The Hasbani and Orontes Rivers are two main transboundary rivers of Lebanon. These waters are a critical resource for the future water security of the co-riparians. This dissertation analyses results of a water resources planning and hydrologic model under a new participatory framework by studying hydro-political aspects and the vulnerability of water resources in the Hasbani basin of Lebanon and the city of Amman under a changing climate pattern and growing water demands. Water policies suggested by the stakeholders were analyzed and the most sustainable solution was presented to the water resources authorities in the basins. Moreover, because of the political situation in the region, field data such as rainfall and evapotranspiration are very difficult to obtain making the use of remote sensing and Geographic Information System very useful to present a complete description of the hydrology of the watersheds and study water availability in the Orontes and Jordan River Basins. The approach used in this research integrates recently compiled data derived from satellite imagery (evapotranspiration, rainfall, and digital elevation model) into a transboundary geospatial database and hydrologic model to measure the contribution of each riparian country to the total available water in the basin. Finally, a mathematical method called the Orontes water allocation optimization method is used based on the nine factors of the UN Convention on the Law of Non-navigational Use of International Water Courses to allocate water equitably between the co-riparians. The optimization results show that Turkey and Lebanon could benefit from additional water if new negotiations are initiated. Once a multilateral agreement occurs, the findings of this research would provide a useful guide to the co-riparians for policy formulation, decision making and dispute resolution. Cooperation between the riparian countries may be improved by building a GIS database that provides access to accurate data for hydrological analysis, facilitate and standardize data sharing to evaluate future policy alternatives.