بررسی زمین ساخت فعال در شمال حوزه آبخیز دشت بیرجند با استفاده از فاکتور‌های مورفومتریک

مورفومتری به عنوان سنجش و توصیف کمی شکل‌ها و چشم اندازهای زمین تعریف شده‌‌اند. دشت بیرجند درشرق کشور ایران و دراستان خراسان جنوبی است. هدف از این پژوهش ارزیابی تکتونیک مناطق فعال با استفاده از پارامترهای مورفومتری می‌باشد. در این تحقیق از داده‌های میدانی و نقشه‌های توپوگرافی استفاده گردیده است. نتایج حاصل از محاسبه شاخص‌ها بدین صورت است که بیشترین میزان کج شدگی af در شمال غربی ، کمترین میزان کج شدگی شمال حوزه می باشد. شاخص tدارای نا متقارن‌ترین حالت حوزه در شمال غربی منطقه است. شاخص s بیشترین مقدار در غرب حوزه و کمترین مقدار شمال مرکزی حوزه می‌باشد. بیشترین مقدار smf در شمال حوزه و کمترین مقدار آن در شمال شرقی حوزه می باشد. محاسبه شاخص vf نشان داد که بیشترین تعداد دره ها در این مناطق واقع شده است. شاخص انتگرال هیپسومتری بیشترین میزان بالاآمدگی در شمال شرقی و کمترین میزان در شمال را نشان می‌دهد، بیشترین مقدار شاخص dd در شمال وکمترین مقدار در شمال غربی می باشد. بیشترین مقدار شاخص te در شمال شرقی حوزه و از طرفی کمترین مقدار شاخص te در شمال غربی است. بیشترین مقدار شاخص cدر شمال غربی و کمترین مقدار در شمال حوزه است. بیشترین مقدار شاخص re در شمال وکمترین مقدار شاخص re در شمال غربی است. پارامترiat نشان می دهد که شمال دشت بیرجند از نظر تغییرات مورفومتریک در درجه فعال قرار دارد و درآینده تغییرات جدیدی خواهد داشت.

An assessment of active tectonic by morphometric factors in north of Birjand plain watershed

Introduction Rivers are the first environmental forms that show a relatively rapid response to changes in the bedding or fluctuations in the outflow of the bed. Regarding the fixedeffect photos of the rivers relative to the occurrence of abnormal changesmainly due to tectonicscan be explained by analyzing them using morphotectonic indices in relation to the occurrence of these changes ( Ramiez Heerea, 1998). Exploring the dynamic processes that affect the formations of Earth and its landscape can be achieved by the Active Tectonics or Active Geomorphology Tectonics One proven and widely used technique is the Morphometric analysis, which helps understand the development of the geomorphic features in the young mountain belt. Morphotectonics can be considered as the knowledge of the study of shapes and patterns created on the ground by tectonic processes .)keller and pinter., 2002.( Mousavi (2006) reviewed the active tectonics in the northwest of Birjand. He points out that structural and morphological factors have been calculated, due to the structural arrangement in the area, the rate of the process of rising in the central part is higher. The principal objective of this study is to Evaluation of active area tectonics using morphometric parameters for the using classification of geomorphological indices considering the geological and physiographic study of watershed and tectonic analysis and geomorphology. Morphometry indicators of active tectonic is concern with the study of the geomorphological conditions of the study area, physical environment and landscape characteristics of the study area which includes drainage pattern, stream order, slope and aspect map.MethodologyIn this paper, Birjand plain is divided into 36 subbasins for ease of computing and comparing the results of using indicators which is from sub basins 1B to 22B of northern part of plain of Birjand, which includes the mountain Shekarab, and from sub basins 23B to 36B is the southern part of Birjand Plain, which includes the mountain range of Bakhran The data used in this research includes the topographic maps 1: 25000, geological map 1: 100000, fault map 1: 100000. the digital elevation model data (DEM of 30 meters of the region) for mapping the location of the region. We use the 10.3Arc GIS software and modules such as 3D Analyst, Editor, Analysis Tools, and also Google Earth software.Result and discussionThe importance of morphotectonic studies is to achieve critical results that are often unavailable through other methods or require a great deal of time and cost. For this purpose, in the course of morphotectonic studies, indicators are being studied that can be of great help in reaching the outcome of the research.The results of calculating the indexes are such that the highest rate of AF in the northwest is the lowest rate of tilting in the north of the area. The T index is the most abnormal case in the northwest of the region. S index is the highest value in the west of the region and the lowest value in the northcentral region. The maximum amount of Smf is in the north of the area and its lowest value is in the northeast of the basin. Calculating the VF index in the mountains of Shekarab showed that the highest number of valleys is located in these areas. hypsometric integral is the highest elevation in the northeast and the lowest in the north, the highest is Dd in the north and the lowest in the northwest. The highest value of Te is in the northeast of the basin and the lowest is Te in the northwest. The highest value of C is in the northwest and the lowest in the north. The highest value of Re is in the north and the lowest value of Re in the northwest. The Iat parameter is used to analyze geomorphologic indices and summarize their results in order to determine the relative status of tectonic activities in the region.The Iat parameter indicates that the northern plain of Birjand is morphometric changes in the active class, and in the future will have new changes.ConclusionThe results obtained from the study of geomorphic evidence show a relative classification of tectonic activity that is useful for studying and identifying the region. The geomorphic indicators used in this project reflect the tectonic activity of the region. In general, the results of geomorphologic indexes indicate that the study area of the study is active in the field of nautical construction, one of the reasons for which is the trusted fault and the extension of slip, and the activity level of the newly constructed motions in The waters of the basin are more active in this regard than anywhere else.