SEDIMENT DRIFT PATTERN IN THE VICINITY OF LAKE BURULLUS MEDITERRANEAN SEA COMMUNICATION OUTLET: RELATIONSHIP TO CHANNEL SILTATION  <B>SEDIMENT DRIFT PATTERN IN THE VICINITY OF LAKE BURULLUS MEDITERRANEAN SEA COMMUNICATION OUTLET: RELATIONSHIP TO CHANNEL SILTATION</B><P>Morad F. Lotfy*, Mohamed A. Rashed** and Omran E. Frihy* </B><I><P> * Coastal Research Institute, 15 EL Pharaana street, 21514, Alexandria, Egypt. Phone <BR> (0203) 5408710; Fax (0203) 4829582. <BR> ** Geology Department, Faculty of Science, Alexandria University, Alexandria, Egypt. Fax (002) (03) 4911794.</I><P> Abstract<P> Lake Burullus is located on the arcuate coastal bulge of the northcentral delta region. It is the second largest of the Nile Delta coastal lakes and is connected to the Mediterranean Sea through an outlet known as Boughaz ElBurullus. This outlet suffers from siltation and shoaling of its channel creating difficulties to the navigation and inhabitants who are mainly fishermen. The present work is aiming principally at the determination of the sediment transport pattern in the vicinity of Lake Burullus outlet and its adjacent nearshore area. The transport paths have been determined from bottom relief deformation which are reflected by the values of vertical shifts of depth contours that have defined from eleven beach profile survey data. Sand grain sizes and heavy mineral ratios beside the recognition of coastal processes affecting the study area were also helpful in the determination of transport paths. The profile types suggest maximum erosion which occurs beyond breaker zone at the extreme western (1.6 m/yr.) and eastern (0.8 m/yr.) parts of the outlet as well as in the surfzone adjacent shoreline along the eastern barrier (1.8 m/yr.). It is shown that the major areas of accretion are positioned to the east of the eroding ones, demonstrating that there are strong longshore gradients in the quantities of the eastward sand transport. Moreover, the areas of erosion provide sediments to areas of accretion (Sinks). The various transport indicators analyzed in this study are generally in agreement and have permitted us to indicate that the accumulated sediments in the outlet (+ 1.2m/yr.) are derived mainly from eroded sand coming mainly from the west, because the predominant littoral current is towards the east and partly from eroded sand coming from the east. The existing western jetty is too short and not suitable to prevent outlet channel siltation. The annual dredging at the narrowest part of the outlet should be considered.<P>