پهنه بندی پتانسیل تحول لند فرمی تحت تأثیر شبکه زهکشی مطالعه موردی: حوضه آبریز رودخانه قشلاق

نویسندگان

چکیده

حوضه رودخانه قشلاق در غرب کشور، در قسمت مرکزی استان کردستان، در یک منطقه کوهستانی دارای شیب زیاد، با اقلیم مدیترانه­ای معتدل و گرم قرارگرفته است. هدف اصلی این پژوهش پهنه­بندی پتانسیل تحولات لندفرمی تحت تأثیر شبکه زهکشی در این حوضه است. بدین منظور جمع‌آوری داده­ها، مطالعات میدانی، تولید لایه­های اطلاعاتی و انطباق آن­ها با وضعیت موجود، تجزیه‌وتحلیل هر یک از لایه­ها و پارامترهای هیدرومورفولوژی جهت یافتن عوامل مؤثر و تلفیق لایه­های اطلاعاتی جهت تعیین پتانسیل تحول لندفرمی مکان­هایی که تحت تأثیر شبکه زهکشی قرار دارند انجام‌گرفته است. هم­چنین با توجه به ویژگی­های زمین­شناسی، ژئومورفولوژی، هیدرولوژی، اقلیمی، عوامل انسانی و زیست‌محیطی منطقه، مطالعات تطبیقی و نظر کارشناسان امر 5 معیار و 13 زیر­معیار جهت تدوین هدف طراحی گردید و از طریق کارهای میدانی و منابع اسنادی نیز کنترل‌شده است. قدم بعدی تهیه لایه­های اطلاعاتی موردنیاز برای پهنه­بندی با نرم‌افزار Arc GIS9.3بود تا زمینه برای تحلیل­های لازم فراهم گردد. درنهایت با استفاده از فرآیند تحلیل سلسله مراتبی(AHP < /span>) به تجزیه‌وتحلیل کمّی معیارها، زیرمعیارها و تلفیق لایه­ها در نرم‌افزارARC GIS نسبت به ارائه مدل و پهنه­بندی منطقه مطالعاتی مبادرت گردید. نتایج در پنج طبقه خیلی­زیاد، زیاد، متوسط، کم و خیلی کم محاسبه شد و نشان داد که حدود 8/27 درصد از حوضه دارای پتانسیل زیاد و خیلی زیاد جهت تحول لند­فرم­ها تحت تأثیر شبکه زهکشی می­باشد. بیشتر قسمت­های شمالی حوضه و بخش­هایی از شرق حوضه دارای پتانسیل کم و خیلی­کم می­باشند که 26/45 درصد از کل حوضه را در برگرفته­اند. سایر قسمت­های حوضه نیز به‌صورت پراکنده دارای پتانسیل متوسط بوده که 94/26 درصد از مساحت حوضه را شامل می­شود.

کلیدواژه‌ها


عنوان مقاله [English]

Zoning landform evolutions potential affects the drainage network Case study: river basin Gheshlagh

چکیده [English]

Introduction
 Flow of water is one of the major transformative landforms of small scale (such as a river beach) to large (planet Earth) .So in each basin management we need a comprehensive view about basins and identify the major problems to solve them   with a planning application. The problems of the region to else show different level but transformation landforms affected drainage network is the most important. Gheshlagh basin is located in the central part of Kurdistan Province and and Like this Provincehas an abundance of water power. Basin located in Esfandaghe- Marivan zone that is the most tectonic active zone in iran. Geological Survey, climatology, soil, land coverage, physiography and hydrology, and particularly field studies defining the role of streams and rivers of the area in the form of the act of creation well water hazards on humans and his work also highlights.so  the main objective of this research  is Zoning landform evolutions potential affects  the  drainage network. 
Methodology
The research is done in this step: the collection of data, field studies, production and conformity layers with the current situation, and an analysis of each layer and the hydromorphology parameters to find effective and integrated layers of information to identify sites that are potential development landform affected by drainage network. The method of collecting data including statistical methods, aerial photographs, fields visit references are documents and etc. Then according to geological properties geology, geomorphology, hydrology, climate, human factors and environmental impact and the use of comparative studies, five criteria and 13 develop objective sub was to investigate through fieldwork and resource documents are controlled. Finally, using AHP to analyze the quantitative criteria, sub criteria and combining the layers in ARC GIS software and mapping Venture to Zoning landform evolutions potential affects the drainage network
Results and discussion
Gheshlagh Basin located in Esfandaghe- Marivan zone that is the most tectonic active zone in iran. According to studies area is not uniform and has a variety of geological formations and a general look including limestone,andesite, basalt, shale and phyllite and etc.number of basin east faults, outed the Zagros general trend. Soils of the study area in two categories: Entisols and Inceptisols. The basin slopes facing north wetter and denser vegetation and thus more resistant to erosion, while south-facing slopes are relatively bare and erosion is more intense. Aarea,shape, slope, aspect, elevation, land cover, etc. all play a vital role in the behavior of the hydrological basin. Winter river basin area by using planimeter measured on 1:50000 map as well as the application environment GIS9.3 measure that is equal to 1834 square kilometers.Major drainage basins along the main channel from the Gheshlagh basin calculated the software ARC GIS9.3that is 94.19kilometers. To evaluate the effect of land slope on hydmorphology issues also influenced the evolution landform affects drainage slope map through the use of (GIS) has been prepared. Acording to Slope map of the study area on western highlands and the eastern highlands have the maximum slope and central and southern of study area have the lowest slope. ). inThe basin slopes facing north wetter and denser vegetation and thus more resistant to erosion, while south-facing slopes are relatively bare and erosion is more intense. Study area the drainage pattern branch tree that can perform general discharge. this pattern as a result of numerous factors, such as lithology and tectonic.by carefully on the studied the surface water network map we easily can expand the branch tree pattern in West and North West study area  Most of the lithology observed that corresponded with silt and phyllite. So lithology and tectonic canconsidered the most important factors in creating the creating this pattern.
Conclusion
The main results indicated that the central parts of the basin to outlet have more potential for landform evolutions compared with other parts. results Was calculated in five categories very high, high, medium, low and very low and found that about 28 percent of the basin have high and very high potential for the development of land forms is affected by drainage. Most parts of northern and northwestern parts of the basin and the East Basin have the low or very low potential for landform evolutions namely about45percent.Other parts of the basin have the medium potential for landform evolution namely about 27 percent. Anywhere in the basin lithology is more resistant landform evolution is lower that this point is the more important point in this study.

کلیدواژه‌ها [English]

  • Landform Evolution
  • Drainage Network
  • Analytic Hierarchical Process (AHP)
  • Gheshlagh