نتایج جستجو برای: total vegetation cover decreased by 362

تعداد نتایج: 7530927  

Journal: :مرتع و آبخیزداری 0
بهزاد رایگانی استادیار دانشکده علوم محیط زیست و منابع طبیعی، دانشگاه محیط زیست غلامرضا زهتابیان استاد دانشکده منابع طبیعی، دانشگاه تهران حسین آذرنیوند دانشیار دانشکده منابع طبیعی، دانشگاه تهران سید جمال الدین خواجه الدین استاد دانشکده منابع طبیعی، دانشگاه صنعتی اصفهان سید کاظم علوی پناه استاد دانشکده جغرافیا، دانشگاه تهران

arid and semi-arid areas, due to the sensitive, have variable ecosystems, so continuous assessment and monitoring of the environment is required for most of managerial and adjustment practices. vegetation is one of the most important assessment tools and used as a criterion for evaluation and monitoring of ecosystem functions. in this study, for the first time in the country, we have evaluated ...

ژورنال: علوم آب و خاک 2004
سیدجمال الدین‌خواجه‌الدین, , احمد جلالیان, , ندا زاهدی‌فرد, ,

Satellite data use is finding global applications because they provide repeated cover, broad information, high electromagnetic spectral resolution, and software-hardware compatibilities. This study aims to evaluate of the Landsat TM data capabilities in land-use mapping of Bazoft River basin (Chahar Mahale Bakhtiary Province). Six spectral bands of the Landsate TM were employed to produce land-...

سیدجمال الدین‌خواجه‌الدین, , احمد جلالیان, , ندا زاهدی‌فرد, ,

Satellite data use is finding global applications because they provide repeated cover, broad information, high electromagnetic spectral resolution, and software-hardware compatibilities. This study aims to evaluate of the Landsat TM data capabilities in land-use mapping of Bazoft River basin (Chahar Mahale Bakhtiary Province). Six spectral bands of the Landsate TM were employed to produce land-...

Urbanization through rapid constructions, is the main cause of high heat absorption in urban centers. In addition, the accumulation of heat energy resulted by removal of vegetation cover, has contributed to formation of urban heat islands (UHIs). The spatial distribution of heat intensity in Tehran Metropolitan Area was studied, and the influence of land use and green cover were analyzed in the...

Urbanization through rapid constructions, is the main cause of high heat absorption in urban centers. In addition, the accumulation of heat energy resulted by removal of vegetation cover, has contributed to formation of urban heat islands (UHIs). The spatial distribution of heat intensity in Tehran Metropolitan Area was studied, and the influence of land use and green cover were analyzed in the...

2010
Nader Jalali

Burning of nearly 700 Kuwaiti oil wells and storage tanks during the Persian Gulf war made a severe impact on the environment of the region by emitting about 5000 tons of smoke daily. The fall out of smoke plumes in forms of dry and wet deposition reached even to the center and north of Iran. The majority of the rich and productive rangelands in the southern parts of Iran were strongly marked b...

ژورنال: علوم آب و خاک 2018

This research was aimed to simulate and prioritize the effective factors on water erosion using USLE-M in the system dynamic model. In this integrated model, by using the system dynamic simulation software (Vensim), all variables and factors involved in erosion and soil loss were considered according to the USLE-M model. After model implementation, the estimated values and observations were com...

2007
PONDEROSA PINE JONATHAN D. BAKKER MARGARET M. MOORE

Long-term studies can broaden our ecological understanding and are particularly important when examining contingent effects that involve changes to dominance by long-lived species. Such a change occurred during the last century in Southwestern (USA) ponderosa pine (Pinus ponderosa) forests. We used five livestock grazing exclosures established in 1912 to quantify vegetation structure in 1941 an...

Journal: :مرتع و آبخیزداری 0
فاطمه هادیان کارشناس ارشد مرتع داری، دانشکدة منابع طبیعی، دانشگاه صنعتی اصفهان رضا جعفری استادیار دانشکدة منابع طبیعی، دانشگاه صنعتی اصفهان حسین بشری استادیار دانشکدة منابع طبیعی، دانشگاه صنعتی اصفهان سعید سلطانی دانشیار دانشکدة منابع طبیعی، دانشگاه صنعتی اصفهان

because soil moisture condition affects vegetation changes hence, monitoring of drought and vegetation changes are among valuable management tools in these ecosystems. nowadays, satellite images are used as a low-cost and fast method for vegetation study in different scales. vegetation change is assessed using vegetation spectral characteristics. this study aimed to analyze and monitor the vege...

Journal: :The Professional geographer : the journal of the Association of American Geographers 2013
Douglas A Stow John R Weeks Sory Toure Lloyd L Coulter Christopher D Lippitt Eric Ashcroft

The objectives are to (1) quantify, map, and analyze vegetation cover distributions and changes across Accra, Ghana, for 2002 and 2010; and (2) examine the statistical relationship between vegetation cover and a housing quality index (HQI) for 2000 at the neighborhood level. Pixel-level vegetation cover maps derived using threshold classification of 2002 and 2010 QuickBird normalized difference...

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