Dominant processes causing the formation of coastal sand masses, case study: western Makran coastal plain

The instability and mobility of sand dunes is a major concern for those involved in the planning processes and management of arid coastal plains. Dune systems are created due to several factors and elements. Regarding environmental planning and the management of coastal zones, the study of their formation and development processes is of great importance. The present study aims at identifying the most influential factors in the dispersion of sand masses in the western region of the Makran Plain. The data for this study consisted of spatial maps of landform distributions, wind velocities and directions, fetch lengths as well as dynamic waves. Thematic topographical and geological maps, satellite images, GPS, and software such as WRPLOT View, Freehand, and Arc GIS were used for data processing and analysis. After the generation of the Geomorphologic units map through the Molitor Equation in WRPLOT View, wind and wave rose diagrams were provided. Also, the elongation and direction of sand mass movements in the plain were obtained through multi-temporal and multisensory data. The main rivers’ monthly discharges were analyzed according to information gathered from previous studies as well as their relevant hydrometric water stations. Results indicated that the location and distribution of coastal sand masses are not affected by wind, but by the geomorphologic characteristics of foreshore and coastal hydrodynamics. Also, the distribution of internal sand masses on the coastal plain is affected mostly by the plain stretches relative to the prevailing wind direction and to the extent of old beds and floodplains that are exposed to the prevailing wind rather than the wind itself