loading page

Tree-Ring Evidence of Increasing Drought Risks over the Past Five Centuries amidst Projected Flood Intensification in the Kabul River Basin (Afghanistan and Pakistan)
  • +1
  • Nasrullah Khan,
  • Hung T.T Nguyen,
  • Stefano Galelli,
  • Paolo Cherubini
Nasrullah Khan
Laboratory of Plant Ecology Department of Botany, University of Malakand, Laboratory of Plant Ecology Department of Botany, University of Malakand
Author Profile
Hung T.T Nguyen
Lamont-Doherty Earth Observatory, Columbia University, Columbia University

Corresponding Author:[email protected]

Author Profile
Stefano Galelli
Singapore University of Technology and Design, Singapore University of Technology and Design
Author Profile
Paolo Cherubini
WSL Swiss Federal Research Institute, WSL Swiss Federal Research Institute
Author Profile

Abstract

Increased flood risks have been projected in the Kabul River Basin, but with large uncertainties. To place future changes in a long-term perspective, we produce a 501-year precipitation reconstruction for the basin using seven tree-ring chronologies of Cedrus deodara, Picea smithiana, and Pinus gerardiana from the Hindukush Mountains, a monsoon-shadow area. The reconstruction proves robust over rigorous cross-validations (R2 = 0.62, RE = 0.61, CE = 0.53). The full reconstruction (1517–2018) shows heterogeneous changes in the precipitation distribution: there is a weak increasing trend in the median annual precipitation, no apparent trend in the 50-year maximum precipitation, and, importantly, a steadily decreasing trend in 50-year minimum precipitation. In other words, our reconstruction shows that drought risks have been increasing over the past five centuries. Drought risks, compounded with projected flood intensification, pose significant threats for the transboundary river. Future water management decisions should factor in past long-term climate variability.