Long-range predictablity of Zimbabwe summer rainfall

The potential for long‐range prediction of Zimbabwe summer rainfall is investigated using an analysis of variance approach. It is assumed that the variance between seasons (inter‐annual variability) is made up of two components: the climate noise (intra‐seasonal variability) and signal (any variance above the noise). The magnitude of the climate noise is estimated by computing the variance of time‐averaged rainfall data based on a statistical model whose parameters are derived from observed daily values at each station. Results from the study indicate that up to approximately 70% of the total variance in Zimbabwe summer rainfall is potentially predictable at long range. Predictability is greatest during the last half of the rainy season, January to March, and much lower during October to December. The south section of the country shows relatively more predictability than the north. Comparisons between signal and noise are discussed in the context of long‐range predictability. The natural variability (noise) is proposed as a lower limit of the standard error of the estimate for any long‐range precipitation forecast for the country

Spatial characterization of Zimbabwe summer rainfall during the period 1920-1996: pages 430-31

Spatial patterns of inter-annual summer rainfall variability over Zimbabwe are investigated using principal component analysis for the period 1920-96. Inter-annual rainfall anomalies for all years and stratified according to warm El Niño - Southern Oscillation (ENSO) events are used in the study. The varimax rotated PC loadings subdivide the country into three regions, north, southwest and southeast. Because of the high correlation between two of the regions, only two regions, north and south, consistent with the underlying physical processes are retained. The two leading PCs are consistent with the main rain-producing synoptic weather systems affecting the country during austral summer. Inter-comparison of the rainfall anomaly time series from the two regions reveals that the major controlling factors influencing inter-annual rainfall variability are possibly of a global or hemispheric nature. The spatially coherent regions have practical use in the development and application of long-range seasonal climate forecasts and climate change studies. The file associated with this record contains pages 430-31 of this article

The impacts of community-based cash management tools on smallholder rural farmers’ access to livelihood assets

Smallholder rural farmers are exposed to diverse idiosyncratic and covariate shocks that lead to high income and consumption volatility. Formal cash management tools, which are important for managing risk and volatility, often break down due to high information asymmetries and the transaction costs of operating in rural areas. Given this, community-based cash management tools have continued to be a dominant means of managing risk in rural areas. Community-based cash management tools can be home grown or externally induced, e.g. NGO-initiated savings groups. This study finds that participation in such savings groups significantly expands access to the financial resources that can be used to purchase goods and services, as well as to the social networks that are needed to support smallholder farmer livelihoods. However, the impact on access to physical and natural capital (at least in the short to medium term) is not significant, thus calling for complementary development interventions to reduce smallholder farmers’ vulnerability