Your search found 8 records
1 Stricevic, R.; Pocuca, V.; Jovanovic, N.. 1992. Supplementary irrigation in semi-humid climatic region - irrigation scheduling problems. In CIHEAM. International Conference on "Supplementary irrigation and drought water management". Vol.1. Adana, Turkey: CIHEAM. pp.S1-3.1-S1-3.8.
Supplementary irrigation ; Irrigation scheduling ; Computer software ; Water requirements / Yugoslavia
(Location: IWMI-HQ Call no: 631.7.2 G000 CIH Record No: H012235)
2 Jovanovic, N.; Jovanovic, Z.; Stricevic, R.; Pocuca, V. 1992. Relative evapotranspiration, leaf water potential of a soybean crop in relation to soil water deficit. In CIHEAM. International Conference on "Supplementary irrigation and drought water management". Vol.3. Adana, Italy: CIHEAM. pp.S5-6.1-S5-6.11.
(Location: IWMI-HQ Call no: 631.7.2 G000 CIH Record No: H012339)
3 Rana, G.; Gigotti, R.; Mastrorilli, M.; Jovanovic, N.; Incarnato, D. 1992. Evapotranspiration measurement under drought conditions. In CIHEAM. International Conference on "Supplementary irrigation and drought water management". Vol.3. Adana, Italy: CIHEAM. pp.S5-7.1-S5-7.11.
(Location: IWMI-HQ Call no: 631.7.2 G000 CIH Record No: H012340)
4 Stirzaker, R.; Stevens, J.; Annandale, J.; Maeko, T.; Steyn, J.; Mpandeli, S.; Maurobane, W.; Nkgapele, J.; Jovanovic, N.. 2004. Building capacity in irrigation management with wetting front detectors. Pretoria, South Africa: Water Research Commission. 85p. (WRC Report No. TT 230/04)
Capacity building ; Irrigation management ; Drip irrigation ; Sprinkler irrigation ; Furrow irrigation ; Irrigation scheduling ; Small scale farming ; Farmers ; Helianthus annuus
(Location: IWMI HQ Call no: 631.7 G000 STI Record No: H044219)
http://www.wrc.org.za/Knowledge%20Hub%20Documents/Research%20Reports/TT230-04.pdf
https://vlibrary.iwmi.org/pdf/H044219.pdf
https://vlibrary.iwmi.org/pdf/H044219.pdf
(2.19 MB) (2.19MB)
Efficient use of water in the agricultural sector is an issue of national importance in South Africa and the science required to achieve this goal is relatively mature. However, a recent survey among commercial farmers showed that they ranked irrigation scheduling as priority number four or five amongst their major concerns. Most farmers are prepared to admit that their system is not perfect, but at least it works. After a period of trial and error they have settled on management system that satisfied them and they need a good reason to re-evaluate it. Small-scale farmers were preoccupied with issues such as their access to land, water, credit and markets and showed little awareness of the importance of water use efficiency. This project introduced a Wetting Front Detector to farmers with the purpose of stimulating a re-think about irrigation management on their farms. The Wetting Front Detector (WFD) was designed to be the simplest tool that could assist farmers to improve their understanding of irrigation. To achieve this aim, the wetting front detector must pass two tests. First, the device itself and how it works must make intuitive sense to farmers. It should be relatively easy to install and give “believable” results that challenge the farmer’s perceptions. Second it must pass the accuracy test. We have to demonstrate that crops irrigated according to the principles of the Wetting Front Detector perform adequately against standard scientific procedures. A combination of research and extension was employed to satisfy these objectives.
5 Walker, D.; Jovanovic, N.; Bugan, R.; Abiye, T.; du Preez, D.; Parkin, G.; Gowing, J. 2018. Alluvial aquifer characterisation and resource assessment of the Molototsi sand river, Limpopo, South Africa. Journal of Hydrology: Regional Studies, 19:177-192. [doi: https://doi.org/10.1016/j.ejrh.2018.09.002]
Alluvial aquifers ; Groundwater recharge ; Resource management ; Rivers ; Groundwater table ; Boreholes ; Water storage ; Water quality ; Hydrology ; Hydraulic conductivity ; Models ; Catchment areas ; Rain / South Africa / Limpopo / Molototsi Sand River
(Location: IWMI HQ Call no: e-copy only Record No: H048914)
https://www.sciencedirect.com/science/article/pii/S2214581818301125/pdfft?md5=1764e9c0a4f0d0074b1aa4ae135626f1&pid=1-s2.0-S2214581818301125-main.pdf
https://vlibrary.iwmi.org/pdf/H048914.pdf
https://vlibrary.iwmi.org/pdf/H048914.pdf
(4.19 MB) (4.19 MB)
Study region: Molototsi sand river, Limpopo, South Africa.
Study focus: Ephemeral sand rivers are common throughout the world’s dryland regions, often providing a water source where more conventional sources are unavailable. However, these alluvial aquifers are poorly represented in the literature. Extensive field investigations allowed estimation of stored water volume and characterisation of an alluvial aquifer.
New hydrological insights for the region: Computed alluvial aquifer properties included hydraulic conductivity of 20–300 m/d, porosity of 38–40%, and aquifer thickness of 0–6 m. Dykes and other subcrops commonly compartmentalise the aquifer though do not form barriers to flow. A hydraulic disconnect between deep groundwater (occurring in fractured metamorphic rocks) and the alluvial aquifer was revealed by groundwater levels and contrasting hydrochemistry and stable isotope signatures. The dominant recharge process of the alluvial aquifer is surface runoff occurring from torrential tributaries in the catchment’s upper reaches. A fraction of available storage is currently abstracted and there exists potential for greater exploitation for smallholder irrigation and other uses.
Study focus: Ephemeral sand rivers are common throughout the world’s dryland regions, often providing a water source where more conventional sources are unavailable. However, these alluvial aquifers are poorly represented in the literature. Extensive field investigations allowed estimation of stored water volume and characterisation of an alluvial aquifer.
New hydrological insights for the region: Computed alluvial aquifer properties included hydraulic conductivity of 20–300 m/d, porosity of 38–40%, and aquifer thickness of 0–6 m. Dykes and other subcrops commonly compartmentalise the aquifer though do not form barriers to flow. A hydraulic disconnect between deep groundwater (occurring in fractured metamorphic rocks) and the alluvial aquifer was revealed by groundwater levels and contrasting hydrochemistry and stable isotope signatures. The dominant recharge process of the alluvial aquifer is surface runoff occurring from torrential tributaries in the catchment’s upper reaches. A fraction of available storage is currently abstracted and there exists potential for greater exploitation for smallholder irrigation and other uses.
6 Clothier, B.; Jovanovic, N.; Zhang, X. 2020. Reporting on water productivity and economic performance at the water-food nexus. Agricultural Water Management, 106123 (Online first) [doi: https://doi.org/10.1016/j.agwat.2020.106123]
(Location: IWMI HQ Call no: e-copy only Record No: H049586)
(0.15 MB)
It is imperative that there be consistent and unambiguous terminology when reporting on irrigation water use, and that the metrics of water productivity and economic benefits be clearly defined. We encourage our readers to study closely the following paper by our colleagues on the definitions and uses of various water-use indicators, along with their use in economic analyses.
7 Jovanovic, N.; Pereira, L. S.; Paredes, P.; Pocas, I.; Cantore, V.; Todorovic, M. 2020. A review of strategies, methods and technologies to reduce non-beneficial consumptive water use on farms considering the FAO56 methods. Agricultural Water Management, 239:106267. (Online first) [doi: https://doi.org/10.1016/j.agwat.2020.106267]
Water use efficiency ; Irrigation management ; Irrigation methods ; Remote sensing ; Soil management ; Water scarcity ; Water stress ; Water conservation ; Crop water use ; Water requirements ; Evapotranspiration ; Water productivity ; Deficit irrigation ; Irrigation systems ; Sprinkler irrigation ; Drip irrigation ; Irrigation scheduling ; Mulching ; Models
(Location: IWMI HQ Call no: e-copy only Record No: H049833)
(0.97 MB)
In the past few decades, research has developed a multitude of strategies, methods and technologies to reduce consumptive water use on farms for adaptation to the increasing incidence of water scarcity, agricultural droughts and multi-sectoral competition for water. The adoption of these water-saving practices implies accurate quantification of crop water requirements with the FAO56 crop coefficient approach, under diverse water availability and management practices. This paper critically reviews notions and means for maintaining high levels of water consumed through transpiration, land and water productivity, and for minimizing non-beneficial water consumption at farm level. Literature published on sound and quantified experimentation was used to evaluate water-saving practices related to irrigation methods, irrigation management and scheduling, crop management, remote sensing, plant conditioners, mulching, soil management and micro-climate regulation. Summary tables were developed on the benefits of these practices, their effects on non-beneficial water consumption, crop yields and crop water productivity, and the directions for adjustment of FAO56 crop coefficients when they are adopted. The main message is that on-farm application of these practices can result in water savings to a limited extent (usually <20%) compared to sound conventional practices, however this may translate into large volumes of water at catchment scale. The need to streamline data collection internationally was identified due to the insufficient number of sound field experiments and modelling work on the FAO56 crop water requirements that would allow an improved use of crop coefficients for different field conditions and practices. Optimization is required for the application of some practices that involve a large number of possible combinations (e.g. wetted area in micro-irrigation, row spacing and orientation, plant density, different types of mulching, in-field water harvesting) and for strategies such as deficit irrigation that aim at balancing water productivity, the economics of production, infrastructural and irrigation system requirements. Further research is required on promising technologies such as plant and soil conditioners, and remote sensing applications.
8 Gaffoor, Z.; Pietersen, K.; Jovanovic, N.; Bagula, A.; Kanyerere, T. 2020. Big data analytics and its role to support groundwater management in the Southern African development community. Water, 12(10):2796. (Special issue: The Application of Artificial Intelligent in Hydrology) [doi: https://doi.org/10.3390/w12102796]
Groundwater management ; Data analysis ; SADC countries ; International waters ; Aquifers ; Data mining ; Machine learning ; Remote sensing ; Monitoring ; Technology ; Hydrological data ; Water levels ; Water storage ; Uncertainty ; Precipitation ; Social media ; Models / Southern Africa
(Location: IWMI HQ Call no: e-copy only Record No: H050040)
(1.58 MB) (1.58 MB)
Big data analytics (BDA) is a novel concept focusing on leveraging large volumes of heterogeneous data through advanced analytics to drive information discovery. This paper aims to highlight the potential role BDA can play to improve groundwater management in the Southern African Development Community (SADC) region in Africa. Through a review of the literature, this paper defines the concepts of big data, big data sources in groundwater, big data analytics, big data platforms and framework and how they can be used to support groundwater management in the SADC region. BDA may support groundwater management in SADC region by filling in data gaps and transforming these data into useful information. In recent times, machine learning and artificial intelligence have stood out as a novel tool for data-driven modeling. Managing big data from collection to information delivery requires critical application of selected tools, techniques and methods. Hence, in this paper we present a conceptual framework that can be used to manage the implementation of BDA in a groundwater management context. Then, we highlight challenges limiting the application of BDA which included technological constraints and institutional barriers. In conclusion, the paper shows that sufficient big data exist in groundwater domain and that BDA exists to be used in groundwater sciences thereby providing the basis to further explore data-driven sciences in groundwater management.
Powered by DB/Text WebPublisher, from
