Your search found 22 records
1 Shalhevet, J.; Liu, C.; Xu, Y.. (Eds.) 1992. Water use efficiency in agriculture: Proceedings of the Binational China-Israel Workshop, Beijing, China, 22-26 April 1991. Rehovot, Israel: Priel Publishers. v, 297p.
(Location: IWMI-HQ Call no: 631.7.2 G592 SHA Record No: H011001)
2 Xu, Y.. 1992. The utilization rate of irrigation water and the effects of irrigation on the environment in the North China Plain. In Shalhevet, J.; Liu, C.; Xu, Y. (Eds.) Water use efficiency in agriculture: Proceedings of the Binational China-Israel Workshop, Beijing, China, 22-26 April 1991. Rehovot, Israel: Priel Publishers. pp.78-89.
(Location: IWMI-HQ Call no: 631.7.2 G592 SHE Record No: H011006)
3 Xu, Y.. 1990. Water resources development in the North China Plain and its effects on the environment. International Journal of Water Resources Development, 6(2):137-142.
(Location: IWMI-HQ Call no: P 2307 Record No: H011064)
4 Wright, K. A.; Xu, Y.. 2000. A water balance approach to the sustainable management of groundwater in South Africa. Water SA, 26(2):167-170.
Water balance ; Groundwater management ; Sustainability ; Legislation ; Recharge ; Water use ; Ecology ; Models / South Africa
(Location: IWMI-HQ Call no: P 5904 Record No: H029132)
5 Lin, S.; Dittert, K.; Tao, H.; Kreye, C.; Xu, Y.; Shen, Q.; Fan, X.; Sattelmacher, B. 2002. The ground-cover rice production system (GCRPS): a successful new approach to save water and increase nitrogen fertilizer efficiency? In Bouman, B. A. M.; Hengsdijk, H.; Hardy, B.; Bindraban, P. S.; Tuong, T. P.; Ladha, J. K. (Eds.), Water-wise rice production. Los Baños, Philippines: International Rice Research Institute (IRRI). pp.187-195.
Rice ; Nitrogen ; Fertilizers ; Water balance ; Water use efficiency / China / Beijing / Nanjing / Guangzhou
(Location: IWMI-HQ Call no: 631.7.2 G000 BOU Record No: H032428)
(3 MB)
6 Xu, Y.; van Tonder, G. J. 2001. Estimation of recharge using a revised CRD method. Water SA, 27(3):341-343.
(Location: IWMI-HQ Call no: P 7109 Record No: H035994)
7 Xu, Y.; Beekman, H. E. (Eds.) 2003. Groundwater recharge estimation in Southern Africa. Paris, France: UNESCO. ii, 207p. (UNESCO IHP series no.64)
Groundwater ; Aquifers ; Recharge ; Estimation ; Models ; Stream flow ; Catchment areas ; Rain ; Climate change ; Water resource management / Southern Africa
(Location: IWMI-HQ Call no: 553.79 G154 XU Record No: H036991)
8 Beekman, H. E.; Xu, Y.. 2003. Review of groundwater recharge estimation in arid and semi-arid Southern Africa. In Xu, Y.; Beekman, H. E. (Eds.), Groundwater recharge estimation in Southern Africa. Paris, France: UNESCO. pp.3-18.
(Location: IWMI-HQ Call no: 553.79 G154 XU Record No: H036992)
9 Bredenkamp, D. B.; Xu, Y.. 2003. Perspectives on recharge estimation in dolomitic aquifers in South Africa. In Xu, Y.; Beekman, H. E. (Eds.), Groundwater recharge estimation in Southern Africa. Paris, France: UNESCO. pp.65-79.
(Location: IWMI-HQ Call no: 553.79 G154 XU Record No: H036996)
10 Xu, Y.; Beekman, H. E. 2003. A box model for estimating recharge – The RIB method. In Xu, Y.; Beekman, H. E. (Eds.), Groundwater recharge estimation in Southern Africa. Paris, France: UNESCO. pp.81-88.
(Location: IWMI-HQ Call no: 553.79 G154 XU Record No: H036997)
11 Xu, Y.; Maclear, L. G. A. 2003. Recharge estimation in fractured rock aquifer from rainfall – spring flow comparisons: The Uitenhage Spring case. In Xu, Y.; Beekman, H. E. (Eds.), Groundwater recharge estimation in Southern Africa. Paris, France: UNESCO. pp.125-134.
Aquifers ; Groundwater ; Recharge ; Estimation ; Water balance / South Africa / Uitenhage Spring / Coega Ridge Aquifer
(Location: IWMI-HQ Call no: 553.79 G154 XU Record No: H037000)
12 Xu, Y.; Wu, Y.; Beekman, H. E. 2003. The role of interflow in estimating recharge in mountainous catchments. In Xu, Y.; Beekman, H. E. (Eds.), Groundwater recharge estimation in Southern Africa. Paris, France: UNESCO. pp.135-145.
Catchment areas ; Mountains ; Recharge ; Estimation ; Hydrology ; Groundwater ; Flow ; Water balance / South Africa / Vermaaks River Valley
(Location: IWMI-HQ Call no: 553.79 G154 XU Record No: H037001)
13 van Tonder, G. J.; Botha, J. F.; Chiang, W. H.; Kunstmann, H.; Xu, Y.. 2001. Estimation of the sustainable yields of boreholes in fractured rock formations. Journal of Hydrology, 241:70-90.
(Location: IWMI-HQ Call no: PER Record No: H037874)
14 Xu, Y.; Mo, X.; Cai, Y.; Li, X. 2005. Analysis on groundwater table drawdown by land use and the quest for sustainable water use in the Hebei Plain in China. Agricultural Water Management, 75(1):38-53.
(Location: IWMI-HQ Call no: PER Record No: H036920)
15 Nonterah, C.; Xu, Y.; Osae, S. 2019. Groundwater occurrence in the Sakumo Wetland Catchment, Ghana: model-setting-scenario approach. Hydrogeology Journal, 27(3):983-996. [doi: https://doi.org/10.1007/s10040-019-01959-4]
Groundwater flow ; Wetlands ; Catchment areas ; Models ; Aquifers ; Water levels ; Groundwater recharge ; Hydrogeology ; Precipitation / Africa South of Sahara / Ghana / Accra / Sakumo Wetland Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H049346)
(3.25 MB)
Water flow is required for the health and integrity of any wetland environment. Based on field investigation, flow simulation and hydrogeological data, a conceptual flow model representing the physical characteristics of the Sakumo wetland (Ghana) was developed. Two major flow systems were identified: interflow (local topsoil water) in the alluvium and shallow groundwater flow in the unconfined unit. A simple two-dimensional finite-difference numerical model was applied to analyse the groundwater flow system in the Sakumo wetland catchment using ModelMuse. The purpose of the model was to explain the groundwater flow system and quantify the water fluxes contributing to the wetland water storage. The main source of groundwater for use in the catchment is the shallow unconfined Quaternary aquifer. The modelling results indicate that changes in recharge significantly affect the wetland water balance. The water table declines during the dry season as there is high evapotranspiration with little rain. The modelling results also confirm that the Sakumo wetland water fluxes are predominately associated with local shallow flows; the calibrated model simulation showed no hydraulic link between the wetland and the underlying deep basement aquifer. This study thus provides valuable hydrogeological information on the Sakumo wetland basin and lays the foundation for development of detailed future predictive models in this under-researched area of hydrogeology in the humid tropics.
16 Olivier, D. W.; Xu, Y.. 2019. Making effective use of groundwater to avoid another water supply crisis in Cape Town, South Africa. Hydrogeology Journal, 27(3):823-826. [doi: https://doi.org/10.1007/s10040-018-1893-0]
Water supply ; Groundwater management ; Water resources ; Legislation ; Water governance ; Water scarcity ; Drought ; Resilience ; Planning / Africa South of Sahara / South Africa / Cape Town
(Location: IWMI HQ Call no: e-copy only Record No: H049350)
(0.42 MB)
The infamous drought of 2015–2017 in Cape Town (South Africa) provides important lessons on water governance. While it is undeniable that an unprecedented sequence of two record-low rainfall years instigated the ‘water crisis’, this essay argues that the severity of the drought may have been mitigated by good governance, both in terms of diversifying water sources and managing existing supplies. Historically, water authorities have focussed on surface-water resources for Cape Town’s water supply. Cape Town’s ample groundwater has not been utilised to any notable extent. It is concluded that the crisis, once passed, may be viewed as auspicious, for not only did it provide the impetus to adapt Cape Town’s water supply, thereby better incorporating its groundwater resources, but the crisis stands as a case in point to justify future investments in water security, not only for Cape Town, but for other cities as well.
17 Matengu, B.; Xu, Y.; Tordiffe, E. 2019. Hydrogeological characteristics of the Omaruru Delta Aquifer System in Namibia. Hydrogeology Journal, 27(3):857-883. [doi: https://doi.org/10.1007/s10040-018-1913-0]
Aquifers ; Deltas ; Hydrogeology ; Groundwater recharge ; Artificial recharge ; Catchment areas ; Groundwater table ; Groundwater flow ; Water balance ; Coastal area ; Sediment ; Sustainability / Africa South of Sahara / Namibia / Omaruru Delta Aquifer System / Omdel Aquifer / Omaruru River
(Location: IWMI HQ Call no: e-copy only Record No: H049357)
https://link.springer.com/content/pdf/10.1007%2Fs10040-018-1913-0.pdf
https://vlibrary.iwmi.org/pdf/H049357.pdf
https://vlibrary.iwmi.org/pdf/H049357.pdf
(2.77 MB) (2.77 MB)
Sustainable utilization of groundwater in parts of hyper-arid Sub-Saharan Africa, like the Namib Desert, is always a challenge due to lack of resources and data. For the Omdel Aquifer in the Omaruru catchment, Namibia, issues to investigate include the lack of information on the geology and hydrogeological setting, the hydraulic properties and geometry of the aquifer at the inflow and outflow sections, groundwater recharge conditions upstream of the aquifer, and the impact of artificial recharge. In this desert environment, the methods applied are hydrogeological surveys and site visits, together with interpretation of geological, hydrological and geomorphological data from investigations carried out to define the hydrogeological characteristics of the Omdel Aquifer. The bedrock geometry of the aquifer indicates that the Main channel (one of four palaeochannels) is the largest reservoir of stored fresh groundwater, estimated at 133 Mm3, and it is deeper than the other three channels, with an average sediment thickness of 80 m. All groundwater chemistry facies of the selected boreholes tapping the Omdel Aquifer reveal a NaCl character, indicating a coastal environment. The yield of the Omdel Aquifer is estimated to have increased from 2.8 Mm3/year before construction of a recharge enhancement dam to 4.6 Mm3/year after the construction. This paper focuses on the understanding of hydrogeological characteristics of the Omaruru Delta Aquifer System in terms of groundwater recharge and discharge, groundwater dynamics within the aquifer and groundwater chemistry, in order to assess whether the current abstractions are operating within the hydrogeological limits of sustainability.
18 Seward, P.; Xu, Y.. 2019. The case for making more use of the ostrom design principles in groundwater governance research: a South African perspective. Hydrogeology Journal, 27(3):1017-1030. (Special issue: Groundwater in Sub-Saharan Africa) [doi: https://doi.org/10.1007/s10040-018-1899-7]
Groundwater management ; Water governance ; Research ; Water resources ; Water user associations ; Monitoring ; Institutions ; Sustainability ; Socioeconomic environment ; Case studies / Africa South of Sahara / South Africa
(Location: IWMI HQ Call no: e-copy only Record No: H049359)
https://link.springer.com/content/pdf/10.1007%2Fs10040-018-1899-7.pdf
https://vlibrary.iwmi.org/pdf/H049359.pdf
https://vlibrary.iwmi.org/pdf/H049359.pdf
(0.68 MB) (692 KB)
This study investigates whether increased use of the Ostrom design principles could improve groundwater governance research. The principles relate to self-organizing governance systems of common-pool resources, which are more likely to be sustainable if all eight design principles—e.g. clear resource and user boundaries, collective-choice arrangements, monitoring, sanctions, conflict-resolution mechanisms—are present. Empirical studies have proven the relevance and effectiveness of the Ostrom design principles for a range of common-pool resources. However, the application of the design principles to groundwater has been limited. The South African institutional landscape was therefore chosen as a case study to investigate the relevance of the design principles. The case study involved (1) comparing the design principles with established global governance benchmarking criteria, (2) assessing how implementable the design principles would be in South Africa, and (3) comparing the aims of the design principles and the broad aims of groundwater governance in South Africa. It was found that the Ostrom design principles provide researchers with a common ‘language’ for learning about the specific issues of a particular setting, learning from experiments in that setting, and learning from the experience of others. The Ostrom design principles and associated adaptive management, social learning, use of the diagnostic approach, and more specific hydrogeological principles are not mutually exclusive and can be complimentary. The implementation of groundwater governance in South Africa has been poor and few Ostrom design principles have been adopted. More use of the Ostrom design principles could improve groundwater governance in South Africa and globally.
19 Pienaar, H.; Xu, Y.; Braune, E.; Cao, J.; Dzikiti, S.; Jovanovic, N. Z. 2021. Implementation of groundwater protection measures, particularly resource-directed measures in South Africa: a review paper. Water Policy, 16p. (Online first) [doi: https://doi.org/10.2166/wp.2021.016]
Groundwater management ; Water resources ; Water conservation ; Water governance ; Institutions ; Legislation ; Strategies ; Aquifers ; Water levels ; Surface water ; Catchment areas ; Water supply ; Water use ; Monitoring / South Africa
(Location: IWMI HQ Call no: e-copy only Record No: H050458)
https://iwaponline.com/wp/article-pdf/doi/10.2166/wp.2021.016/904391/wp2021016.pdf
https://vlibrary.iwmi.org/pdf/H050458.pdf
https://vlibrary.iwmi.org/pdf/H050458.pdf
(0.96 MB) (980 KB)
This review paper on groundwater protection measures in South Africa focuses on the actual implementation of groundwater protection measures, in particular, the resource-directed measures (RDM) as described in Chapter 3 of the National Water Act (NWA). Significant catchment-wide implementation of RDM has taken place in a phased manner throughout various catchments since 2012. By 2015, approximately R380 million had been expended on the catchment-wide implementation of the water resource protection measures over a period of 15 years. Considerable effort went into refining the RDM methodology, taking into account the groundwater component of the overall resource. In this paper, we contend that RDM, in its present form, will not make a significant contribution to groundwater resource protection and security in the country. This is a major concern because the Groundwater Strategy of the Department of Human Settlements, Water and Sanitation (DHSWS) had declared the protection of groundwater as a national priority. This paper also examines institutional and governance arrangements (or lack thereof) as well as providing recommendations to support the effective implementation of groundwater protection provisions as prescribed by South Africa's water legislation.
20 Qiao, X.; Schmidt, A. H.; Xu, Y.; Zhang, H.; Chen, X.; Xiang, R.; Tang, Y.; Wang, W. 2021. Surface water quality in the upstream-most megacity of the Yangtze River Basin (Chengdu): 2000–2019 trends, the COVID-19 lockdown effects, and water governance implications. Environmental and Sustainability Indicators, 10:100118. [doi: https://doi.org/10.1016/j.indic.2021.100118]
Surface water ; Water quality ; Water management ; River basins ; Water governance ; COVID-19 ; Urban areas ; Water pollution ; Faecal coliforms ; Nitrogen ; Phosphorus ; Economic growth ; Downstream ; Monitoring / China / Yangtze River Basin / Chengdu / Sichuan Basin / Min Basin / Tuo Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050539)
https://www.sciencedirect.com/science/article/pii/S2665972721000192/pdfft?md5=019ccf161166ca9e1fe600744729056a&pid=1-s2.0-S2665972721000192-main.pdf
https://vlibrary.iwmi.org/pdf/H050539.pdf
https://vlibrary.iwmi.org/pdf/H050539.pdf
(2.99 MB) (2.99 MB)
Water is essential for a sustainable economic prosperity, but rapid economic growth and intensive agricultural activities usually cause water pollution. The middle and lower reaches of China’s Yangtze River Basin were urbanized and industrialized much earlier than the upper reach and have been suffering from water pollution. In the past two decades, economic growth accelerated in the upper reach due to several national economic initiatives. Based on analyzing water quality changes from 2000 to 2019 and during the COVID-19 lockdown in 2020 for Chengdu in the upper reach, we hope to provide some water governance suggestions. In 2019, water at 66% of 93 sites in Chengdu did not achieve the national III standards using measurements of 23 water quality parameters. The top two pollutants were total nitrogen (TN) and fecal coliform (FC). From 2000 to 2019, water quality was not significantly improved at the non-background sites of Chengdu's Min Basin, and the pollution in this basin was mainly from local pollutants release. During the same period, water quality deteriorated in Chengdu’s Tuo Basin, where pollution was the result of pollutant discharges in Chengdu in addition to inter-city pollutant transport. During the COVID-19 lockdown, water quality generally improved in the Min Basin but not in the Tuo Basin. A further investigation on which pollution sources were shut down or not during the lockdown can help make pollution reduction targets. Based on the results, we provide suggestions to strengthen inter-jurisdictional and inter-institutional cooperation, water quality monitoring and evaluation, and ecological engineering application.
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