Hydro-climatic Dynamics and Water Resource Vulnerability: The Case of Nabatieh Governorate, Lebanon |Chapter 8 | Current Research on Geography, Earth Science and Environment Vol. 5

 

Climate variability and ongoing warming in the eastern Mediterranean are increasingly reshaping water availability and demand in Lebanon. This study aims to assess how key climatic elements (precipitation regime, snow cover, temperature, wind, solar radiation, and cloudiness) influence water-resource vulnerability in Nabatieh Governorate, and to identify priority vulnerability hotspots and feasible adaptation options. Methods and materials combined (i) high-resolution observations from a digital meteorological station, (ii) analysis of historical station rainfall records and spatial precipitation classes to estimate annual precipitation volumes, (iii) field questionnaire data on household water consumption by season and elevation, and (iv) evaporation measurements, alongside standard climatic indices (e.g., Gaussen) to delineate dry months and examine daily wind temperature interactions relevant to irrigation timing. Results show that although the governorate receives an average annual precipitation volume of about 969.6 million m³ (semi-humid conditions), water security is undermined by a long dry season, strong interannual variability, and rising temperatures that intensify evaporation and evapotranspiration, producing annual losses of roughly 414 million m³ (≈43% of precipitation). Warming also increases demand: per-capita daily consumption rises from winter to summer and is projected to increase by ~5% under a ~2°C warming scenario, while higher temperatures accelerate snowmelt on Mount Hermon, shifting runoff toward winter and reducing summer water availability. Wind and solar radiation exacerbate dry-season evaporation but also offer operational opportunities: economically viable wind speeds (~6 m/s) occur for several continuous hours midday, and the lowest combined wind temperature window (about 5:00–7:00 AM) minimises irrigation losses. Conclusions indicate that scarcity is driven less by absolute rainfall shortage than by warming-amplified losses, seasonal supply demand mismatch, and limited adaptive infrastructure. Prioritise integrated adaptation, optimise irrigation scheduling (early morning), expand storage/ recharge and demand management, and pilot renewable energy-supported pumping with carefully conditioned cloud-enhancement assessments where meteorologically justified.

 

 

Author(s) Details

Nasser Farhat
The Lebanese Center for Water and Environment (LCWE), Beirut, Lebanon.

 

 

Please see the book here :- https://doi.org/10.9734/bpi/crgese/v5/6948