Modeling Applications in Water Resources Management
Tarih:
Konum: A116
This seminar intends to give a brief overview on the significance of fresh water resources and a conceptual understanding on the application of models for the solution of water-related real life problems in civil engineering. Fresh water has always been an indispensable natural resource for humans throughout the course of history and managing water (by supplying and distributing water fresh water, coping with floods and droughts) has ever been one of the preliminary sub-disciplines of the civil engineering profession. In today's modern society, not only its absence, but also its abundance might create problems for engineering applications; therefore, scales and scope of the problems might range from “Construction-Scale Dewatering Systems Design" to "Basin-Scale Management of Water Resources". However, given the complex nature of such problems, most of the times, several simplifications and assumptions have to be made in order to analyze the systems and to create solutions. Modeling tools are widely used for the solution of water-related problems to comprehend the mechanisms of the real world systems and to predict the responses of these systems under different pressures.
Modeling tools at the core of this presentation are specifically "mathematical groundwater flow models", where attempt is to simulate the actual behavior of an aquifer system through the solution of a set of mathematical equations (representing the flow of water through porous media). These equations can either be solved by analytical methods (providing exact solutions in the presence of very simple conditions) or by numerical methods (utilizing approximations like finite differences or finite elements to simulate very complex conditions). Several applications of mathematical groundwater flow models in the solution of water-related civil engineering problems are to be discussed:
First application of numerical groundwater flow models to be presented is "dewatering". In big scale mining and construction projects involving deep excavations that have to be completed below the static groundwater level; excavation area must be dewatered in order to provide safe and stable conditions during and sometimes after the operations. Modeling tools might be used (i) in planning phase of such operations by providing preliminary assessments on the amount of groundwater that would flow into the excavation area; (ii) in design phase by allowing the determination of the optimal dewatering systems with the number, location, depth and pumping rate of wells, as well as the depth, thickness and permeability of the retaining walls, if required; (iii) in post- operational phase by predicting the water levels and hydraulic relations of the excavation area with its surrounding after dewatering process ceases.
Second application to be discussed is on the "impact analysis" and "sustainability assessment" regarding water resources. Groundwater flow models might be used in basin-scale projects to simulate the available water budget and dynamic responses of the system to the future water-use scenarios. Alternatively, groundwater flow models might be used to simulate the impacts of the external pressures on the system, such as climate change predictions (decreasing recharge rates, increasing sea level) and population increase projections (increasing freshwater demand). Moreover, simulation results obtained from the models can further be used to set up trade- off curves for different water management alternatives. These trade-off relations, which are used to determine the safe yield, sustainable yield and sustainable pumping rate for the aquifer under study; form the basis of sustainability assessment in terms of both the quantity and the quality of water.
Third and final application of the numerical groundwater flow models to be presented is for the feasibility assessment and design of the "subsurface dams", which aim to store water underground by construction of impermeable structures along the direction of groundwater flow and provide artificial recharge to the aquifer system. Models can simulate the site conditions (before and after the implementation of the proposed subsurface dams) and the amount of water that can be stored with different operational alternatives (like different combinations of water intake elevations and methods). The outcomes of these simulations are used to derive trade-off relations between the yield of the subsurface dams and various construction components; and hence, provide significant inputs for the economic analysis of the construction of such structures.
After a technical discussion summarizing the previous researches on "Modeling Applications in Water Resources Management"; in the closing remarks of this seminar, possible contributions of the ongoing works and future research plans to the missions of both Department of Civil Engineering and TEDU will also be presented to the audience; together with a brief overview on the proposed teaching plan.