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.”     

An innovative method for the analysis of vehicle movements in roundabouts based on image processing

The objective of this paper is to propose a method, based on the image processing of field survey data, to analyze vehicles movements into roundabouts. This research study consisted of three stages: a field survey to collect vehicular flow images captured by video cameras, the processing of these images using a proprietary software (VeTRA—Vehicle Tracking for Roundabout Analysis), and finally, the analysis of the collected data. The main feature of the software is that it allows the automatic computation of the main variables necessary to rank and evaluate a generic roundabout: the entry/exit (E/E) matrix with classification of vehicles (e.g., heavy, light, and motorbikes), vehicle trajectories, and vehicular speed diagrams along the paths inside the roundabout. The processing system is robust enough to withstand classic problems affecting image processing such as variable wind conditions, cloud cover, shadows, and obstructions. Calibration and error evaluation have been deduced from data collected by a high precision Real Time Kinematic GPS video recording system mounted on a probe vehicle. Data of E/E matrices generated by VeTRA are compared with those manually counted on the corresponding video images. A case study of an existing roundabout is featured in the paper. The results indicate that the software has a high capability of generating the E/E matrix. The analysis of vehicular trajectories with both the plot of curvature diagrams and the corresponding speed diagrams enable the evaluation of driver behavior relative to the geometric shape of the roundabout. Copyright © 2011 John Wiley & Sons, Ltd.