the study area at three different depths of 0.5m, 1.5 m, and 2.5 m in three replicates at each depth, using peat auger between March and July, 2013 during the secondary maximum rainfall. Parameters evaluated in soil analysis included - pH, moisture content, carbon, nitrogen, sulphur and heavy metals such as manganese, zinc, iron, copper, and phosphorus. Heavy metals were determined using the double acid extraction method while carbon, nitrogen, and sulphur was determined using Trumac CNS Analyzer. From the pH values, the soil close to the surface is more acidic with a mean pH of 3.36 and standard error of 0.15. The mean values of the moisture contents were 363.54 % with SEM of 27.01 and 154.56 % with SEM of 54.64 at 0.5 m and 2.5 m depths respectively. Carbon, had the highest value of 44.27 % at 0.5 m, nitrogen, 0.36 %, sulphur, 0.15 % and heavy metals like manganese, iron, and copper, except zinc, and phosphorus had their mean values either increasing or decreasing with soil depth. Soil carbon was observed to decrease with depth unlike nitrogen and soil pH. All the parameters were observed to either decrease or increase with depth which shows their spatial distribution across the soil mass. This assessment of the tropical peatland soils chemistry has helped in appraising the important roles played by intact peatlands in overall global environmental sustainability

Investigating the influence of rainfall on soil carbon quantity in a Tropical Peatland

Conversion of peat swamp forests to oil palm plantations has been a common practice in Southeast Asia in the face of oil palm boom. Soil carbon has been one of the numerous nutrients that are lost as a result of this practice. This work therefore attempts to study the influence of rainfall as one of the drivers of carbon loss in the peatlands. Four different sites were selected for the study which considered both dry and wet seasons. The results from the two seasons were analyzed and it was observed that soil carbon during the dry season was lower compared to the wet season's