نتایج جستجو برای: arid flora and vegetation

تعداد نتایج: 16844048  

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 ...

2006
SERGIO M. VICENTE-SERRANO

This paper analyses monthly differences in drought impact on vegetation activity in a semi-arid region in the north-east of the Iberian Peninsula between 1987 and 2000. The study determines spatial differences in the effects of drought on the natural vegetation and agricultural crops by means of the joint use of vegetation indexes derived from AVHRR images, a drought index (standardized precipi...

Based on the importance of runoff harvesting method in arid lands, effect of these systems on vegetation production and cover and soil moisture was evaluated. Soil and vegetation were sampled in three sampling areas (Control, Curved pits, Catchment ponds) using randomly-systematic method and in each site (50 hectares), 98 plots were sampled with intervals of 70 m within plots of 1*2 m and in to...

Journal: :Remote Sensing 2017
Yuqiu Jia Lina Tang Lin Wang

Estimation of impervious surface area is important to the study of urban environments and social development, but surface characteristics, as well as the temporal, spectral, and spatial resolutions of remote sensing images, influence the estimation accuracy. To investigate the effects of regional environmental characteristics on the estimation of impervious surface area, we divided China into s...

2017
Wenbin Sun Hongdan Zhang Yungang Cao Xiaolei Zhang Xuefeng Ji Fashuai Li

Original scientific paper Evaluating the deterioration of ecological environment and vegetation of coalfields caused by China’s large-scale coal mining activities is important because of the fragile ecological environment and low temperature in cold and arid areas. This study takes the open coal pits of Haizhou, Gulianhe, and Huolinhe as examples and proposes a method for evaluating their ecolo...

2005
K. E. Keese B. R. Scanlon R. C. Reedy

[1] Understanding climate, vegetation, and soil controls on recharge is essential for estimating potential impacts of climate variability and land use/land cover change on recharge. Recharge controls were evaluated by simulating drainage in 5-m-thick profiles using a one-dimensional (1-D) unsaturated flow code (UNSAT-H), climate data, and vegetation and soil coverages from online sources. Soil ...

Journal: Desert 2019
H. Azarnivand H. Khosravi, M. Behrang Manesh P. Dehghana S. Ahmadi

     Drought is a disaster phenomenon especially in arid and semi-arid areas. Vegetation and its production play a main role in the social and economic issues in every country. In this study, Standardized Precipitation Index (SPI) and Normalized Difference Vegetation Index (NDVI) data have been used to monitor drought and the vegetation condition in Sonqor Abad in, Kermanshah province.  Meteoro...

Journal: :Remote Sensing 2016
Paul Schumacher Bunafsha Mislimshoeva Alexander Brenning Harald Zandler Martin Brandt Cyrus Samimi Thomas Koellner

Remote sensing-based woody biomass quantification in sparsely-vegetated areas is often limited when using only common broadband vegetation indices as input data for correlation with ground-based measured biomass information. Red edge indices and texture attributes are often suggested as a means to overcome this issue. However, clear recommendations on the suitability of specific proxies to prov...

2005
G. S. Okin J. E. Herrick

Aeolian processes are tightly linked to soil and vegetation change in arid and semi-arid systems at multiple spatial and temporal scales. Wind influences patterns of vegetation and soil within the landscape, and these patterns control wind erosion at patch to landscape scales. Aggregated at larger scales, patterns in soil and vegetation distributions influence global distributions of dust and i...

Journal: :desert 2008
a. a. shamsipour s. k. alavipanah h. mohammadi a. azizi f. khoshakhlagh

drought is a major problematic phenomenon for the mostly semi-arid country of iran. the north centralregions of iran (north of esfahan and ghom province) have suffered from severe droughts several times duringthe last three decades. the frequent occurrence of drought in these regions is due to low and inconsistentprecipitation, abnormally high temperatures, increases in surface albedo and evapo...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید