دانشگاه آزاد اسلامی واحد آستارا
عنوان مقاله [English]
In the analysis of the neotectonic concept in the regions, the main focus has been to study the dynamic and effective processes on the formation and deformation of land forms and phenomena. Thus, geomorphological forms are too sensitive to tectonic activities and as a result of these movements change. Of the most important geomorphological problems applied in tectonic studies, cliffs, alluvial fields and canals in folded belts can be mentioned, that through changes in the process and form of canals, we can study the neotectonic in the region.
The present article is the result of the research titled, "Preparing Geomorphological Map 1:25000 in West of Gilan". To do this, the researcher applied the common and the prevalent tools in geography. Field surveys and close observation of land forms and phenomena shared the most in completion of this project. To recognize the neotectonic activities in the study, the researcher used comparative-analytic and field survey. Initially, under-study watersheds based on the land construction were divided into north and south. Then, adjustment and interpretation of topographic, hydrographic, fault and geologic maps and air photographs with geomorphological map were done by the use of ArcGIS software. Finally, SPSS software was applied for data analysis.
The region in the present study involved 4 watersheds in north-west of Gilan, namely, Chelavand, Chubar, Kargan Rud, and Navrood. For the evaluation and analysis of the neotectonic in the region, the researcher used the geomorphological indicators.
The geomorphological indicators provide useful and valid tools for surveying neotectonic activities. When, in a particular region, several morphotectonic indicators rather than one are used together to survey and analyze tectonic activities, the result will be more logical, valid, and meaningful. Therefore, 7 different morphotectonic indicators including River Sinuosity (S), Basin Shape Factor (BS), Transverse Topographic Symmetric Factor (T), Hypsometric Integral (HC), Stream Length (SL), Drainage Asymmetry Factor (AF), and Ratio of Valley-Floor with to Valley Height (VF) were used to achieve the valid results in the study of tectonic activity.
In this study, the status of the tectonic activities in the 4 watersheds located in north-west of Gilan were surveyed. To achieve the valid results, the researcher used 7 different morphotectonic indicators (VF, AF, SL, HC, T, BS, S). The results indicated that the general status of the watersheds is largely the result of tectonic activities and particularly the function of various faults in the region. Hence, the results of the geomorphological indicators in the 4 watersheds showed the active neotectonic movements in the watersheds and the fault system function. In addition, the watersheds under consideration had strong neotectonic activity, but regarding the indicator of AF, they had an inactive status.