نتایج جستجو برای: soil and vegetation classes
تعداد نتایج: 16884126 فیلتر نتایج به سال:
Introduction: Soil erosion is the most important factor in damaging and decreasing the productivity of agricultural soils. Moreover, as the transfer of sediments rich in nutrients through the soil leads to soil erosion and in turn to the decrease in the dams’ reservoirs’ storage capacity, bringing about adverse economic and eco-environmental consequences such as damage to land resources and dec...
vegetation that is allowed to naturally decompose isn’t realized by many ranchers and some range mangers. Mulch plays a critical role in soil-water relationships that is often overlooked. This, coupled with current drought conditions in the southwestern United States justifies a consideration of the importance of mulch on rangelands. Several early classic studies (reviewed in this article) reve...
A multitemporal algorithm, originally conceived for the C-band radar aboard the Sentinel-1 satellite, has been updated to retrieve soil moisture from L-band radar data, such as those provided by the National Aeronautics and Space Administration Soil Moisture Active/ Passive (SMAP) mission. This type of algorithm may deliver more accurate soil moisture maps that mitigate the effect of roughness ...
sange siyah dam is located two kilometers down the kabod khani village. the environ of ghorrve city in kurdestan province. this is an clay core dam. in this dam instrumentation is performed in three section and consist of electrical piezometers, total pressure cells, settlement cells and so on. the main objective of instrumentation is to control the behavior of dam body and foundation, end else...
The objective of the present study was to investigate the pasture vegetation changes using satellite data in Semirom, Isfahan province. This study was conducted in 2004 as a wet year and 2009 as a dry year. The WiFS and AWiFS satellite images were acquired and used for the year 2004 and 2009, respectively. First, the vegetation percentage was simultaneously measured in the two years. Then, cons...
abstract the main purpose of this study was to investigate whether there was any significant difference between the speaking achievement of learners who were trained by means of consciousness raising of sociolinguistic skills and that of learners who were trained without the above mentioned task. the participants of this study consist of 60 intermediate level students participating languag...
Risks assessment of forest project implementation in spatial density changes of forest under canopy vegetation using artificial neural network modeling approach Nowadays, environmental risk assessment has been defined as one of the effective in environmental planning and policy making. Considering the position and structure of vegetation on the forest floor, the main role of forest under ca...
Soil erosion is of the most important environmental challenges and factors of forest damage, which is, occur because of the land use change, road construction and lack of vegetation cover. Forest soil is naturally penetrable but forest roads are not. This issue causes the flows runoff on road surface and washes soil particles. Thus, forest roads must be planned and constructed accurately. So, t...
abstract this study investigates the teachers’ correction of students’ spoken errors of linguistic forms in efl classes, aiming at (a) examining the relationship between the learners’ proficiency level and the provision of corrective feedback types, (b) exploring the extent to which teachers’ use of different corrective feedback types is related to the immediate types of context in which err...
abiotic factors, as topographic and physicochemical properties of soil, are the most important effective factor on vegetation in rangeland ecosystems which have the most important performances to forming and succession of plant vegetation. ecologic management of rangelands can be desired by better understanding of these effective factors. then, rangeland of javaherdeh (ramsar) in the northern a...
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