Assessment of climate change impact on water resources in the Pungwe river basin

Abstract

A B S T R A C T The Rossby Centre Regional Climate Model (RCA3) and the hydrological model HBV were linked to assess climate change impacts on water resources in the Pungwe basin until 2050. RCA3 was capable of simulating the most important aspects of the climate for a control period at the regional scale. At the subbasin scale, additional scaling was needed. Three climate change experiments using ECHAM4-A2, B2 and CCSM3-B2 as input to RCA3 were carried out. According to the simulations annual rainfall in 2050 would be reduced by approximately 10% with increasing interannual variability of rainfall and dry season river flow and later onset of the rainy season. The ECHAM4-A2 driven experiment did also indicate a slight increase of high flows. If the results indeed reflect the future, they will worsen the already critical situation for water resources, regarding both floods and droughts. Uncertainties, however in the downscaled scenarios make it difficult to prioritize adaptation options. This calls for inclusion of more climate change experiments, in an ensemble of climate scenarios possibly by using a combination of dynamical and statistical downscaling of general circulation models, as well as extending the simulations to 2100 to further ensure robustness of the signal.

Adaptation to climate change and other stressors among commercial and small-scale South African farmers

“…They then discussed the implications of the effects of the climate change projections and identified relevant adaptation strategies and their limitations and facilitating factors (Andersson et al 2009;Andersson et al 2010). The empirical material used in this paper is mainly based on the results of interviews undertaken in the PAMO project supplemented by material from the project's participatory workshops.…”

“…While climate scenarios show a drying in the western region of South Africa (Schulze 2011), regionally downscaled climate change projections for the study area, indicated wetter conditions with higher average annual and summer rainfall and fewer days with low river flow. In addition, the frequency of dry and wet extremes could increase (Andersson et al 2009;Graham et al 2011).…”

“…caused by sleeping in damp houses or standing in water logged areas. Suggested adaptive strategies included making contours, building stone structures to hinder runoff and digging furrows to lead water away from fields and houses (Andersson et al 2009). …”

“…In South Africa, knowledge transmission between farmers can be an important means of selecting and adopting new and better farming techniques and practices (Chikhozo 2005;Andersson 2009). Introductions of new techniques are more readily adopted if adapted to local conditions, tested by leader farmers on experimental plots and if sufficient time is allocated to allow farmers to gain familiarization, trust and new skills (Chikozho 2005;SSI 2009).…”

Hydropower Production in Future Climate Scenarios: The Case for Kwanza River, Angola

“…Although there have been some studies on climate change within this region there are none specific to the Kwanza River Basin, in Angola. Some of the most recent studies in southern Africa region assessed the Zambezi River Basin [10], the Okavango delta in Botswana [11][12][13][14] and the Pungwe River Basin in Zimbabwe and Mozambique [15].…”