18 Developing a Framework for the Water-Energy …
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3.3.2 Indices
The Nexus City Index (NXI), developed by the United Nations, considers food,
energy, and water resources and includes an equity index. The UN-Habitat approach
forms the basis for NXI and offers indices to monitor the development of productivity,
infrastructure development, quality of life, equity, and environmental sustainability.
The approach is based on urban resilience, which is targeted in Goal 11 of the SDGs
(Schlör et al. 2018). Along with the NXI region , the World City Prosperity Index, the
Regional City Prosperity Index, and the Regional City Index (NXI city ) were developed
to assess the resilience of various regions and cities in the world (Schlör et al. 2018).
They provide data to support decision-making to identify, monitor, plan, and manage
urbanization in cities and regions, with special attention to developments within the
WEF sectors (Schlör et al. 2018). These indices are useful for South Africa, but do
not consider policy implications, nor do they include scenario-based predictions of
population growth, climate change, or economic growth.
3.3.3 Models
The South Africa TIMES model (SATIM-W) tool considers trade-offs between water
and energy systems for cost-effective sustainable planning (Ahjum et al. 2018). As
the name suggests, it is specific to South Africa and incorporates large amounts of
quantitative data relating to the country’s water supply, usage, and costs (including
water quality and treatment). Scenarios include climate change impacts, economic
growth, local environmental best practice, policy compliance, and low carbon technologies (Ahjum et al. 2018). To address the hydrological gaps of the model, the
World Bank, with the SADC secretariat, has launched a project to build sustainable
groundwater management in the region (The World Bank, 2016). This model may
be altered to include the food sector of the WEF nexus as well as social aspects; it
has great potential to effectively evaluate the WEF nexus in South Africa.
A new model for integrated assessment of global change (ANEMI) was established as an integrated assessment model to simulate all relevant variables, including
climate, the carbon cycle, the economy, population, land use, the hydrological cycle,
and water demand and quality (Davies and Simonovic, 2011). It emphasizes the
interconnections and feedback of each element, and is a significant improvement
over previous models because it includes food production and considers factors that
optimize the energy-economy factor (Akhtar et al. 2013).
Ozturk (2017) formulated simple non-linear regression equations using a set of
explanatory variables of agricultural sustainability to create an understanding of
the water-energy-food nexus within six sub-Saharan African countries. The study
utilized three panel regressions, including the least squares regression (“common
constant method”); fixed effects (“least squares dummy variables”); and the random
effects model (“Dynamic Model”).
425
3.3.2 Indices
The Nexus City Index (NXI), developed by the United Nations, considers food,
energy, and water resources and includes an equity index. The UN-Habitat approach
forms the basis for NXI and offers indices to monitor the development of productivity,
infrastructure development, quality of life, equity, and environmental sustainability.
The approach is based on urban resilience, which is targeted in Goal 11 of the SDGs
(Schlör et al. 2018). Along with the NXI region , the World City Prosperity Index, the
Regional City Prosperity Index, and the Regional City Index (NXI city ) were developed
to assess the resilience of various regions and cities in the world (Schlör et al. 2018).
They provide data to support decision-making to identify, monitor, plan, and manage
urbanization in cities and regions, with special attention to developments within the
WEF sectors (Schlör et al. 2018). These indices are useful for South Africa, but do
not consider policy implications, nor do they include scenario-based predictions of
population growth, climate change, or economic growth.
3.3.3 Models
The South Africa TIMES model (SATIM-W) tool considers trade-offs between water
and energy systems for cost-effective sustainable planning (Ahjum et al. 2018). As
the name suggests, it is specific to South Africa and incorporates large amounts of
quantitative data relating to the country’s water supply, usage, and costs (including
water quality and treatment). Scenarios include climate change impacts, economic
growth, local environmental best practice, policy compliance, and low carbon technologies (Ahjum et al. 2018). To address the hydrological gaps of the model, the
World Bank, with the SADC secretariat, has launched a project to build sustainable
groundwater management in the region (The World Bank, 2016). This model may
be altered to include the food sector of the WEF nexus as well as social aspects; it
has great potential to effectively evaluate the WEF nexus in South Africa.
A new model for integrated assessment of global change (ANEMI) was established as an integrated assessment model to simulate all relevant variables, including
climate, the carbon cycle, the economy, population, land use, the hydrological cycle,
and water demand and quality (Davies and Simonovic, 2011). It emphasizes the
interconnections and feedback of each element, and is a significant improvement
over previous models because it includes food production and considers factors that
optimize the energy-economy factor (Akhtar et al. 2013).
Ozturk (2017) formulated simple non-linear regression equations using a set of
explanatory variables of agricultural sustainability to create an understanding of
the water-energy-food nexus within six sub-Saharan African countries. The study
utilized three panel regressions, including the least squares regression (“common
constant method”); fixed effects (“least squares dummy variables”); and the random
effects model (“Dynamic Model”).