Robust optimization for emergency logistics planning: Risk mitigation in humanitarian relief supply chains

This paper proposes a methodology to generate a robust logistics plan that can mitigate demand uncertainty in humanitarian relief supply chains. More specifically, we apply robust optimization (RO) for dynamically assigning emergency response and evacuation traffic flow problems with time dependent demand uncertainty. This paper studies a Cell Transmission Model (CTM) based system optimum dynamic traffic assignment model. We adopt a min–max criterion and apply an extension of the RO method adjusted to dynamic optimization problems, an affinely adjustable robust counterpart (AARC) approach. Simulation experiments show that the AARC solution provides excellent results when compared to deterministic solution and sampling based stochastic programming solution. General insights of RO and transportation that may have wider applicability in humanitarian relief supply chains are provided.     

Biological effects of dilution of Dead Sea brine with seawater: implications for the planning of the Red Sea–Dead Sea “Peace Conduit”

The Dead Sea is a severely disturbed ecosystem. Its water level has been decreasing at a rate of nearly 1 m per year during the last decade due to anthropogenic intervention in its water balance. Since the peace treaty between Israel and Jordan was established in 1994, a proposal for the construction of a water carrier, the “Peace Conduit,” between the Gulf of Aqaba (Red Sea) and the Dead Sea is being investigated. This water carrier is intended to mitigate damaging processes that currently occur in the Dead Sea and its surrounding area. The difference in elevation of about 416 m could be exploited for seawater desalination by reverse osmosis. To examine the possible effects of the mixing of Dead Sea brines with seawater and seawater concentrates on the Dead Sea as an ecosystem, we have set up simulation experiments under field conditions in experimental ponds at Sedom, in which Dead Sea water was diluted with Red Sea water. The main components of the Dead Sea biota are the unicellular green alga Dunaliella and several types of red halophilic Archaea. Phosphate is the limiting inorganic nutrient. Massive Dunaliella blooms developed, accompanied by dense communities of red halophilic Archaea, in some of the experimental ponds, imparting a brown-red coloration to the brines. The extent of biological development depended on the extent of dilution and on phosphate availability. The results of the simulation experiments show that biological phenomena and their impact on the Dead Sea ecosystem should be taken into consideration during the planning of the “Peace Conduit.”