**4. Conclusions**

Monitoring groundwater resources using remote sensing techniques alleviates the pressure on the routine monitoring of sparsely distributed monitoring wells. Moreover, the use of satellites allows for the acquisition of data at spatio-temporal scales that would otherwise be inaccessible.

Although the historical data used in the study do not take into consideration anthropogenic impacts on changes in groundwater storage, the results show that groundwater resources in the region are declining, and these changes can be attributed to the effects of climate change.

Thus, with improved monitoring (taking into consideration anthropogenic activities) coupled with sound management, the protection, conservation and sustainability of groundwater resources in Southern Africa may be improved.

The study shows that the poor management of water resources (local, regional and international) as a result of the lack of data and information as well as the lack of resources (human, financial and infrastructural) can be overcome with the use of

<sup>1</sup> Agreement on the Al-Sag/Al-Disi Aquifer, Franco-Swiss Genevese Aquifer, Iullemeden Aquifer System, Guarani Aquifer System, North-Western Sahara Aquifer System, and the Nubian Sandstone Aquifer.

remote sensing techniques coupled with the application of geographical information systems. The results obtained in this study are applicable at all spheres of water management and governance (freshwater resources including both surface and groundwater resources, as well as brackish and marine water resources), from the local, municipal, provincial, national as well as regional and international scales. Moreover, similar results can be achieved in other fields of study too wherever RS data are available and accessible and where GIS is applicable.
