Hydropower potential in the Kabul River under climate change scenarios in the XXI century

Abstract

Global policies for mitigation of global warming GW will require countries to rely as possible upon renewable, clean energy sources. This includes developing countries, in need to foster suitable life conditions under population growth. Hydropower can deliver such renewable energy, pending water availability and proper management. In central Asia, water resources management is an urgent challenge, especially given desert climate, and the expected impacts of transient climate change hereon. While some catchments will still receive large shares of water from transient melting of the water towers in the Himalayas, others will not, given their little ice cover, in spite of the high altitudes. This is the case of Kabul River of Afghanistan, displaying low rainfall and high altitude, and yet displaying very small ice cover, and where further the present hydropower network is limited and partly damaged by recent conflicts. The goal of this work is to evaluate hydropower potential of the Kabul River and subsequently potential hydropower coverage of energy demand, under the hypotheses that (i) the present network would work at its largest potential and (ii) that hydrological regimes will change in response to scenarios of climate change, until the end of XXI century. To do so, we use a sparse array of data to tune the Poli-Hydro model, able to model hydrology of high altitude, poorly monitored catchments as here. Using modelled (and otherwise unknown) streamflows entering the present power plants (reservoirs + power-houses), we then simulate water management for hydropower purposes. We use two conditions, namely (i) run-of-river ROR and (ii) storage, and (optimal) regulation STO, allowing multipurpose use of water when necessary (e.g. irrigation needs). We then feed Poli-Hydro with IPCC climate scenarios (plus downscaling) until 2100, to carry out a sensitivity analysis (what if? scenarios) of (i) hydrological cycle and (ii) hydropower production. The future hydrological regimes are largely affected by uncertain future precipitation, and so is hydropower production. In spite of potentially increased hydropower on average (+ 1.4% at mid-century, + 1.7% at 2100), driven by variably changing stream flows, some scenarios indicate decreased overall production (down to − 3%) at half century. We provided here a tool usable to (i) assess present and future hydropower potential in the Kabul River, (ii) direct improvement of the present plants network and (iii) benchmark proposals for future network extension.