Sedimentological analysis of fluvial systems

In this research, in addition to some of the researching views of rivers are discussed, achievments and sedimentological views of the Iranian rivers are studied in more detail. One of the most important environmental problems, is pollution of sediments or river water. Concentration of pollutant metals in fluvial sediments depends on various indicators such as the physico-chemical properties of the fluvial environment and geochemical charactristics of the metals. Methods for determination of total content and sequential extraction of different species of metals are used to determine the pollution of metals. In GIS-based researchs, river changes maps (in specific time periods) and flood zoning are widely used in flood plan management. In the river engineering debate, some common methods for investigating the flood phenomenon, including digital altitudinal model, hydrological trend model and triangular irregular net, are used. Also, other related topics in this regard, include the threshold of grain movement and predicting the behavior of rivers (based on artificial neural networks models and models based on statistical methods such as linear and nonlinear regression, Pearson, Spesarman and Man-Kendall correlation methods). Investigation of the threshold of grains movement will be done by methods such as flow unit discharge, critical shear stress and critical mean flow velocity. The most important subject in fluvial sedimentology include river morphology, flow regime and bedforms, classification of fluvial channel bodies and valley fills, fluvial styles, sedimentary scales in fluvial sediments, sedimentary facies, architectural elements, sediment load and fining trend of river sediments. Fluvial architecture consists of geometry and internal arrangement of channel and overbank deposits in fluvial sequences. The analysis of architectural elements is a relatively new method for the interpretation of fluvial facies. The variation of channel types and sediments in fluvial environments are due to the wide range of dependent factors governing on the fluvial sedimentation. Classifications of lithofacies, bounding surfaces and architectural elements are one of the most important methods for analyzing of fluvial architectural elements.