نتایج جستجو برای: especially in vegetation areas

تعداد نتایج: 17004845  

ژورنال: مرتع 2021

Drought as a complex ecosystem crisis can affect vegetation density and health. Iran with an arid and semi-arid climate is exposed to this phenomenon. Therefore, it is necessary to evaluate the effect of drought on vegetation. The purpose of this study is to evaluate the effect of meteorological drought on vegetation dynamics in Iran. In this regard, using MATLAB software, SPEI index with time ...

Journal: :Remote Sensing 2016
Siqin Tong Jiquan Zhang Si Ha Quan Lai Qiyun Ma

Long-term remote sensing normalized difference vegetation index (NDVI) datasets have been widely used in monitoring vegetation changes. In this study, the NASA Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g dataset was used as the data source, and the dimidiate pixel model, intensity analysis, and residual analysis were used to analyze the changes of vegetation coverage in Inner M...

2006
Cort J. willmott

Numerical and observational studies have documented the climatic importance of land surface variability, especially in soil moisture and surface roughness. Land surface representations within global c h a t e models, however, have been based on global vegetation data sets that characterize the surface as invariant at scales smaller than about (100 km12. Within climate model grid areas, the vege...

2012
Lorelei J Alvarez Howard E Epstein Junran Li Gregory S Okin

Many arid grassland communities are changing from grass dominance to shrub dominance, but the mechanisms involved in this conversion process are not completely understood. Aeolian processes likely contribute to this conversion from grassland to shrubland. The purpose of this research is to provide information regarding how vegetation changes occur in an arid grassland as a result of aeolian sed...

Journal: :محیط شناسی 0
علیرضا ذاکر اصفهانی استادیار پژوهشگاه علوم انسانی و مطالعات فرهنگی

although the geographic and climatic conditions of the desert itself is not really growing, knowing about the iranian desert is important. what expands the deserts is the relationship of the desert areas with of the natural environment itself. degradation of water resources, soil and especially vegetation in the desert belt of iran provided conditions caused desertification and their spread on ...

2003
N. Blaunstein D. Censor D. Katz I. Matityahu

In this paper we describe radio wave propagation within mixed residential area consisting of vegetation and houses. We assume no specific knowledge of the houses and vegetation location, but only of their statistical parameters. A three-dimensional (3D) stochastic approach, which is based on the statistical description of the terrain features, houses and vegetation, and deterministic descriptio...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه مازندران 1388

target tracking is the tracking of an object in an image sequence. target tracking in image sequence consists of two different parts: 1- moving target detection 2- tracking of moving target. in some of the tracking algorithms these two parts are combined as a single algorithm. the main goal in this thesis is to provide a new framework for effective tracking of different kinds of moving target...

2014
Shan Khazendar Jessica Farren Hisham Al-Assam Hongbo Du Ahmed Sayasneh Tom Bourne Sabah Jassim

Ultrasound is one of the most widely used multipurpose imaging modalities that is ideal for monitoring and diagnosing early pregnancy events. The first sign and measurable element of an early pregnancy is the Gestational Sac (GS). Currently, the size of GS is manually measured from an ultrasound image of the GS. This paper argues that the Mean Sac Diameter (MSD) derived from the manual measurem...

More than one-third of the earth is characterized by arid and semi-arid climate and desertification phenomenon in these areas has been intensified in recent decades. This study aims to investigate the trend of desertification using vegetation indices and Iranian Model of Desertification Potential Assessment (IMDPA) in Abarkooh Plain, Yazd province, Iran. The satellite images (Landsat images in ...

Iran has high vegetation diversity due to different climates and ecological conditions. Golestan province is one of the most diverse vegetation provinces in the country. Among the plant species of this province, the Juniper genus, with the presence of 6 native species, is one of the few coniferous species which is an important part of the under story vegetation flora of the area. Chahar Bagh Ju...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید