نتایج جستجو برای: watershed depend on river system

تعداد نتایج: 9406183  

Journal: :محیط زیست طبیعی 0
مهدی شیخ گودرزی دانشجوی کارشناسی ارشد، دانشکده منابع طبیعی، دانشگاه تهران، ایران افشین علیزاده شعبانی استادیار، دانشکده منابع طبیعی، دانشگاه تهران، ایران عبدالرسول سلمان ماهینی دانشیار، دانشکده منابع طبیعی، دانشگاه گرگان، ایران جهانگیر فقهی دانشیار، دانشکده منابع طبیعی، دانشگاه تهران، ایران

environmental degradation model is one of the environmental impact assessment (eia) methods in which ecological cumulative effects of human activities on his surrounding nature could be evaluated and quantified. as a special trait of landscape ecological metrics is the ability of rapid assess and recognize of human activities in the shortest time. thus in this study, we used a landscape degrada...

Journal: :مرتع و آبخیزداری 0
محبوبه حاجی بیگلو دانش آموختة کارشناسی ارشد آبخیزداری دانشکدة منابع طبیعی یزد محمدتقی دستورانی دانشیار دانشکدة منابع طبیعی و محیط زیست دانشگاه فردوسی مشهد عباسعلی قزل سوفلو استادیار گروه عمران دانشگاه آزاد اسلامی، واحد مشهد محمد رضا اختصاصی دانشیار دانشکدة منابع طبیعی دانشگاه یزد

the morphology of a river system is affected by dominant watershed processes includingclimatic, hydrologic, hydraulic, erosion and sedimentation, geological and topographicalcharacteristics of the river environment and watershed. understanding the interaction betweenthe river form and dominant watershed processes in river systems is necessary for recognitionof river behavior and of importance f...

H. R. Payrovan Naser Shamskia

One of the most important subjects in relation of water resources quality in the many of river is the chemical composition of waters and conservation of water quality in the watershed. Geological formations in any region of the earth are the main surface and foundation that water flows on the bed and strata of formation, which in fact they affect their characteristics on water quality as positi...

2010
Rong Zeng Yanwei Zhao Zhifeng Yang

The shrinking Baiyangdian Lake and drying up rivers are widely observed in recent years. Due to the significant advantages in integrated analyses of natural and economic systems, emergy analysis is introduced in this paper to assess the health status of Baiyangdian Watershed. First, we establish a emergy based conceptual framework for the assessment, delineate an emergy flow diagram of Baiyangd...

Journal: :ecopersia 0
rezvan alijani former m.sc. student, department of watershed management engineering, faculty of natural resources, tarbiat modares university, iran mehdi vafakhah associate professor, department of watershed management engineering, faculty of natural resources, tarbiat modares university, iran arash malekian assistant professor, department of rehabilitation of arid and mountainous regions, faculty of natural resources, university of tehran, karaj, iran

drought is a complex natural phenomenon that can occur in any climate. hydrologic drought in the river flow of arid and semi-arid areas causes serious shortages, threatens the quality of life, and impacts on the economy. understanding this feature is then essential for the management of water resources. hydrologic drought in the sense of deficient river flow is defined as the periods that river...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد - دانشکده علوم انسانی 1391

the rise and stublishment of safavid dynasty was depend on triangle of tasavof, tashayo and royalty, kings legitimized their power upon these. therefore for the understanding the functions of that period we must explore the role of this elements. although application and emphsise upon dignities such as; complete mentor (morshede kamel), deputy of absent imam (nayebe imame ghayeb), and god’s sha...

2004
Yongsheng Ma

Traditionally watersheds were spatial extents that capture rainwater. Recently it has been identified that unless the watersheds are not managed in an integrated sustainable manner, then not only the water resources but also other resources such as vegetation, fertile soil, fauna and flora get depleted. Rational management of upper and lower parts of a watershed is equally important for the sus...

2006
Shreeram Inamdar Aleksey Naumov

The Soil Water Assessment Tool (SWAT) was implemented to determine annual sediment yields and critical source areas of erosion for the Buffalo River Watershed. Model calibrations were performed by comparing simulated streamflow discharge and sediment concentrations against measured values. Monte-Carlo simulations were performed to identify the most sensitive parameters and the “best-fit” parame...

1998
JAMES R. KARR

1. Society benefits immeasurably from rivers. Yet over the past century, humans have changed rivers dramatically, threatening river health. As a result, societal well-being is also threatened because goods and services critical to human society are being depleted. 2. `Health' Ð shorthand for good condition (e.g. healthy economy, healthy communities) Ð is grounded in science yet speaks to citize...

Journal: :نشریه علمی - پژوهشی هیدرولوژی کاربردی 0
homayoun khoshravan km8 khezerabad,sari, mazandaran, iran, environmental management research group fatemeh nasehi azad university of ardebil

the main purpose of the study is determination of the pollutants hazard potential as well as environmental vulnerability of qarah su river. first the most significant pollutant sources in the qarah su river watershed were identified and then accordingly the pollution hazard potential rate was calculated in universal ranking system model setting. then, by generalizing the algebraic sum of the re...

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