Search results for "water supply"
showing 10 items of 199 documents
Urban Stormwater Management, A Tool for Adapting to Climate Change: From Risk to Resource
2020
The effects of climate change on rainfall in the Mediterranean region are manifested in an overall decreasing trend, and greater irregularity in annual volumes and the city of Alicante is no exception. In addition, there has also been a spread of the urbanised area, which has led to an increase in the flood risk in urban areas (due to a greater runoff and the occupation of flood hazard areas) and drought events due to an increase in the water demand. In light of these new scenarios, the Mediterranean cities should design adaptation systems based on rainwater harvesting within the framework of a circular economy. This study analyses the integration of rainwater in flood and water demand mana…
Evaluating the Effects of the Rill Longitudinal Profile on Flow Resistance Law
2022
In this paper, for the first time, the effect of the longitudinal profile shape of the rill (uniform, concave, and convex) on flow resistance law was studied. The first part of the paper is based on a theoretical equation to estimate the Darcy–Weisbach friction factor f, deduced from the power velocity distribution and rill measurements performed on a plot. At first, the equation to estimate the Γ parameter of the velocity profile was calibrated using all available measurements. Then an analysis of the hydraulic characteristics at reach scale, for comparable values of discharge, was carried out, comparing the different profile shapes. To assess the influence of the rill profile …
Household water source and the risk of childhood brain tumours: results of the SEARCH International Brain Tumor Study.
2004
Background The period in utero is a time of increased vulnerability. Offspring of pregnant women exposed to carcinogenic substances in drinking water may be more likely to develop cancer. We examined whether household water source and the presence of nitrates or nitrites in residential water were associated with increased risks of childhood brain tumours (CBT). Methods We used data from a multicentre, case-control study with maternal information on residential water source, and nitrate/nitrite levels of tap water measured by dipstick. Subjects included 836 CBT cases and 1485 controls from five countries. Results The risks of CBT associated with reliance on well water (versus public water) d…
Investigating the Performance of Enhanced Permeable Groins in Series
2020
The enhanced permeable groin is a novel eco-friendly and cost-effective technique for bank protection and restoration of meander bends. The behavior of bed deformations due to the distance between the structures has to be studied to design enhanced permeable groins in series properly. In this study, scour morphologies around enhanced permeable groins in series, characterized by four different distances and located in a 180°
Geospatial analysis of drought tendencies in the Carpathians as reflected in a 50-year time series
2019
Climate change is one of the most important issues of anthropogenic activities. The increasing drought conditions can cause water shortage and heat waves and can influence the agricultural production or the water supply of cities. The Carpathian region is also affected by this phenomenon; thus, we aimed at identifying the tendencies between 1960 and 2010 applying the CarpatClim (CC) database. We calculated the trends for each grid point of CC, plotted the results on maps, and applied statistical analysis on annual and seasonal level. We revealed that monthly average temperature, maximum temperature and evapotranspiration had similar patterns and had positive trends in all seasons except aut…
Comparison between energy balance and mass balance models for actual evapotranspiration assessment
2009
The assessment of the water needs for a specific crop has a fundamental importance in the management of water resources. The application of empirical models able to retrieve estimates of the actual evapotranspiration (ETa) to assess the need for water could give a valid tool for the planning of water supply, avoiding unnecessary water losses. In this context, two independent models for estimating actual evapotranspiration were compared. The first model is based on an energy balance and uses remotely sensed data and ancillary data from weather stations to assess the ETa. The second model also uses remotely sensed data and climatic data on a daily basis from a weather network. Field measureme…
Submerged speleothems and sea level reconstructions: a global overview and new results from the Mediterranean Sea
2021
This study presents a global overview of the submerged speleothems used to reconstruct paleo sea levels and reports new results from two stalactites collected in the Mediterranean Sea. Coastal cave deposits significantly contributed to the understanding of global and regional sea-level variations during the Middle and Late Quaternary. The studied speleothems cover the last 1.4 Myr and focused mainly on Marine Isotope Stages (MIS) 1, 2, 3, 5.1, 5.3, 5.5, 7.1, 7.2, 7.3 and 7.5. The results indicate that submerged speleothems represent extraordinary archives that can provide detailed information on former sea-level changes. The two stalactites collected in the central Mediterranean Sea, at Fa…
Willingness to pay to improve urban water supply: the case of Sucre, Bolivia
2014
In this study the contingent valuation method is applied in order to estimate the willingness to pay (WTP) of the inhabitants of Sucre (Bolivia) for an improvement in the urban water supply system. The study finds that about 55 per cent of households would be willing to pay an increase in their water bill for an improvement in the service. In order to deal with the problem of protest responses and the possible presence of a sample selection bias, a Heckman two-step model was estimated. More specifically, the econometric analysis undertaken reveals that there is no evidence of sample selection bias and that WTP positively relates to the respondents' household income, their level of education…
How much should customers be compensated for interruptions in the drinking water supply?
2017
Water supply interruptions directly affect customers, and customers should be compensated accordingly. However, few water regulators have applied compensation policies given the difficulty of estimating the economic value of compensation to customers. In this study, a pioneering approach based on the concept of shadow prices is proposed to determine the compensation that customers should receive for unplanned water interruptions. The Chilean water industry was selected as a case study because there is an ongoing policy discussion between the use of penalties or compensation as an incentive to prevent water supply interruptions. The estimated results indicate that for 2014, the value of comp…
A composite indicator index as a proxy for measuring the quality of water supply as perceived by users for urban water services
2021
Abstract The objective of this study is to develop a composite indicator (CI) to measure the quality of water supply based on the variables that are considered to affect users’ perceptions of water supply quality. The proposed CI includes six relevant aspects that determine users’ perceptions of water supply quality (network quality, water quality, water price, complaints, inconvenience caused by upgrading the network, and continuity of service) in a simple, economical, and objective way, using multi-criteria decision analysis (MCDA) with weights based on data envelopment analysis (DEA). The CI was applied to 32 municipalities in the metropolitan area of Valencia (Spain). The results show t…