A prime focus of UNESCO's initiatives under the groundwater component of the IHP has been on hydrogeological information, research and analysis and their role in policy, public dialogue and integrated water resource management (including risk analysis and transboundary aspects). In particular, the collaboration with the International Association of Hydrogeologists (IAH) has yielded authoritative work in the areas of:
mapping and modelling of large-scale aquifer systems;
the nature and variability and recharge styles;
the scale and intensity of groundwater degradation;
techniques for enhancing recharge.
The only systematic regional surveys of groundwater occurrences were compiled in the 1980s by the then UNDTCD (now merged into the UNDESA) under the Water Series publications. This comprehensive work has not been updated, but at the time it represented the only systematic portrait of groundwater occurrences on a country-by-country basis with an indication (where possible) of trends in groundwater resource use.
The degree to which the broad array of information on specific aquifers, systems and scientific themes related to groundwater can be combined to present a coherent 'state of the art' on the resource base is questionable. The proliferation of relevant material at country level would overwhelm a global exercise and the benefits would be negligible in comparison with the urgent local problems on which groundwater management has to focus.
The specific role of groundwater in socio-economic development has been widely recognized for the past 50 years (United Nations, 1960 and 2000). The specific advantage of groundwater is its ubiquity, and this ubiquity presents particular problems in its management. The spatial and temporal distribution of groundwater occurrences has presented certain opportunities for the development of rural communities, urban centres and irrigated agriculture. It is the patterns of groundwater use that serve as a starting point for considering management options. For example, the patterns and management of groundwater and aquifer use in urban areas are distinguishable from those in rural areas. There are two distinct styles of use that exhibit and require distinct management solutions for each setting. In many arid and semi-arid urban areas, local aquifers are often the water resource of last resort and also the ultimate pollution sink. In these areas, the range of services provided by underlying aquifer systems is usually more complex than that demanded by adjacent rural dwellers. The systems of rights in use differ markedly. Rural users generally abstract groundwater themselves through wells that they own and control. Urban users are one step removed with extraction being the responsibility of organizations such as municipal supply utilities. This difference has legal implications. Rural users anticipate access in the form of direct abstraction from local aquifers (irrespective of their legal or customary status). It is important that this access be protected in the form of a property right or a declared right in use. On the other hand, most urban dwellers and businesses anticipate municipal services derived from groundwater resources without any sense of real engagement with the resource (or right in use).
The rural pattern is characterized by a mix of dispersed potable, stock-watering and irrigation applications. The irrigation can often be locally intensive and crowd out other uses. Drawdown externalities are evident in many systems as shallow wells dry up and pressures are lost. The urban pattern differs markedly as the aquifer systems are expected to provide reliable sources of potable water from dedicated well fields (and supplementary private sources where reticulated systems are unreliable) and also to absorb effluent. Groundwater rise in superficial aquifers underlying urban areas poses geotechnical and public health problems
Irrigated agriculture and municipalities are often perceived as the predominant users of groundwater; urban centres looking for low to moderate volumes of high-quality water, and irrigated agriculture looking for high volumes of raw water, being indifferent about quality unless the groundwater is saline.
In practice, urban centres are struggling to maintain the quality of local groundwater sources and urban development is expanding on recharge areas. Irrigated agriculture is using large volumes of high-quality groundwater in inefficient field distribution and drainage systems with attendant problems of salinity and waterlogging. The advent of mechanized boreholes has encouraged rapid depletion of deeper, non-renewable sources. While this pattern of groundwater use is unsustainable in terms of renewable water resources, planned depletion and the assumption of substitutionality (Schiffler, 1998) are seen as valid development paths.
What is much more difficult to resolve is the sustainable development of the apparently low-intensity use of shallow groundwater in rural communities. In fact, this use is highly intensive in terms of the available resource base. In many semi-arid zones of the world, the locally exploitable groundwater resource is often depleted or drained by the end of the dry season. In addition, domestic use is not limited to potable water and personal hygiene use, but also to stock watering and small-scale irrigation. In aggregate, these uses are significant and key to the welfare and development of the bulk of the populations in developing countries.
There is now increasing pressure for the specific role of groundwater in environmental systems to be realized and accounted for. To this extent, environmental systems could be counted as a 'user'. The problem lies in finding a way to allocate between uses and the need to value the set of environmental benefits and compare them with extractive uses. This is not a trivial issue, and a range of standard cost-benefit analysis and multicriteria analyses have been deployed to try and reconcile these competing uses.
The bulk of hydrogeological and groundwater development/protection research remains largely technocratic. The volume of social research related to groundwater use is small in comparison with the volume of research on groundwater flow and remediation. This trend is changing to the extent that the 2002 IAH Congress focused specifically on the human uses of groundwater (the 2001 Congress dealt with new approaches to characterizing groundwater flow). Box 6 shows how use issues are also being recognized increasingly within UNESCO's IHP VI.
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BOX 6: IMPLEMENTATION PLAN OF THE GROUNDWATER COMPONENT OF UNESCO'S IHP VI 1. Establishment of guidelines for transboundary aquifer resources management. 2. Improvement of the management of shared river basins through understanding groundwater interactions. 3. Establishment of an international groundwater resources assessment centre. 4. Effects of global changes on groundwater recharge, especially in arid and semi-arid regions in relation to water resources management. 5. Methodologies for risk assessment of wastewater reuse on groundwater quality. 6. Development of methodology for studying responses of aquifers to extreme hydrological events. 7. Study of the dynamics of groundwater flow and chemistry in closed basins including long-term effects, especially in arid zones. 8. Guidelines for delineation of protection zones around public groundwater supplies and management policy. 9. Development of groundwater policy and management for wetlands protection and biodiversity conservation. 10. Evaluation of the impact of land-based sources of pollution on coastal zone resources. 11. Methodology for enhancing communication between water specialists, decision-makers and communities to strengthen public participation in groundwater protection. |
In addition, two cross-cutting programme components FRIEND and HELP interact through their operational concept with IHP VI and will support any joint UN-agency programmes. Other specific initiatives on groundwater quality protection and remediation will require the application of innovative and especially cost-effective methods to clean up pollution in soils and aquifers including:
in situ bioremediation approaches;
reactive barriers;
source zone treatment;
flow and transport modelling;
site characterization.
These activities respond to declared needs from the specialist groups to examine institutional and policy issues in tandem with the technical matters.
However, there appears to be a reluctance to view groundwater resource management from the perspective of the de facto regulator, i.e. the individual user with a mechanized pump. This suggests a need to approach groundwater management as a socio-economic issue together with a sound technical perspective. The institutions 'responsible' for managing and regulating groundwater resources need to focus on social mobilization as a priority. This does not imply that the role of technical understanding of aquifer systems is reduced. Rather, it strengthens the case for enhanced understanding and communication of these systems within broader political and socio-economic frameworks. However, the fact remains that aquifer systems are difficult (and expensive) to characterize, monitor and regulate.
The work by Shah (1993) is one of the few attempts to analyse the political and socio-economic context of groundwater. However, the distributed nature of the resource necessitates managing a large number of diffuse, low-intensity investment decisions. If these investments in groundwater are to be realized, then it is contingent upon the investors to examine the sustainability of the resource and the regulation of its abstraction by the multiplicity of users.
Therefore, project formulators need to be aware of the potential problems associated with groundwater development. In many cases, these have less to do with volumes of abstracted water than with the changes in groundwater levels that the abstraction produces. Thus, resource assessments need to focus on establishing the local hydrodynamic limits of abstraction and waste disposal. Equally important is the understanding of the potential for managing or influencing the new patterns of use, patterns that are often highly dispersed and individualized (Burke and Moench, 2000).
