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Both surface topography and vegetation heterogeneity are important factors introducing biases in regional ecological modeling, especially when the modeling is made at large grids. Several studies have demonstrated that gridding the land surface into coarse homogeneous pixels may cause important biases on ecosystem model estimations of carbon budget components at local, regional and global scales....
A good calibration of satellite is necessary to derive reliable quantitative measurements of the surface parameters or to compare data obtain from different sensors. DCSRS (Demonstration Center for Spaceborne Remote Sensing of China National Space Administration) went to inner-Mongolia Plateau to seek fairly uniform reflectance sites as a part of Beijing multifunctional test site network in May and...
Boreal forests comprise one third of global forested area and are the largest terrestrial carbon store. Forest fires are the regions most dynamic disturbance factor, occurring mainly in Siberia, Russian Far East, Canada and Alaska, and these fires represent a globally important release of terrestrial carbon to the atmosphere, via the burning of vegetation and organic soils. Currently the boreal region...
Selected WanDing river basin as a case study which is located in Yunnan frontier area, based on comprehensive integrated application of remote sensing and GIS technology, this research used interpretation method to extract study area's land use/land cover information in 2004, and adopted spectrum direct comparison method to extract its land use/land cover change information from 1990 to 2004. In consideration...
Selected frontier zone as a study area, based on the application of remote sensing monitoring and GIS spatial analysis, completed the study on landscape structure change and the space extension effect. The preliminary results indicate that: 1) woodland was the main landscape as the matrix, while the mountain's lawn, dry land, paddy field, water area, and construction land etc. as the landscape's patch...
The Heihe River is located in the northwest of the country. The river which originates on the northern side of the Qilian Mountain, flows through the north of the Hexi corridor and disappears in the Badan Jiran Desert on the Ala-shan Plateau. The weather in this region is controlled by the continental climate and the Tibet Plateau climate. The Eji-na Oasis in the Heihe River's downstream is generally...
There are three characteristics for ecosystem services, zonal characteristics, complexity and conventional civilization, which affect ecological valuation directly. Considering regional environment and anthropogenic influence, grassland's ecosystem services in Gansu Province are concluded 11 types, including gas regulation, climate regulation, disturbance regulation, wind erosion control and sand...
In this paper, harmonic analysis of 10-year time series (1995-2005) NOAA/AVHRR yearly composite images is performed to develop an innovative technique for hotspot detection and land-features classification based on temporal changes in the NDVI and various AVHRR band values. NOAA/AVHRR images are used due to wide coverage, high frequency and free acquisition offered by NOAA/AVHRR sensors. Proposed...
This paper gives an overview of the ECOCLIMAP-II database, which is a new surface parameters global dataset at a 1 km resolution. The aim of this database is to initialize soil-vegetation-atmosphere-transfer (SVAT) schemes in meteorological and climate modeling. The overall objective of this paper is then to provide elements of the method used to derive surface parameters at 1 km resolution departing...
Monitoring changes in the vegetation cover during the intercrop season is of a special interest in intensive agricultural regions. The presence of bare soils leads to detrimental environmental effects such as soil erosion or water quality degradation. To identify and monitor winter land cover at a regional scale in the Brittany region in France, data from the moderate resolution imaging spectroradiometer...
Information on the distribution of forest species is critical to sustainable management of the forest resources. However, forest species structure information accuracy remains low. Most of the current multi-angle data algorithms are based on the satellite-borne or simulated datasets. In this study, we exploited the use of structural information derived from airborne data to compare the signatures...
In this paper we present a study exploring the medium spatial resolution images of recently launched ENVISAT MERIS for land cover characterization in Portugal. The goal is to take advantage of enhanced spectral and temporal resolutions of images acquired by this sensor to discriminate properly between 19 land cover classes. We test both unitemporal and multitemporal classifications, trying to augment...
A coherent scattering formulation is developed for radar remote sensing of Sahelian grassland. This African vegetation is composed of shrubs and annual grass. The proposed model includes a vegetation generator tool in order to create vegetation structure with realistic architectures and botanical information. This is important in the development of the coherent scattering model, since the relative...
The spatial organization of above-ground plant material plays an important role in controlling not only plant functional activities like photosynthesis and evapotranspiration, but also the photo-vegetation interactions. To improve our understanding of such interactions, the acquisition of highly detailed information about the 3D architecture of individual plants and communities of plants is required...
The main objective of the present study is to investigate the problem of coherent scattering from a half-space of discrete scatterers by importing a simple version of the renormalization formalism, which has been of great use in other fields such as solid state physics or particle physics. The problem of scattering from vegetation involves a great number of parameters including shape, size and spatial...
This study aims at using forward model simulations and ground-measurements (biophysical and spectral) to estimate chlorophyll concentration from hyperspectral data and imagery. Its specific objectives were: (i) to evaluate various combinations of indices as estimators of chlorophyll content from simulated spectra (PROSPECT and SAILH); (ii) to establish chlorophyll predictive equations using spectral...
Hyperspectral, directional remote sensing data as provided from the CHRIS sensor on PROBA open new facilities for land applications, since this kind of optical data allows quantitative analyses using physically based models both for radiative transfer in the atmosphere and canopy, as well as for land surface processes. It is demonstrated how hyperspectral and directional information can deliver required...
Simulating forest scattering by electromagnetic waves has been proposed with both coherent and incoherent models. However, to our best knowledge, most models consider a description of the forest as infinite in the horizontal plane and layered vertically. Such description is relevant in most cases, but fail when border effects are present near the boundaries : the shadowing effects as well as the reinforcement...
SAR images from the Swedish airborne CARABAS-II and LORA systems have been visually analyzed over simulated wind-thrown forest at both single tree and stand level. In ideal conditions, the results show that LORA is more accurate than CARABAS-II at detecting wind-thrown trees, regardless of tree size and direction of the fallen trees relative to flight heading. Furthermore, the visible single trees...
The objective of this paper is to assess increase and decrease of forest area and estimate shrub encroachment between 1997 and 2002 in open mire land using CIR aerial images,DSMs derived from it and LiDAR data. The present study was carried out in the framework of the Swiss Mire Protection Program, where changes of forested area are a key issue. The study area is located in the Pre-alpine zone of...
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