Study of the climatic and hydrological trends in Lebanon and implications with water resources management

Project leaders

Vincenzo Lapenna, Amin Shaban

Agreement

LIBANO - CNRS-L- not in force - National Council for Scientific Research of Lebanon

Call

CNR- CNRS (Libano) 2017-2018

Department

Earth system science and environmental technologies

Thematic area

Earth system science and environmental technologies

Status of the project

New

Research proposal

In the recent years the shortage in water supply in Lebanon has been occurred due to several physical and anthropogenic reasons, like resulting turbulence phenomena in rainfall regime, observed increase in temperature by about 1.5 °C, which led to reduced volume of water resources, discharge in many issuing rivers declined by 60%, several springs now dried or not so lasting for long time, groundwater table levels lowered in many boreholes. This fact has special implications in a country where water is a pressure for socioeconomic development and, at same time, it may represent a risk of drought events.
Although significant advancements in water resource management have been done in Lebanon; however, still many questions need to be solved. Interactions among environmental variables are subjected to complex nonlinear relationships and vary depending on considered spatio-temporal scales. Additionally, the extremely varying climatic and environmental conditions of the topographic heterogeneity of Lebanon, which experiences several micro-climates from the Mediterranean one Basin on the seaside to the Alpine one on the high mountains, is another source of complexity. Therefore, robust and advanced statistical approaches are necessary to enhance the understanding of dynamical mechanisms that control climatic and hydrologic trends and their relationships in Lebanon.
The project methodology will consists in the following tasks: 1) collection of climatic and hydrologic data over Lebanon for log time period; 2) development and application of advanced statistical tools, like spectral (Power spectrum, correlogram-based periodogram), fractal (detrended fluctuation analysis, DFA), multifractal (multifractal DFA), entropic (Shannon entropy), informational (Fisher Information Measure) and decompositional (Singular spectrum analysis, wavelets) to individuate dynamical patterns in the collected hydrologic and climatic series and to contribute in elucidating the role of the different actions affecting the hydrologic regime in Lebanon; 3) interpretation and dissemination of the results
Knowing the time dynamic behaviour of these variables for as many as possible sites in Lebanon will drive the research program toward the application of forecasting schemes based on AR, ARMA processes and neural network approaches. These linear and nonlinear forecasting techniques will contribute in getting the hydro-climatic future scenarios for water resources in Lebanon.
The project intends to perform, thus, a detailed investigation of rainfalls, stream flow in springs and river, snow cover, temperature, etc., measured in several investigated sites in Lebanon. In order to deeply investigate the occurrence of drought phenomena, the project will focus also on the statistical analysis of the time series the Standard Precipitation Index (SPI) and the Standard Precipitation Evapotranspiration Index (SPEI) that are two important drought indices developed for defining and monitoring drought and determining the rarity of a drought at a given time scale of interest for any rainfall station with historic data. Both the indices are very effective in depicting the seriousness of drought and, thus, the shortage of available water.
The feasibility of the proposed research program is reinforced by the availability of several types of resources: 1) rainfall data measured by rain gauges and ambient temperature in many representative sites, covering the entire territory of Lebanon at different time periods, 2) hydrographs and flow-meters on rivers and springs watercourses to record water discharges measures, 3) scale-levels to measure water level in lakes and ponds, 4) remote sensing data (e.g. Radarsat, NOAA, MODIS, etc.) to monitor snow coverage, 5) manometers to measure groundwater level in the main aquifers, 6) equipments and laboratory testing to measure soil moisture, 7) statistical and time series analysis tools and know-how.
The expected results will have great impact on the hydrology of Lebanon and the processed hydrological and climatic records will contribute to define future scenarios and implications for water resources availability and extreme-events occurrence. The results, including documentations, maps, satellite images and illustrations, will be disseminated through intermediate and final technical reports, papers submitted to international journals and conferences with the acknowledgement of the CNR-CNRSL agreement, a webpage dedicated to the project and seminars focused on the topics of the project that will be held on both the involved institutions and related national agencies during the mutual visits.
Added value and broader impact: This project entails a joint research effort among experts in different disciplines from Italy and Lebanon: IMAA-CNR, ARPAB (Italy), NCRS-CNRS, LTA. It is even planned the cooperation with the Centre d'Etudes Spatiales de la Biosphère in France, concerning the investigation of snow cover satellite time series. Therefore, the findings of this project will improve noticeably the ability to assess the impact of climatic scenarios projected for the coming decades on water resources availability and risks associated to extreme drought events in Lebanon. The optimal results be obtained from this project are envisaged to be of world-wide importance for this kind of researches. Users of the results could be administrative and research institutions at a regional level of interest. Moreover, the end users of the expected results could be public institutions (regional authorities, public entities for water management as Litani River Authority or Lebanese Standard Institution) which are responsible to monitor water availability and hazardous phenomena in Lebanon.

Research goals

The main goal of the proposed research program is to get the most complete picture on water resources in Lebanon by characterizing and the time dynamics of measured hydrologic and climatic variables (precipitation, temperature, snow accumulation, etc.). Using the available data the project will accomplish the following specific objectives: 1) to individuate and characterize the different hydrologic regimes in monitored areas of Lebanon; 2) to characterize the time dynamics of the measured hydro-climatic variables in terms of correlation structure, scaling behaviour and persistence; 3) to calculate the Standard Precipitation Index (SPI) series for the sites of major hydrologic interest in Lebanon; 4) to obtain the Standard Evapotranspiration Precipitation Index (SPEI) series for the sites of major hydrologic interest in Lebanon; 5) to characterize the time dynamics of SPI and SPEI time series in terms of trends and periodicities; 6) to define the implications of the reached findings from historical period on the perspective of water resources availability and drought occurrence in the region; 7) to provide a wide dissemination of the intermediate and final results of the project within the scientific community and attendance of the involved stakeholders.

Last update: 27/09/2024