en Environmental Study مقاله پژوهشي Research Paper Although there exist advanced models which predict beach profile for natural beaches, the behavior of the beaches in front of seawalls still suffers from the lack of appropriate theoretical models and sufficient measured data. In this paper, following the results obtained from the measurements, a beach profile evolution model is developed, using the measured probability distribution of the near-bed horizontal velocities as input, to predict the short-term bed level changes in the vicinity of a partially reflective seawall. The present model introduces a new approach in which based on integrating the probability density functions of the near-bed horizontal velocities, the sediment displacements and consequently bed level changes are calculated in front of a partially reflective structure. The results obtained from the model in comparison with the experiments are promising and encouraging for further developments of the proposed model. Seawall, Beach, Sediment, Probability density functions (PDF) 47 55 http://ijmt.ir/browse.php?a_code=A-10-86-1&slc_lang=en&sid=1 Mir-Ahmad Lashteh-Neshaei maln@guilan.ac.ir 10031947532846003012 10031947532846003012 No Department of Civil Engineering, Guilan University, Rasht, Iran Mohammad Ali Lotfollahi-Yaghin a_lotfollahi@yahoo.com 10031947532846003013 10031947532846003013 Yes Civil Engineering Faculty, University of Tabriz, Tabriz, Iran Morteza Biklaryan mrtz_b@yahoo.com 10031947532846003014 10031947532846003014 No Civil Engineering Faculty, University of Tabriz, Tabriz, Iran Sadegh Nadimy sadegh.nadimy@yahoo.com 10031947532846003015 10031947532846003015 No Langroud Islamic Azad University, Langroud, Iran