Chapter 3 Assessing the Hydrological Impacts of Climate Change on the Amu Darya River, Afghanistan

Abstract

It is now established by the global scientific community that climate change is a hard reality but the changes are complex in nature and to a great extent uncertain. Global circulation models (GCMs) have made significant contributions to the theoretical understanding of potential climate impacts, but their shortcomings in terms of assessing climate impacts soon became apparent. GCMs demonstrate significant skill at the continental and hemispheric scales and incorporate a large proportion of the complexity of the global system. However, they are inherently unable to represent local subgrid-scale features and dynamics. The first generation approaches of climate change impact and vulnerability assessments are derived from GCMs downscaled to produce scenarios at regional and local scales, but since the downscaled models inherit the biases of their parent GCM, they produce a simplified version of local climate. Furthermore, their output is limited to changes in mean temperature, rainfall, and sea level. For this reason, hydrological modeling with GCM output is useful for assessing impacts. The hydrological response due to change in climate variables in the Amu Darya River Basin was investigated using the Soil and Water Assessment Tool (SWAT). The modeling results show that there is an increase in precipitation, maximum and minimum temperature, potential evapotranspiration, surface runoff, percolation, and water yields. The above methodology can be practiced in this region for conducting adaptation and mitigation assessments. This initial assessment will facilitate future simulation modeling applications using SWAT for the Amu Darya River Basin by including variables of local changes (e.g., population growth, deforestation) that directly affect the hydrology of the region.

Citation

Mohanty, A., Mishra, M., Sharma, D. and Waheed Ibrahimzada, M. (2012), "Chapter 3 Assessing the Hydrological Impacts of Climate Change on the Amu Darya River, Afghanistan", Lamadrid, A. and Kelman, I. (Ed.) Climate Change Modeling For Local Adaptation In The Hindu Kush-Himalayan Region (Community, Environment and Disaster Risk Management, Vol. 11), Emerald Group Publishing Limited, Leeds, pp. 33-52. https://doi.org/10.1108/S2040-7262(2012)0000011009