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The design of alternative urban water supply interventions for a community located in a low-income country requires detailed and precise knowledge of the nature, frequency and intensity of various characteristic water end-uses in the community. Without the availability of this characteristic water use information, high resolution metering experiments are the usually preferred methods to measure the water use volumes. However, in the developing world, these high resolution experiments are not an available option. Leaving the imprecise household interviewing process of data collection as the only option. This paper presents a novel methodology that improves and expands on the socially collected water uses data, through the use of a stochastic modelling process of the water use volumes to estimate the total monthly water use of the community. The methodology not only improves the estimates of water use volumes but also provides a mathematical modelling description of the household water uses in the community. [ABSTRACT FROM AUTHOR]

A study of water consumption data collection and processing in the context of on-line monitoring and burst detection in water distribution networks is presented using a methodology for positioning of flow meters and selection of a monitoring time step. A stochastic model analyzes the propagation of initial uncertainty in water consumption through a water supply network and its influence on calculated flows. The model combines EPANET and a Monte Carlo based random sampling procedure that simulates the usage of domestic appliances. The model is validated on a medium-sized water distribution network, located in the southeast region of England. Statistical analysis of the calculated flows suggests that flow meters should be located at pipes with the highest variance in flow in order to make sudden changes in monitored flow detectable. As a result, an appropriate size of a district metering area (DMA) can be proposed. For the case study network studied here, a compromise DMA size of 250 properties is suggested. [ABSTRACT FROM AUTHOR]

This study assessed the magnitude of variations in the concentrations of disinfection by-products, specifically trihalomethanes and haloacetic acids, which occur in two UK water distribution networks of different sizes due to changes in the hydraulic operation of the networks. These operational changes included varying the fill levels of water storage tanks and pumping conditions within the network. This was investigated through modelling which combined a conventional distribution network flow model (EPANET) with previously developed models for disinfection by-product formation, and using network information obtained from water company partners. The modelling demonstrated that there is the potential for significant variations in disinfection by-product concentrations, up to a 40% change in some simulations, due to what may be considered routine variability in the hydraulic operation of the network. Smaller networks may be especially susceptible to these variations. These findings may influence how water companies plan disinfection by-product monitoring programmes for regulatory reporting. [ABSTRACT FROM AUTHOR]

Wild rocket,Diplotaxis tenuifolia(L.) DC. (Brassicaceae), is one of the three cultivated rocket species, the demand and production of which have recently increased in Mediterranean countries where irrigation water is scarce. Besides its use as a crop,D. tenuifoliahas been observed to flower for a long period and to be attractive to pollinators. In this study we assessed the effect of drought stress and moderate- and severe-deficit irrigation on growth, flower development, and attractiveness to pollinators inD. tenuifolia. The results showed that in greenhouse conditions, pottedD. tenuifoliacould be without irrigation for 4 days without affecting its growth, flowering, and attractiveness to pollinators. However, lack of irrigation for 8 days or longer significantly reduced the vegetative growth, number of open flowers, total floral area, flower diameter, corolla tube diameter, and corolla tube length ofD. tenuifolia. This study shows that regulated-deficit irrigation can improve water use efficiency, and depending on the purpose of growingD. tenuifolia, as a crop or as a beneficial plant to attract pollinators, it can reduce water consumption from 40% to 70% without affecting its vegetative and floral development and without reducing its attractiveness to pollinators. [ABSTRACT FROM AUTHOR]

The applicability of the operational radar and raingauge networks for urban hydrology is insufficient. Radar rainfall estimates provide a good description of the spatiotemporal variability of rainfall; however, their accuracy is in general insufficient. It is therefore necessary to adjust radar measurements using raingauge data, which provide accurate point rainfall information. Several gauge-based radar rainfall adjustment techniques have been developed and mainly applied at coarser spatial and temporal scales; however, their suitability for small-scale urban hydrology is seldom explored. In this paper a review of gauge-based adjustment techniques is first provided. After that, two techniques, respectively based upon the ideas of mean bias reduction and error variance minimisation, were selected and tested using as case study an urban catchment (∼8.65 km2) in North-East London. The radar rainfall estimates of four historical events (2010-2012) were adjusted using in situ raingauge estimates and the adjusted rainfall fields were applied to the hydraulic model of the study area. The results show that both techniques can effectively reduce mean bias; however, the technique based upon error variance minimisation can in general better reproduce the spatial and temporal variability of rainfall, which proved to have a significant impact on the subsequent hydraulic outputs. This suggests that error variance minimisation based methods may be more appropriate for urban-scale hydrological applications. [ABSTRACT FROM AUTHOR]