Flooding is a critical issue around the world. The objective of this chapter is to define a strategy for the real-time determination control gate operation of a river-reservoir system. This is accomplished through the development of an optimization-simulation model by interfacing simulation software for rainfall forecasting, rainfall-runoff modeling (HEC-HMS), and a one and two-dimensional unsteady flow model (HEC-RAS) interfaced with a genetic algorithm within MATLAB. This new optimized model can be utilized to manage the reservoir release schedules before, during, and after an extraordinary rainfall storm event causing flooding through optimal gate operations. Through real-time observations and optimal gate controls, downstream water surface elevations are controlled to avoid the exceedance of threshold flood levels in target cells to minimize the damage and direct effects both up and downstream. An example application of the optimized simulation model illustrates the value of the overall approach.

Wastewater systems are one of the most crucial systems for urban infrastructure, especially in regions with large population densities. Determining the optimal (minimum cost) sewer pipe layout and the location of wastewater treatment plants (WWTPs) must take into considerations of economic, environmental, and hydraulics of pipe flows. This paper presents an optimization model for mini-mum cost design of sewer system layout and wastewater treatment plant locations of the combined systems. The model can be used to minimize the total costs associated with a sewer network and WWTPs by determining an optimal layout of sewer pipes and the locations of WWTPs that meet connectivity, continuity, and capacity requirements. The model is formulated as a 0-1 Integer nonlinear programming (INLP) problem solved using in the general algebraic modeling system (GAMS). The application of the model is illustrated using a simple example to demonstrate that the method allows for significant cost savings.

Climate change is causing shifts in seasonal weather patterns and variation in seasonal time scales in India. Factors including uneven distribution of water, faulty agricultural practices and water policies, low prices of farm products, and debt are leading farmers to commit suicide in Umarkhed Taluka of the Yavatmal District. This study aimed to develop a sustainable solution to water scarcity in the surrounding watershed by introducing optimization modeling in reservoir operation. Past studies have conducted different hydrologic analyses to address the water scarcity issue in this region. However, none of the studies incorporated optimization in their models. This study developed an integrated hydrologic and optimization model that can predict the daily reservoir releases for climate change scenarios from 2020 to 2069 based upon Representative Concentration Pathway (RCP-4.5 and RCP-8.5) climate change scenarios from 2020 to 2069. The integrated simulations were able to deliver around 19% more water than the historical discharge at the most downstream station of the Wardha Watershed. The simulated approaches store less water than the actual unoptimized scenario and deliver water when there is a need at the downstream locations. Finally, because the downstream locations of the Wardha Watershed receive more water, a localized storage system can be developed and a transfer method can be utilized to deliver sufficient water to the Umarkhed Taluka.

An application is presented of a new methodology for the real-time operations of river-reservoir systems. The methodology is based upon an optimization/simulation modeling approach that interfaces optimization with a one and/or two-dimensional unsteady flow simulation model (U.S. Army Corps of Engineers HEC-RAS). The approach also includes a model for short-term rainfall forecasting, and the U.S. Army Corps of Engineers HEC-HMS model for rainfall-runoff modeling. Both short-term forecasted rainfall in addition to gaged streamflow data and/or NEXRAD (Next-Generation Radar) can be implemented in the modeling approach. The optimization solution methodology is based upon a genetic algorithm implemented through MATLAB. The application is based upon the May 2010 flood event on the Cumberland River system in the USA, during which releases from Old Hickory dam caused major flooding in the downstream area of Nashville, TN, USA, and allowed the dam to be placed in an emergency operational situation. One of the major features of the modeling effort and the application presented was to investigate the use of different unsteady flow modeling approaches available in the HEC-RAS, including one-dimensional (1D), two-dimensional (2D), and the combined (1D/2D) approach. One of the major results of the application was to investigate the use the different unsteady flow approaches in the modeling approach. The 2D unsteady flow modeling, based upon the diffusion wave approach, was found to be superior for the application to the Cumberland River system. The model application successfully determined real-time operations that would have maintained the flood water surface elevations at the downstream control point in Nashville below the 100-year return period river water surface and maintaining the gate openings at the Old Hickory Dam from reaching an emergency operational situation, which could have caused major losses at the dam.

Optimization models are developed for simultaneously determining the pipe layout and the pipe design for storm sewer systems. The pipe design process includes computation of commercial diameters, slopes, and crown elevations for the storm sewer pipes. The optimization models aim to minimize the total costs of the layout and the pipe design for most of system elements. The optimization models are formulated as a 0–1 Integer Nonlinear Programming problem and solved using the General Algebraic Modeling System without the use of heuristic models which were characteristic of all previous models for the simultaneous determine of the pipe layout and pipe design of sewer networks. The models are based upon two different optimization approaches: (1) considers one or more commercial diameters of pipe connecting two manholes and (2) considers only one commercial diameter in a pipe connecting two manholes. The commercial diameters, pipe slopes, crown elevations, and total costs of the storm sewer system were compared for the two approaches using an example that illustrates the savings in cost by allowing multiple pipe sizes. The two new optimization modeling approaches developed herein can simultaneously determine the minimum cost pipe design (commercial diameters, slopes, and crown elevations) and pipe layout of storm sewer systems and satisfy all design constraints.

Since prehistoric times, water conflicts have occurred as a result of a wide range of tensions and/or violence, which have rarely taken the form of traditional warfare waged over water resources alone. Instead, water has historically been a (re)source of tension and a factor in conflicts that start for other reasons. In some cases, water was used directly as a weapon through its ability to cause damage through deprivation or erosion or water resources of enemy populations and their armies. However, water conflicts, both past and present, arise for several reasons; including territorial disputes, fight for resources, and strategic advantage. The main reasons of water conflicts are usually delimitation of boundaries, waterlogging (e.g., dams and lakes), diversion of rivers flow, running water, food, and political distresses. In recent decades, the number of human casualties caused by water conflicts is more than that of natural disasters, indicating the importance of emerging trends on water wars in the world. This paper presents arguments, fights, discourses, and conflicts around water from ancient times to the present. This diachronic survey attempts to provide water governance alternatives for the current and future.

A new methodology was developed for the real-time determination gate control operations of a river-reservoir system to minimize flooding conditions. The methodology is based upon an optimization-simulation model approach interfacing the genetic algorithm within MATLAB with simulation software for short-term rainfall forecasting, rainfall–runoff modeling (HEC-HMS), and a one-dimensional (1D), two-dimensional (2D), and combined 1D and 2D combined unsteady flow models (HEC-RAS). Both real-time rainfall data from next-generation radar (NEXRAD) and gaging stations, and forecasted rainfall are needed to make gate control decisions (reservoir releases) in real-time so that at time t, rainfall is known and rainfall over the future time-period (Δt) to time t + Δt can be forecasted. This new model can be used to manage reservoir release schedules (optimal gate operations) before, during, and after a rainfall event. Through real-time observations and optimal gate controls, downstream water surface elevations are controlled to avoid exceedance of threshold flood levels at target locations throughout a river-reservoir system to minimize the damage. In an example application, an actual river reach with a hypothetical upstream flood control reservoir is modeled in real-time to test the optimization-simulation portion of the overall model.

Agricultural developments require changes in land surface and subsurface hydraulic functions as protection from floods, reclamation of flooded land, irrigation, and drainage. Drainage of agricultural land has a long history and apparently traces back to the earliest civilizations of Mesopotamia and Iran before 4000 BC. In the Eastern Mediterranean, the Minoan and Mycenaean civilizations developed techniques and strategies of drainage of agricultural lands from the middle of the 2nd millennium BC. After the collapse of the Aegean Bronze-age civilizations, society building and agricultural innovation in the archaic and Classical periods (ca. 800–300 BC) included successful attempts at controlling drainage and irrigation techniques. In addition, China, India, and Mesoamerica have extensive histories of drainage. The aim of this review paper is to trace the evolution of the main foundings on agricultural drainage technologies through the centuries until the present. This historical review reveals valuable insights into ancient hydraulic technologies as well as irrigation and drainage management that will help to find bright horizons for sustainable agriculture in future.

Water-supply systems (WSSs) and electrical power systems (EPSs) are highly interdependent critical infrastructures. The electrical energy required for pumping in WSSs and cooling water required for power plants in EPSs are major interdependencies. Failure of either of the two independently operated infrastructures can lead to a cascading failure of both the systems. A combined operations control methodology for WSSs and EPSs taking into consideration the inherent interdependencies is required to ensure reliable operations. An optimization-simulation model is presented for the real-time operation of water-supply canal systems (WSCSs) under critical conditions during short-term and long-term emergency events such as limited electrical energy and/or limited water availability, electrical grid failures, extreme droughts, or other severe conditions related to natural and manmade disasters. WSCSs are used for the conveyance of raw water from sources such as lakes, reservoirs, or rivers to water treatment plants that supply treated water to consumers through water distribution systems (WDSs). The approach interfaces the optimization-simulation model for WSCSs with an optimization-simulation model for WDSs to provide for a comprehensive decision-making tool for the control of WSCSs and WDSs. Two WSCSs optimization methodologies are presented including a nonlinear programming approach and an optimization-simulation approach that interfaces a genetic algorithm (MATLAB) with the US Army Corps of Engineers Hydraulic Engineering Center's (HEC) River Analysis System (HEC-RAS) simulation model. A steady-state analysis of the WSCSs is performed for each time period of operation. The new methodologies for determining pump and gate operations under limited power and/or water availability are illustrated using two example canal systems.

The phrase water-energy nexus is commonly used to describe the inherent and critical interdependencies between the electric power system (EPS) and the water distribution system (WDS). In this study, the analytical framework capturing the interactions between these two critical infrastructures is examined and a mathematical model to describe the associated dynamics is developed. Based on the time scale of these associated dynamics, the EPS simulation is conducted using time-series power flows following unit commitment and optimal power flow solutions. The WDS control optimisation–simulation model formulated here is solved using a genetic algorithm solution technique interfaced with EPANET. An integrated simulation engine of the interdependent infrastructure systems was created to conduct long-term simulations. The simulation engine was applied using representative WDS and EPS networks. The implemented control optimisation benefits both systems by reducing the effect of severe contingencies. The results of the simulations conducted prove the applicability of the proposed methodology for long-term, water-energy nexus contingency simulations having both power outages and droughts.

New metrics and a new methodology for determining system infrastructural–operational resilience are presented for the optimal real-time operation of two critical interdependent infrastructure systems—the water distribution systems (WDS) and the electric power system (EPS) under critical conditions of limited water and/or limited electrical energy resulting from extreme drought or electric grid failure, respectively. Operational resilience (OR) and infrastructural resilience are defined. The integrated resilience computation method is presented and utilizes results from a combined optimization–simulation framework, which involves capturing the interactions and associated dynamics between the EPS and WDS. A realistic example of the WDS and EPS is used to demonstrate the application of the resilience concepts to assess the interdependent systems’ performance.

An optimization–simulation model is developed for the operation of pumps and valves in water distribution systems (WDS) requiring storage tank turnover. …

A methodology for determining system operation resilience is presented for the real-time operation of water distribution systems (WDS) under critical conditions of limited water or electrical energy resulting from extreme drought or electric grid failure. Resilience for water distribution systems is defined as how quickly the WDS recovers or bounces back from emergency to normal operations. The algorithm for operational resilience was interfaced with an optimization-simulation model for the real-time optimal operation of water distribution systems. The resilience methodology considered both demand and water quality requirements of both the municipal WDS and the power plant cooling systems. The optimization-simulation modeling approach interfaced a genetic algorithm optimization procedure with the WDS hydraulic and water quality simulator (EPANET) in the framework of an optimal control problem. The interfacing of the genetic algorithm in MATLAB and the EPANET model was implemented using a MATLAB-EPANET toolkit. An example WDS including two cities, five power plants, and reclaimed water from a wastewater treatment plant was used to demonstrate the application of system operation resilience concepts to assess the performance. The resilience computation methodology presented in this study is applicable to both short-term and long-term failures of WDS. For the purposes of this study, the methodology was applied to three scenarios of short-term (2-6 h) power outages for the example WDS. A sensitivity analysis was performed for resilience of example WDSs under varying degrees of long-term system-level power and water shortages. Applications of the methodology are used to illustrate improved operation resilience of the system.

A new methodology is developed for the real-time operation of water distribution systems (WDS) under critical conditions of limited electrical energy and/or water availability due to emergencies such as extreme drought conditions, electric grid failure, and other severe conditions including natural and manmade disasters. The methodology is tested for three different scenarios of limited electrical energy availability for an example WDS, but it is also applicable for conditions of limited water availability. The basic objective of optimizing the operations of WDS under critical conditions is to minimize the difference between requested demands and satisfied demands while meeting pressure requirements of the system. The approach adopted here is to interface an optimization procedure (genetic algorithm) with a simulator (EPANET) in the framework of an optimal control problem to determine the real-time optimal operation (pump and valve operations) of a water distribution system. Interfacing of the simulator and the genetic algorithm has been accomplished within the framework of MATLAB.

A new methodology is presented for real-time operation of water distribution systems (WDS) under the critical condition of limited electrical energy. The critical conditions could arise due to electric grid failure, extreme drought, or other severe conditions related to natural and artificial disasters such as sabotage, vandalism, terrorism, or war. The methodology presented considers both quantity and quality requirements of various water demands. The basic objective of optimizing water distribution system operations under limited availability of electrical power and/or water is to satisfy the required (requested) demand for service areas (or pressure zones) while meeting system pressure and water quality requirements of the system. The approach combines a genetic algorithm optimization procedure with the simulator EPANET in the framework of an optimal control problem. Combining the simulator and the genetic algorithm is accomplished within a MATLAB framework. The new methodology is illustrated using an example system incorporating both a WDS and electrical power distribution system (PDS) cooling-water system to evaluate the operations of the WDS under limited power supply conditions.

A methodology for computation of system resilience for the real-time operation of water distribution systems (WDS) under critical conditions of limited water and limited electrical energy is presented. Critical emergencies in WDS operations can result from extreme drought, electric grid failure, and other severe natural conditions. The basic objective of this study is to apply the concepts of system resilience within an optimization-simulation model for real-time optimal operation of water distribution systems under conditions of limited water and energy availability. The modeling approach interfaces a genetic algorithm optimization procedure with the WDS hydraulic simulator (EPANET) in the framework of an optimal control problem. The methodology is implemented within the framework of MATLAB. An example WDS is used to demonstrate the application of the resilience concepts to assess the performance.

The magnitude of water resources shortages in the Middle East represents an important factor in the stability of the region and it is a vital element in protecting sustained economic development in the region. This investigation addresses the ongoing challenge of water governance in Iraq by examining how profitability, at both the farm and basin levels, is affected by various water appropriation systems. Farmland irrigation in Iraq was evaluated using three water appropriation systems; upstream (UPR), downstream (DPR) and proportional (PSR) sharing rule. Their impacts on farm income under normal, dry, and drought water supply scenarios were evaluated using an irrigation water model coupled with a nonlinear programming (NLP) optimization model. As compared to UPR, PSR provided a 32% and 75% increase in total farm income for the Tigris River under dry and drought supply conditions, respectively. As compared to DPR, PSR provided a 47% and 83.5% increase in total farm income for the Euphrates River under dry and drought supply conditions, respectively.

Reclaimed water (RW) is a reliable alternative water supply for irrigation in the agricultural sector, which is the predominant consumer of water in Iraq. A mixed-integer nonlinear programming reclaimed water allocation optimization model was developed to maximize the net benefit generated from the cultivation of different types of crops, comparing the use of reclaimed water type A (tertiary treated water), and reclaimed water type B (secondary treated water). The model was solved using the Algorithms for coNTinuous/Integer Global Optimization of Nonlinear Equations (ANTIGONE) optimizer in the general algebraic modeling system (GAMS). A total of 84 agricultural farms located on 5300 ha to the south of Baghdad, Iraq were available for irrigation with reclaimed water. Analysis considered varying quantities of available reclaimed water and different irrigation efficiencies (45–85%). The net benefits from using lower quantities of reclaimed water were similar for both types of reclaimed water, and the highest net benefit crop was cultivated on 384 ha. As the quantities of water increased, the amount of cultivated land increased and the net benefit per hectare decreased as the model required the cultivation of more crops with lower economic value. Irrigation with reclaimed water has potential to increase agricultural and economic activity adjacent to Baghdad.

Climate change, pollution, civil conflicts, political instability, and a high rate of population growth all contribute to water shortages in Iraq which are predicted to increase in the future. Due to the importance of agriculture in Iraq which forms more than 75 percent of total demand, a sustainable agricultural water allocation scheme is necessary to find practical and applicable water conservation measures that helps mitigate the impact of potential droughts and water shortages. An agricultural irrigation reclaimed wastewater allocation optimization model was developed to optimally allocate crops and reclaimed wastewater (RW) on cultivated farmlands in order to maximize the net benefit. The optimization model is formulated using mixed-integer nonlinear programming (MINLP) solved by the branch and reduce optimization navigator (BARON) in the general algebraic mathematical solver (GAMS). The model maximizes the net farm income to determine the cultivated crop assigned to each farmland using three types of reclaimed wastewater (RW); tertiary treated wastewater; secondary treated wastewater; and primary treated wastewater. Constraints in the optimization model include: (1) reclaimed wastewater availability constraints and (2) irrigated farmlands constraints. The optimization model has been applied to 7045 hectares of farms located in the Alrustumia district to the south east of Baghdad, Iraq with 5.5 × 105 m3/d of treated wastewater. The use of tertiary treated wastewater provided the greatest net benefit under most scenarios evaluated while primary effluent provided the lowest net benefit as only low value crops could be cultivated.