GCRO’s academic publications January-May 2023

Academic publications by GCRO staff during the first five months of 2023 tackle a diversity of topics: heteronormativity in Southern Africa and its impact on healthcare; migrant livelihoods; social and environmental justice in housing projects; the use of remote sensing techniques to measure the height of tree canopies and the changing structure of vegetation.

Mkhize, S.P., and Mthembu, A. (2023). 'Unpacking pervasive heteronormativity in sub-Saharan Africa: Opportunities to embrace multiplicity of sexualities'. Progress in Human Geography, 0(0): 1-15. Online first DOI https://doi.org/10.1177/03091325231166402

Abstract: This article provides a critical review of research on geographies of sexuality and acknowledges how sexual identities are constructed through an intersection of multiple dimensions in the sub-Saharan Africa region. Although the region is experiencing a gradually changing landscape regarding the rights of queer people, ongoing discriminatory practices attached to heteronormativity suppress the expression of non-normative sexual identities. Upon exploration of queer theory and a review of literature on the challenges facing queer people, this article argues for reimagining an African society that embraces a multiplicity of sexualities. It also advocates for tackling hetero- and binary-defined norms by presenting counterarguments and scenarios that demonstrate the significance of deconstructive and non-binary approaches towards sexuality and space in sub-Saharan Africa.

Mkhize, S.P. and Maharaj, P. (2023). 'Heteronormativity in health settings: realities of LGBT youth access to health care in South Africa'. In: K Naidoo and O Adeagbo (eds), Young People, Violence & Strategic Interventions in African Countries. Springer. Online first https://link.springer.com/chapter/10.1007/978-3-031-20679-5_6

In South Africa, sexual and gender minorities experience a wide array of health inequities and face many difficulties in accessing health services. This is largely due to the general heteronormative-based health system that is not well equipped to meet the needs of those not conforming to “normal” forms of gender and sexuality. In addition, the heteronormative-based approach to LGBT health has rendered the unique needs and experiences of sexual and gender minorities invisible within mainstream health data, systems and policies. Increasing evidence suggests that the COVID-19 pandemic has worsened health disparities and this is likely a consequence of existing challenges related to structural violence that persisted prior to its emergence. Given the current structure of South Africa's health system, this chapter examines structural violence in the context of healthcare and draws on in-depth interviews conducted with 12 LGBT students at a university in South Africa. The findings highlight the importance of raising awareness on the spectrum of sexual orientation and gender identity, applying an intersectional lens to the health system to address health inequities and gearing healthcare programs to provide services for all.

Modiba, M. and Mdluli, T.N. (2023). 'The Inclusion of International Migrants in the Informal Economy: From Policy to Practice'. In Maharaj, P. (ed) Migrant Traders in South Africa. Palgrave MacMillan. Cham; https://doi.org/10.1007/978-3-031-21151-5.

Globally and particularly in South Africa, the inclusion of international migrants in the informal economy has received significant attention in recent years in the face of rising hostility. One of the areas of contention is that international migrants dominate the sector and are often seen as a threat rather than making an economic contribution. International migrants, like South Africans typically work in the informal economy, in order to support their livelihoods in the context of rising unemployment and poverty. Drawing on a policy review and documentary analysis, this chapter unpacks the inclusion of international migrants in South Africa’s informal economy. It argues that while the country’s Constitution protects the rights of international migrants, this does not translate into inclusive policies and practices. The plight of international migrants is exacerbated in the COVID-19 pandemic as they are excluded from accessing support.

Culwick Fatti, C. and Patel, Z. (2023). 'In pursuit of just sustainability: decision-making and conflicting rationalities in government-led housing projects'. Local Environment. 28(3): 277–303. DOI: 10.1080/13549839.2022.2136636.

Social justice and environmental sustainability are often joint policy objectives, however, achieving the dual goal of just sustainability has proved difficult in both theory and practice. Scholars argue that a key challenge is balancing trade-offs between sustainability and justice objectives. This is evident within government-led housing, where there is little consensus regarding how to balance the housing needs within the context of existing unsustainable and unjust urban forms, resource constraints and high inequality. This paper explores this conundrum by examining how different logics and motivations influence justice and sustainability outcomes of two government housing projects in Johannesburg, South Africa – Pennyville and Lufhereng. We apply the concept of conflicting rationalities [Watson, Vanessa. 2003. “Conflicting Rationalities: Implications for Planning Theory and Ethics.” Planning Theory & Practice 4 (4): 395–407] within a new context, thereby extending the theory and understanding of planning in the face of tensions and trade-offs. Three themes are used to surface different rationalities that influence just sustainability: (1) the assumption that justice and sustainability can be achieved simultaneously within government-led housing, (2) how power, influence and coordination within government contribute to disjunctures between justice and sustainability, and (3) assumptions around infill versus urban expansion for achieving just sustainability. The paper reveals how institutional dynamics, politics and conflicting rationalities diverted each project from their envisioned outcomes. The results show that disconnects between theory and practice are not necessarily driven by conflicts between justice and sustainability, but rather obscured rationalities. Focusing on conflicts between justice and sustainability can deviate attention away from the practical, and sometimes mundane, processes that cumulatively undermine progress towards justice and sustainability.

Li, X., Wessels, K., Armston, J., Hancock, S., Mathieu, R., Main, R., Naidoo, L., Erasmus, B. and Scholes, R.(2023) First validation of GEDI canopy heights in African savannas. Remote Sensing of Environment; 285 (113402); https://doi.org/10.1016/j.rse.2022.113402

Abstract: Savannas have complex, discontinuous woody vegetation structures that vary greatly in vertical and spatial arrangement and change due to climatic, ecological and management impacts. While airborne laser scanning (ALS) data have provided detailed information on vertical vegetation structure and is widely used in ecological studies, it is lacking in availability and repeat frequency. Although the Global Ecosystem Dynamics Investigation (GEDI) waveform Light Detection and Ranging (LiDAR) sensor and algorithms were optimized for measuring dense forests, it was anticipated that GEDI metrics could provide useful characterization of lower stature, sparse savannas structures. This study provided the first baseline validation of Version 2 GEDI (L2A) relative height 98 (RH98) by comparing the on-orbit GEDI-RH98_orb to the simulated GEDI-RH98_sim derived from ALS data across diverse savanna vegetation. It furthermore determined the influence of various factors on error, e.g. algorithm setting group (SGs), beam type, day vs. night, beam sensitivity, and vegetation phenology. After applying quality flags, 22,813 GEDI footprints were analyzed across 11 sites. SGs 4–6 that are aimed at dense forests had much larger errors than SGs 1–3. The phenological conditions at the time of GEDI data acquisition had a very large influence on the error of RH98_orb. During leaf-on conditions for savanna vegetation with RH98_sim < 15 m, RH98_orb was very accurate with R² = 0.61, mean bias = −0.55 m, %bias = −11.1%, RMSE = 1.64 m and %RMSE = 29.8%. In leaf-off conditions where RH98_sim < 15 m, RH98_orb was less accurate with R² = 0.43, mean bias = −1.47 m, %bias = −26.5%, RMSE = 2.03 m and %RMSE = 40.9%. During leaf-off conditions, the GEDI LiDAR signal at the start of the waveform may be weaker as it interacts with denuded branches and may be truncated as noise, leading to a large negative height bias. Therefore, assessments of deciduous vegetation structures should be conducted during leaf-on periods. In leaf-on conditions, GEDI's RH98_orb was very accurate between canopy heights of 3 and 7 m, with a mean bias of −0.79 m (−10%). The bias of RH98_orb was not influenced by canopy cover. Due to the GEDI LiDAR pulse width of 15.6 ns, the GEDI-RH98 data product cannot reliably estimate canopy heights of shrubs below 2.34 m and will require more complex deconvolution of the waveform. GEDI's RH98 accurately estimates the canopy height of trees between 3 and 15 m allowing assessment of canopy heights over vast savanna areas.

Wessels, K., Li, X., Bouvet, A., Mathieu, R., Main, R., Naidoo, L., Erasmus, B., Asner, G.P. (2023). 'Quantifying the sensitivity of L-Band SAR to a decade of vegetation structure changes in savannas'. Remote Sensing of Environment; 284 (113369); https://doi.org/10.1016/j.rse.2022.113369

Global savannas are the third largest carbon sink with large human populations being highly dependent on their ecosystem services. However, savannas are changing rapidly due to climate change, fire, animal management, and intense fuelwood harvesting. In southern Africa, large trees (>5 m in height) are under threat while shrub cover (<3 m) is increasing. The collection of multi-date airborne LiDAR (ALS) data, initiated over a decade ago in the Lowveld of South Africa, provided a rare opportunity to quantify the ability of L-band SAR to track changes in savanna vegetation structure and this study is the first to do so, to our knowledge. The objective was to test the ability of ALOS PALSAR 1&2, dual-pol (HH, HV) data to quantify woody cover and volume change in savannas over 2-, 8- and 10-year periods through comparison to ALS. For each epoch (2008, 2010, 2018), multiple PALSAR images were processed to Gamma0 (γ⁰) at 15 m resolution with multi-temporal speckle filtering. ALS data were processed to fractional canopy cover and volume, and then compared to 5 × 5 aggregated (75 m) SAR mean γ0. The ALS cover change (∆CALS) and volume change between pairs of years were highly correlated, with (R² > 0.8), thus results for cover change applied equally to volume change. Cover change was predicted using (i) direct backscatter change or (ii) the difference between annual cover map product derived using the Bayesian Water Cloud Model (BWCM) and logarithmic models. The linear relationship between ∆γ0 and ∆CALS varied between year pairs but reached a maximum R² of 0.7 for 2018–2010 and a moderate R2 of 0.4 for 2018–2008. Overall, 1 dB ∆γ⁰ corresponded to approximately 0.1 cover change. The three cover change models had very similar uncertainties with mean RMSE = 0.15, which is 13% of the observed cover change range (−0.6 to +0.6). The direct backscatter change approach had less underestimation of positive and negative cover change. The L-band backscatter had a higher sensitivity than suggested by previous studies, as it was able to reliably distinguish cover change at 0.25 increments. The SAR-derived cover change maps detected the loss of stands of big trees, and widespread increases in cover of 0.35–0.65 in communal rangelands due to shrub encroachment. In contrast, the maps suggest that cover generally decreased in conservation areas, forming distinct fence-line effects, potentially caused by significant increases in elephant numbers and frequent, intense wildfires in reserves.