Surface water - groundwater interactions: development of methodologies suitable for South African conditions
Abstract
English: Winter (1999) succinctly, made a profound statement to the effect that understanding the
basic principles of the interaction between surface water and groundwater is needed for
effective management of water resources. Hence, the research investigation was aimed at
identifying appropriate methodologies for assessment of surface water - groundwater
interaction, thus enhancing the understanding thereof. The methodology used entailed a
review of national and international literature on related previous and current models,
systems and methods used in assessment and quantification of water exchange between
groundwater and surface water. This was then followed by relevant case study analyses
where distinct areas where chosen based on availability of relevant data and information by
previous investigators. The findings were that various methods and classification systems
are widely available but the applicability thereof under the South African conditions
depends on the conceptual understanding of the area or system under investigation,
availability of data and the basic assumptions associated with the particular model or
method. The surface water - groundwater interaction cannot easily be quantified with
confidence without requisite data available. The other finding is that use of multiple
techniques to reduce uncertainties and to confirm or verify the existence or non-existence
of the interaction is essential. Preferably, at least one method should be utilised to trace
flow or qualitatively establish the water exchange while the alternative method is used for
quantitative estimation of the interaction between surface water and groundwater. Some
of the products emerging from this research investigation include decision tables for
choosing applicable analytical method, applicable numerical method and the framework for
guiding the selection of appropriate methodologies for assessing or quantifying the
interaction between surface water and groundwater. Knowledge generated is applicable
to water resource management, resource protection, water allocation and monitoring. Afrikaans: Winter (1999) het In diepgaande verklaring gemaak tot die effek dat die begrip van die
basiese beginsels van die interaksie tussen oppervlak-en grondwater is wat nodig is vir die
doeltreffende bestuur van waterhulpbronne. Dus, is die navorsingsondersoek gemik op die
identifisering van toepaslike metodologieë vir die assessering van oppervlak water
grondwater interaksie, en om die begrip daarvan te verbeter. Die metodologie wat gebruik
word behels 'n oorsig van die nasionale en internasionale literatuur oor verwante vorige en
huidige modelle, stelsels en metodes wat gebruik word in die bepaling en kwantifisering van
water uitruil tussen grondwater en oppervlakwater. Dan was die regte gevallestudie
ontleding gemaak,en duidelike gebiede gekies, en op die beskikbaarheid van data en
inligting deur vorige navorsers gebaseer. Die bevindinge was dat verskeie metodes en
klassifikasie stelsels is wyd beskikbaar, maar die toepaslikheid daarvan onder die Suid-
Afrikaanse toestande hang af van die konseptueie begrip van die gebied of stelsel wat
ondersoek word, beskikbaarheid van data en die basiese aannames wat verband hou met
die spesifieke model of metode. Die oppervlak water grondwater interaksie kan nie met
selfvertroue gekwantifiseer word sonder die nodige data. Die ander bevinding is dat die
gebruik van verskeie tegnieke om onsekerhede te verminder en om te bevestig of te
verifieer die bestaan of nie-bestaan van die interaksie, is noodsaaklik. Moet verkieslik ten
minste een metode gebruik word op te spoor vloei of kwalitatief die water ruil vestig terwyl
die alternatiewe metode word gebruik vir kwantitatiewe skatting van die interaksie tussen
oppervlak-en grondwater. Die produkte wat na vore kom uit hierdie navorsingsondersoek
sluit besluit tafels vir die keuse van toepaslike analitiese metode, toepaslike numeriese
metode, en die raamwerk vir die begeleiding van die seleksie van toepaslike metodologieë
vir die beoordeling of die kwantifisering van die interaksie tussen oppervlak-en grondwater.
Kennis wat deur hierdie navorsing gegenereer is op waterhulpbronbestuur, beskerming van
die hulpbronne, water toekenning en monitering van toepassing.