Monitoring changes in South Africa’s surface water extent for reporting Sustainable Development Goal sub-indicator 6.6.1.a

For the first progress reporting on the Sustainable Development Goal sub-indicator 6.6.1a in 2020, the South African and global statistics related to wetlands were compared. Firstly, in terms of the total wetland extent, the South African National Wetland Map version 5 (NWM5) represented 87% more inland, surface aquatic ecosystems than the Global Surface Water (GSW) product. More than half of the lacustrine systems and none of the palustrine and arid systems in NWM5 are represented in the GSW layer. Secondly, in terms of changes in the extent of wetlands, both the global and South African statistics showed a decreasing trend in the spatial extent of surface aquatic ecosystems in South Africa. These trends should be further investigated against systematic assessments of decadal drought periods. The hydroperiod information (permanent, seasonal and ephemeral inundation periods) of the GSW products show that South African lacustrine wetlands do not have a single dominant class (≥70% of the extent of a polygon) of inundation, but consist of a mosaic of these classes.Significance: The South African National Wetlands Map version 5 represents 87% more of the extent of lacustrine, palustrine and arid wetlands than the Global Surface Water products that are used for progress reporting on the Sustainable Development Goal sub-indicator 6.6.1a. South African and global statistics suggest a decline in the extent of lacustrine wetlands, although a systematic comparison with decadal drought periods is required to confirm these trends. South African lacustrine wetlands consist of a mosaic of hydroperiod classes (permanent, seasonal and ephemeral inundation periods) with no individual class dominating (≥70% of the extent of) wetlands polygons

Remote sensing of wetland tree species in the iSimangaliso Wetland Park, KwaZulu-Natal, South Africa.

Doctor of Science in Geography.The impact of global change is expected to result in changes in the distribution and composition of species. Coastal swamp and mangrove forests are some of the most threatened forest types in the world. Remote sensing is a suitable tool for monitoring species distribution and varying condition because of its spatial extent and repeatability. The ability of remote sensing to separate between species can be attributed primarily to its capability to quantify the absorption features in the electromagnetic spectrum which relate to plant biochemical and biophysical properties such as pigments, nutrients (proteins and starch), leaf water content, leaf angle distribution, leaf area index and foliage biomass. For some species, these phenological variations are extreme, as in the case of deciduous tree species, thus enhancing the ability to differentiate between species, whereas others are less pronounced, such as with evergreen tree species, making spectral distinction between species much more challenging. Few studies have assessed the pigment and nutrient phenology of evergreen tree species in subtropical forested wetlands, let alone their spectral differences. This study assesses whether multi-season data across a number of phenological phases of evergreen wetland tree species will improve their classification accuracy when compared to a single season and single phenological event. The objectives were to (i) assess whether tree species had unique seasonal profiles of foliar biochemicals; (ii) ascertain the spectral bands of plant properties which remain important across phenological phases for species classification; (iii) determine whether leaf reflectance spectra from multiple seasons would improve species classification when compared to a single season; and (iv) whether multi-season imagery would improve species discrimination when compared to a single season. Thus, the study made use of leaf level and canopy level spectra collected using a handheld spectrometer and spaceborne RapidEye imagery, respectively. Six dominant evergreen tree species from forested wetlands in the subtropical region of KwaZulu-Natal, South Africa, were sampled across four seasons (winter, spring, summer and autumn). Differences in foliar biochemical concentration were assessed for two pigments, including carotenoids and chlorophylls, as well as two nutrients, nitrogen and phosphorous. The results showed that the majority of species had no significant changes in foliar pigments across the four seasons. Foliar nitrogen showed a significantly higher variability in the spring, summer and autumn seasons compared to the winter, whereas foliar phosphorus also varied across the seasons but to a lesser degree. The highest percentage of species pairs was separable using foliar nitrogen, compared to the pigments and phosphorus, emphasizing the importance of nutrients such as leaf proteins for species discrimination. The study found a changing relationship between leaf spectra and foliar nutrient concentration across the four seasons for the six evergreen tree species. Twenty-two spectral bands which are related to known absorption features of plant properties were identified across the four seasons as important for tree species discrimination. The relationship between leaf spectra and foliar nitrogen was highest during the spring, summer and autumn seasons for narrow bands associated with absorption features of proteins compared to the red-edge region. The spectra band combination 2130 nm and 2240 nm yielded the highest coefficient of determination between leaf spectra and foliar nitrogen across three of the four seasons. Season-specific prediction models were found to be more accurate in predicting foliar nitrogen than prediction models from across all seasons. The twenty-two bands were effective for the data reduction of the hyperspectral data and yielded a similar overall accuracy compared to 421 bands. Multi-seasonal data improved tree species classification for multispectral sensors with a few bands. The classification, in which multi-season leaf spectra or canopy data from RapidEye imagery was used, resulted in higher overall and user’s accuracies when compared to the single-season classifications. In contrast, the use of multi-season data for the classification of leaf spectra with 22 narrow bands, showed no statistical significance of differences compared to the classification results of the single season in which the highest overall accuracy of all single seasons had been obtained. The value of an increased classification accuracy should however be measured against the increase of cost when using images from multiple seasons. The study concludes that although seasonal profiles of foliar biochemicals overlap, multi-season information do improve species discrimination at foliar biochemical, leaf-spectra and canopy-spectra levels

Current state, pressures and protection of South African peatlands

Temperate regions in the Southern Hemisphere make a small contribution to the global carbon sequestration of peatlands which, in these drier regions, are relatively rare and vulnerable to increasing anthropogenic and climate change pressures. Using South Africa as a case study, we review the availability of spatially explicit information on peatlands and their protection. The South African Peatland Database recorded 635 peatland observations, which reflect a carbon storage capacity of 29,254,495 ± 5,798,831 (total ± standard deviation) tons. Of the total 121,128 ha of peatlands mapped in this study, forested peatlands (11,851 ha, 10 % of all peatlands) were considered vulnerable. Non-forested peatlands (109,277 ha) had higher levels of uncertainty with regard to extent and degree of degradation, and most (74 %) of these had only partial protection. Cumulative anthropogenic pressures have resulted in an increase in the number and temporal frequency of peat fires, with 49 peatland sites having burned in the past five years, compared to 23 in the 24-year period preceding it. The total loss of carbon due to peat fires equates to 280,513 tons to date. The inventory, assessment and management of forested and non-forested peatlands in South Africa, and most probably in other southern-hemisphere temperate regions, requires urgent attention. The information presented demonstrates that forested peatlands have been historically well mapped because of their ease of detection with remote sensing. In contrast, the paucity of information on non-forested palustrine peatlands dictates that more extensive infield validation should be undertaken before their conservation status can be determined.The Water Research Commission; the CSIR’s Parliamentary Grant Project P1BEO00, titled “Marine Observational and Predictive System Capabilities (MAROPS)”; as well as the African Union Global Monitoring for Environment and Security (GMES) Marine and Coastal Operations for Southern Africa (MarCOoSouth) projects.http://www.mires-and-peat.netam2022Geography, Geoinformatics and Meteorolog

The start of sexual health curriculum development and evaluation at Stellenbosch University

Background: Stellenbosch University’s (SU) Faculty of Medicine and Health Sciences (FMHS), developed a sexual health course to be integrated throughout the revised medical curriculum. Aim: To use the Sexual Health Education for Professionals Scale (SHEPS) to gather baseline and future follow-up data to inform curriculum development and evaluation. Setting: The first-year medical students (N = 289) of the FMHS SU. Methods: The SHEPS was answered before the start of the sexual health course. The knowledge, communication and attitude sections were answered with a Likert-type scale. Students had to describe their perceived confidence in their knowledge and communication skills to care for patients within specific sexuality-related clinical scenarios. The attitude section measured the students’ level of agreement or disagreement on sexuality-related opinion statements. Results: The response rate was 97%. Most students were female, and 55% of the class were first taught about sexuality in the age group 13–18 years. The students had more confidence in their communication skills than knowledge before any tertiary training. The attitude section revealed a binomial distribution, ranging from acceptance to a more restrictive attitude towards sexual behaviour. Conclusion: It is the first time the SHEPS has been used in a South African context. The results provide novel information about the range of perceived sexual health knowledge, skills and attitudes of first-year medical students before they start tertiary training. Contribution: Findings from this study will guide content development and evaluation of the sexual health course at the institution where the study was conducted, as well as allow for culture sensitive education

Conservation conundrum – red listing of subtropical-temperate coastal forested wetlands of South Africa

Africa’s range-restricted and transitional subtropical-temperate coastal forested wetlands are facing interlinking threats of climate and anthropogenic pressures. We assessed their conservation status using the criteria of the International Union for Conservation of Nature (IUCN). Their total areal extent was hind-casted to the reference epoch 2000, followed by the quantification of subsequent total losses in areal extents for the epochs 2005, 2008, 2011 and 2017. South Africa had 120 km2 of coastal swamp and floodplain forests in 2000 of which the majority (116.5 km2) occurred on the Maputaland Coastal Plain (MCP). By 2011, 20% of the areal extent was lost, and at the lowest rate of decline we estimate that ≥ 80% of the rest will be lost in the next 50 years. An ecosystem collapse assessment therefore indicated that the habitat is very likely Critically Endangered. Fragmentation and types of transformations were used as degradation indices to show functional collapse. These results showed that forest patches became increasingly fragmented, from 511 to 1 145 patches between 2000 and 2017 and that > 23% of the areal extent showed severe transformation. Several faunal species, with a close association to the forested wetlands of the MCP, are considered threatened with numbers declining because of transformation to timber plantations or agriculture and coupled with a prolonged drought. Of these, a sub-species of the Samango monkey, Cercopithecus mitis erythrarchus, considered to be a primary ecosystem engineer of the habitat, was red listed with a restricted distribution, being endemic, Near Threatened and declining. Also under pressure, because of habitat fragmentation and degradation is the Peregrine crab (Varuna litterata), a euryhaline species requiring connectivity across the land-seascape, ranging from freshwater forested wetlands to estuarine and off-shore environments. Functionally, these coastal forested wetlands are therefore also considered Critically Endangered. The final IUCN conservation status of South Africa’s subtropical-temperate coastal forested wetlands are recommended to be very likely Critically Endangered. Irrespective of 62% of the areal extent of these forested wetlands being within protected areas, severe degradation (metrics of fragmentation and transformation) were observed even inside these areas for the past two decades. The conservation conundrum is that despite existing legislation and management measures, there has been no stop or reversal of the negative trends to date. As a supplementary method, we therefore recommend a transdisciplinary community-based approach to conservation practice, continued and improved monitoring of the habitat losses, the identifying priority areas for rehabilitation and addressing data deficiencies in important species associations.CSIR’s Parliamentary Grant Project P1BEO00/P1CCS02, titled “Marine Observational and Predictive System Capabilities (MAROPS)”; as well as the African Union Commission (AUC) Global Monitoring for Environment and Security (GMES) MARCOSOUTH (K8MARCO). The Department of Science and Innovation (DSI) and National Research Foundation (NRF) Chair in Shallow Water Ecosystems (UID 84375) supported time of Prof. Janine Adams.https://www.elsevier.com/locate/ecolindam2022Geography, Geoinformatics and Meteorolog

Using geographical information systems for mapping commercial farmers' perceptions on land reform in Mpumalanga, RSA

Thesis (MA)--Stellenbosch University, 2000.ENGLISH ABSTRACT: Traditional top-down decision-making models have become unpopular since public institutions have been demanding more democracy at local level. New approaches and techniques have focused on how the majority of people can be involved in a bottom-up approach to development and decision making. Techniques, such as Participatory Rural Appraisals (PRAs), have identified people's concerns regarding the use of natural resources centred on land issues. Land is essentially a subject of public concern. Land as a spatial phenomenon controlled politically and used by all for survival and other purposes needs to be assessed in an integrated and time-spatial way for better planning and decision making. Geographical Information Systems (GISs) have often been used by statutory "experts" in evaluating, analysing and mapping of land and land-related features. GISs have a lot of potential in being applied as decision-making tools. If this is the case, how can public perceptions and politics be presented and mapped in a GIS to improve and democratise decision making even further? The study has investigated new methods of representing people's perspectives at grassroots level in a non-traditional way. A sub-region of the Lowveld, situated in the Mpumalanga province, has been selected because of the various kinds of land owners in the region. The Kruger National Park lies to the east of the study area, from where some black communities claim to have been removed. To the west of that is one of the districts of the former homeland KaNgwane, namely Nsikazi, and west of that two areas of intensive large-scale commercial fruit and vegetable production in the Nelspruit-White River and Kiepersol-Hazyview areas. Towards the escarpment north-west of these lie large commercial exotic forest plantations, owned mainly by Safcol and MandL Given the high demand and need for land from the overpopulated Nsikazi district, the process of land reform is a matter of great concern. White male commercial farmers in both regions where commercial farming is active were interviewed about their knowledge and perceptions of land reform. Various themes were presented to the farmers to comment on, namely the history of forced removals, land use, land potential, hydrology and where land reform should take place. Interviews were taped in Afrikaans, transcribed and translated to English. "Mental maps" were drawn on tracing paper overlaid on topographical maps of the Land Surveyor General, Mowbray. These were digitised and managed in Arclnfo, and displayed and analysed in ArcView, from where output maps were produced. The results of this technique proved to be very useful and can certainly broaden the use of GISs in decision making and public participation. However, GISs alone cannot be seen as the solution to better development and better decision-making. Public participation is of the utmost value in facilitating and initiating these processes. Land use planning needs to be the responsibility and concern of all land users and owners at a local level, where GISs can be applied as a tool to provide easier and more effective analysis and results for the implementation of initiatives.AFRIKAANSE OPSOMMING: Tradisionele bo-na-onder besluitnemingsmodelle het in die laaste paar dekades baie ongewild geraak met die totstandkoming van instellings wat die publiek se mening hoog ag en demokrasie op grondvlak probeer bevorder. Nuwe benaderings en tegnieke poog nou om die publiek se mening in 'n onder-na-bo benadering tot ontwikkeling en besluitneming te integreer. Grondhervorming is basies die erns van die publiek, meer so as die staat. Grond is 'n ruimtelike verskynsel wat polities beheer word maar deur die meerderheid gebruik word vir oorlewing asook ander doeleindes. Dit behoort op 'n tyd-ruimtelike basis op 'n geïntegreerde wyse vir beter beplanning en besluitneming ondersoek te word. Geografiese Inligtingstelsels (GISs) word hoofsaaklik deur statutêre "kenners" gebruik in die evaluering, analise en kartering van grond en verbandhoudende verskynsels. Dit beskik verder oor die potensiaal om in besluitnemingsprosesse gebruik te word. Die vraag ontstaan egter hoe die publiek se menings en politieke strukture met 'n GIS verteenwoordig en gekarteer kan word ter verbetering van besluitneming op 'n meer demokratiese wyse. Die studie het nuwe metodes ondersoek waarvolgens mense op grondvlak se persepsies op nie-tradisionele maniere verteenwoordig en ondersoek kan word. 'n Sub-streek van die Laeveld wat geleë is in die Mpumalanga provinsie, is geselekteer vanweë die verskeidenheid grondeienaars wat daar voorkom. Die Kruger Nasionale Park is geleë in die oostelike deel van die studiegebied vanwaar sekere swart gemeenskappe gedurende die Apartheidsregime verskuif is. Direk wes hiervan lê die voormalige tuisland KaNgwane se Nsikazi distrik en wes daarvan twee areas, naamlik Nelspruit-Witrivier en Kiepersol-Hazyview, waar die kommersiële boerdery van vrugte en groente op groot skaal beoefen word. In die noordwestelike gedeeltes van die studiegebied kom grootskaalse uitheemse bosbouplantasies voor wat aan Safcol en Mondi behoort. Met die stygende aanvraag na grond vir residensiële- en landbougebruik in die streek, veral vanuit die Nsikazi distrik, is grondhervorming en die toepassing daarvan, 'n probleem, indien nie 'n bedreiging, vir die meeste grondeienaars. Onderhoude is met blanke manlike kommersiële boere, in albei die kommersiële streke gevoer om hul menings en kennis van grondhervorming te ondersoek. Verskeie temas is as besprekingspunte gestel, naamlik die geskiedenis van gedwonge verskuiwings, grondgebruik, grondpotensiaal, water hulpbronne en waar hul meen grondhervorming sou moes plaasvind. Onderhoude was in Afrikaans opgeneem, getranskribeer en in Engels vertaal. "Kognitiewe kaarte" was op deursigtige papier geteken wat oor 'n reeks topografiese kaarte van die gebied gelê is. Die resultate is versyfer en in Arelnfo gemanipuleer en daarna in ArcView ontleed en vir verslaglewering gekarteer. Die resultate van die tegniek beloof om vir beide besluitnemers en die publiek as deelnemers in die proses baie bruikbaar te wees. Dit verbreed ook die gebruik en toepassing van GISs en die sisteem se vermoëns. GISs kan egter nie alleenlik aangewend word om ontwikkeling en besluitneming vir die publiek beter of meer aanvaarbaar te maak nie. Alle mense se deelname is van die uiterste belang en waarde in die inisiëring, fasilitering en implementering van strategieë en projekte. Grondgebruiksbeplanning moet die verantwoordelikheid van almal word wat grond op plaaslike vlak gebruik of besit, nie net van die wat deur 'n probleem of program, soos grondhervorming, geraak word nie. 'n GIS kan aangewend word om die prosesse van ontwikkeling en besluitneming te vergemaklik deur analises vinniger en op 'n meer effektiewe manier te ondersoek vir beter en meer demokratiese besluitneming

Monitoring changes in South Africa’s surface water extent for reporting Sustainable Development Goal sub-indicator 6.6.1.a

For the first progress reporting on the Sustainable Development Goal sub-indicator 6.6.1a in 2020, the South African and global statistics related to wetlands were compared. Firstly, in terms of the total wetland extent, the South African National Wetland Map version 5 (NWM5) represented 87% more inland, surface aquatic ecosystems than the Global Surface Water (GSW) product. More than half of the lacustrine systems and none of the palustrine and arid systems in NWM5 are represented in the GSW layer. Secondly, in terms of changes in the extent of wetlands, both the global and South African statistics showed a decreasing trend in the spatial extent of surface aquatic ecosystems in South Africa. These trends should be further investigated against systematic assessments of decadal drought periods. The hydroperiod information (permanent, seasonal and ephemeral inundation periods) of the GSW products show that South African lacustrine wetlands do not have a single dominant class (≥70% of the extent of a polygon) of inundation, but consist of a mosaic of these classes. SIGNIFICANCE : • The South African National Wetlands Map version 5 represents 87% more of the extent of lacustrine, palustrine and arid wetlands than the Global Surface Water products that are used for progress reporting on the Sustainable Development Goal sub-indicator 6.6.1a. • South African and global statistics suggest a decline in the extent of lacustrine wetlands, although a systematic comparison with decadal drought periods is required to confirm these trends. • South African lacustrine wetlands consist of a mosaic of hydroperiod classes (permanent, seasonal and ephemeral inunThe Council for Scientific and Industrial Research (CSIR)http://www.sajs.co.zahj2021Geography, Geoinformatics and Meteorolog

Monitoring changes in South Africa’s surface water extent for reporting Sustainable Development Goal sub-indicator 6.6.1.a

For the first progress reporting on the Sustainable Development Goal sub-indicator 6.6.1a in 2020, the South African and global statistics related to wetlands were compared. Firstly, in terms of the total wetland extent, the South African National Wetland Map version 5 (NWM5) represented 87% more inland, surface aquatic ecosystems than the Global Surface Water (GSW) product. More than half of the lacustrine systems and none of the palustrine and arid systems in NWM5 are represented in the GSW layer. Secondly, in terms of changes in the extent of wetlands, both the global and South African statistics showed a decreasing trend in the spatial extent of surface aquatic ecosystems in South Africa. These trends should be further investigated against systematic assessments of decadal drought periods. The hydroperiod information (permanent, seasonal and ephemeral inundation periods) of the GSW products show that South African lacustrine wetlands do not have a single dominant class (≥70% of the extent of a polygon) of inundation, but consist of a mosaic of these classes.Significance: The South African National Wetlands Map version 5 represents 87% more of the extent of lacustrine, palustrine and arid wetlands than the Global Surface Water products that are used for progress reporting on the Sustainable Development Goal sub-indicator 6.6.1a. South African and global statistics suggest a decline in the extent of lacustrine wetlands, although a systematic comparison with decadal drought periods is required to confirm these trends. South African lacustrine wetlands consist of a mosaic of hydroperiod classes (permanent, seasonal and ephemeral inundation periods) with no individual class dominating (≥70% of the extent of) wetlands polygons

Assessing leaf spectral properties of Phragmites australis impacted by acid mine drainage

The decanting of acid mine drainage (AMD) from the Western Basin on the Witwatersrand in late 2010 raised concerns about AMD risks in other gold, coal and copper mining areas of South Africa. Field spectroscopy and the use of vegetation indices could offer an affordable and easy means of monitoring the impact of mine water and/or AMD on vegetation. The impact of raw and treated mine water or contaminated soil on wetland vegetation often manifests in growth inhibition and reduction of foliar pigments and nutrient levels. Surveying the impact on wetland vegetation or underlying soils can be difficult and expensive considering the cost of laboratory analysis of samples. The potential of field spectroscopy for detecting the impact of mine water on wetland vegetation was examined by assessing (1) whether there was a significant difference in leaf spectra between sites receiving mine water and a non-impacted control site and (2) whether there was a gradation of vegetation condition downstream from the decanting site. Two vegetation indices were derived from portable field spectrometer-measured spectra of five green leaves of Phragmites australis – the chlorophyll red edge position (REP) and the normalised difference vegetation index (NDVI) – for two dormant (winter) and peak growth (summer) seasons in 2011–2012. Mean REP and NDVI values were significantly (p<0.05) lower for affected sites compared to the control site for both seasons and years. The range of REP values for young green leaves in winter for affected sites was 695–720 nm compared to the narrower range of 705–721 nm for the control site. The mean REP values for young green leaves in winter was 708 nm for the affected sites compared to 716 nm for the control site. The downstream gradation, however, fluctuated for REP and NDVI over the study period. We conclude that field spectroscopy shows potential to serve as a relatively quick and affordable means to assess the condition and health of vegetation affected by AMD

Estimating soil moisture using Sentinel-1 and Sentinel-2 sensors for dryland and palustrine wetland areas

Soil moisture content (SMC) plays an important role in the hydrological functioning of wetlands. Remote sensing shows potential for the quantification and monitoring of the SMC of palustrine wetlands; however, this technique remains to be assessed across a wetland–terrestrial gradient in South Africa. The ability of the Sentinel Synthetic Aperture Radar (SAR) and optical sensors, which are freely available from the European Space Agency, were evaluated to predict SMC for a palustrine wetland and surrounding terrestrial areas in the grassland biome of South Africa. The percentage of volumetric water content (%VWC) was measured across the wetland and terrestrial areas of the Colbyn Wetland Nature Reserve, located in the City of Tshwane Metropolitan Municipality of the Gauteng Province, using a handheld SMT-100 soil moisture meter at a depth of 5 cm during the peak and end of the hydroperiod in 2018. The %VWC was regressed against the Sentinel imagery, using random forest, simple linear and support vector machine regression models. Random forest yielded the highest prediction accuracies in comparison to the other models. The results indicate that the Sentinel images have the potential to be used to predict SMC with a high coefficient of determination (Sentinel-1 SAR = R²&gt;0.9; Sentinel-2 optical = R²&gt;0.9) and a relatively low root mean square error (Sentinel-1 RMSE =&lt;17%; Sentinel-2 optical = RMSE &lt;21%). Predicted maps show higher ranges of SMC for wetlands (&gt; 50%VWC; p&lt;0.05) compared to terrestrial areas, and therefore SMC monitoring may benefit the inventorying of wetlands, as well as monitoring of their extent and ecological condition. Significance: The freely available and space-borne Sentinel sensors show potential for the quantification of surface soil moisture across a wetland–terrestrial gradient. Significant differences between the surface soil moisture of palustrine wetlands and terrestrial areas, imply that inventorying and monitoring of the extent and hydroperiod of palustrine wetlands can potentially be done