Assessment Of Criteria To Make Topological Changes In Water Distribution Systems Under Future Water Demand Scenarios

Population growth is one of the most challenging factors around the design, operation and renewal of Water Distribution Systems (WDS). Nowadays, cities are subjected to many dramatic changes that may disturb the performance and original approach of urban infrastructure; among these are the informal settlements (slums) and overcrowding phenomena, mainly found in cities of developing countries as Colombia. This research focuses on the definition of a new WDS rehabilitation criteria, Available Power, and its subsequent evaluation and comparison with the Specific Power criteria, previously developed in the Water Supply and Sewer Systems Research Center of Universidad de los Andes (CIACUA). Both criteria were assessed under different future demand scenarios in five study cases: two networks of different Colombian towns of less than 12000 inhabitants and three District Metering Areas (DMA) of main Colombian cities. To this end, based in the minimum pressure requirement, a pipe-to-pipe rehabilitation methodology was proposed and programmed in MATLAB with EPANET?s toolkit. Capital costs and some surrogate measures of networks reliability were taken into account to assess the rehabilitated networks, and its results were compared with OPUS optimal designs. Both criteria proved to be good benchmarks to improve the hydraulic performance in each rehabilitated network. Additionally, was found a great difference in the suitability of each criteria considering the topological and topographic complexity of different networks layouts.

This Book includes selected papers that has been published in the Water journal Special Issue (SI) on Water Supply and Water Scarcity. Moreover, an overview of the SI is included. The papers selected for publication in the SI include review and research papers on water history, on water management issues under water scarcity regimes, on rainwater harvesting, on water quality and degradation, and on climatic variability impacts on water resources. Overall, the issue identify and highlight the main challenges in water sector, and particularly in management and protection of water resources and in use of alternative (non-conventional) water resources, especially in areas with demographic change and climate vulnerability in order to achieve sustainable and secure water supply. Furthermore, general guidelines and possible solutions for an improved and sophisticated water management system are proposed and discussed, such as the adoption of advanced technological solutions and practices that improve water-use efficiency and the use of alternative water resources, to address the growing environmental and health issues and to reduce the emerging conflicts among water users.

The Special Issue on Advances in Modeling and Management of Urban Water Networks (UWNs) explores four important topics of research in the context of UWNs: asset management, modeling of demand and hydraulics, energy recovery, and pipe burst identification and leakage reduction. In the first topic, the multi-objective optimization of interventions on the network is presented to find trade-off solutions between costs and efficiency. In the second topic, methodologies are presented to simulate and predict demand and to simulate network behavior in emergency scenarios. In the third topic, a methodology is presented for the multi-objective optimization of pump-as-turbine (PAT) installation sites in transmission mains. In the fourth topic, methodologies for pipe burst identification and leakage reduction are presented. As for the urban drainage systems (UDSs), the two explored topics are asset management, with a system upgrade to reduce flooding, and modeling of flow and water quality, with analyses on the transition from surface to pressurized flow, impact of water use reduction on the operation of UDSs, and sediment transport in pressurized pipes. The Special Issue also includes one paper dealing with the hydraulic modeling of an urban river with a complex cross-section.

Utilities often experience difficulty planning and designing distribution systems to meet spatial water demands. Water system demand characteristics (quantity, quality, timing, and location) drive many distribution system management, operation, and design decisions. Characteristics such as average-annual use, maximum-day use, maximum-hour use, and fire-flow requirements constrain the makeup, size, and timing of distribution system modifications and expansions. Although sophisticated network models are often used to design and analyze distribution system modifications and expansions, these models traditionally treat nodal demand characteristics as a fixed parameter. In many cases, the spatial distribution of water demand is not well defined.The goals of the project were to * assess existing tools and methodologies used for identification, prediction, and spatial allocation of water demands for distribution system planning and design * make use of state-of-the-art technologies, water consumption data, and other regional data to develop improved empirical depictions of the spatial distribution of water demand * develop common tools and methodologies for predicting and allocating demand in water distribution planning and design models * describe methods for quantifying uncertainties associated with water demand predictions that are used for system planning and design. The project produced practical approaches to working with utility consumption data for developing spatial demand allocation in water distribution modeling and system planning. Furthermore, the researchers introduced innovative statistical methods (e.g., robust statistics, continuous time functional form, and fixed effects methodology). The researchers also explained the potential applications of spatial demand allocation to distribution planning.

Fully Updated Hydrology Principles, Methods, and Applications Thoroughly revised for the first time in 50 years, this industry-standard resource features chapter contributions from a “who’s who” of international hydrology experts. Compiled by a colleague of the late Dr. Chow, Chow’s Handbook of Applied Hydrology, Second Edition, covers scientific and engineering fundamentals and presents all-new methods, processes, and technologies. Complete details are provided for the full range of ecosystems and models. Advanced chapters look to the future of hydrology, including climate change impacts, extraterrestrial water, social hydrology, and water security. Chow’s Handbook of Applied Hydrology, Second Edition, covers: · The Fundamentals of Hydrology · Data Collection and Processing · Hydrology Methods · Hydrologic Processes and Modeling · Sediment and Pollutant Transport · Hydrometeorologic and Hydrologic Extremes · Systems Hydrology · Hydrology of Large River and Lake Basins · Applications and Design · The Future of Hydrology

China and its neighbours face a series of water security issues, in which international law plays a vital role. Paramount to both policymakers and researchers in the field of water law, the current status of transboundary water cooperation schemes and how these operate in China is of global significance. Grounded in international experience, this comprehensive volume provides readers with an up-to-date overview of current international transboundary water resource sharing policies and practices, including detailed case studies at both domestic and international levels. The authors discuss existing international laws, treaties, and principles that may stimulate transboundary water cooperation and dialogue, and then analyse a number of international experiences with treaties in North America, Eastern Europe, and Central Asia. They take stock of China’s water resource issues, legal practices and options, examine case studies of China’s southern shared rivers, and explore some innovative approaches to cooperative management of shared waters within China. The articles in this book were originally published in the journal Water International.