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There are 1, 162 content items of different types and languages related to système d'information géographique on the Land Portal.
Displaying 325 - 336 of 367

Principles and Applications of the Global Human Settlement Layer as Baseline for the Land Use Efficiency Indicator—SDG 11.3.1

Reports & Research
Janvier, 2019
Global

The Global Human Settlement Layer (GHSL) produces new global spatial information, evidence-based analytics describing the human presence on the planet that is based mainly on two quantitative factors: (i) the spatial distribution (density) of built-up structures and (ii) the spatial distribution (density) of resident people. Both of the factors are observed in the long-term temporal domain and per unit area, in order to support the analysis of the trends and indicators for monitoring the implementation of the 2030 Development Agenda and the related thematic agreements.

Vegetation in Drylands: Effects on Wind Flow and Aeolian Sediment Transport

Peer-reviewed publication
Septembre, 2017
Global

Drylands are characterised by patchy vegetation, erodible surfaces and erosive aeolian processes. Empirical and modelling studies have shown that vegetation elements provide drag on the overlying airflow, thus affecting wind velocity profiles and altering erosive dynamics on desert surfaces. However, these dynamics are significantly complicated by a variety of factors, including turbulence, and vegetation porosity and pliability effects. This has resulted in some uncertainty about the effect of vegetation on sediment transport in drylands.

Using Historical Maps within a GIS to Analyze Two Centuries of Rural Landscape Changes in Southern Italy

Peer-reviewed publication
Septembre, 2017
Global

The current characteristics of a rural landscape may be better understood if suitable information related to its past is available. The availability of a Geographical Information System (GIS) can enable the analysis of landscape features in relation to several aspects, e.g., the evolution and mutual inter-relation among different ecosystems, the impact and sustainability of human activities, the visual characteristics of a landscape, etc.

Determining the Frequency of Dry Lake Bed Formation in Semi-Arid Mongolia From Satellite Data

Peer-reviewed publication
Décembre, 2017
Global

In the Mongolian Plateau, the desert steppe, mountains, and dry lake bed surfaces may affect the process of dust storm emissions. Among these three surface types, dry lake beds are considered to contribute a substantial amount of global dust emissions and to be responsible for “hot spots” of dust outbreaks. The land cover types in the study area were broadly divided into three types, namely desert steppe, mountains, and dry lake beds, by a classification based on Normalized Difference Water Index (NDWI) calculated from MODIS Terra satellite images, and Digital Elevation Model (DEM).

Monitoring Changes in Croplands Due to Water Stress in the Krishna River Basin Using Temporal Satellite Imagery

Peer-reviewed publication
Décembre, 2017
Inde

Remote sensing-based assessments of large river basins such as the Krishna, which supplies water to many states in India, are useful for operationally monitoring agriculture, especially basins that are affected by abiotic stress. Moderate-Resolution Imaging Spectroradiometer (MODIS) time series products can be used to understand cropland changes at the basin level due to abiotic stresses, especially water scarcity.

Mapping Land Cover and Estimating the Grassland Structure in a Priority Area of the Chihuahuan Desert

Peer-reviewed publication
Novembre, 2017
Amérique septentrionale

A field characterization of the grassland vegetation structure, represented by the coverage of grass canopy (CGC) and the grass height, was carried out during three years (2009–2011) in a priority area for the conservation of grasslands of North America. Landsat Thematic Mapper (TM5) images were selected and the information of reflectance was obtained based on the geographical location of each field-sampling site.

Investigating the Diversity and Variability of Eastern Mediterranean Landscapes

Peer-reviewed publication
Décembre, 2017
Jordanie
Chypre
Grèce
Liban

The aim of the paper is to examine the variability of eastern Mediterranean landscapes using a common mapping framework relying on Landscape Character Mapping (LCM). LCM was adapted to the region’s specificities placing emphasis on the area’s coastal nature, landform variation, land use, in particular pastoral tradition, and settlement patterns, an important output of this study.

Towards a Reproducible LULC Hierarchical Class Legend for Use in the Southwest of Pará State, Brazil: A Comparison with Remote Sensing Data-Driven Hierarchies

Peer-reviewed publication
Juin, 2018
Brésil

Land Use and Land Cover (LULC) classes defined by subjective criteria can diminish the significance of a study, hindering the reproducibility and the comparison of results with other studies. Having a standard legend for a given study area and objective could benefit a group of researchers focused on long-term or multidisciplinary studies in a given area, in the sense that they would be able to maintain class definition among different works, done by different teams.

Assessing the Land and Vegetation Cover of Abandoned Fire Hazardous and Rewetted Peatlands: Comparing Different Multispectral Satellite Data

Peer-reviewed publication
Juin, 2018
Fédération de Russie

Since the 1990s, many peatlands that were drained for peat extraction and agriculture in Russia have been abandoned with high CO2 emissions and frequent fires, such as the enormous fires around Moscow in 2010. The fire hazard in these peatlands can be reduced through peatland rewetting and wetland restoration, so monitoring peatland status is essential. However, large expanses, poor accessibility, and fast plant succession pose as challenges for monitoring these areas without satellite images.

Temporal and Spatial Analysis of Flood Occurrences in the Drainage Basin of Pinios River (Thessaly, Central Greece)

Peer-reviewed publication
Septembre, 2018
Grèce

Historic data and old topographic maps include information on historical floods and paleo-floods. This paper aims at identifying the flood hazard by using historic data in the drainage basin of Pinios (Peneus) River, in Thessaly, central Greece. For this purpose, a catalogue of historical flood events that occurred between 1979 and 2010 and old topographic maps of 1881 were used. Moreover, geomorphic parameters such as elevation, slope, aspect and slope curvature were taken into account.

Applying Built-Up and Bare-Soil Indices from Landsat 8 to Cities in Dry Climates

Peer-reviewed publication
Septembre, 2018
Iraq

Arid and semi-arid regions have different spectral characteristics from other climatic regions. Therefore, appropriate remotely sensed indicators of land use and land cover types need to be defined for arid and semi-arid lands, as indices developed for other climatic regions may not give plausible results in arid and semi-arid regions. For instance, the normalized difference built-up index (NDBI) and normalized difference bareness index (NDBaI) are unable to distinguish between built-up areas and bare and dry soil that surrounds many cities in dry climates.

Prioritizing Suitable Locations for Green Stormwater Infrastructure Based on Social Factors in Philadelphia

Peer-reviewed publication
Décembre, 2018
États-Unis d'Amérique

Municipalities across the United States are prioritizing green stormwater infrastructure (GSI) projects due to their potential to concurrently optimize the social, economic, and environmental benefits of the “triple bottom line”. While placement of these features is often based on biophysical variables regarding the natural and built environments, highly urbanized areas often exhibit either limited data or minimal variability in these characteristics.