approach is important. The latter has to ensure
that working groups, steering committees, etc.
work efficiently and independently.
5 Conclusions and Outlook
Coming back to the introductory statement, we
indeed conclude that “the nexus is more relevant
than ever” as stated by Bouma (2021) and this
can be deduced both from positive examples of
nexus implementations (e.g., Eichhorn et al.
2021; Gebrezgabher et al. 2021; Tesfahunegn
and Ayuk 2021) as well as from those studies,
which show that the lack of nexus-oriented
policies results in unsustainable management
practices (e.g., Jaghdani and Kvartiuk 2021;
Riera and Brümmer 2021; Sang and Maina 2021)
or from studies which demonstrate the feasibility
of positive outcomes if a nexus approach would
be adopted (e.g., von Koerber et al. 2021; Wiśniewski 2021; Yong Ngondjeb and Ayuk 2021).
The positive examples include the case of a
compost business model for Nairobi (Gebrezgabher et al. 2021), the successful adoption of
integrated resources management practices in
Northern Ethiopia (Tesfahunegn and Ayuk 2021)
and the implementation of a comprehensive
participatory planning process towards SDGs
(Eichhorn et al. 2021). The chapter by Ariyanti
et al. (2021) stands out since they report on the
case of resources management based on cultural
ecological knowledge, which clearly contains
nexus elements that are still in use. So here, it is
rather about preserving nexus thinking than
about implementing it as a new concept. Negative examples in this book include cases of
purely agriculture oriented policies providing
economic incentives that lead to groundwater
overexploitation (Jaghdani and Kvartiuk 2021;
Riera and Brümmer 2021). Other cases show that
unsustainable land-use practices in watersheds of
reservoirs result in high sediment loads and loss
of water storage capacity (Sang and Maina 2021)
and of hydropower potential (Yong Ngondjeb
and Ayuk 2021). These studies, conversely, also
show the potentials of switching to more holistic
and sustainable policies and practices. Similarly,
the studies of Ramakrishna and Hanisch (2021)
and Fiebrig and van de Wiel (2021) mainly
demonstrate the potentials of adopting a nexus
approach. The former describes a case of
wastewater use, a “golden” example of a nexus
approach—if practiced in a safe manner (Hettiarachchi et al. 2018). However, this was not yet
the case in the study by Ramakrishna and
Hanisch (2021), but they present solutions on
how to mitigate the risks of using untreated
wastewater. Also, the study by Fiebrig and van
de Wiel (2021) mainly shows potentials, since in
the studied case the reservoir built for rainwater
harvesting was badly designed, based on insufficient data. But if planned well, methods of
rainwater harvesting may provide solutions for
sustainable food production under water scarcity.
The studies by von Koerber et al. (2021) and
Wiśniewski (2021) were conceptualized as feasibility studies from the beginning. Both show
convincingly the potential of nexus thinking to
result in increased resource efficiency (von
Koerber et al. 2021) and to foster the transition to
a low carbon economy (Wiśniewski 2021).
Several studies point to the importance of
knowledge transfer, education and capacity
development in a broad sense. This aspect is
explicitly addressed in Haupt et al. (2021) for the
case of city-to-city learning with regard to climate adaptation. Knowledge transfer is also
addressed by Bouma (2021), who talks about
scientists as “knowledge brokers”. Ramakrishna
and Hanisch (2021) stress the importance of
capacity development to foster safe use of
wastewater, Sang and Maina (2021) point to the
limited capacities for sediment monitoring both
in terms of equipment and trained staff, Tesfahunegn and Ayuk (2021) report about various
means of knowledge transfer such as farmer’s
field days.
Several studies presented here had started
quite a while ago and had been originally conceptualized as IWRM projects. This holds, e.g.,
for Sang and Maina (2021), Tesfahunegn and
Ayuk (2021), von Koerber et al. (2021) and
Ariyanti et al. (2021). However, since taking a
balanced approach towards at least two resources, they easily qualified convincingly as nexus10
S. Hülsmann and M. Jampani
that working groups, steering committees, etc.
work efficiently and independently.
5 Conclusions and Outlook
Coming back to the introductory statement, we
indeed conclude that “the nexus is more relevant
than ever” as stated by Bouma (2021) and this
can be deduced both from positive examples of
nexus implementations (e.g., Eichhorn et al.
2021; Gebrezgabher et al. 2021; Tesfahunegn
and Ayuk 2021) as well as from those studies,
which show that the lack of nexus-oriented
policies results in unsustainable management
practices (e.g., Jaghdani and Kvartiuk 2021;
Riera and Brümmer 2021; Sang and Maina 2021)
or from studies which demonstrate the feasibility
of positive outcomes if a nexus approach would
be adopted (e.g., von Koerber et al. 2021; Wiśniewski 2021; Yong Ngondjeb and Ayuk 2021).
The positive examples include the case of a
compost business model for Nairobi (Gebrezgabher et al. 2021), the successful adoption of
integrated resources management practices in
Northern Ethiopia (Tesfahunegn and Ayuk 2021)
and the implementation of a comprehensive
participatory planning process towards SDGs
(Eichhorn et al. 2021). The chapter by Ariyanti
et al. (2021) stands out since they report on the
case of resources management based on cultural
ecological knowledge, which clearly contains
nexus elements that are still in use. So here, it is
rather about preserving nexus thinking than
about implementing it as a new concept. Negative examples in this book include cases of
purely agriculture oriented policies providing
economic incentives that lead to groundwater
overexploitation (Jaghdani and Kvartiuk 2021;
Riera and Brümmer 2021). Other cases show that
unsustainable land-use practices in watersheds of
reservoirs result in high sediment loads and loss
of water storage capacity (Sang and Maina 2021)
and of hydropower potential (Yong Ngondjeb
and Ayuk 2021). These studies, conversely, also
show the potentials of switching to more holistic
and sustainable policies and practices. Similarly,
the studies of Ramakrishna and Hanisch (2021)
and Fiebrig and van de Wiel (2021) mainly
demonstrate the potentials of adopting a nexus
approach. The former describes a case of
wastewater use, a “golden” example of a nexus
approach—if practiced in a safe manner (Hettiarachchi et al. 2018). However, this was not yet
the case in the study by Ramakrishna and
Hanisch (2021), but they present solutions on
how to mitigate the risks of using untreated
wastewater. Also, the study by Fiebrig and van
de Wiel (2021) mainly shows potentials, since in
the studied case the reservoir built for rainwater
harvesting was badly designed, based on insufficient data. But if planned well, methods of
rainwater harvesting may provide solutions for
sustainable food production under water scarcity.
The studies by von Koerber et al. (2021) and
Wiśniewski (2021) were conceptualized as feasibility studies from the beginning. Both show
convincingly the potential of nexus thinking to
result in increased resource efficiency (von
Koerber et al. 2021) and to foster the transition to
a low carbon economy (Wiśniewski 2021).
Several studies point to the importance of
knowledge transfer, education and capacity
development in a broad sense. This aspect is
explicitly addressed in Haupt et al. (2021) for the
case of city-to-city learning with regard to climate adaptation. Knowledge transfer is also
addressed by Bouma (2021), who talks about
scientists as “knowledge brokers”. Ramakrishna
and Hanisch (2021) stress the importance of
capacity development to foster safe use of
wastewater, Sang and Maina (2021) point to the
limited capacities for sediment monitoring both
in terms of equipment and trained staff, Tesfahunegn and Ayuk (2021) report about various
means of knowledge transfer such as farmer’s
field days.
Several studies presented here had started
quite a while ago and had been originally conceptualized as IWRM projects. This holds, e.g.,
for Sang and Maina (2021), Tesfahunegn and
Ayuk (2021), von Koerber et al. (2021) and
Ariyanti et al. (2021). However, since taking a
balanced approach towards at least two resources, they easily qualified convincingly as nexus10
S. Hülsmann and M. Jampani