نتایج جستجو برای: total vegetation cover decreased by 362

تعداد نتایج: 7530927  

Abstract The forest road is most important sediment sours in the forest regions. the forest roads with remove vegetation cover and disorder hydraulic behavior regions, causes sediment product and problems due of sediment. This study has been done to surveying sediment factors roll in the sediment producing in the northern forest road. For this goal were selected purpose road sections by using h...

Vegetation in any landscape reflects its health condition. Monitoring land use change and land cover plays a key role in environmental planning and management. Mazandaran province has always been considered by tourists due to its high tourism potential and consequently the vegetation, especially the forest, has been damaged. In this study, vegetation Contiguity and integrity in Mazandaran using...

Journal: :journal of rangeland science 2015
mohamad taghi kashki amr ali shahmoradi ehsan zandi esfahan

abstract. rangeland vegetation dynamics encompass all processes of changes in vegetation composition and structure over time. investigating the rangeland ecosystem dynamics makes it possible to determine the effects of climatic and management conditions on qualitative and quantitative changes of the vegetation in a specific period of time. accordingly, data collection and measurements for evalu...

The rangeland in the Khangai mountain region in Mongolia has degraded for the last decades mainly because of overgrazing and climate change. Livestock production is important part of the economy and is based on natural rangeland. In this research we seek to elucidate the influence of five years (2004-2009) of protection from grazing on vegetation cover of different degradation levels of Fes...

احمد جلالیان, , حسین خادمی, , مریم یوسفی فرد, ,

Improper use of natural resources, especially soil, causes its degradation and severe soil erosion. Water erosion is an important factor causing soil degradation. Land use change of pasture would result in severe soil erosion mainly due to the reduction of vegetation cover and also surface soil disturbance. The objectives of this study were to estimate the amount of sediment, runoff and nutrien...

Journal: :pollution 2015
somayyeh jabbari seyed jamaledin khajedin reza jafari saeed soltani

to determine the suitable indices for vegetation cover and production assessment based on the remote sensing data, simultaneous digital data with field data belonging to the spring rangeland of the semirom-isfahan province were analyzed. during two years of monitoring the annual, grass, forb, and shrub vegetation cover and the total production data from 86 were collected. the global positioning...

ژورنال: :مرتع و آبخیزداری 2012
فاضل امیری حسن یگانه

assessment process of vegetation cover by remote-sensing images should be based on understanding of the vegetation indices. vegetation indices are widely used for assessing and monitoring ecological variables such as vegetation cover, above-ground biomass and leaf area index. the aim of the present research was to study of the aster data capabilities to estimate the vegetation cover percentage ...

Journal: :Environmental management 2008
James D Wickham Timothy G Wade Kurt H Riitters

Meta-analyses reveal that nutrient yields tend to be higher for watersheds dominated by anthropogenic uses (e.g., urban, agriculture) and lower for watersheds dominated by natural vegetation. One implication of this pattern is that loss of natural vegetation will produce increases in watershed nutrient yields. Yet, the same meta-analyses also reveal that, absent land-cover change, watershed nut...

2007
ANDREW N. FRENCH THOMAS J. SCHMUGGE JERRY C. RITCHIE ANN HSU FREDERIC JACOB KENTA OGAWA

Detecting land cover change over semi-arid rangeland is important for monitoring vegetation responses to drought, population expansion, and changing agricultural practices. Such change can be detected using vegetation indices, but these do not represent non-green vegetation and are dominated by seasonal changes. An alternative is to observe spatial changes in thermal emissivities, a measure tha...

جباری, سمیه , جعفری, رضا, خواجه‌الدین, سید جمال‌الدین , سلطانی, سعید,

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...

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