Regional-Scale Study on Sediment Processes of Khuran Strait at Persian Gulf with Implicati

Regional-Scale Study on Sediment Processes of Khuran Strait at PersianGulf with Implications for Engineering DesignA. Shanehsazzadeha, H. Ardalanb, *aFaculty of Civil Engineering and Transportation, University of Isfahan, Isfahan, IranbWater Research Institute (WRI), Tehran, IranReceived August 26, 2018; revised November 18, 2018; accepted December 28, 2018©2019 Chinese Ocean Engineering Society and Springer-Verlag GmbH Germany, part of Springer NatureAbstractIn this article, the sediment transport processes in the Khuran Strait between the mainland Iran and Qeshm Island atNorth Central Persian Gulf are studied in regional scale in a comprehensive manner. The objectives of this studyinclude defining the type and origin of the sediment, the influencing factors, and the dominant mode of sedimenttransport. Four possible scenarios of sediment processes in terms of sediment sources and influential environmentalforces are examined. The results of the conceptual and 2D numerical model of MIKE21 applied for this purposesindicate that the sediment sources in the transport processes are mainly provided by the sediments suspended fromthe central and eastern zones of the strait bed. Other sources including input from rivers do not have direct influenceon the processes. The results are applied to the study of morphological changes for engineering applicationsincluding the pattern and amount of deposit in the Rajaee port approach channel and harbor basin. The pattern andamount of annual sediment deposits in the approach channel predicted by the model is satisfactory, compatible withannual dredging records.Key words: sediment transport, morphodynamics, 2D numerical model, Persian Gulf, Khuran Strait, Rajaee PortCitation: Shanehsazzadeh, A., Ardalan, H., 2019. Regional-scale study on sediment processes of Khuran Strait at Persian Gulf with implicationsfor engineering design. China Ocean Eng., 33(3): 356–364, doi: 10.1007/s13344-019-0034-4

1 IntroductionImpacts caused by human interferences on coastal sys-tem result in a change in the coastline and its surroundings’behavior and consequently influence the functionality of thecoastal facilities. Prediction of these mutual influences istherefore vital for the long term operation of the coastal in-frastructures such as ports and navigation channels. Assess-ment of the environmental impacts also requires true under-standing of the involved processes (Reible, 2008). Most act-ive studies in the field of coastal sediment problems in re-cent years focus on morphodynamics, i.e. the modeling ofthe processes determining the coupled evolution of sea bedtopography and the wave–current field (Battjes, 2006). As ageneral practice, the local scale of a given area is mainlyemployed in project designs for engineering applications,while, larger scale area and longer time including regionalprocesses within coastal cells boundaries have been well ap-plied at managerial level and decision makings (Shaneh-sazzadeh and Parsa, 2013; Luo et al., 2013; Li, 2008; Lar-son et al., 2002).Tidal networks which consist of a complex system of bi-furcating channels, are one of the most remarkable naturalpatterns observed in environments. Morphodynamical pro-cesses in tidal networks depend on a balance between sedi-mentary processes and hydrodynamics. In fact, coasts partlyprovide local sources and sinks of sediment, which may in-teract with shelf-sea evolution (van der Molen et al., 2004;Bird, 2008). In modeling the geomorphology evolutions forengineering purposes such as siltation in navigation chan-nels and harbor basins, true designation of sediment sourceand pathway contribute to correct simulation of the pro-cesses and accurate predictions.In this article, the sediment transport processes in theKhuran Strait (KS hereafter) between mainland Iran andQeshm Island at North Central Persian Gulf (Fig. 1) are studiedin a comprehensive manner. The study area is mostly a shal-low channel (maximum depth of 42 m) which is located inthe Hormozgan province coastline (Fig. 1). The detailed fea-ture of the coastline was presented by Shanehsazzadeh et al.(2014). KS consists of a tidal network with a broad range ofecosystem functions. Mangrove forests and deltas of sever-al permanent and seasonal rivers are among the main fea-tures of this strait (Fig. 2). Understanding the underlyingphysics that govern the formation and evolution of theselandscapes, their functionality and evolutionary processesare of the highest environmental priority (Danehkar, 1996).China Ocean Eng., 2019, Vol. 33, No. 3, P. 356–364DOI: 10.1007/s13344-019-0034-4, ISSN 0890-5487http://www.chinaoceanengin.cn/ E-mail: coe@nhri.cn