eNews
#02 2024
Engaged research for impact: Understanding the Maputaland social-ecological system
By Sue Janse van Rensburg, Coordinator, Grasslands Node, NRF-SAEON
A decline in the water table in the Umhlabuyalingana Local Municipality (ULM) in Northern KwaZulu-Natal (KZN) has had significant consequences for the local communities and the surrounding wetland ecosystems. Livelihoods, food security, reed availability for crafts, livestock health and overall water security have all been adversely affected.
Emerging evidence suggests that the impact of commercial eucalyptus plantations is responsible for precipitating these consequences through reducing the water table within this groundwater-driven system. The reduction in water availability diminishes the region’s capacity to adapt, particularly when urgent action is needed to accelerate climate change adaptation efforts.
A decline in the water table in the Umhlabuyalingana Local Municipality in Northern KwaZulu-Natal has had severe consequences for livelihoods, food security, livestock health and water security (Photo: Shutterstock)
Emerging evidence suggests that the impact of commercial eucalyptus plantations is responsible for reducing the water table within this groundwater-driven system (Photo: Shutterstock)
The evidence emerged from a three-year multidisciplinary project led by the SAEON Grasslands Node and funded by the Water Research Commission (WRC) (Advancing Water and Income Security in The Unique Maputaland Coastal Plain: A Strategic Decision Support Tool to Explore Land Use Impacts Under a Changing Climate, Project No. C2020/2021-00430), which has shed light on the interconnections between socioeconomic, climate and hydrological dynamics in assessing land use impacts.
Driven by a societal need to improve water and economic security, a multiscaled, integrated approach was used to assess the potential impacts of alternative future land uses, defined by traditional councils, under different climate future storylines. It attempted to integrate hydrological, climate and economic models to provide decision support to land custodians. Furthermore, it sought to understand the current sources of employment, income and livelihoods within these areas, along with the future land use preferences of the community.
Climate analyses, from the past to the current period, were undertaken. Hydrological and plant water use parameters were measured in the field and used for a loosely coupled, gridded ACRU-MODFLOW model. Furthermore, household surveys were conducted to gather socioeconomic data which was used to inform a systems dynamics model. The systems dynamics model, while primarily an economic model, integrated climatological as well as hydrological impacts.
Context
Water levels in Lake Sibaya (within the ULM), South Africa’s largest natural freshwater lake, started declining in 2001. This decline can be attributed to below-average rainfall patterns coupled with the presence of commercial eucalyptus plantations in the region. Lake Sibaya’s water levels are linked to the groundwater system, which serves as the primary water source for the area. With no rivers importing water into the area, it is particularly sensitive to rainfall.
Water levels in Lake Sibaya, South Africa’s largest natural freshwater lake, started declining in 2001 (Photo: Shutterstock)
Impact of climate: Past to present
In assessing past to current rainfall patterns, a significantly lower frequency of extreme rainfall events >20 mm since 2001 (analysis periods 1980–2019) was noted. At the same time, isotopic studies in the project revealed that groundwater recharge is predominantly from extreme rainfall events.
An existing MODFLOW groundwater model, that was improved on within the project, simulated lake responses to rainfall, aligning with observed data – an improvement on the existing model. The declining lake level trends coincided with the period within the rainfall analysis which shows significantly fewer rainfall events and extreme drought phases.
With the hydrological models configured, and improved confidence in the groundwater model, future scenarios could be tested.
Impact of commercial eucalyptus plantations: Past to present
The recommended drought threshold for Lake Sibaya specifies that water levels should not drop below 16.5 metres above mean sea level (AMSL) for more than five consecutive years. Unfortunately, by 2015, this threshold had been breached.
Even today, nine years later, the lake level has not recovered above this critical threshold. However, simulations using an updated MODFLOW model demonstrate that without the introduction of commercial eucalyptus plantations, the drought reserve threshold would not have been breached. Water levels would have remained above 16.6 metres AMSL, despite a declining trend due to below-average rainfall.
This underscores the detrimental impact of this land use choice on livelihoods at the household level, providing evidence for the role commercial forestry has played in precipitating negative consequences. In its absence, the adverse impacts on livelihoods would likely have been avoided.
The lessons from Lake Sibaya emphasise the importance of considering the long-term implications of land use decisions. By making informed choices today, we can safeguard water security and resilience for future generations.
Members of the SAEON project team working with Department of Water and Sanitation colleagues to survey the water level of the Lake Sibaya South Basin.
Prof. Bruce Kelbe (centre) sharing information with SAEON technician Siphiwe Mfeka and Mkholo Maseko, who completed his MSc under Dr Kelbe’s mentorship within the project and is now working with SAEON as a junior groundwater hydrology scientist.
Engaging with the affected communities to explore future prospects
A common narrative in the region is that commercial eucalyptus plantations are an important source of income for people living in the area. This is often coupled with the acknowledgement that these plantations use a lot of water. This project was initiated in response to the challenge posed by local community members of “give us an alternative and we will change”.
The project aspired to develop a means of empowering vulnerable local communities to make informed and “least regret” land use choices for the optimisation of beneficial outcomes in the context of an uncertain future climate. From the outset, the project team engaged with traditional councils to understand what their key challenges were, as well as what their ideas were for alternatives to eucalyptus plantations.
The four key challenges identified by the traditional councils were water security, employment, economic status and ecological integrity. Alternative land use choices, to be modelled from 2020 to 2050, included substituting 50% of the commercial eucalyptus plantations with crops, marula trees and macadamia orchards (dryland and irrigated scenarios for all), one at a time. Members of the project team were also asked by the community to simulate the impact of bush encroachment.
For comparative purposes, a “status quo” scenario and a “no forestry” scenario were also simulated to compare with alternatives. The project team aimed to assess the impact of these choices holistically in relation to the four key challenges identified by the communities themselves.
Mkholo Maseko explaining results of the hydrological component of the project to the Mabasa Traditional Council. SAEON invited other researchers and stakeholders in the area to participate, such as Dr Heidi van Deventer from the CSIR (centre, in blue dress), a reference group member of the project conducting her own research on wetlands in the region.
Participatory activities in the Mbila/Zikhali Traditional Council final feedback workshop, discussing changes in the landscape over time.
SAEON intern Londiwe Gule (right) facilitating discussions on changes in the Lake Sibaya water levels in the final feedback workshop at the Mbila/Zikhali Traditional Council.
Mkholo Maseko and Londiwe Gule from the project team providing feedback at the final Tembe Traditional Council workshop. Many cattle farmers came to the workshops, providing an opportunity for the team to explain more about the project and SAEON’s activities in the landscape as the farmers had not previously interacted with the project team.
Future LULC-climate storylines
To assess the alternative land-use land cover (LULC) scenarios from 2020 to 2050, different future climates were required. A major challenge was to develop data sets for future climate scenarios.
Fine spatial scale climate projections at the scale that decision-makers need them at are fraught with uncertainty. Hence, we used a “storyline” approach, assessing LULC alternatives to forestry under three climate futures. Two storylines (Wet_LER and Dry_LER) were characterised by a low number of extreme rainfall events, with one being slightly wetter than the other, and the third climate storyline (Wet_HER) was a much wetter future, with a higher frequency of extreme rainfall events. The net outcomes of these are addressed in a separate article within this issue.
Fact or fiction? The “benefits” of commercial plantation forestry
Economic and employment data from household surveys, as well as system model simulations, disproved the notion that commercial plantation forestry provides major benefits relative to other sources of income and alternative land use options at the household levels. Furthermore, data on future land use preferences pointed to an aversion to commercial plantation forestry, both at the traditional council and household levels.
Of concern is the low climate literacy level in the area, with less than 50% (49%) of household survey respondents indicating that they were aware of climate change and its potential impacts. Given the combined impact of climate and land use on the water table, there is an urgent need to address the climate literacy gap for people to understand the potential threats and make appropriate land use choices.
SAEON hydrology intern Nosihle Mkhize (left) assisting Thobeka Nsibande, who completed her MSc in hydrology as part of the project.
Mkholo Maseko (left) and Thobeka Nsibande, funded through the WRC project, conducting field work around Lake Sibaya. Mkholo and Thobeka are both University of KwaZulu-Natal Centre for Water Resources Research Hydrology students.
Challenges and knowledge advancements
In the attempt to integrate climate, hydrological and economic components, numerous challenges were encountered. These included scaling issues, data paucity, model limitations and inter-modelling coupling constraints. Despite this, several knowledge advances were made and a significant amount of hydrological, micro-metrological and household socioeconomic data was collected to inform integration processes, as well as aid in the interpretation of results.
The importance of extreme rainfall events for recharging the groundwater table emphasises the significance of the further exploration of the controlling mechanisms that influence regional weather patterns in this area, particularly tropical storms, and how these are likely to change in the future. Furthermore, the study revealed that the indigenous Indian Ocean Coastal Belt Biome grassland is the best land cover for achieving optimal recharge, but these areas are being rapidly transformed.
A key recommendation therefore is that every effort should be made to protect and appropriately manage all remaining grassland areas within quaternary catchment W70A. This can only be achieved if these areas are providing value to the communities that live within them.
Engaging to bridge the gap towards impact
To foster an understanding of the need to adopt water-sustainable livelihoods to improve adaptive capacity in the face of climate change, the project team endeavoured to align the research with the scale at which decisions are made. This involved grounding the research in the local socioeconomic context and active engagement with decision-makers in the research process.
By engaging with community members, emergent opportunities were identified that would otherwise have been overlooked. One such example is a common interest in commercialising cattle. To this end, the project team facilitated a knowledge exchange, taking members from the communities we worked with to Matatiele to learn from Environmental Rural Solutions (ERS) and the communities they work with about animal husbandry, rangeland management and mobile cattle auctions. This proved a powerful intervention and served to promote personal agency in those who participated.
Feedback from workshops with the traditional councils in November 2023 indicates that the project did serve to enhance awareness of climate change risks and was rooted in the local context. SAEON has been requested to share the information with the broader community and create awareness about the uniqueness of the system and the risks climate change may pose.
So practically, what are the “least regret” decisions that can be made today for a resilient water secure future?
It takes a team – Mkholo Maseko, Thobeka Nsibande and Nosihle Mkhize after completing their final sampling session, location South Basin Lake Sibaya
Integrating across disciplines, Siphiwe Mfeka (Grasslands Node technician), Mkholo Maseko (groundwater hydrologist), Londiwe Gule (SAEON biodiversity intern) and Sulinkhundla Maseko (resource economist) preparing for the final feedback workshops to the traditional councils. “It was wonderful to see the growth of these team members in both their scientific and engagement skills through the project, going from being guided by the senior members of the team to leading the final feedback engagement workshops with the traditional councils,” says Grasslands Node coordinator Sue Janse van Rensburg. “They were able to translate complex integrated issues in a way for all to understand the essence of the outcomes. The integrated scientific approach and working together to engage with society meaningfully are crucial skills needed to ensure knowledge and societal impact.”
A call to action
A key outcome was that participants now want tangible action on the ground to implement economically attractive and water-wise alternatives. To achieve this, the project team need to forge collaborations with multiple stakeholders and NGOs that are focused on action-based interventions.
To this end, we will be hosting a think tank to identify interested parties, investors and opportunities that we can then connect with the communities. Anyone interested in making a difference on the ground, please contact Sue Janse van Rensburg.
Acknowledgements
WILDTRUST, GroundTruth and all authors on the project (Ross Blamey, James Blignaut, Paul Gordijn, Nokwanda Gule, Seifu Kebede, Bruce Kelbe, Mkholo Maseko, Sulinkhundla Maseko, Siphiwe Mfeka, Nosihle Mkhize, Thobeka Nsibande, Marc Pienaar, Chris Reason and Michele Toucher).
This multifaceted and crucial project would not have been possible without the funding of the WRC.
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