In this thesis, an interdisciplinary modelling approach for water resources management
and its application is presented that is able to deal with sociotechnical
systems that are characterised by a multiplicity of variables, interdependencies,
and actors. The case study area is the Cuvelai-Etosha Basin, which
is located in central northern Namibia. Approximately 850,000 people or 40 %
of the Namibian population live in this area, which comprises only about 14 %
of the country’s area. The region is characterised by high precipitation variability
(50-990 mm per year), a very high evaporation rate, the lack of perennial
rivers, and the salinity of the groundwater in large parts of the area. These issues
are a challenge for the regional water supply. The water supply regime in
central northern Namibia is a hybrid between a centralised large technical system
and several decentralised or traditional water supply techniques (e. g.
Oshanas, earth dams (Omatale), dug wells (Omuthima and Oshikweyo), rainwater
harvesting). The large technical system is fed by the Namibian-Angolan
border river Kunene and consists of an open canal and a pipeline scheme with a
length of about 2,000 km. A growing water demand due to population growth,
migration and urbanisation, as well as technical and organisational problems,
illegal extractions, and vandalism will probably jeopardise the situation since
the local water demand exceeds the natural resources.
The main research question is how the observed socio-technical system can be
transformed in a sustainable manner and which key factors enable or impede
such systemic transformations. The study is based on theories and concepts of
systems theory, cybernetics, technological transitions, as well as socio-technical
systems. Several modelling techniques were used in order to answer the research
question. The foundation of the model was formed by the Grounded
Theory, which is a qualitative method of social empirical research. Interviews
with relevant stakeholders provided a deeper insight into their problem perceptions
and world views. After the identification of relevant system variables,
their interrelations and roles within the system were analysed by using the Sensitivity
Model. In doing so, it was possible to identify outstanding variables as
well as processes and to reveal potential regulators, systemic hazards, and viability
indicators. Furthermore, cause-effect chains and feedback loops were analysed,
based on cybernetic approaches. These findings helped to identify regulation
mechanisms for open and closed loop control. Finally, various water supply
scenarios were simulated and then assessed and compared in terms of systemic
risks and viability indicators.