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WATER


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OVERVIEW

Of all the natural resources, water perhaps demonstrates most fully the interdependence of
the physical and human spheres. Human societies have a great impact on the hydrological
cycle, diverting rivers, damming flow and abstracting water from surface and groundwater
stores. Human societies are also greatly susceptible to changes in water resources such
as flooding, droughts and the availability of potable water.

This chapter discusses basic hydrological processes and examines wetlands as aquatic habitats of international importance. Extreme flows of floods and droughts are considered, and also how humans affect water quantity and quality.

LEARNING OUTCOMES

After reading this chapter, you should be able to understand:

• Basic hydrological processes
• The nature of extreme flow: floods and droughts
• Wetlands as a fragile and diverse habitats
• The impact of human activities on the hydrological cycle from the creation of urban
  surfaces, building of dams, groundwater abstraction and the deterioration of water
  quality
• International concerns facing water supply and management.
  

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SUMMARY

Water is an essential and precious resource governing human health and activities from agriculture to industrial development. The hydrological cycle has the ability to greatly affect human society through floods and droughts; and it is generally the most vulnerable groups, such as shanty dwellers on floodplains and those dependent upon rain-fed agriculture, that suffer the most. Climate change will influence global precipitation patterns and distribution, which in turn will affect
the magnitude, frequency and severity of floods and droughts in the future.

The effects upon human societies are likely to be immense. In turn, human activities – the draining of wetlands, overexploitation of groundwater, pollution of watercourses and so forth – affect all aspects of the hydrological cycle and all aquatic habitats. Human activities have severely affected water quantity and quality, with concomitant negative impacts on aquatic habitats and human health. The growing understanding of water flows and processes, and the awareness of human impacts, have initiated attempts to regulate and control activities within the catchment. An example is the European Water Framework Directive, which takes a holistic approach to stop and prevent further deterioration of water resources and promote the sustainable use of water. However, the long-term effects of some impacts and pollutants mean that the problems will not be easy to solve in the short-term future.

Looking ahead, global attention needs to focus on the major problems of insufficient water resources, and the provision of affordable safe drinking water, particularly in the developing world, where unsafe drinking water and waterborne diseases claim too many lives.

QUESTIONS

1. What might be the impact of climate     change on precipitation and evaporation     patterns and how might this affect runoff,     soil moisture and groundwater levels? 5. What are the advantages and    disadvantages of sourcing water from a    large dam and from pumping groundwater? 2. Why have wetland environments been the     focus of drainage and destruction? What     benefits and goods do wetlands provide for     society? 6. What are the concerns about deteriorating    water quality in surface and groundwater    stores? 3. How can the risk of floods and droughts be    managed, and what can be done to    minimize their impacts? 7. How can a secure and clean water supply    be provided in an equitable and affordable    way in the face of water shortages? 4. What are the short- and long-term effects    of the increase in irrigation in terms of    water demand, supply and security? 8. How does the position of water as a    human right conflict with privatization of    water supply and profit making?

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FURTHER READING

Good texts on the topics introduced in this chapter include:

• Arnell, N. (2002) Hydrology and Global Environmental Change. Harlow: Prentice Hall.
  Full of useful information and ideas.
  
• Jones, J. A. A. (1997) Global Hydrology: Processes, Resources and Environmental Management. Harlow: Longman.
  An excellent text on water in a global setting.
  
• Newson, M. (1994) Hydrology and the River Environment. Oxford: Clarendon Press.
  A good text linking hydrology with aquatic ecology.
  
• Ward, R. C. and Robinson, M. (1999) Principles of Hydrology, 4th edn. London: McGraw-Hill.
  Classic hydrology text covering the subject in a detailed non-mathematical way.
  
• Fetter, C. W. (1994) Applied Hydrogeology, 3rd edn. Upper Saddle River, New Jersey: Prentice Hall.
  An excellent introduction to hydrogeology.