نتایج جستجو برای: arid area

تعداد نتایج: 599002  

Desertification is the result of a series of important processes. Among them, climate change and human activity are the most important. Arid and semi-arid regions cover a vast area of Iran (85%). The hazard assessment of desertification and preparation of desertification intensity maps are key tools for management of desert regions. This research assessed the efficiency of the MICD model for ha...

Journal: :Zeitschrift fur Naturforschung. C, Journal of biosciences 2001
O Muñoz R C Peña E Ureta G Montenegro B N Timmermann

Viscidone (0.5%), vanillin, 3',4'-(methylendioxy)acetophenone, 3-ethoxy-4-methoxybenzaldehyde, cinnamic acid, 3-methoxy-4-hydroxymethyl ester were isolated from propolis of hives from Cuncumen. This is the first report on propolis composition of an arid and a Mediterranean type climate area.

Journal: :Int. J. Applied Earth Observation and Geoinformation 2009
Valérie Soti Annelise Tran Jean-Stéphane Bailly Christian Puech Danny Lo Seen Agnès Bégué

100-150 words) Remote sensing methods for locating and monitoring temporary ponds over large areas in arid lands were tested on a study site in Northern Senegal. Three main results are presented, validated with field data and intended to highlight different spectral, spatial and temporal characteristics of the methods: 1) Among several water indices tested, two Middle InfraRed-based indices (MN...

Journal: :Journal of environmental sciences 2007
Wei-de Li Zi-zhen Li Ji-quan Wang

Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis e...

Journal: :Remote Sensing 2016
Romeo Mendez-Estrella Jose Raul Romo-Leon Alejandro E. Castellanos Fabiola J. Gandarilla-Aizpuro Kyle A. Hartfield

Riparian Zones are considered biodiversity and ecosystem services hotspots. In arid environments, these ecosystems represent key habitats, since water availability makes them unique in terms of fauna, flora and ecological processes. Simple yet powerful remote sensing techniques were used to assess how spatial and temporal land cover dynamics, and water depth reflect distribution of key land cov...

2009
Thomas Schmid José Antonio Domínguez Jesús Solana José Gumuzzio Magaly Koch

The National Park of Las Tablas de Daimiel in Central Spain is a wetland area of great value regarding biodiversity and wildlife habitat. This type of ecosystem is unique within a semi-arid climate and especially sensitive to degradation processes caused by growing pressure on natural resources (agricultural practices, groundwater depletion and land use change) as well as climatic changes. The ...

Journal: :ISPRS Int. J. Geo-Information 2016
Senwang Huang Jiming Kong

Land degradation is a major threat to the sustainability of human habitation, and it is essential to assess it quantitatively. Assessment of the human-induced aspect is especially important for planning appropriate prevention measures. This paper used the Three-North Shelter Forest Program region as the study area, and assessed the land degradation dynamic using a time series of summed normaliz...

2015
Chenchen Huo Yanyan Gao Hui Qian Jia Yang

The Northern Yinchuan Plain is a productive agricultural area of northwest China, which is under threat due to soil salinization. According to the formation and restoring history of soil salinization, the analytic hierarchy process (AHP) was adopted for analyzing the causes of soil salinization and efficiency of various restoring measures. The calculated results of the relative weights of the i...

Journal: :desert 2005
gh. r. zehtabian h. ahmadi h. khosravi a. rafiei emam

desertification process as a great problem affects most of the countries in the world specially developing countries. this process has a high rate in arid and semi-arid countries such as iran. the main objective of this research was to investigate land degradation status and desertification mapping of kashan area. different studies have been carried out in the world in order to assess desertifi...

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