OR/15/047 Introduction

From MediaWiki
Jump to navigation Jump to search
MacDonald A M, Bonsor H C, Taylor R, Shamsudduha M, Burgess W G, Ahmed K M, Mukherjee A, Zahid A, Lapworth D, Gopal K, Rao M S, Moench M, Bricker S H, Yadav S K, Satyal Y, Smith L, Dixit A, Bell R, van Steenbergen F, Basharat M, Gohar M S, Tucker J, Calow R C and Maurice L. 2015. Groundwater resources in the Indo‐Gangetic Basin: resilience to climate change and abstraction. British Geological Survey Internal Report, OR/15/047.

The Indo Gangetic Basin (IGB) alluvial aquifer system is one of the world’s most important water resources. Formed with sediments eroded from the Himalayas and redistributed by the Indus, Ganges and Brahmaputra rivers, the IGB forms a flat fertile plain across Pakistan, northern India, southern Nepal and Bangladesh — Figure 1. The groundwater abstracted from the aquifer system comprises approximately a quarter of the world’s total groundwater abstraction (Wada 2010[1], Seibert 2007[2]) with more than 90% used for irrigation which underpins the dramatic agricultural success of the region (Shah 2009[3]). The IGB alluvial aquifer system has been regarded as comprising one highly permeable continuous aquifer, and is often represented as one category on hydrogeological maps (Struckmeier and Richts 2008[4]; CGWB 2012[5]). However, in practice the system is complex and heterogeneous with large spatial differences in groundwater recharge, permeability, storage and water chemistry. This complexity controls how each part of the aquifer responds to current and future stresses.

There are an estimated 15–20 million[6]To continue to develop and use groundwater, while minimising the unwanted side effects, it is important to first understand the aquifer systems and how they respond to abstraction, pollution and climate variability (Foster and MacDonald 2014[7]). To help this process we have developed a series of groundwater typologies for the Indo Gangetic Basin, highlighting areas which are likely to respond in a consistent manner, regardless of international boundaries. In doing so, we have developed several basin wide data sets: building on the geology and sedimentology of the basin; using national datasets of groundwater abstraction, water level change and chemistry; drawing on international climate data; and reviewing many individual studies, publications and datasets. We do not consider here the many different approaches to governing groundwater across the region; rather, by systemising information on the nature of the aquifer, the current pressures on it, and the resilience of groundwater to change, we provide information that should be useful in assessing the efficacy of current and future approaches to groundwater management.

Figure 1 Location map of the IGB with rivers and digital elevation map.

References and footnote

  1. Wada, Y, Beek, L P H, van, van Kempen, C M, Reckman, J W T M, Vasak, S, Bierkens, M F P. 2010. Global depletion of groundwater resources, Geophysical Research Letters, 37; L20402
  2. Siebert S et al. 2007. Global Map of Irrigation Areas version 4.0.1. Johann Wolfgang Goethe University, Frankfurt am Main, Germany/Food and Agriculture Organisation of the United Nations, Rome Italy.
  3. Shah T. 2009. Climate change and groundwater: India’s opportunities for mitigation and adaptation, Enironmental Research Letters, 4; doi: 10.1088/1748‐9326/4/3/035005
  4. Struckmeier W and Richts A 2008. Groundwater resources of the World (1:25 000 000). World Wide hydrogeological mapping and assessment programme, UNESCO/BGR
  5. CGWB. 2014. Ground Water Year Book 2012–13 — India. CGWB. 100 pp
  6. Estimated 8–12 million in Bangladesh (Khan et al. 2007, Holly and Voss 2009); approx.1 million in Sindh and Punjab in Pakistan (Yu et al. 2013; estimated 6–7 million in aquifer within India in 2007 (GOI 2012; Rawat and Mukherji 2012
  7. Foster S and MacDonald A M. 2014. The 'water security' dialogue: why it needs to be better informed about groundwater. Hydrogeology Journal, 22; 7, 1489–1492.