Several models that can be used to optimally size water distribution pipes were applied a hypothetical system. The results are summarized in this paper. produced solutions with costs within 10% of one another, although the quite different. While helpful sizing pipes, some manual calculations and good deal engineering judgment required apply them.

This paper presents the basic framework for a model that can be used to determine optimal (least‐cost) design of water distribution system subject continuity, conservation energy, nodal head bounds, and reliability constraints. Reliability is defined as probability satisfying demands pressure heads various possible pipe failures (breaks) in system. The overall includes three are linked: steady‐state simulation model, an optimization model. implicitly solve continuity energy constraints...

A new methodology is developed for determining the optimal (minium‐cost) design of water distribution systems. The components that can be sized are pipe network, pumps or pump station, and tanks. In addition, settings control pressure‐reducing valves determined. This couples nonlinear programming techniques with existing simulation models. Previous methodologies have typically simplified system hydraulics to able solve optimization problem. retains generality hydraulic model so problem only...

A chance constrained model is presented for the minimum cost design of water distribution networks. This methodology attempts to account uncertainties in required demands, pressure heads, and pipe roughness coefficients. The optimization problem formulated as a nonlinear programming which solved using generalized reduced gradient method. Details mathematical formulation are along with example applications. Results illustrate that future head requirements, can have significant effects on...

The hydraulic reliability of a water distribution system can be defined as the probability that provide demanded flowrate at required pressure head. Due to random nature future demands, heads, and pipe roughness, estimation for is subject uncertainty. A methodology presented estimate nodal reliabilities systems accounts uncertainties. framework based upon Monte Carlo simulation consisting three major components: number generation, network simulation, computation reliability. For purposes...

A practical measure for water‐distribution system reliability, based on hydraulic availability is presented and incorporated in an optimal design procedure component sizing. The combines mechanical a form that defines the proportion of time will satisfactorily fulfill its function. However, rather than simple discrete failure relationship with absolute if pressure heads fall below prescribed minimum modeled continuous increasing acceptability as higher pressures occur. Availability...

The use of water cisterns has been traced back to the Neolithic Age; this paper thus presents a brief historical development worldwide over last 5500 years. This is not an exhaustive presentation all that known today about cisterns, but rather provides some characteristic examples cistern technology in chronological manner extending from prehistoric times present. technologies and management practices given may have importance for resource sustainability present future. Cisterns used store...

A reliability‐based optimization model for water‐distribution systems has been developed. The is aimed at the following goals: (1) Design of pipe network including number, location, and size pumps tanks; (2) design pumping system using a procedure considering both hydraulic failures entire mechanical failure system; (3) determination optimal operation pumps. problem large mixed‐integer, nonlinear programming that solved heuristic algorithm consisting master sub‐problem. pure 0‐1 integer...

A methodology based on solving a large‐scale nonlinear programming problem is presented for the optimal operation of pumping stations in water distribution systems. Optimal refers to scheduling pump that results minimum operating cost given set conditions. The mathematical model large programing problem. an control framework which optimization interfaces with hydraulic simulation model, used implicitly solve conservation flow and energy equations describing hydraulics model. has been applied...

In the design of flood levee systems there are many parameters and variables with associated uncertainties. This paper presents models which systematically analyze various types uncertainties in hydrologic aspect as well hydraulic analysis to define risk reliability overtopping. Both static time dependent developed. Results show that evaluated by simple return period method can be underestimated 10% 50%, depending on loading distribution model used. The risk‐safety factor relationships shown...

Techniques using dynamic programing (DP) and discrete differential (DDDP) to achieve optimal cost design of pipe sizes elevations branched sewer systems have been developed demonstrated by an example. The system is decomposed into equivalent serial subsystems, which are then solved in sequence. DDDP requires less computer time than DP, although it cannot guarantee global optimization. Major factors affecting the efficiency location width initial trial trajectory corridor, number states...

Agricultural developments require changes in land surface and subsurface hydraulic functions as protection from floods, reclamation of flooded land, irrigation, drainage. Drainage agricultural has a long history apparently traces back to the earliest civilizations Mesopotamia Iran before 4000 BC. In Eastern Mediterranean, Minoan Mycenaean developed techniques strategies drainage lands middle 2nd millennium After collapse Aegean Bronze-age civilizations, society building innovation archaic...

A new methodology has been developed for determining the optimal operation of water distribution system pumps with quality considerations. The is based upon describing as a discrete time scheduling problem that can be used to determine schedules in systems. solution mathematical programming approach resulting large-scale nonlinear cannot solved using existing codes. optimization obtained by interfacing hydraulic and simulation code, EPANET, GRG2. Bound constraints on state variables are...

This paper describes a new methodology that can select the pipes to be rehabilitated and/or replaced in an existing water‐distribution system and determine increase pumping capacities so water demand pressure requirements at all nodes are satisfied while total rehabilitation energy cost is minimized. Four functions considered: pipe replacement cost, repair cost. The considers trade‐offs among decisions regarding each pipe: replace pipes, reline or leave as is. mathematical formulation...