Browsing by Author "Jacobs, Heinz E."

Now showing 1 - 7 of 7
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    Analysis of water use by gated communities in South Africa
    (South African Water Research Commission, 2018) Du Plessis, Jacques J. L.; Jacobs, Heinz E.
    ENGLISH ABSTRACT: Gated communities (hereafter GCs) are popular in many countries, including South Africa, because added security and lifestyle improvements are offered relative to homes built on freestanding properties. One of the key factors for the popularity of GCs is the availability of amenities to support the demands of the residents, such as gymnasia, walkways, golf courses, play parks and polo fields. Further benefits include the improved management of infrastructure such as telecommunication services, roads, water, sewer, electrical and stormwater assets. GCs are often governed by trustees or homeowners’ associations, responsible for the operation and the maintenance functions of the infrastructure, as well as implementing and adhering to legislation that pertains to the GC. As part of this study, the monthly water-use records of 2 888 GCs in 3 different South African cities were analysed. Water use was evaluated for each GC as a whole, and also per household in each case. The average number of homes per GC was 33 households/GC, with the smallest GC in the study sample containing 3 houses and the largest 524 houses. One of the study sites was in the winter rainfall region, while 2 sites were in the summer rainfall region. The average annual water use of individual households in each GC was plotted against current guidelines and was found to be relatively low. The average annual daily demands of all properties in the winter rainfall region was 0.63 kL/d, compared to 0.66 kL/d and 0.49 kL/d for the two study sites in the summer rainfall region. The results highlighted peculiarities in the water use of GCs that have not been reported on before, in particular the relatively low water use and the differences between GC homes’ water use in the various rainfall regions.
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    Applying geographic information systems to delineate residential suburbs and summarise data based on individual parcel attributes
    (AOSIS Publishing, 2013) Sinske, Stefan A.; Jacobs, Heinz E.
    Background: Information aggregation to suburb level is of interest to engineers and urban planners. Readily available suburb boundaries do not always correspond to the suburb names recorded for individual properties in different data bases and unwanted errors are inherent. This mismatch of suburb names at different spatial scales poses a particular problem to analysts. As part of a parallel research project into the development of a robust guideline for suburb-based water demand analyses it was necessary to evaluate a large number of suburbs in terms of various attributes, one of which was the total suburb area. Objectives: Suburb boundaries were needed to assess the total suburb area. The objective of this research was to develop a novel geographic information system (GIS) application to delineate suburbs with boundaries corresponding to information contained in another data base comprising individual property records. The suburb boundaries derived in this manner may not relate to municipal boundaries, or sociopolitical boundaries, nor do they have to. The fundamentally correct suburb boundary would be the one encompassing what is perceived to be the suburb based on the suburb name in a particular data base that also contains other interesting attributes, such as water use, of individual properties. Method: The ArcGIS environment was used to delineate suburbs by means of triangulated irregular network (TIN) modelling. Boundaries for suburbs with predominantly residential land use were created that included all residential properties according to the suburb name field as recorded in the treasury system. Other vacant areas were also included so as to obtain the total suburb area. The methodology was developed to assist research in the field of potable water services, but the method presented could be applied to other services that require management of information at suburb level. Results: This article illustrates how a tedious task of suburb delineation could be automated in the GIS environment. The tool prevents subjective results that would be prone to error. The automated procedure described could effectively delineate a large number of predominantly residential suburbs in a relatively short time span and produce repeatable results. A reasonable outline could only be obtained if a sufficient number of parcels in the area contained the same suburb name. Functionality was added to the tool so that a limit could be set for this purpose. The default was that if more than 20% of the records were erroneous it was considered impractical to delineate a suburb. The derived suburb boundaries correspond to useful information in other data bases and would thus enable more effective management of the information. Conclusion: A novel procedure to delineate suburb boundaries in the GIS environment was illustrated in this article. Information at two different spatial scales, namely, individual consumers and suburbs, could be married for the purpose of further research into suburban attributes. The tool was applied as part of a parallel research project to delineate 468 suburbs in this manner, results of which were submitted for publication elsewhere.
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    A chronological review of South African guidelines for residential average annual water demand with property size as independent variable
    (AOSIS OpenJournals, 2008-12) Jacobs, Heinz E.
    ENGLISH ABSTRACT: Guidelines for residential average annual water demand (AADD) based on property size were introduced to the South African Civil Engineering fraternity in about 1960, with the most recent publication of such guidelines in 2008. The AADD forms the basis of calculations performed during the design and analysis of water systems. Over the years technology has improved, scientific progress was made and demand has changed, resulting in improved and updated guidelines for AADD. Changes in the guidelines over the years could be considered to be a result of improvement – larger and more accurate data sets are nowadays analysed statistically by improved computer technology. Also, the changes are considered to be the result of scientific advances in the fields of metering, modelling and analysis of water demand. Finally, actual changes in demand occur with time. This research provides the first documented review of the chronological development of AADD guidelines in South Africa. It is noted that only two guidelines were used for relatively long periods of time. In both cases the guidelines would not compare favourably to others from a pure research perspective, but their successful application is the result of a co-ordinated educational and marketing effort. The value of a sustained guideline structure (AADD versus stand size in this case) is also underlined.
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    ’n Chronologiese oorsig van Suid-Afrikaanse riglyne vir residensiële gemiddelde jaarlikse waterverbruik met erfgrootte as onafhanklike veranderlike
    (AOSIS OpenJournal, 2008) Jacobs, Heinz E.
    ENGLISH ABSTRACT: Guidelines for residential average annual water demand (AADD) based on property size were introduced to the South African Civil Engineering fraternity in about 1960, with the most recent publication of such guidelines in 2008. The AADD forms the basis of calculations performed during the design and analysis of water systems. Over the years technology has improved, scientific progress was made and demand has changed, resulting in improved and updated guidelines for AADD. Changes in the guidelines over the years could be considered to be a result of improvement– larger and more accurate data sets are nowadays analysed statistically by improved computer technology. Also, the changes are considered to be the result of scientific advances in the fields of metering, modelling and analysis of water demand. Finally, actual changes in demand occur with time. This research provides the first documented review of the chronological development of AADD guidelines in South Africa. It is noted that only two guidelines were used for relatively long periods of time. In both cases the guidelines would not compare favourably to others from a pure research perspective, but their successful application is the result of a co-ordinated educational and marketing effort. The value of a sustained guideline structure (AADD versus stand size in this case) is also underlined.
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    Drinking water temperature around the globe : understanding, policies, challenges and opportunities
    (MDPI, 2020-04) Agudelo-Vera, Claudia; Avvedimento, Stefania; Boxall, Joby; Creaco, Enrico; De Kater, Henk; Di Nardo, Armando; Djukic, Aleksandar; Douterelo, Isabel; Fish, Katherine E.; Rey, Pedro L. Iglesias; Jacimovic, Nenad; Jacobs, Heinz E.; Kapelan, Zoran; Solano, Javier Martinez; Pachongo, Carolina Montoya; Piller, Olivier; Quintiliani, Claudia; Ručka, Jan; Tuhovčák, Ladislav
    ENGLISH ABSTRACT: Water temperature is often monitored at water sources and treatment works; however, there is limited monitoring of the water temperature in the drinking water distribution system (DWDS), despite a known impact on physical, chemical and microbial reactions which impact water quality. A key parameter influencing drinking water temperature is soil temperature, which is influenced by the urban heat island e ects. This paper provides critique and comprehensive summary of the current knowledge, policies and challenges regarding drinking water temperature research and presents the findings from a survey of international stakeholders. Knowledge gaps as well as challenges and opportunities for monitoring and research are identified. The conclusion of the study is that temperature in the DWDS is an emerging concern in various countries regardless of the water source and treatment, climate conditions, or network characteristics such as topology, pipe material or diameter. More research is needed, especially to determine (i) the e ect of higher temperatures, (ii) a legislative limit on temperature and (iii) measures to comply with this limit.
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    Garden footprint area and water use of gated communities in South Africa
    (Water Research Commission, 2020-04) Du Plessis, Jacques L.; Knox, Ashley J.; Jacobs, Heinz E.
    Gated community homes in South Africa are popular amongst property buyers in urban environments such as cities and metropoles due to the increased security and lifestyle improvements offered. Garden design and layout requirements are prescribed in architectural guidelines compiled by the homeowners associations of these communities. Garden footprint area in gated community homes is of importance to researchers and planners, because of the influence on water use. This study used a quantitative approach to evaluate the spatial data of garden footprint area as a percentage of total plot area for 1 813 gated community homes in different regions of South Africa. The research reviewed how garden footprint area is prescribed and how it is applied in gated community homes. The impact of garden footprint area on water use was also analysed. The results were compared to relevant information lifted from specific architectural design guidelines developed for each gated community. Data from 11 gated communities were analysed and the average garden footprint area was found to be 36% of the total plot area. Gated community homes with a garden area smaller than 100 m2 were found to have limited influence on monthly water consumption, while the water use of gated community homes with a larger garden footprint area increased proportionally with garden footprint area. The seasonal fluctuation of water use is illustrative of garden irrigation and other outdoor water use. The results provided useful input for incorporation in outdoor water use modelling of gated community homes.
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    A tool to increase information-processing capacity for consumer water meter data
    (AOSIS Publishing, 2013) Jacobs, Heinz E.; Fair, Kerry A.
    Background: Water service providers invoice most South African urban consumers for the water they use every month. A secure treasury system generates water invoices at municipalities’ financial departments. Information about the water usage of customers initially comes from reading the water meters, usually located in gardens near the front boundaries of properties. Until as recently as 1990, the main purpose of the water meter readings was to generate invoices for water usage. There are various treasury systems for this purpose. Objective: The objective of this research article was to describe the development of Swift, a locally developed software tool for analysing water meter data from an information management perspective, which engineers in the water field generally use, and to assess critically the influence of Swift on published research and industry. This article focuses on water usage and the challenge of data interchange and extraction as issues that various industries face. Method: This article presents the first detailed report on Swift. It uses a detailed knowledge review and presents and summarises the findings chronologically. Results: The water meter data flow path used to be quite simple. The risk of breaches in confidentiality was limited. Technological advances over the years have led to additional knowledge coming from the same water meter readings with subsequent research outputs. However, there are also complicated data flow paths and increased risks. Users have used Swift to analyse more than two million consumers’ water meter readings to date. Studies have culminated in 10 peer-reviewed journal articles using the data. Seven of them were in the last five years. Conclusion: Swift-based data was the basis of various research studies in the past decade. Practical guidelines in the civil engineering fraternity for estimating water use in South Africa have incorporated knowledge from these studies. Developments after 1995 have increased the information processing capacity for water meter data.