Assessment of groundwater availability from recession flows and instream flow requirements of rivers in South Africa

Simple item page
cg.contributor.crpWater, Land and Ecosystemsen_US
cg.coverage.countrySouth Africaen_US
cg.coverage.iso3166-alpha2ZAen_US
cg.coverage.regionSouthern Africaen_US
cg.identifier.urlhttp://www.wrc.org.za/Pages/Preview.aspx?ItemID=11354&FromURL=%2fPages%2fDisplayItem.aspx%3fItemID%3d11354%26FromURL%3d%252fPages%252fKH_DocumentsList.aspx%253fdt%253d%2526ms%253d3%253b%2526d%253dAssessment%2bof%2bGroundwater%2bAvailability%2bfrom%2bRecession%2bFlows%2band%2bInstream%2bFlow%2bRequirements%2bof%2bRivers%2bin%2bSouth%2bAfrica%2526start%253d1en_US
cg.identifier.wlethemeDecision Analysis and Informationen_US
cg.identifier.wlethemeManaging Resource Variability and Competing Useen_US
dc.contributor.authorEbrahim, Girma Yimeren_US
dc.contributor.authorVillholth, Karen G.en_US
dc.date.accessioned2016-09-20T04:42:36Zen_US
dc.date.available2016-09-20T04:42:36Zen_US
dc.identifier.urihttps://hdl.handle.net/10568/77078en_US
dc.titleAssessment of groundwater availability from recession flows and instream flow requirements of rivers in South Africaen_US
dcterms.abstractGroundwater is an important resource for multiple uses in South Africa. However, setting limits to its sustainable abstraction while assuring basic human needs is a must. Due to prevalent data scarcity related to groundwater replenishment, which is the traditional basis for estimating groundwater availability, the present report presents a novel method for determining allocatable groundwater in quaternary catchment through information on streamflows. Using established methodologies for assessing baseflows, recession flows, and instream ecological flow requirements, the methodology develops a combined stepwise methodology to determine annual groundwater storage volumes in the catchments using linear reservoir theory, essentially linking low flows proportionally to upstream groundwater storages. The approach was trialled for twenty-one perennial and relatively undisturbed quaternary catchments with long-term and good streamflow records. Using the Desktop Reserve Model to estimate instream ecological flow requirements of the streams and equating these with ecological groundwater reserve, excess baseflows were converted into groundwater storages on an annual basis. Results show that groundwater development potential exists in nineteen of the catchments, with upper limits to allocatable groundwater volumes ranging from 0.01 to 1.58 MCM/yr over the catchments. With a secured availability of these volumes 75% of the years, variability between years is assumed to be manageable. A significant (R2 = 0.86) correlation between baseflow index and the drainage time scale for the catchments underscored the physical basis of the methodology and also enables the reduction of the procedure by one step, omitting recession flow analysis. The method serves as an important complementary tool for the assessment of the groundwater part of the Reserve and the groundwater directed measures.en_US
dcterms.accessRightsLimited Accessen_US
dcterms.bibliographicCitationEbrahim, Girma Yimer; Villholth, Karen Grothe. 2015. Assessment of groundwater availability from recession flows and instream flow requirements of rivers in South Africa. Gezina, Pretoria, South Africa: Water Research Commission. 60p. (Water Research Commission Report KV 339/15)en_US
dcterms.issued2015en_US
dcterms.languageenen_US
dcterms.publisherWater Research Commissionen_US
dcterms.subjectgroundwater rechargeen_US
dcterms.subjectgroundwateren_US
dcterms.subjectwater storageen_US
dcterms.subjectwater availabilityen_US
dcterms.subjectwater allocationen_US
dcterms.subjectwater requirementsen_US
dcterms.subjectstream flowen_US
dcterms.subjectflow rateen_US
dcterms.subjectriversen_US
dcterms.subjectcatchment areasen_US
dcterms.subjectdrainageen_US
dcterms.subjectenvironmental flowsen_US
dcterms.subjectrainen_US
dcterms.subjectmultiple useen_US
dcterms.subjectecological factorsen_US
dcterms.subjectaquifersen_US
dcterms.typeReporten_US

Files

License bundle

Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.89 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Decision Analysis and Information
Managing Resource Variability and Competing Use