تحلیل فضایی مخاطرات محیطی

تحلیل فضایی مخاطرات محیطی

تحلیل تغییرات فضایی و زمانی رسوب معلق در حوزه آبخیز نکارود استان مازندران

نویسندگان
1 دانشگاه پیام نور
2 دانشگاه علوم کشاورزی و منابع طبیعی
3 دانشکده جغرافیا، دانشگاه تهران
چکیده
مشکل رسوب­زایی، انتقال رسوب، فرسایش و رسوب­گذاری از بحث­های مهم در برنامه­ریزی راهبردهای خرد و کلان آبخیزداری و مدیریت حوزه­های آبخیز است. گردآمدن رسوب در منطقه­های پایین­دست موجب بروز خسارت برون­منطقه­ای، تخریب مسیر آبراهه­ها، گل آلودگی آب مصرفی، انباشت نهرها از رسوب و کاهش ظرفیت مخازن سدها و تنگناهای زیست­محیطی بسیاری می­شود. رسوبات ناشی از فرسایش حوزه‌های آبخیز علاوه بر هدر رفت خاک و کم شدن حاصلخیزی، موجبات کاهش کیفیت آب را فراهم آورده و عمر مفید سدها را به­دلیل انباشت رسوبات در مخازن آن‌ها به خطر می‌اندازد. در این تحقیق تغییرات زمانی و مکانی بار رسوب معلق، در سه ایستگاه هیدرومتری سفیدچاه، گلورد و آبلو واقع در شاخه اصلی نکارود با استفاده از منحنی­های سنجه رسوب و مدل خطی رگرسیونی در محیط نرم­افزارهایMINITAB وEXCEL مورد بررسی قرار گرفت. همچنین به­منظور تعیین بهترین مدل، از شاخص ضریب همبستگی(R2) استفاده گردید. نتایج این تحقیق نشان داد که در تغییرات زمانی مدل فصلی بهار در هر سه ایستگاه با حداکثر ضریب همبستگی (89/0) به­عنوان مناسب­ترین مدل برآورد بار رسوبی معلق از بین مدل­های مورد بررسی است. در مطالعات مکانی نیز ایستگاه آبلو واقع در خروجی حوزه آبخیز نکارود دارای بیشترین میزان ضریب همبستگی (934/0) بین دبی جریان و دبی رسوب است.
کلیدواژه‌ها

عنوان مقاله English

Analysis of Spatial and temporal variations of suspended sediment in Neka-Rood watershed, Mazandaran province

نویسندگان English

Behrooz Mohseni 1
kaka shahedi 2
Seyyed Mohsen Manavi 2
Narjes Mahmoodi-Vanolya 3
1 Department of Engineering and Agricultural Technology, Payam-e- Noor University (PNU)
2 Department of Watershed management, Sari Agricultural Sciences and Natural Resources University
3 Faculty of Geography, University of Tehran
چکیده English

The sedimentation, sediment transport, erosion and sedimentation problems are important discussions in the planning of wisdom and macro watershed strategies and management of watershed basins. The sediment collection in lower areas causes regional damage, the destruction of the pathway of the waterways, the flow of water pollution, the accumulation of streams of sediment and reducing the capacity of reservoirs of dams and environmental bottlenecks. The sediment resulting from the watersheds erosion, in addition to soil loss and its degradation results in a decrease in water quality and endangers the useful life of dams due to the accumulation of deposits in their reservoirs. In this research, Spatiotemporal variations of suspended sediment load were investigated at three hydrometric stations of Sefidchah, Gelevard and Ablou located on the main channel of the Nakaroud Basin using sediment rating curves and linear regression model through applying MINITAB and EXCEL softwares. In order to determine the best model, determination coefficient (R2) was used. The results of this study showed that in seasonal variations of spring season in all three stations with a determination coefficient of at least 82% and a maximum of 89% as the most suitable model for estimating suspended sediment load among the models studied. In spatial studies, the Ablou station located at the outlet of the watershed has the highest determination coefficient (0.934) between sediment discharge and streamflow discharge.

کلیدواژه‌ها English

Spatiotemporal variations
Regression Linear Model
MINITAB
Nakaroud
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