Data Assimilation in Water Distribution Systems

Abstract Operational management of water distribution networks (WDNs) requires assimilating observations such as pressures at junction nodes, flows in pipes and, whenever available, monitored demand. Although several data assimilation techniques are today available, ranging from 1-2-3-4 DVAR to Kalman Filters, a problem is posed by the need of preserving the structural relations among state variables in a WDN, such as for instance pressure head, discharge and demand. Ensemble Kalman Filters certainly can be used to account for non-linearities but, for example, if one tries to assimilate pressure heads and pipe flows at the same time, nothing guarantees that the resulting variables after the data assimilation step, will still obey to the hydraulic structural relations mathematically describing a WDN. In this work an EnKF based procedure has been implemented, which allows to assimilate three types of observations, namely pressures at junction nodes, flows in pipes and monitored demand. The procedure allows to assimilating all the observations in three successive steps, while guaranteeing the full satisfaction of the structural relations. The results, demonstrated over an operational network, show the high performance of the chosen approach

Water–tourism nexus research in the Mediterranean in the past two decades: a systematic literature review

The water–tourism nexus requires better knowledge, management and governance to address environmental and societal challenges. This review takes stock of the approaches used to address this nexus in the Mediterranean from 2000 to 2020. Bibliometric and exploratory content analysis targeted tourism impacts on water supply, determinants of water consumption, and water-saving mechanisms and technologies. A fundamental insight is that the literature remains rather water centric and technical, paying little attention to behavioural change and stakeholder action. Promising avenues to reinforce sustainable water use include transdisciplinary approaches and integrated tools such as hydrosocial cycle analysis, concept mapping and agent-based modelling.The authors thank the European Commission, the Dutch Research Council, the State Investigation Agency (Spanish Ministry of Economic Affairs and Digital Transformation) and the Italian Ministry of Education, Universities and Research for funding in the frame of the collaborative international consortium (SIMTWIST) financed under the 2018 Joint Call of the WaterWorks 2017 ERA-NET Cofund. This ERA-NET is an integral part of the activities developed by the Water JPI

Intervention concepts for energy saving, recovery and generation from the urban water system

There are numerous options for energy measures in the water sector ranging from water conservation and process efficiency improvements to new technologies and redesigning water systems. Next to energy efficiency improvements, there is a need for new concepts in which water is viewed as a carrier of energy. Municipal wastewater is a potential source of chemical energy, i.e. organic carbon that can be recovered as biogas in sludge digestion. Even more so, domestic (waste)water is a source of thermal energy. And in areas with altitude differences, installing micro-hydro technologies in water distribution systems can convert energy from the pressure and flow into electricity. This report presents intervention concepts for energy saving, recovery and generation from the urban water system. Summarised, the main outcomes of research undertaken at 9 case studies are: i) Algarve and Alcoy water supply system: by performing an energy audit, the most energy efficient operating scheme can be determined. ii) Oslo and Amsterdam water cycle: the thermal energy recovery potential from wastewater is large, and it is in particular feasible if coupled to aquifer thermal energy storage systems. iii) Schiphol and Athens wastewater treatment: the energy generation at wastewater treatment plants through biogas can be enhanced by co-digestion and thermophilic digestion. iv) Lanhirano, Athens and Algare water supply system: in a water distribution system, water and energy can be saved by integrating pressure and energy management., i.e. by installing micro-turbines.Frijns, J.; Monteiro, A.; De Graaff, M.; Carriço, N.; Covas, D.; Cabrera Marcet, E.; Lausund, E.... (2014). Intervention concepts for energy saving, recovery and generation from the urban water system. http://hdl.handle.net/10251/4662