Okavango Delta Management Plan - Ramsar Convention on Wetlands

3.2.3.1 Climate change
The issue of the potential impact of climate change on the ecosystem has regularly been
raised in meetings and was captured during the ODMP project design phase (ODMP –
Project Proposal, 2002). In order to address this issue, an integrated hydrological model
was developed during the ODMP planning phase to assess the <strong>Okavango</strong> <strong>Delta</strong> hydrological
response to various natural and anthropogenic scenarios (ODMP – Integrated Hydrological
Model, 2006).
The scenario simulations showed that projected climatic change has potentially the greatest
impact on the basin and the <strong>Delta</strong> reducing both inflows from upstream and rainfall over
the <strong>Delta</strong>, and increasing temperature and the rate of evapotranspiration. The lower
envelope of flooding is reduced by 68%, from 2,770km 2 to 900km2 (ODMP – Analysis of
Water Resources Scenarios, 2006). It is believed that climatic change in Southern Africa
will result in decrease in rainfall and temperature increase in the longer term, leading to
reduced flows and high evaporation rates (ODMP – Water Resources Scenarios, 2006).
It is important that the sectors such as tourism, agriculture, susbsistance and commercial
use of vegetation resources, water and fisheries which are likely to be affected by the
impact of climate change initiate the development of coping strategies.
3.2.3.2 Seismic Activities
The <strong>Delta</strong> area is tectonically active and the last major earthquake in Maun 1954 had a
magnitude of 6.4 on the Richter scale. At that time most buildings were low, made of mud,
reeds and grass so the damage was probably limited (NDSS, 2004). Now an earthquake of
the same magnitude could cause major damage to the modern building structures.
The impact of such seismic activities may also accelerate the river channels and flood
distribution in the <strong>Delta</strong> which otherwise are moving over time scales of decades and
decennia. Gumbricht and McCarthy (2002) attribute the present sediment accumulation in
the Panhandle, the Xho flats, and the secular water distribution changes on the fan surface
from Jao-Boro towards Xudum to small scale tectonic activities. Areas that now are dry
with developments and buildings on them may again come under water. Developments like
tourist lodges that are located close to scenic water ways may find that the river suddenly
has taken another route.
Although geotechnical investigations indicate a 100 year maximum probability of such an
earthquake event happening (Patridge, Maude Associates, 1998), there is need to introduce
building codes which would specify special requirements for foundations and structural
designs in the district.
In as far as the impacts on the tourism business are concerned, a precautionary principle
should be applied in the sector’s business and management plans.
Sesmic events have a potential to have profound impacts on the functioning and dynamics
of the <strong>Okavango</strong> <strong>Delta</strong>. Small sesmic activities will possibly afecte the flooding partterns
while large ones will have far reaching consequences. It is crucial that predictive models are
developed that can be used to inform responsive actions.
3.2.3.3 Fires
Fire plays a major part in the ecological functioning and processes of the <strong>Okavango</strong> <strong>Delta</strong>.
The fires that occur in the <strong>Delta</strong> are a result of two causal agents, anthropogenic and
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