TC Afghanistan: Hydrogeology of the Kabul Basin

Report of the project:

• Afghanistan – Verbesserung des Grundwasserschutzes zur präventiven Abwehr von Dürreproblemen im Kabul-Becken

The Kabul Basin Source: BGR

Shallow groundwater represents at present the main source for water supply in Kabul. Detailed information on the hydrogeology of the Kabul basin is therefore needed to improve the current supply situation and to develop sustainable concepts of groundwater use. The basin comprises three major aquifers, all consisting of coarse sandy to gravely material originating from the surrounding mountains. Usually the aquifers are covered by loess loams which are an important feature in groundwater protection. The coarse aquifer material implies a high permeability. Deeper parts are affected by cementation of pore spaces, resulting in formation of semi-diagenetic conglomerates causing a decreased well yields. The main groundwater recharge stems from direct exfiltration from the rivers after the snowmelt and from foothill infiltration.

The draught of the last few years and a steadily rising population have lead to a strong overexploitation of the groundwater resource. The groundwater is characterised by slightly oxic redox conditions. Interactions with aquifer carbonates lead to high degrees of hardness and near-neutral pH. The mostly negative water budget of the Kabul basin results in strong evaporation which leads to an increase in salt contents and also of some undesirable constituents, e.g. borate. The shallow groundwater in the city has received tremendous amounts of pollutants due to a lack of proper waste and wastewater disposal. Common indicators are elevated concentrations of nutrients such as nitrate and faecal bacteria. The high infant mortality can at least partially be attributed to the insufficient water hygiene. Acid generated during the mineralization of the waste water is hidden due to the strong pH buffering capacity. Redox and pH conditions preclude significant mobilisation of trace metals and metalloids.

Literature:

• Summary Report (PDF, 492 KB)
  
  
• TÜNNERMEIER, T. & HOUBEN, G. (2005): Hydrogeology of the Kabul Basin, Part I: Geology, aquifer characteristics, climate and hydrography. - Report of the project "Improving groundwater protection for the preventative avoidance of drought problems in the Kabul Basin, Afghanistan"; 46 p., Hannover. (PDF, 2 MB)
  
  
• HOUBEN, G. & TÜNNERMEIER, T. (2005): Hydrogeology of the Kabul Basin, Part II: Groundwater geochemistry and microbiology. - Report of the project "Improving groundwater protection for the preventative avoidance of drought problems in the Kabul Basin, Afghanistan"; 97 p., Hannover. (PDF, 4 MB)
  
  
• NIARD, N. (2006): Hydrogeology of the Kabul Basin, Part III: Modelling approach - conceptual and numerical groundwater models. - Report of the project "Improving groundwater protection for the preventative avoidance of drought problems in the Kabul Basin, Afghanistan"; 103 p., Hannover. (PDF, 3 MB)
  
  
• KREKEKER, T. (2008): Decentralised Sanitation and Wastewater Treatment. Revised 2nd edition: 65 p., Hannover. (PDF, 1 MB)
  
  
• NIARD, N. (2005): Approche par modélisation pour améliorer la compréhension du fonctionnement hydrogéologique dans la région de la ville de Kaboul en Afghanistan. 117 p., Hanovre. (PDF, 7 MB)