干旱区生态环境知识资源中心(Arid): Engineering, hydrogeological and vadose zone hydrological aspects of Proterozoic dolomites (South Africa)

Arid

DOI	10.1016/j.jafrearsci.2018.07.024
	Engineering, hydrogeological and vadose zone hydrological aspects of Proterozoic dolomites (South Africa)
	Dippenaar, Matthys A.; van Rooy, J. Louis; Diamond, Roger E.
通讯作者	Dippenaar, Matthys A.
来源期刊	JOURNAL OF AFRICAN EARTH SCIENCES
ISSN	1464-343X
EISSN	1879-1956
出版年	2019
卷号	150 页码:511-521
英文摘要	Large parts of the urban land between Pretoria (City of Tshwane Municipality, South Africa's capital city) and Johannesburg (South Africa's largest city) are situated on Proterozoic dolomites of the Malmani Subgroup (Chuniespoort Group, Transvaal Supergroup) formed in the Transvaal Basin. As South Africa's economic hub, development is progressively becoming denser, higher, and deeper underground, increasing the risks posed by surface subsidence and sinkholes. Tshwane also sources more than 40 million liters of drinking water per day (5-8% of requirements) from the dolomite aquifers. A second basin comprising the Ghaap Group is found to the more arid western portions of the country. Even though a fair understanding exists with respect to the karst aquifer hydraulics and the surface stability issues, a distinct knowledge gap exists in the karst vadose zone. Recent research efforts focused on vadose zone hydrology has resulted in a significantly improved understanding of the behaviour of variable saturated soil and fractured rock systems, both at discreet localities and on a regional scale. However, with more than 90% of the sinkholes in this region forming due to water ingress from leaking pipelines (especially given that the latter non-revenue water is estimated in the order of 30% of the reticulated supply), the flow mechanisms, and unsaturated or vadose zone behaviour of the karst system becomes increasingly important. The ingress scenario results in downward erosion of soil (chert rubble, residual dolomite, transported soil or other residual products of younger caprock) with percolating water. The high lithological variability in South African karst adds to the uncertainty, and is related to chert abundance, the presence of residual dolomite (wad), subsurface cavities (receptacles) and so forth contributing to the heterogeneity and anisotropy. The review paper presents state-of-the-science on the karst vadose zone, including recent advances, appropriate geological models, and knowledge gaps.
英文关键词	Soluble rock Subsidence Karst Chuniespoort group Ghaap group Sinkhole
类型	Review
语种	英语
国家	South Africa
收录类别	SCI-E
WOS记录号	WOS:000460195100038
WOS关键词	VARIABLY SATURATED FLOW ; GEOLOGICAL MODELS ; KARST GROUNDWATER ; LANSERIA GNEISS ; WATER ; TRANSVAAL ; JOHANNESBURG ; GUIDELINES ; SEQUENCE ; SINKHOLE
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/216596
作者单位	Univ Pretoria, Dept Geol, Engn Geol & Hydrogeol, Private Bag X20, ZA-0028 Pretoria, South Africa
推荐引用方式 GB/T 7714	Dippenaar, Matthys A.,van Rooy, J. Louis,Diamond, Roger E.. Engineering, hydrogeological and vadose zone hydrological aspects of Proterozoic dolomites (South Africa)[J],2019,150:511-521.
APA	Dippenaar, Matthys A.,van Rooy, J. Louis,&Diamond, Roger E..(2019).Engineering, hydrogeological and vadose zone hydrological aspects of Proterozoic dolomites (South Africa).JOURNAL OF AFRICAN EARTH SCIENCES,150,511-521.
MLA	Dippenaar, Matthys A.,et al."Engineering, hydrogeological and vadose zone hydrological aspects of Proterozoic dolomites (South Africa)".JOURNAL OF AFRICAN EARTH SCIENCES 150(2019):511-521.