Viability of karezes (ancient water supply systems in Afghanistan) in a changing world

• DOI: 10.1007/s13201-015-0336-5
• Publication Date: 2015-09-09T22:55:23Z
• Authors: G. L. Macpherson; W. C. Johnson; Huan Liu
• Keywords: Snowmelt; MODFLOW

The Afghanistan population living far from rivers relies upon groundwater delivered karezes (sub-horizontal tunnels). Karezes exploit unconfined in alluvial fans recharged largely by snowmelt the Hindu Kush, central mountain range of country. Since multi-year drought that began 1998, many have stopped flowing. This study characterizes hydraulics a kariz, potential for reduced recharge because climate change, and impact increasing on kariz water production. A typical is 1–2 km long with cross-section m2 gradient 1 m km−1. MODFLOW simulations show delivery can be modeled imposing high ratio hydraulic conductivity to aquifer cells representing kariz. model sensitive conductivity, gradient, length contact table. Precipitation data are scarce Afghanistan, but regional long-term trend decreased snow cover, therefore strong likelihood recharge. Population has increased at rate about 2.2 % over past several decades. An assessment six-district region within Kandahar Province where most likely source indicates demand could caused tables decline 0.8–5.6 m, more than enough cause stop These results suggest production not sustainable under current climate- population-growth trends.