Monitoring of water resources and vegetation in the Helmand Basin using satellite image time-series and border hydro-political challenges

Abstract

Helmand is the most important river in Afghanistan and an indispensable water resource for southeastern Iran. Recent water depletions in the river, however, have caused environmental issues in the region with further repercussions on long-term hydro-political debates between the countries of Iran and Afghanistan. The primary reasons underlying depletions in the river's water levels remain, however, unclear, and are the main objective of this study.Therefore, this study proposes a hydro-political analysis of the Helmand Basin by analyzing precipitation through Global Precipitation Measurement (GPM) data, Gravity Recovery and Climate Experiment (GRACE) land data for groundwater analysis, and Landsat 5 and 8 Images from 1991 to 2020 to classify vegetation and waterbodies using a Support Vector Machine classifier and identify the prime cause of downstream water depletions. Despite severe droughts, the preliminary findings indicated increases in rainfall, groundwater sources, water bodies, and vegetation in the river upstream, which conveys the inconsequential share of droughts to the overall water shortage as opposed to human interventions and water usage which have also shown to increase in the river upstream. Further findings suggest that the severe downstream water depletions are primarily on account of upstream water consumptions that have triggered environmental degradations and are a threat to human habitations. HIGHLIGHTS Water shortages in the Lower Helmand are caused by increased water storage at the basin upstream.; The Support Vector Machine algorithm produced reasonable results on vegetation and waterbodies classification.; Increases in water storage at the Upper Helmand have evoked environmental degradation at the downstream section.;

Keywords

• afghanistan
• catchment
• helmand
• iran
• landsat
• vegetation