نتایج جستجو برای: wind water erosion crisscross region

تعداد نتایج: 1150573  

Journal: :desert 2006
m. r. rajabi f. rohani m. r. ekhtessassi n. ghazanfarpoor

the majority of iran’s area is covered by arid and semiarid climates. in these areas, wind causes more erosion compared to water. therefore, determination of wind characteristics especially its velocity is very important. one of the simplest methods that can supply researchers with the origin of wind erosion in the shortest time is synthesizing sand rose model and interpretation of aerial photo...

2016
L. Kerber

Introduction: Yardangs are wind-eroded ridges common in regions of Mars [1] and in the most arid deserts on Earth. Yardangs have also been documented on both Venus [2] and Titan [3]. Throughout the years, studies of yardangs have concentrated on particular field sites, and therefore conclusions relating to the controlling parameters on yardang morphology have been highly divergent. Many variabl...

2013
Olafur Arnalds Elin Fjola Thorarinsdottir Johann Thorsson Pavla Dagsson Waldhauserova Anna Maria Agustsdottir

Volcanic eruptions can generate widespread deposits of ash that are subsequently subjected to erosive forces which causes detrimental effects on ecosystems. We measured wind erosion of the freshly deposited Eyjafjallajökull ash at a field site the first summer after the 2010 eruption. Over 30 wind erosion events occurred (June-October) at wind speeds > 10 m s(-1) in each storm with gusts up to ...

Journal: Desert 2016
F. Amiraslani M. Hanifehpoor N. Mashhadi, Sh. Mohamadkhan

Aeolian process and subsequently soil erosion are key factors in dryland environments. Such phenomena are related not only to geoecological factors (lithology, topography, and climatology) but also to land-use and plant cover changes. Formation of new sand dunes in Damghan explains the development of human activities over the past. The aim of this study is to explain the land use changes and th...

2006
Robert N. Carrow

Science-based, holistic, site-specific water conservation practices can reduce water use on turfgrass sites without adversely affecting turfgrass performance. However, when water use is decreased below a certain threshold, performance declines. Water conservation measures that reduce turfgrass performance essentially decrease its economic, environmental, recreational, and aesthetic values, whic...

Journal: :مرتع و آبخیزداری 0
لیلا بخشنده مهر دانش آموختة کارشناسی ارشد بیابان‏زدایی دانشکدة منابع طبیعی دانشگاه صنعتی اصفهان سعید سلطانی دانشیار گروه مرتع و آبخیزداری دانشکدة منابع طبیعی دانشگاه صنعتی اصفهان عادل سپهر استادیار دانشکدة منابع طبیعی و محیط زیست دانشگاه فردوسی مشهد

according to the unccd definition, “desertification” is land degradation in arid, semi-aridand dry sub-humid areas resulting from various factors, including climatic variations andhuman activities. it has been recognized as a major economic, social, and environmentalproblem in many countries of the world. the medalus methodology is a practical approachto assess the present status of desertifica...

Journal: Desert 2006
F. Rohani M. Ekhtessassi M. Rajabi, N. Ghazanfarpoor

The majority of Iran’s area is covered by arid and semiarid climates. In these areas, wind causes more erosion compared to water. Therefore, determination of wind characteristics especially its velocity is very important. One of the simplest methods that can supply researchers with the origin of wind erosion in the shortest time is synthesizing sand rose model and interpretation of aerial photo...

ژورنال: علوم آب و خاک 2017

The Ab-Barik watershed in Bam is a part of Lut desert basin. It is like all other desert areas which has erosion problems caused by wind erosion, sand and soil storms. The result of these sand storms appears as continuous and isolated sand hills. In this paper it was attempted to identify direction and source of harvest points by using sedimentological methods. This was accomplished by step by ...

Journal: Desert 2017

Yardangs are one of the most amazing geomorphic features of Lut desert, Iran developed in alluvial deposits of Pleistocene. They appear as the streamlined hills that are separated by U-shaped troughs with a flat-topped. The study of yardang’s morphometric parameters is important to define their morphological indices. In This study, we describe the morphology of yardangs in the Lut playa, analyz...

Journal: :مرتع و آبخیزداری 0
شیما نیکو استادیار دانشکدة کویرشناسی، دانشگاه سمنان حسین آذرنیوند استاد دانشکدة منابع طبیعی، دانشگاه تهران غلامرضا زهتابیان استاد دانشکدة منابع طبیعی، دانشگاه تهران حسن احمدی استاد دانشکدة منابع طبیعی، دانشگاه تهران محمد علی زارع چاهوکی دانشیار دانشکدة منابع طبیعی، دانشگاه تهران

combating desertification which is a serious threat for the environment and human welfare requires understanding complex issues of this phenomenon using evaluation, awareness of severity of it's processes and determination of it's factors. so here, after recognizing the characteristics of the region showing existence desertification, we assess its current status with emphasis on clima...

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