نتایج جستجو برای: arid region

تعداد نتایج: 552339  

Journal: :Mediterránea. Serie de Estudios Biológicos 2014

Journal: :مرتع و آبخیزداری 0
الهام السادات شکوهی دانش آموخته کارشناس ارشد مدیریت مناطق بیابانی، دانشکده منابع طبیعی، دانشگاه تهران، ایران. غلامرضا زهتابیان استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران. علی طویلی دانشیار دانشکده منابع طبیعی، دانشگاه تهران، ایران.

more than 80% of iran’s area has arid and semi arid climate. therefore, iran is exposed to desertification process. practical activities in controlling desertification must be based on current desertification situation and its severity. based on this theory, evaluating desertification rate indices in khezrabad region was done based on imdpa model. in this research two factors with 10 indices we...

Recognition of desertification criteria and indices and determining the most effective factors on it are the first steps for logical planning to combat desertification. In this study, the sensitivity of the Jaz-Murian region to desertification was evaluated using IMDPA model which is one of the desertification assessment methods in arid and semi-arid regions, on the basis of geology-geomorpholo...

The main parts of Iran have been countered in arid and hyper arid area that in result of especial environmental condition as low precipitation and vegetation density can be caused wind erosion, whereas wind erosion usually has a tiny destruction quantity than water erosion due to wide its activity. Because of not matching presented models by other countries with climate and edaphic condition of...

Prunus eburnea (Spach) Aitch. & Hemsl. is an endemic plant species of Iran-Afghanestan, which has medicinal and nutritional value and distributed in extensive parts of arid and semi-arid ecosystems of Iran. The aims of this study were to investigate the life forms and chorology of associated perennial plant species and biodiversity indices in 52 habitats. Habitats were divided into ten main reg...

2014
Xiaohua Gou Fahu Chen Meixue Yang Fen Zhang

Global mean surface temperatures have risen by 0.85 ± 0.20 °C, over the period 1880–2012, and projections of future climate change suggest further global warming (IPCC 2013). Warming of the global climate is expected to be accompanied by increase of global precipitation, as warmer air is able to hold more water vapour (Wentz et al. 2007). However, precipitation changes are expected to differ fr...

2002
Richard T. Wetherald Syukuro Manabe

[1] Using the results obtained from a coupled ocean-atmosphere-land model with medium computational resolution, we investigated how the hydrology of the continents changes in response to the combined increases of greenhouse gases and sulfate aerosols in the atmosphere, which are determined based upon the IS92a scenario. In order to extract the forced response from natural, internal variability,...

2014
C. Fontanier

As of 2010, it is estimated that 10.5 million people live along the trans -national Rio Grande (RGV) with 83% of the population residing in Mexico and several of the fastest growing cities in the U.S. (SandovalSolis et al., 2013). Historically, agricultural irrigation has been the largest water consumer for each country accounting for 86% of total consumption (Sandoval-Solis et al., 2013). Urba...

2016
Lyubing Zhang Zhigang Jiang Alexander Mikheyev

Biological invasion is one of the most threatening factors for biodiversity conservation. Lacking information on alien species in certain regions of the world hampers a balanced understanding of invasion processes and efficient data exchange among stakeholders. Current knowledge gaps are in need of urgent concern. We therefore conducted a review on alien animals in Xinjiang, an unknown region o...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید