Drought in Africa has been extensively researched, particularly from meteorological, agricultural, and food security perspectives. However, the impact of drought on water security, particularly ground water dependent rural water supplies, has received much less attention. Policy responses have concentrated on food needs, and it has often been difficult to mobilize resources for water interventions, despite evidence that access to safe water is a serious and interrelated concern. Studies carried out in Ghana, Malawi, South Africa, and Ethiopia highlight how rural livelihoods are affected by seasonal stress and longer-term drought. Declining access to food and water is a common and interrelated problem. Although ground water plays a vital role in buffering the effects of rainfall variability, water shortages and difficulties in accessing water that is available can affect domestic and productive water uses, with knock-on effects on food consumption and production. Total depletion of available ground water resources is rarely the main concern. A more common scenario is a spiral of water insecurity as shallow water sources fail, additional demands are put on remaining sources, and mechanical failures increase. These problems can be planned for within normal development programs. Water security mapping can help identify vulnerable areas, and changes to monitoring systems can ensure early detection of problems. Above all, increasing the coverage of ground water-based rural water supplies, and ensuring that the design and siting of water points is informed by an understanding of hydrogeological conditions and user demand, can significantly increase the resilience of rural communities to climate variability.

Assessment of recharge in a structurally complex upland karst limestone aquifer situated in a semi-arid environment is difficult. Resort to surrogate indicators, such as measurement of spring outflow and borehole discharge, is a common alternative, and attempts to apply conventional soil moisture deficit analysis may not adequately account for the intermittent spate conditions that arise in such environments. A modelling approach has been made using the West Bank Mountain Aquifer system in the Middle East as a trial. The model uses object oriented software which allows various objects to be switched on and off. Each of the main recharge processes identified in the West Bank is incorporated. The model allows either conventional soil moisture deficit analysis calculations or wetting threshold calculations to be made as appropriate, and accommodates both direct recharge and secondary recharge.Daily time steps enable recharge and runoff routing to be calculated for each node.Model runs have enabled a series of simulations for each of the three aquifer basins in the West Bank and for the whole of the West Bank. These provide recharge estimates Recharge to an upland karst aquifer in a semi-arid environment -Version 3 (7/12/07) 2 comparable to those prepared by earlier workers by conventional means. The model is adaptable and has been successfully used in other environments.

Long-term trends of changes in the quality of water discharging from abandoned coal mines have been studied for 32 long-established discharges in the Midland Valley of Scotland. Six discharges have been studied in greater detail, providing insights into discharge quality evolution over more than a century. It has been found that minewater pollution is most severe in the first few decades after a discharge begins (the 'first flush'), and that even the largest systems settle down to a lower level of pollution (particularly in terms of iron concentration) within 40 years. Long-term iron concentrations of less than 30 mg/1 are typical, and many are less than 10 mg/1. Low pH values (which might justify the over-used term 'acid mine drainage') do not generally persist, due to the rapid buffering of localized acidic waters by carbonates (both natural carbonates, and those introduced as rock powder for fire precautions during mining). This is corroborated by alkalinity concentrations, which tend to be highest in the early years of a discharge. While the pyrite content of the worked sequence strongly influences initial water quality (in terms of pH, iron and sulphate) during the 'first flush', there appears to be no correlation between long-term iron concentrations of discharges and pyrite content of local strata. Rather, higher levels are found in any sequence where there is scope for fluctuations of the water table in worked ground near to the discharge. A scientific approach to minewater remediation should allow for active treatment of discharges for the first decade or two, followed by long-term passive treatment after asymptotic pollutant concentrations are attained.

A BSTRACT The issues pertaining to groun dw ater droug ht are review ed w ith particular regard to the historical and present situations in M alaw i, northern G hana and the N orthern Province of So uth A frica. These three quite different exam ples highlight som e of the m ajor dif® culties facing respective governm ents and donor agencies, not least the shortcom ings of drought-relief drilling program m es,the general lack of routine m onitoring and the need for long er term ana lysis and assessm ent of ground w ater system s than is currently possible. The distinct character of groun dw ater system s and their reaction to prevailing and chang ing env ironm ental conditions is discussed, and it is argued that essentially pred ictable variations in ground w ater drought vulnerability are rarely planned for or acted up on. M anagem ent issues arising are discussed and it is sug gested that governm ents, and particularly donors, should place m ore em phasis on long er term , pre-droug ht m itigation m easures to reduce the need for costly and som etimes ineffective em ergency interventions.

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