Suchergebnisse

ABSTRACTMore than a decade has passed since the International Panel on Climatic Change began to study (in depth) the possibility that the global climate was changing. Increasing attention is also being paid to the impact of such changes on society in general, and on the planning and management of water resources. Not least among the water resources planning problems is the estimation of the changes which might occur in public water‐supply demands. Such changes are notoriously difficult to evaluate, particularly in the UK where most domestic premises remain un‐metered. Elsewhere, econometric models involving climatic parameters as independent variables have had some success, but a recent application of this approach in the UK was unable to identify particular parameters which had a consistent influence over the summer period. This lack of success might be partly caused by the public reaction to summer conditions being a complex function of several parameters, such as duration of sunshine, temperature and rainfall. This complexity has already been recognised by climatologists, who have devised forms of summer indices involving weighted combinations of climatic variables to determine how 'good' or 'bad' a particular period might be perceived by the general public. The use of one such summer index to explain the variations in an index of demand for public water supply in the London supply area has shown that simple and consistent relationships can be derived. Application of these relationships to scenarios of changes in temperature, sunshine duration and rainfall totals for the year 2050 shows an increase of 0.6‐ 2.9 index points in water‐supply demand over the 1950‐1990 period average.

ABSTRACTThe Government's intention to abolish the rateable value system has made it urgent for the water industry to develop an alternative method of charging for its domestic customers. Metering is one option, and a description is given of the national programme of metering trials. These trials will provide better information on which to base future charging and metering decisions.One area of 53 000 properties and eleven smaller areas of 1000 properties will be included in the trials. The paper covers their design and objectives and the location of the selected sites. The various metering systems are described including the meters, the installation location, the reading and billing systems and the metered tariffs to be used.

ABSTRACTWHEN THE Component Method is applied to produce a forecast of future water demand, particular attention must be paid to the unmeasured consumption. This component consists largely of domestic water demand and takes into account the major water uses within the home. A knowledge is therefore required of the ownership of water‐using appliances, the volumes of water involved and the frequency of use. These data are best obtained by the metering of individual households, supplemented by questionnaire surveys and the completion of diaries for each major element of water use.Such a survey was carried out by South West Water over a 13‐month period during 1977‐78. Subsequent updating, which has included further surveys of appliance ownership in the original sample of households and of the capacities of individual appliances, has shown that domestic per capita consumption has increased from 113.4 1/hd/d in 1977 to 131.6 1/hd/d in 1985.