نتایج جستجو برای: total edge and largest patch index influence water quality indexes including ec

تعداد نتایج: 17238218  

زمینه و هدف: سرعت تغییر اکوسیستم ها در سال های اخیر چنان بوده که امکان سازگاری موجودات زنده با تغییرات محیطی به سختی صورت می گیرد و این عارضه ناشی از عدم توجه به تغییرات کاربری اراضی و بهره‌برداری از منابع طبیعی است. هدف از این تحقیق، بررسی روند تغییرات کمی سیمای سرزمین در حوزه آبخیز قره سو و مرگ در استان کرمانشاه است.روش بررسی: به منظور پایش تغییرات از تصاویر ماهواره لندست در تاریخ های E...

ژورنال: سلامت و محیط زیست 2020

Background and Objective: Increased untreated wastewater and unsustainable development of agriculture has deteriorated water quality of rivers. The aim of this study was to determine the quality of water in Gorganrud River basin using NSFWQI IRWQISC and Liou Pollution Index and compare them with the global standards. To do this, GIS software.was used Materials and Methods: In this study, 5 sam...

Introduction: The ecological, economic, and social potential of an area for large and large uses is influenced by the quantity and quality of the waters. Therefore, appropriate methods of surface water and groundwater have been investigated qualitatively and quantitatively in order to use its results in assessing the power of the land. One of the important factors for sustainable development is...

2010
HANNAH M. MURPHY GREGORY P. JENKINS JEREMY S. HINDELL ROD M. CONNOLLY

This study has investigated the taxon-specific responses of fauna to patch edges, and how these relate to patch attributes (patch size, seagrass biomass and water depth), and hydrodynamics in the seagrass habitat. Faunal abundances were sampled at the edge, 2 m in from the edge, and in the middle of 10 seagrass patches of variable size in Port Phillip Bay, Australia. Five of nine taxa showed ed...

2013
Gilberto Pasinelli Kim Meichtry-Stier Simon Birrer Bruno Baur Martin Duss

Impacts of habitat loss and fragmentation on distribution and population size of many taxa are well established. In contrast, less is known about the role of within-patch habitat quality for the spatial dynamics of species, even though within-patch habitat quality may substantially influence the dynamics of population networks. We studied occurrence patterns of two Orthopteran species in relati...

Journal: :جغرافیا و توسعه ناحیه ای 0
داداش پور داداش پور آفاق پور آفاق پور رفیعیان رفیعیان

the aim of this paper is to examine and analyze the spatial distribution of population in cities of the southern coastal region of iran by using common models and techniques in the field and to study the trends of evolution in a time period of 40 years (1345-1385). models used in the study can be classified into three main groups. the first group is the primate city indexes (including jefferson...

Amouei, Abdoliman , Asgharnia, Hosseinali , Fallah, Hourieh , Miri, Somayyeh , Momeni, Habibe ,

Background & purpose: One of the major factors in the quality of drinking water is corrosion and scaling. The aim of the present study was to evaluate corrosion and scaling potential of drinking water supply network in Juybar (A city in Iran). Materials and Methods: 60 samples of drinking water in distribution network were collected randomly in summer and autumn seasons and transferred into ...

Journal: :desert 0
gh.r. zehtabian professor, faculty of natural resources, university of tehran, karaj, iran h. mohammad asgari assistant professor, khoramshahr university of marine science and technology, khoramshahr, iran m. tahmoures ph.d. student, faculty of natural resources, university of tehran, karaj, iran

our main objective in the present study was to assess the spatial variation of chemical and physical water properties. prior to the design of groundwater quality monitoring networks, it is essential to investigate the spatial structure of the groundwater quality variables. a case study is presented which used ground water quality observations from groundwater domestic wells in the dameghan, ira...

2011
Xinli Xu Yun Guo

Let G be a connected graph with vertex set V (G) and edge set E(G). The eccentric connectivity index of G, denoted by ξc(G), is defined as ∑ v∈V (G) deg(v)ec(v), where deg(v) is the degree of a vertex v and ec(v) is its eccentricity. In this paper, we propose the edge version of the above index, the edge eccentric connectivity index of G, denoted by ξc e(G), which is defined as ξc e(G) = ∑ f∈E(...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه کاشان - دانشکده علوم انسانی 1390

increasing academic and professional language demands around the world are not a deniable fact. the purpose of this study was to investigate english language needs and communication needs of the chemistry students at master and ph.d. levels at the iranian universities. in this research, different methods were used including un-structured interview, structured interview, and two sets of question...

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