Akwa Ibom State is located in the Niger delta region of Nigeria. The coastal plain sand aquifer, which underlies the area, is the major source of potable water for domestic, agricultural, and industrial use. The incre...Akwa Ibom State is located in the Niger delta region of Nigeria. The coastal plain sand aquifer, which underlies the area, is the major source of potable water for domestic, agricultural, and industrial use. The increase in demand for water has led to an increased exploitation of the aquifer in the last few years. Hence it is essential to quantify the amount of exploitable water in the aquifer. To achieve this goal, a regional numerical groundwater flow model using MODFLOW was calibrated under steady-state conditions to determine the aquifer’s hydraulic conductivity (K) and the recharge characteristics of the area. The hydraulic conductivity and recharge values from the pilot points calibration ranged from 1 to 75 m/d and 5.89 × 10-6 m3/d to1.23 × 10-4 m3/d. The calculations of the model showed that the average recharge rate amounts 0.40l/s/km2 or 12.60 mm/year. The estimated recharge suggests a high groundwater potential for the area. This is the first time that such a study has been carried out in the area, and it will serve as an important basis for future groundwater management and simulation of transient groundwater flow modeling in Akwa Ibom State.展开更多
Investigating and modeling fluid flow in fractured aquifers is a challenge. This study presents the results of a series of packer tests conducted in a fractured aquifer in Freiberg, Germany, where gneiss is the domina...Investigating and modeling fluid flow in fractured aquifers is a challenge. This study presents the results of a series of packer tests conducted in a fractured aquifer in Freiberg, Germany, where gneiss is the dominant rock type. Two methods were applied to acquire hydraulic properties from the packer tests: analytical and numerical modeling. MLU (Multi-Layer Unsteady state) for Windows is the analytical model that was applied. ANSYS-FLOTRAN was used to build a two-dimensional numerical model of the geometry of the layered aquifer. A reasonable match between experimental data and simulated data was achieved with the 2D numerical model while the solution from the analytical model revealed significant deviations with respect to direction.展开更多
Egypt is mainly covered by desert and only 4% of total lands is arable, mainly the alluvial plain of the Nile and its delta. In order to cope with the increasing population, the government of Egypt has been pressed in...Egypt is mainly covered by desert and only 4% of total lands is arable, mainly the alluvial plain of the Nile and its delta. In order to cope with the increasing population, the government of Egypt has been pressed into the development of Sinai Peninsula. So, it is indispensable to evaluate the potential groundwater resources for the development of the Sinai Peninsula. The key components are a conceptual model and a groundwater model with certain mathematical components. The conceptual model is a system analysis of the hydrogeological understanding of how water flows into, through and out of a groundwater system. Based on available borehole data, the study area is characterized to reach to the most representative conceptual models. Finally, a finite difference groundwater model was applied utilizing the graphic user interface GMS were used. In order to handle problems at regional scale, automated parameter estimation (PEST) was used in GMS. Moreover, recharge was parameterized using zones by defining these zones several factors were considered;for example, surface geology, density of vegetation, general land use, and LANDSAT image. However, Groundwater flow model successfully calibrated. Calibrated groundwater model helped to identify the heterogeneity in the aquifer.展开更多
文摘Akwa Ibom State is located in the Niger delta region of Nigeria. The coastal plain sand aquifer, which underlies the area, is the major source of potable water for domestic, agricultural, and industrial use. The increase in demand for water has led to an increased exploitation of the aquifer in the last few years. Hence it is essential to quantify the amount of exploitable water in the aquifer. To achieve this goal, a regional numerical groundwater flow model using MODFLOW was calibrated under steady-state conditions to determine the aquifer’s hydraulic conductivity (K) and the recharge characteristics of the area. The hydraulic conductivity and recharge values from the pilot points calibration ranged from 1 to 75 m/d and 5.89 × 10-6 m3/d to1.23 × 10-4 m3/d. The calculations of the model showed that the average recharge rate amounts 0.40l/s/km2 or 12.60 mm/year. The estimated recharge suggests a high groundwater potential for the area. This is the first time that such a study has been carried out in the area, and it will serve as an important basis for future groundwater management and simulation of transient groundwater flow modeling in Akwa Ibom State.
基金supported by the Department of Hydrogeology at TU Freiberg.
文摘Investigating and modeling fluid flow in fractured aquifers is a challenge. This study presents the results of a series of packer tests conducted in a fractured aquifer in Freiberg, Germany, where gneiss is the dominant rock type. Two methods were applied to acquire hydraulic properties from the packer tests: analytical and numerical modeling. MLU (Multi-Layer Unsteady state) for Windows is the analytical model that was applied. ANSYS-FLOTRAN was used to build a two-dimensional numerical model of the geometry of the layered aquifer. A reasonable match between experimental data and simulated data was achieved with the 2D numerical model while the solution from the analytical model revealed significant deviations with respect to direction.
文摘Egypt is mainly covered by desert and only 4% of total lands is arable, mainly the alluvial plain of the Nile and its delta. In order to cope with the increasing population, the government of Egypt has been pressed into the development of Sinai Peninsula. So, it is indispensable to evaluate the potential groundwater resources for the development of the Sinai Peninsula. The key components are a conceptual model and a groundwater model with certain mathematical components. The conceptual model is a system analysis of the hydrogeological understanding of how water flows into, through and out of a groundwater system. Based on available borehole data, the study area is characterized to reach to the most representative conceptual models. Finally, a finite difference groundwater model was applied utilizing the graphic user interface GMS were used. In order to handle problems at regional scale, automated parameter estimation (PEST) was used in GMS. Moreover, recharge was parameterized using zones by defining these zones several factors were considered;for example, surface geology, density of vegetation, general land use, and LANDSAT image. However, Groundwater flow model successfully calibrated. Calibrated groundwater model helped to identify the heterogeneity in the aquifer.
