Estimating domestic outdoor water demand for residential estates

Du Plessis, Jacobus Lodewikus (2014-04)

Thesis (MEng)--Stellenbosch University, 2014.

Thesis

ENGLISH ABSTRACT: The outdoor water consumption of residential properties is a major contributor to the seasonal fluctuation of the overall water consumption of these properties. The estimation of the relating outdoor water demand has become valuable to property developers and planners alike. This could enable designers to optimise designs of water distribution networks and assist in water resource planning and gaining legislative approvals. For the purposes of this study the outdoor water-use components were mathematically defined and combined to develop an outdoor water-demand model. In order to evaluate the results of an outdoor water demand model on a monthly temporal scale it was necessary to develop a proxy outdoor water consumption evaluation method based on the metered monthly consumption of residential properties. The method entailed verifying that the generally non-seasonal indoor water consumption as a function of the winter water consumption. This entailed analysis of the total monthly, indoor and outdoor water consumption data adopted from a noteworthy North American water end-use project. The indoor water consumption estimated in this manner could then be subtracted from the overall monthly water consumption to obtain estimated monthly outdoor water consumption data. The estimated outdoor consumption could be compared with the simulated outdoor water demand, as described by the model. The parameters that formed part of the mathematical outdoor water demand model were formulated from data available for residential estates, where conditions such as types of vegetation, irrigated area and size of pool could be prescribed in a constitution, usually instituted by a home owners association. The data was derived from one estate located in the Western Cape Province of South Africa. The mathematical model was simulated using the Monte Carlo method and the @Risk software. Three residential estates located in South Africa were subsequently modelled. Additionally, the model was employed to estimate outdoor water demand for houses located in Northern America for verification purposes. The Monte Carlo simulations of the outdoor water demand model presented in this study yielded realistic results when compared with the proxy outdoor consumption figures as well as the metered actual outdoor water consumption data analysed. The peak monthly outdoor water demand estimation results were particularly close to the consumption data. This study serves as a baseline for further research into outdoor water demand. Research into the effects of water restriction and conservation potential could follow from this work, especially in today’s environmentally conscious society.

AFRIKAANSE OPSOMMING: Die buite waterverbruik van residensiëel eiendomme dra grootliks by tot die seisoenale fluktuasie van die algehele water verbruik van hierdie eiendomme. Die beraming van die dienooreenkomstige buite wateraanvraag kan waarde toevoeg vir eiendomsontwikkelaars and beplanners, indien dit ontwerpers kan instaat stel om water verspreindingsnetwerke te optimeer en te help met water hulpbron beplanning en wetlikke goedkeurings. Vir die doeleindes van hierdie studie is die buite waterverbruik komponente wiskundig gedefinieër en gekombineer om ‘n buite wateraanvraag model te ontwikkel. Ten einde die resultate van ‘n buite water aanvraag model op ‘n maandelikse tydskaal te evalueer, was dit nodig om ‘n benaderingsmetode te ontwikkel, gebaseer of die gemeterde maandelikse water verbruike gebruik. Die metode behels dat die data, verkry van ‘n bekende Noord-Amerikaanse water eindverbruikprojek, van die algmeen nie-seisoenale binneshuise water verbruik vergelyk word met die maandelikse winter water verbruik. Derhalwe kon die binneshuise waterverbruik wat op hierdie manier beraam is afgetrek word van die algehel maandelikse waterverbruik om die maandelikse buitewater verbruik te beraam. Die beraamde buitewater verbruik kon sodoende vergelyk kan word met ‘n gesimuleerde buite wateraanvraag soos beskryf deur die gesimuleerde model. Die parameters wat deel uitgemaak het van die wiskundige buite waterverbuik model was gedefinieër uit data wat beskikbaar was vir residensiële ontwikkelings, waar voorwaardes soos plantegroei, besproeiingsarea of swembad grote dikwels voorgeskryf kan word in ‘n grondwet ingestel deur ‘n huiseienaarsvereniging. Die data wat in hierdie model gebuik word is hoofsaaklik afskomstig van ‘n landgoed geleë in die Weskaap provinsie, Suid-Afrika. Die wiskundige model was gesimuleer met behulp van die Monte Carlo metode en die @Risk sagteware. Drie residensiële landgoede geleë in Suid-Afrika was daaropvolgend gemodelleer. Daarbenewens is die model gebruik die buite watergebruik van groepe huise geleë in Noord-Amerika te beraam vir verifikasie doeleindes. Die Monte Carlo simulasies van die buite water aanvraag model van hierdie studie het realistiese resultate in vergelyking met die beraamde buite verbruike sowel as die werklike gemeterde buite water verbruiksdata opgelewer. Die piek maandelikse buite water aanvraag beramings resultate was veral vergelykbaar met die piek maandeliks waterverbruik data. Hierdie studie dien as 'n basis vir verdere navorsing in buite waterverbruik. Navorsing gefokus op die gevolge van water beperkings en bewaring potensiaal kan as aanvullende voordele van hierdie studie ontstaan, veral in vandag se omgewingsbewuste samelewing.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/86695
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