Khan et al. (2025) Impacts of Climate Change on water availability for Agriculture in Indus Basin: A review and Policy Implications

Identification

• Journal: Planta Animalia
• Year: 2025
• Date: 2025-12-22
• Authors: Asif Khan, Muhammad Arif Goheer, Muhammad Ijaz, Ehtisham Wajid
• DOI: 10.71454/pa.004.06.0300

Research Groups

• Global Climate Change Impact Studies Centre, MOCCEC, Pakistan
• National University of Science & Technology Islamabad, Pakistan

Short Summary

This review synthesizes the impacts of climate change on water availability for agriculture in the Indus Basin, finding that while near-term glacier melt may increase summer flows, long-term water availability will decrease, exacerbating existing water stress and necessitating integrated management and adaptation strategies.

Objective

• To critically examine the impacts of climate change (variability in precipitation, temperature, glacier dynamics, and hydrological processes) on surface and groundwater resources for agriculture in the Indus Basin.
• To framework recommendations for improving water availability under changing climate uncertainties and propose policy implications and adaptation strategies.

Study Configuration

• Spatial Scale: Indus Basin, Indus Basin Irrigation System (IBIS), Upper Indus Basin (UIB), Hindu Kush–Karakoram–Himalayan region, Pakistan (including specific regions like Northern, Southern, Central, Coastal Belt, Baluchistan Plateau, Khyber Pakhtunkhwa, Sindh).
• Temporal Scale: Historical records (e.g., 20th century, 1951–2000, 1961–2010, 1937–2011, 1968–2007, 1975–2001, 1976–2005), Near-term, Long-term, Future projections (2020s, 2050s, 2031–2060, 2071–2100, 2005–2100).

Methodology and Data

• Models used: General Circulation Models (GCMs), PRECIS, CCAM, RegCM, CROPWAT (FAO). Specific GCMs mentioned include Inmcm4r1i1p1, IPSL-CM5A-LR r3i1p1, MRI-CGCM3 r1i1p1, CanESM2r4i1p1, MPI-ESM-LR r1i1p1, CSIRO-Mk3-6-0_ r1i1p1, MIROC5 r3i1p1.
• Data sources: Historical records, basin-scale hydrological assessments, climate model projections, satellite imagery, databases, CRU precipitation data, IRSA-2008, Water Resources Management Directorate WAPDA, CMIP 5 data.

Main Results

• Rising temperatures are projected to enhance glacier and snowmelt in the near term, increasing summer flows and flood risks, but will ultimately lead to reduced long-term water availability as glacier mass retreats.
• Precipitation trends show spatial and seasonal heterogeneity with uncertain future projections. Overall, Pakistan experienced a significant increase of 25% (63 mm) in precipitation over the 20th century.
• Rabi season agriculture is particularly vulnerable due to reduced winter precipitation and limited meltwater contribution.
• Historical data (1991–2008) indicates a declining trend in total Indus River System flows, with a mean value of 173.91 km³ for the period.
• Future projections for the Upper Indus Basin (UIB) show an increase in total runoff for 2031–2060, primarily due to increased rainfall runoff, while snowmelt runoff is projected to decrease. Long-term projections (2071–2100) indicate a decrease in total runoff.
• Future Indus flows at Tarbela are projected to range from 55.99 km³ to 90.99 km³ (78% to 126% of mean historical discharge).
• Crop water requirements for wheat and maize in D.I. Khan are projected to increase by 17% to 21% by mid-century under RCPs 4.5 and 8.5, respectively.
• Climate change has reduced mean annual western river flows by approximately 2.9% in the post-storage era (1968–2007) compared to the pre-storage era (1937–1967).
• Canal diversions are projected to drop to 115.40 km³ in dry years (75% probability), which is 5.5% less than the mean canal diversions.
• Current total groundwater recharge is approximately 67.84 km³, with 44.40 km³ refreshing the fresh groundwater zone. Current abstraction is around 61.67 km³, indicating that all fresh groundwater recharge is utilized, with an additional 17.27 km³ abstracted from marginal to brackish zones.

Contributions

• Provides a comprehensive review and synthesis of existing literature on climate change impacts on water availability for agriculture in the Indus Basin.
• Integrates findings from historical records, basin-scale hydrological assessments, and various climate model projections (GCMs, PRECIS, CCAM, RegCM, CROPWAT).
• Highlights the complex and often uncertain nature of climate change impacts on glacier dynamics, precipitation patterns, and river flows in the region.
• Develops and presents scenarios for future river flows, canal water supplies, and groundwater recharge/abstraction to inform policy and planning.
• Emphasizes the critical need for integrated water resources management, enhanced monitoring, and climate-resilient agricultural strategies to ensure food security in Pakistan.

Funding

Not explicitly mentioned in the paper.

Citation

@article{Khan2025Impacts,
  author = {Khan, Asif and Goheer, Muhammad Arif and Ijaz, Muhammad and Wajid, Ehtisham},
  title = {Impacts of Climate Change on water availability for Agriculture in Indus Basin: A review and Policy Implications},
  journal = {Planta Animalia},
  year = {2025},
  doi = {10.71454/pa.004.06.0300},
  url = {https://doi.org/10.71454/pa.004.06.0300}
}