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Hydrological response to climate variability at different time scales: A study in the Ebro basin

Journal Articles & Books
Dezembro, 2013
Espanha

In this study we analyzed the response of monthly runoff to precedent climatic conditions at temporal scales of 1–48months in 88 catchments of the Ebro basin (northeast Spain). The standardized precipitation evapotranspiration index (SPEI) was used to summarize the climatic conditions at different time scales, and was correlated with the standardized streamflow index (SSI) calculated at the mouth of each catchment. The Ebro basin encompasses a gradient from Atlantic to Mediterranean climates, and has remarkable complexity in topography, geology and land cover.

Is land cover an important asset for addressing the subjective landscape dimensions?

Journal Articles & Books
Dezembro, 2013
Portugal

This paper explores which physical landscape components relate to subjective landscape dimensions. The ways in which people describe their surrounding cultural landscape was analyzed through an assessment of their representations of it. A special focus was placed on assessing the role of land cover as a means to communicate landscape meanings regarding a specific geographical region. The methodological framework was built on the basis of a questionnaire survey, multivariate statistical analysis and mapping approaches.

Land use changes and its impacts on water resources in Nile Delta region using remote sensing techniques

Journal Articles & Books
Dezembro, 2013

Sustainable water resources management plans depend on reliable monitoring of land use –land cover (LULC) changes. The use of the remote sensing techniques in LULC changes detection brings consistency and reliability to the decision maker at regional scale. Three temporal data sets of images were used to obtain the land cover changes in this study: Landsat-5 Thematic Mapper (TM) acquired in 1984, and Landsat-7 enhanced Thematic Mapper acquired in 2000 and 2005 consequently. Each temporal data set consists of four Landsat scenes, which were mosaicked to cover the whole Nile Delta.

Long-term land cover changes and climate variations – A country-scale approach for a new policy target

Journal Articles & Books
Dezembro, 2013
Itália

This study provides a framework for the joint analysis of long-term land cover changes and climatic variations at regional scale. The land cover distribution observed in Italy in 1960, 1990, and 2006 was compared with trends in annual precipitation and the aridity index estimated during 1951–2007. Annual rainfall decreased by 0.41% per year during the examined period with the consequent increase in the aridity index (0.48% per year). Both rainfall decrease and aridity increase followed a non-uniform spatial distribution impacting differently the Mediterranean landscape mosaic.

spatio-temporal responses of the carbon cycle to climate and land use/land cover changes between 1981–2000 in China

Journal Articles & Books
Dezembro, 2013
China

This paper represents the first national effort of its kind to systematically investigate the impact of changes in climate and land use and land cover (LULC) on the carbon cycle with high-resolution dynamic LULC data at the decadal scale (1990s and 2000s).

Changes of net primary productivity in China during recent 11 years detected using an ecological model driven by MODIS data

Journal Articles & Books
Dezembro, 2013
China

Net primary productivity (NPP) is an important component of the terrestrial carbon cycle. Accurately mapping the spatial-temporal variations of NPP in China is crucial for global carbon cycling study. In this study the process-based Boreal Ecosystem Productivity Simulator (BEPS) was employed to study the changes of NPP in China’s ecosystems for the period from 2000 to 2010. The BEPS model was first validated using gross primary productivity (GPP) measured at typical flux sites and forest NPP measured at different regions.

Improved Band Selection Technique for Hyperspectral Data Using Factor Analysis

Journal Articles & Books
Dezembro, 2013

This paper discusses a statistical and band transformation based approach to select bands for hyperspectral image analysis. Hyperspectral images contain large number of spectral bands with redundant information about the spectral classes in the image scene. It is necessary to reduce the high dimensionality of the data for the processing of hyperspectral data. We report a feature selection technique that removes correlated spectral bands using band decorrelation technique and obtains maximum variance image bands based on factor analysis.

Incorporating the uncertainty of linguistic-scale reference data to assess accuracy of land-cover maps using fuzzy intervals

Journal Articles & Books
Dezembro, 2013

The reference classifications that serve as the fundamental basis of accuracy assessment of land-cover maps are subject to uncertainty. A fuzzy interval approach is proposed in which linguistic-scale labels assigned to each land-cover class at each sample observation are converted to fuzzy intervals. These fuzzy intervals are then used to produce a fuzzy confusion matrix from which fuzzy thematic accuracy measures analogous to overall, user's, and producer's accuracy are produced.

Monitoring the status of forests and rangelands in the Western United States using ecosystem performance anomalies

Journal Articles & Books
Dezembro, 2013
Estados Unidos

The effects of land management and disturbance on ecosystem performance (i.e. biomass production) are often confounded by those of weather and site potential. The current study overcomes this issue by calculating the difference between actual and expected ecosystem performance (EEP) to generate ecosystem performance anomalies (EPA). This study aims to delineate and quantify average EPA from 2000–2009 within the Greater Platte and Upper Colorado River Basins, USA.

Use of ensemble simulations to evaluate the urban effect on a localized heavy rainfall event in Tokyo, Japan

Journal Articles & Books
Dezembro, 2013
Japão

Recently, localized heavy rainfall over highly urbanized areas has caused severe damage in Japan. Although studies have indicated that the presence of urban areas can intensify rainfall, the chaotic noise caused by differences in initial conditions can change the urban effect. Therefore, the usability of ensemble simulation methods for urban effects on a single localized heavy rainfall event must be clarified to synthesize state-of-the-art observations and numerical model studies. This study examined the difference in a localized heavy rainfall event under different initial conditions.

Land-cover change in the conterminous United States from 1973 to 2000

Journal Articles & Books
Dezembro, 2013
Estados Unidos

Land-cover change in the conterminous United States was quantified by interpreting change from satellite imagery for a sample stratified by 84 ecoregions. Gross and net changes between 11 land-cover classes were estimated for 5 dates of Landsat imagery (1973, 1980, 1986, 1992, and 2000). An estimated 673,000km²(8.6%) of the United States’ land area experienced a change in land cover at least one time during the study period. Forest cover experienced the largest net decline of any class with 97,000km² lost between 1973 and 2000.

How do policy options modify landscape amenities? An assessment approach based on public expressed preferences

Journal Articles & Books
Dezembro, 2013
Portugal
França

Facing the changes in the agricultural sector as well as new growing demands from society in relation to the European countryside, new questions emerge as to the management of the agricultural landscapes. The multiple combination of production with the support of multiple functions is a challenge for present day management. Tools are needed that make it possible to assess how a certain landscape can support in particular cultural and amenity functions, those that directly depend on the public preferences.