نتایج جستجو برای: extent of forest lands considered for recreation
تعداد نتایج: 22759298 فیلتر نتایج به سال:
Nationally, the causes and extent of fire on lands administrated by the United States Forest Service varied significantly from 1940 to 2000, with California experiencing the largest relative annual burned areas.The south-east and California experienced the largest relative area burned by fires from human ignitions. No significant differences were detected in the relative area burned by lightnin...
the main purpose of the present study was to investigate the relationship between listening proficiency and metacognitive listening strategies awareness among low, mid, and highly self-regulated students. three hundred and seventy one efl students participated in this study (all grade 3 and 4 high-school students who were studying in khansar in academic year 1391-92). to gather the data, three ...
abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...
This paper analyzes the interactions between land use and forest cover in the Upper Midwest, USA from 1970 to 1990. New data are presented and interpreted to evaluate the effects of land-use changes, especially abandonment of agriculture and dispersed development, on forest cover throughout the region. Forest-cover data were collected from Landsat satellite imagery and land use was interpreted ...
al. 2001, Loomis et al. 2001, Hesseln et al. 2003). Postfire recreation use can differ by activity and location and depends on initial forest conditions, fire characteristics, and timing of fires (e.g., Kline 2004). In wilderness areas postfire recreation likely fluctuates over time in response to changing forest conditions. Immediately after fire, recreation use may decline substantially in re...
abstract present research considered to examine and compare shahrray 14 years girls and boys narrative concerning with their responsibilities in this research, statistical society are 14 years girls and boys of shahrry . for performing this research. first, 14 years of 50 boys and 50 girls were selected in accidental method and have filled memati hormaled adolescents responsibility questioner...
The extent and distribution of global forests is a matter of considerable concern. The overall rate of deforestation remains high although recent reports suggest it is fi nally beginning to decline (FAO 2011 ) . But this hides regional differences. In temperate regions net forest cover is increasing because of afforestation and natural expansion of forests. By contrast, net forest cover in most...
the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...
The forest soils are the key parts of the Earth system that are globally degraded through anthrop induced deforestation, mainly converting to other landuses. The present study was conducted in Gazafolya village located in Merek watershed, Kermanshah, Iran, in which the soil quality of the forest and converted forest (rainfed lands) with the same topographic and geologic conditions were compared...
boron nitride semiconducting zigzag swcnt, $b_{cb}$$n_{cn}$$c_{1-cb-cn}$, as a potential candidate for making nanoelectronic devices was examined. in contrast to the previous dft calculations, wherein just one boron and nitrogen doping configuration have been considered, here for the average over all possible configurations, density of states (dos) was calculated in terms of boron and nitrogen ...
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