نتایج جستجو برای: vegetation cover maps
تعداد نتایج: 249983 فیلتر نتایج به سال:
There is a public perception that large high-severity wildfires decrease biodiversity and increase fire hazard by homogenizing vegetation composition and increasing the cover of mid-story vegetation. But a growing literature suggests that vegetation responses are nuanced. LiDAR technology provides a promising remote sensing tool to test hypotheses about post-fire vegetation regrowth because veg...
A major challenge in hydrologic modeling remains the mapping of vegetation dynamics in an urban landscape. The impact of vegetation on interception storage varies over time and needs to be quantified in order to enable proper management of water resources in urban areas. However, the heterogeneity and complexity of the urban landscape makes it challenging to monitor urban vegetation. A more det...
Overstory vegetation maps of species and canopy cover were developed from Landsat 7 Thematic Enhanced Thematic Mapper satellite imagery. Ecosystem Monitoring plot data, collected during the 1997-2001 field seasons, were used as training sites for the image classification. Sixty-two species classes and four canopy cover classes were mapped. The maps will be used to support a Joint Fire Science P...
Ecosystem maps are foundational tools that support multi-disciplinary study design and applications including wildlife habitat assessment, monitoring and Earth-system modeling. Here, we present continuous-field cover maps for tundra plant functional types (PFTs) across ~125,000 km2 of Alaska’s North Slope at 30-m resolution. To develop maps, we collected a field-based training dataset using a p...
Soil erosion risk assessment at the watershed of Alqueva is urgently needed to conserve water resources and prevent the accelerated dam siltation. The variation of soil properties is one of the most important reasons for the spatial variability of vegetation cover and erosion. In order to achieve more and better management of rangelands around the largest reservoir of Europe, it is essential to...
the analysis of the relationship between spatial distribution of environmental factors andvegetation types is crucial for understanding mountainous ecosystems. in this research agis based approach was used to produce a vegetation map for sabzkouh protected area inthe chaharmahal-va-bakhtiari province. to identify environmental parameters affecting thevegetation cover, 6 primary and secondary en...
land cover is one of basic data layers in geographic information system for physical planning and environmentalmonitoring. digital image classification is generally performed to produce land cover maps from remote sensing data,particularly for large areas. in the present study the multispectral image from irs liss-iii image along with ancillary datasuch as vegetation indices, principal componen...
Land use may be regarded as one of the most important factors affecting theenvironment with respect to human activities. So far, destroying the rangelands andchanging them into the waste lands and poor rangelands has been proposed as the mostsignificant variations of land use done by human beings. This paper has been conducted toevaluate the variations of vegetation percentage and land uses in ...
The spatial variabi]Lity and co-variability of two different types of remote sensing derivatives that portray vegetation and geomorphic patterns are analyzed in the context of estimating regional-scale CO 2 flux from land surfaces in the arctic tundra. For a study area encompassing the Kuparuk River watershed of the North Slope of Alaska, we compare satellite-derived maps of the normalized diff...
Traditional change detection approaches have been proven to be difficult in detecting vegetation changes in the moist tropical regions with multitemporal images. This paper explores the integration of Landsat Thematic Mapper (TM) and SPOT High Resolution Geometric (HRG) instrument data for vegetation change detection in the Brazilian Amazon. A principal component analysis was used to integrate ...
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