List of Titles

The Role of Ecological Infrastructure (EI) in Mitigating the Impacts of Droughts

- Mantel, Sukhmani K, Xoxo, Sinetemba, Mahlaba, Bawinile, Tanner, Jane L, Le Maître, David

Authors: Mantel, Sukhmani K , Xoxo, Sinetemba , Mahlaba, Bawinile , Tanner, Jane L , Le Maître, David
Date: 2021
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438209 , vital:73443 , ISBN 978-0-6392-0304-1 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2928_web.pdf
Description: To explain how well-managed ecological infrastructure can help to miti-gate the impacts of droughts on human livelihoods and well-being and to propose strategic responses that will maintain and enhance the value of this service that people will embrace and implement.
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Date Issued: 2021

Impacts of Climate Change in Determining the Ecological Reserve

- Tanner, Jane L, Griffin, Neil J, Slaughter, Andrew R, Mantel, Sukhmani K, Dabula, Pumza, Hughes, Denis A, Wolff, Margaret G

Authors: Tanner, Jane L , Griffin, Neil J , Slaughter, Andrew R , Mantel, Sukhmani K , Dabula, Pumza , Hughes, Denis A , Wolff, Margaret G
Date: 2020
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438128 , vital:73437 , ISBN 978-0-6392-0124-5 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2834 final.pdf
Description: The intermediate and long-term impacts of climate change require evaluation of the adaptive capacity of the riverine ecosystems to pro-mote sustainability. The predicted climate change impacts are the moti-vation behind the current research which targets the knowledge gap of the impacts of climate change on the ecological Reserve (or Ecological Water Requirements [EWR]). In order for the Department of Water and Sanitation (DWS) to meet their mandate to protect aquatic ecosystems, given the constraints of climate change, it is necessary to take cogni-sance of the implications of climate change and to make the necessary adjustments and changes to the ecological Reserve determination methodology. These adjustments will help ensure that sufficient water, at the right time, distributed in the right flow pattern and of adequate quality is provided, so that key ecological processes are sustained, and that biotic communities maintain their health and integrity.
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Date Issued: 2020

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Measuring and modelling evapotranspiration in a South African grassland: Comparison of two improved Penman-Monteith formulations

- Gwate, Onalenna, Mantel, Sukhmani K, Palmer, Anthony R, Gibson, Lesley A, Munch, Zahn

Authors: Gwate, Onalenna , Mantel, Sukhmani K , Palmer, Anthony R , Gibson, Lesley A , Munch, Zahn
Date: 2019
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438167 , vital:73440 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/44_03_16_3530.pdf
Description: Accurately measuring evapotranspiration (ET) is important in the con-text of global atmospheric changes and for use with climate models. Direct ET measurement is costly to apply widely and local calibration and validation of ET models developed elsewhere improves confidence in ET derived from such models. is study sought to compare the per-formance of the Penman-Monteith-Leuning (PML) and Penman-Monteith-Palmer (PMP) ET models, over mesic grasslands in two study sites in South Africa. The study used routine meteorological data from a scientific-grade automatic weather station (AWS) to apply the PML and PMP models. The PML model was calibrated at one site and validated in both sites. On the other hand, the PMP model does not require cali-bration and hence it was validated in both sites.
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Date Issued: 2019

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Rehabilitation of grasslands after eradication of alien invasive trees

- Palmer, Anthony R, Gwate, Onalenna, Gushaa, Bukho, Gibson, Lesley A, Münch, Zahn, Mantel, Sukhmani K, Murata, Chenai, de Wet, Chris, Zondani, Thantaswa, Perry, Adam

Authors: Palmer, Anthony R , Gwate, Onalenna , Gushaa, Bukho , Gibson, Lesley A , Münch, Zahn , Mantel, Sukhmani K , Murata, Chenai , de Wet, Chris , Zondani, Thantaswa , Perry, Adam
Date: 2019
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438195 , vital:73442 , ISBN 978-0-6392-0098-9 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT 786_final web.pdf
Description: Invasive alien plants (IAPs) remain a serious threat to the water supply and to stor-age reservoirs throughout South Africa. IAPs are known to use a large quantity of water through evapotranspiration, and the clearing and control of IAPs has been a major activity of the Working for Water (WfW) programme. Successful clearing of these often aggressive woody trees and shrubs requires careful regeneration of ef-fective indigenous vegetation cover after the physical clear-felling and removal of the IAPs. Application of effective post-clearing management regimes is required in order to improve the grass cover within catchments and this can ensure that there is controlled runoff and groundwater re-charge. South Africa's water catchment areas receive insufficient rainfall (Blignaut and De Wit 2004). In addition, limited options for the construction of new reservoirs and water schemes has stimulated the need to explore other options for increasing and conserving water supplies (Ashton and Seetal 2002) and improved demand management.
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Date Issued: 2019

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Extending functionality and knowledge transfer of the Water Quality Systems Assessment Model

- Slaughter, Andrew R, Gwapedza, David, Mantel, Sukhmani K, Hughes, Denis A, Griffin, Neil J

Authors: Slaughter, Andrew R , Gwapedza, David , Mantel, Sukhmani K , Hughes, Denis A , Griffin, Neil J
Date: 2018
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438115 , vital:73436 , ISBN 978-0-6392-0059-0 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2448_final.pdf
Description: This report has been generated by the Water Research Commission (WRC) funded project Developing Climate Change Adaptation Measures and Decision-Support System for Selected South African Water Boards (Project No. K5/2018).
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Date Issued: 2018

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Land cover models to predict non-point nutrient inputs for selected biomes in South Africa

- Slaughter, Andrew R, Mantel, Sukhmani K

Authors: Slaughter, Andrew R , Mantel, Sukhmani K
Date: 2017
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438152 , vital:73439 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/3390.pdf
Description: WQSAM is a practical water quality model for use in guiding southern African water quality management. However, the estimation of non-point nutrient inputs within WQSAM is uncertain, as it is achieved through a combination of calibration and expert knowledge. Non-point source loads can be correlated to particular land cover types. Although observed water quality data through which non-point source loads can be estimated are scarce, land cover databases exist covering the entire area of South Africa. To reduce the uncertainty associated with estimat-ing non-point source loads, this study describes a formal model to link the nutrient signatures of incremental flow to land cover. Study catch-ments incorporating the fynbos, grassland, savanna and thicket biomes were identified. Instream nutrients of 25 sites were modelled using WQSAM and calibrated against observed data. Multiple regression was used to investigate the relationships between the calibrated nutrient signatures of incremental flow from WQSAM and land cover within study sites. The regression models reflected greater non-point loads from cultivation-and urban-related land cover categories. The nutrient signatures of incremental flow obtained through the multiple regres-sions were consistent with those obtained through calibration of the WQSAM model at higher signature values, whereas discrepancies were evident at lower values. It is argued that this formal modelling ap-proach for linking land cover to nutrient signatures of incremental flow can be implemented for situations where it is known that there are strong non-point inputs of nutrients into a river reach. The statistical model presented in the current study could potentially be applied as an alternative to the water quality model as a relatively simple method to estimate non-point source loads of nutrients from tributary catchments in South Africa.
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Date Issued: 2017

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Informing the Responses of Water Service Delivery Institutions to Climate and Development Changes: A Case Study in the Amatole Region, Eastern Cape

- Hughes, Denis A, Mantel, Sukhmani K, Slaughter, Andrew R

Authors: Hughes, Denis A , Mantel, Sukhmani K , Slaughter, Andrew R
Date: 2014
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438140 , vital:73438 , ISBN 978-1-4312-0520-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2018-1-14.pdf
Description: This report has been generated by the Water Research Commission (WRC) funded project Developing Climate Change Adaptation Measures and Decision-Support System for Selected South African Water Boards (Project No. K5/2018).
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Date Issued: 2014

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Prediction of water temperature metrics using spatial modelling in the Eastern and Western Cape, South Africa

- Rivers-Moore, Nick A, Mantel, Sukhmani K, Dallas, Helen F

Authors: Rivers-Moore, Nick A , Mantel, Sukhmani K , Dallas, Helen F
Date: 2012
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438180 , vital:73441 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2651.pdf
Description: Key aspects of a river’s temperature regime are described by magnitudes, timing and durations of thermal events, and frequencies of extreme exceedance events. To understand alterations to thermal regimes, it is necessary to describe thermal time series based on these statistics. Classification of sites based on their thermal met-rics, and understanding of spatial patterns of these thermal statistics, provides a powerful approach for comparing study sites against reference sites. Water tem-perature regime dynamics should be viewed regionally, where regional divisions have an inherent underpinning by an understanding of natural thermal variability. The aim of this research was to link key water temperature metrics to readi-lymapped environmental surrogates, and to produce spatial images of temperature metrics: 37 temperature metrics were derived for 12 months of sub-daily water temperatures at 90 sites in the Eastern Cape and Western Cape provinces, South Africa.
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Date Issued: 2012

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Evaluating The Potential Contribution Of Episodic Toxicity Data To Environmental Water Quality Management In South Africa

- Gordon, Andrew K, Mantel, Sukhmani K, Muller, Nikite W J

Authors: Gordon, Andrew K , Mantel, Sukhmani K , Muller, Nikite W J
Date: 2011
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438310 , vital:73450 , ISBN 978-1-4312-0070-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV259-10.pdf
Description: An important aspect of the dynamics of nutrients and pollutants in natural systems is captured in the concept of allochthony, founded on the observation that nutrients and energy in a variety of forms are transferred between adjacent habitats, com-munities and ecosystems that are not routinely considered as connected. Different forms of nutrients and energy move across the conceptual boundaries of habitats via organisms’ activities or physical processes such as wind or water currents, and these transfers can represent important food subsidies. Such cross-partition ecolog-ical subsidies can augment the nutritional condition, biomass and biodiversity of communities, particularly where local production (or autochthony) alone may be inadequate to support local food webs. Furthermore, organic subsidies can influ-ence population dynamics, community interactions and ecosystem processes, and can represent dominant flux inputs in ecosystem budgets. Our intention was to explore organic nutrient fluxes in relation to a primarily lotic (i.e. flowing) aquatic sys-tem at the scale of a hydrological catchment.
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Date Issued: 2011

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Ecological impacts of small dams on South African rivers Part 1: Drivers of change–water quantity and quality

- Mantel, Sukhmani K, Hughes, Denis A, Muller, Nikite W J

Authors: Mantel, Sukhmani K , Hughes, Denis A , Muller, Nikite W J
Date: 2010
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438099 , vital:73435 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2398.pdf
Description: Impacts of large dams are well-known and quantifiable, while small dams have generally been perceived as benign, both socially and envi-ronmentally. The present study quantifies the cumulative impacts of small dams on the water quality (physico-chemistry and invertebrate biotic indices) and quantity (discharge) of downstream rivers in 2 South African regions. The information from 2 South African national data-bases was used for evaluating the cumulative impacts on water quality and quantity. Physico-chemistry and biological data were obtained from the River Health Programme, and discharge data at stream flow gauges was obtained from the Hydrological Information System. Multivariate analyses were conducted to establish broad patterns for cumulative impacts of small dams across the 2 regions–Western Cape (winter rain-fall, temperate, south-western coast) and Mpumalanga (summer rain-fall, tropical, eastern coast). Multivariate analyses found that the chang-es in macroinvertebrate indices and the stream’s physico-chemistry were more strongly correlated with the density of small dams in the catchment (as a measure of cumulative impact potential) relative to the storage capacity of large dams. T-tests on the data, not including sam-ples with upstream large dams, indicated that the high density of small dams significantly reduced low flows and increased certain physico-chemistry variables (particularly total dissolved salts) in both the re-gions, along with associated significant reductions in a macroinverte-brate index (SASS4 average score per taxon). Regional differences were apparent in the results for discharge reductions and the macroin-vertebrate index. The results suggest that the cumulative effect of a high number of small dams is impacting the quality and quantity of wa-ters in South African rivers and that these impacts need to be systemat-ically incorporated into the monitoring protocol of the environmental wa-ter requirements.
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Date Issued: 2010

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Ecological impacts of small dams on South African rivers Part 2: Biotic response–abundance and composition of macroinvertebrate communities

- Mantel, Sukhmani K, Muller, Nikite W J, Hughes, Denis A

Authors: Mantel, Sukhmani K , Muller, Nikite W J , Hughes, Denis A
Date: 2010
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438087 , vital:73434 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2354.pdf
Description: This paper investigates the cumulative impacts of small dams on inver-tebrate communities in 2 regions of South Africa–the Western Cape and Mpumalanga. Previous research found reduced discharge, in-creased total dissolved salts, and a decrease in average score per tax-on (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigat-ed using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catch-ment in foothill-gravel streams (in both Western Cape and Mpuma-langa) and in foothill-cobble streams (in Western Cape only). Opportun-istic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and sea-sons) and detailed (at species level) collection of data to verify the re-sults of cumulative effects of small dams. This can further the devel-opment of a framework for small-dam construction and management that will limit their impact on river catchments.
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Date Issued: 2010

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Links between water temperatures, ecological responses and flow rates: a framework for establishing water temperature guidelines for the ecological reserve

- Rivers-Moore, Nick A, Hughes, Denis A, Mantel, Sukhmani K

Authors: Rivers-Moore, Nick A , Hughes, Denis A , Mantel, Sukhmani K
Date: 2008
Subjects: To be catalogued
Language: English
Type: text , report
Identifier: http://hdl.handle.net/10962/438295 , vital:73449 , ISBN 978-1-77005-738-8 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV214-CONSERVATION.pdf
Description: Global ecosystems face unprecedented crises in habitat fragmentation, destruction and ultimately extinction (Groves, 2003), and of all the vary-ing ecological systems rivers are the most neglected and endangered (Groves, 2003; Driver, et al., 2005; Roux et al., 2005). The greatest threat to these systems is the loss or degradation of natural habitat and processes (Driver et al., 2005), and water temperatures, after flow vol-umes, are a primary abiotic driver of species patterns within river sys-tems. Stuckenberg (1969) highlighted the links between temperature, topography and faunal assemblages, while Rivers-Moore et al.(2004) highlights the major impacts of water temperatures on organisms, and illustrate how water temperatures are one of the primary environmental drivers structuring fish communities in the Sabie River, arguably the most icthyologically species-rich river in South Africa.
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Date Issued: 2008

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