Browsing Research Articles (Earth Sciences) by Author "Xu, Yongxin"
Now showing items 1-20 of 31
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Assessment of microbial contamination of groundwater in upper Limphasa River catchment, located in a rural area of northern Malawi
Kanyerere, Thokozani; Levy, Jonathan; Xu, Yongxin; Saka, John (Water Research Commission, 2012)In rural Africa, scientific evidence is often lacking to guide the scaling-up of groundwater as the safest source of potable water. An investigation was conducted in the Upper Limphasa Catchment in northern Malawi to ... -
Book review: estimating groundwater recharge
Xu, Yongxin (Springer Verlag, 2011) -
Book review: urban geology
Xu, Yongxin (Springer Verlag, 2012) -
Borehole dilution experiment in a Karoo aquifer in Bloemfontein
Xu, Yongxin; van Tonder, Gerrit J.; van Wyk, B.; van Wyk, E.; Aleobua, B. (Water Research Commission, 1997)This paper shows that a borehole dilution experiment using common salt is a useful technique for better understanding of some hydrogeological features of a fractured aquifer. A sense of such tracer experiments was performed ... -
Capture zone simulation for boreholes located in fractured dykes using the linesink concept
Xu, Yongxin; van Tonder, Gerrit J. (Water Research Commission, 2002)Delineation of capture zones for groundwater source protection is normally performed by using numerical codes which are based on the porous medium flow equation. However, boreholes are often sited in or along permeable ... -
Characterization of macropore structure of Malan loess in NW China based on 3D pipe models constructed by using computed tomography technology
Li, Yanrong; He, Shengdi; Deng, Xiaohong; Xu, Yongxin (Elsevier, 2018)Malan loess is a grayish yellow or brownish yellow, clastic, highly porous and brittle late Quaternary sediment formed by the accumulation of windblown dust. The present-day pore structure of Malan loess is crucial for ... -
Climate change and its influence on the Karst groundwater recharge in the Jinci Spring Region, Northern China
Jia, Zhenxing; Zang, Hongfei; Zheng, Xiuqing; Xu, Yongxin (MDPI, 2017)Due to climate change and human activities over the last fifty years, the spring flow volume of karst groundwater has sharply diminished in China. Climate change is one of the critical factors that initiates a series of ... -
A conceptual model for the development and management of the Cape Flats aquifer, South Africa
Adelana, Segun; Xu, Yongxin; Vrbka, Petr (Water Research Commission, 2010)This paper provides an integrated approach to the analysis of the geological, hydrological and hydrogeological characteristics of the Cape Flats: a coastal plain sand formed within the mountains of the Cape Town metropolitan ... -
Conservation status of large branchiopods in the Western Cape, South Africa
De Roeck, Els R.; VanSchoenwinkel, Bram J.; Day, Jenny A.; Xu, Yongxin; Raitt, Lincoln; Brendonck, Luc (Springer Verlag, 2007)Temporary wetlands are an ecologically and economically important habitat in South Africa. They harbor large branchiopods, known to be flagship species of nonpermanent aquatic habitats, and sensitive to land use changes. ... -
Editor’s message: Building capacity and partnerships towards sustainable utilization of groundwater in Africa
Xu, Yongxin (Springer, 2008)This Editor’s Message advises the international groundwater fraternity of new opportunities in hydrogeological developments in Africa. It is a fact that groundwater plays a vital role in socio-economic and ecological ... -
Effect of temperature on microorganisms and nitrogen removal in a multi-stage surface flow constructed wetland
Wang, Huiyong; Xu, Yongxin; Chai, Beibei (MDPI, 2023)The effect of low temperature on microbial nitrogen metabolism in constructed wetlands has yet to be extensively investigated. In this study, we analyzed the effects of temperature changes on nitrogen-associated microorganisms ... -
Estimation of recharge using a revised CRD method
Xu, Yongxin; van Tonder, Gerrit J. (Water Research Commission, 2001)The cumulative rainfall departure (CRD) method, based on the water-balance principle, is often used for mimicking of water level fluctuations. Because of its simplicity and minimal requirement of spatial data, the CRD ... -
Foreword to special section: groundwater in Africa
Bradbury, Kenneth R.; Xu, Yongxin (Wiley-Blackwell, 2010) -
Groundwater discharges to aquatic ecosystems associated with the Table Mountain Group (TMG) aquifer: a conceptual model
Roets, Wietsche; Xu, Yongxin; Raitt, Lincoln; Brendonck, Luc (Water Research Commission, 2008)This paper reports on a conceptual model that was developed to describe the different groundwater discharge ‘types’ from the Table Mountain Group (TMG) aquifer, that contributes to the different components of the flow ... -
Groundwater management issues in Southern Africa – An IWRM perspective
Braune, Eberhard; Xu, Yongxin (Water Research Commission, 2008)In contrast to its strategic role as essential resource to help achieve community development and poverty alleviation in the Southern African Development Community (SADC), groundwater has remained a poorly understood and ... -
A hydrogeomorphological approach to quantification of groundwater discharge to streams in South Africa
Xu, Yongxin; Holness, S.D.; Zhang, J.; van Tonder, Gerrit J. (Water Research Commission, 2002)In South Africa, the flow requirements for maintaining the normal functioning of aquatic ecosystems is termed the “ecological reserve”, and these should be determined when a licence application for water allocation is ... -
On the use of electrical resistivity methods in monitoring infiltration of salt fluxes in dry coal ash dumps in Mpumalanga, South Africa
Muchingami, Innocent; Nel, Jacobus; Xu, Yongxin; Steyl, Gideon; Reynolds, Kelley (Water Research Commission, 2013)One of the principal environmental concerns relating to coal combustion waste disposal is the potential for groundwater contamination from salt fluxes and trace elements that may be leached into the underlying groundwater ... -
Quantitative study on the changes of Karst groundwater level and hydrochemistry in Jinci spring catchment, Shanxi, China
Wang, Zhaoliang; Zhang, Zhixiang; Xu, Yongxin (Springer Nature, 2020)Since Jinci spring ceased to flow on April 30, 1994, it has never been reflowed, which seriously affects the sustainable utilization of karst groundwater. The purpose of this paper is to provide the basis for the reflow ... -
Reply to comment on “spatio-temporal variation of groundwater recharge in response to variability in precipitation, land use and soil in Yanqing Basin, Beijing, China
Pan, Yun; Gong, Huili; Xu, Yongxin (Springer Verlag, 2013) -
Review: groundwater management and groundwater/surface-water interaction in the context of South African water policy
Levy, Jonathan; Xu, Yongxin (Springer Verlag, 2011)Groundwater/surface-water interaction is receiv¬ing increasing focus in Africa due to its importance to ecologic systems and sustainability. In South Africa's 1998 National Water Act (NWA), water-use licenses, including ...