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Effects of classification approaches on CRHM model performance

Journal Articles & Books
декабря, 2012

The cold regions hydrological model (CRHM) platform, a physically based hydrological model using a modular and object-oriented structure, has been applied for simulating the redistribution of snow by wind, snowmelt, infiltration, evapo-transpiration, soil moisture balance, surface depression storage and run-off routing. Land use and land cover classification is a preprocessing procedure to provide the required parameters for CRHM. Per-pixel-based and object-oriented classifications are the two major classification approaches currently in practice.

effect of input data transformations on object-based image analysis

Journal Articles & Books
декабря, 2012
Ghana

The effect of using spectral transform images as input data on segmentation quality and its potential effect on products generated by object-based image analysis are explored in the context of land cover classification in Accra, Ghana. Five image data transformations are compared to untransformed spectral bands in terms of their effect on segmentation quality and final product accuracy. The relationship between segmentation quality and product accuracy is also briefly explored.

2010 land cover map of insular Southeast Asia in 250-m spatial resolution

Journal Articles & Books
декабря, 2012

In this letter, we present the methodology and accuracy assessment of a new regional 250-m spatial resolution land cover map of insular Southeast Asia. Nearly 500 daily Moderate Resolution Imaging Spectroradiometer images (acquired 2 January–3 July 2010) were used in the production of the map. Additionally, peatland maps, elevation information and Daichi-Advanced Land Observing Satellite mosaic data were utilized in the mapping process.

Spatial variability of evapotranspiration of old-growth cypress forest using remote sensing — a case study of Chilan Mountain cypress forest in Taiwan

Journal Articles & Books
декабря, 2012
Taiwan

The Chilan Mountain cypress forest, northeastern Taiwan, is the only one where the genus Chamaecyparis is situated in a subtropical region. The health of a forest ecosystem is closely tied to the evapotranspiration (ET) of water through forests. This study focused on estimating the ET of old-growth cypress in the Chilan Mountain area and investigated its spatial variability in different watershed divisions using remote sensing.

Multi-month memory effects on early summer vegetative activity in semi-arid South Africa and their spatial heterogeneity

Journal Articles & Books
декабря, 2012
South Africa
Botswana
Southern Africa

In semi-arid African regions (annual rainfall between 200 and 600 mm), variability of vegetative activity is mainly due to the rainfall of the current rainy season. In most of South Africa, the rainy season occurs from October to March. On average, vegetative activity lags rainfall by 1 to 2 months. The interannual variability in early summer (December to September) normalized difference vegetation index (NDVI) depends primarily on precipitation at the beginning (October to November) of the rainy season.

Pre-survey suitability evaluation of the differential synthetic aperture radar interferometry method for landslide monitoring

Journal Articles & Books
декабря, 2012

The active remote-sensing technique differential radar interferometry (D-InSAR) is a powerful method for detection and deformation monitoring of landslides. But the radar-specific imaging geometry causes specific spatial distortions in radar images (as e.g. the layover and shadowing effect), which have a negative impact on the suitability of these images for D-InSAR applications. To address this issue, we present a geographical information system (GIS) procedure to accurately predict the areas in which layover and shadowing will occur, before the area of interest is recorded by radar.

Land-cover classification of partly missing data using support vector machines

Journal Articles & Books
декабря, 2012

Land-cover classification based on multi-temporal satellite images for scenarios where parts of the data are missing due to, for example, clouds, snow or sensor failure has received little attention in the remote-sensing literature. The goal of this article is to introduce support vector machine (SVM) methods capable of handling missing data in land-cover classification.

Object-based change detection

Journal Articles & Books
декабря, 2012

Characterizations of land-cover dynamics are among the most important applications of Earth observation data, providing insights into management, policy and science. Recent progress in remote sensing and associated digital image processing offers unprecedented opportunities to detect changes in land cover more accurately over increasingly large areas, with diminishing costs and processing time.

Analysis of broadband surface BRDFs derived from TOA SW CERES measurements for surfaces classified by the IGBP land cover

Journal Articles & Books
декабря, 2012

Most studies on the reflectance properties of the Earth's surface are addressed estimating the bidirectional reflectance distribution function (BRDF) of high spatial resolution and high spectral resolution satellite measurements. This article assesses the development of broadband (BB) BRDFs from radiances corresponding to large footprints classified according to the International Geosphere-Biosphere Programme (IGBP) land-cover classification.

Impacts of Land Use Change on Malaria Vector Abundance in a Water-Limited, Highland Region of Ethiopia

Journal Articles & Books
декабря, 2012
Ethiopia

Changes in land use and climate are expected to alter the risk of malaria transmission in areas where rainfall limits vector abundance. We use a coupled hydrology–entomology model to investigate the effects of land use change on hydrological processes impacting mosquito abundance in a highland village of Ethiopia. Land use affects partitioning of rainfall into infiltration and runoff that reaches small-scale topographic depressions, which constitute the primary breeding habitat of Anopheles arabiensis mosquitoes.

Land cover classification using CHRIS/PROBA images and multi-temporal texture

Journal Articles & Books
декабря, 2012

Most existing multi-temporal classification studies use spectral information alone and ignore the temporal correlation between two-date images. This article proposes a new method to characterize the local temporal correlation using multi-temporal texture measured with a geostatistical function called the pseudo cross variogram (PCV). The derived multi-temporal texture, as an additional band, was combined with the spectral information in multi-temporal classification.

Spatial variability of soil CO₂ efflux linked to soil parameters and ecosystem characteristics in a temperate beech forest

Journal Articles & Books
декабря, 2012

The aim of this study was to determine the amplitude and the driving factors of the spatial variability in soil CO₂ efflux in a young European beech forest. Soil CO₂ efflux was measured in 2003 and 2004 in seven beech plots differing in terms of soil type and leaf area index. After eliminating temporal fluctuations due to soil temperature and soil water content, standardized soil CO₂ efflux varied significantly among plots over a large range given the homogeneity of the land cover type.