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Issueschangement climatiqueLandLibrary Resource
There are 5, 899 content items of different types and languages related to changement climatique on the Land Portal.
Displaying 685 - 696 of 1721

Spatio-temporal distribution pattern of vegetation coverage in Junggar Basin, Xinjiang

Journal Articles & Books
Décembre, 2016

Vegetation coverage is an indicator used for exploring the growth of vegetation, which has attracted attention from ecologists owing to its significant role in ecological conservation and restoration. As an important component of the terrestrial ecosystem, changes in vegetation coverage reflect changes in the environment, especially with respect to arid areas. A change of vegetation coverage will trigger desertification, degradation of the eco-environment, and regional climate change.

Land-cover data improve bioclimatic models for anurans and turtles at a regional scale

Journal Articles & Books
Décembre, 2009
Canada

We investigated whether accounting for land cover could improve bioclimatic models for eight species of anurans and three species of turtles at a regional scale. We then tested whether accounting for spatial autocorrelation could significantly improve bioclimatic models after statistically controlling for the effects of land cover. Nova Scotia, eastern Canada. Species distribution data were taken from a recent (1999-2003) herpetofaunal atlas. Generalized linear models were used to relate the presence or absence of each species to climate and land-cover variables at a 10-km resolution.

Effect of catchment properties on runoff coefficient in a karst area of southwest China

Journal Articles & Books
Décembre, 2014
Chine

Frequent human activities and climate change in the karst region of southwest China since the 1950s have led to the investigation of response of runoff to climate and catchment properties. Runoff coefficient (Rc) as an expression variable of the catchment response to rainfall is important to describe runoff dynamics and to estimate available streamflow for utilization. In this study, the equations of Rc associated with its attributors of climate condition and catchment property were derived using the Budyko framework.

assessment of long-term overtopping risk and optimal termination time of dam under climate change

Journal Articles & Books
Décembre, 2013
Taiwan

Reservoir management faces a wide range of new challenges resulting from the impact of climate change. One set of challenges arises from the non-stationary nature of hydrological conditions. Another crucial issue is watershed sedimentation, which can significantly influence the sustainability and safety of reservoirs. To address these concerns, this study developed a framework for the management of reservoir risk. An analytical conceptual model coupling physical governing relationships and economic tools was proposed, which was then applied to the Shihmen Reservoir in Taiwan.

comparison of alternative modelling approaches to evaluate the European forest carbon fluxes

Journal Articles & Books
Décembre, 2010
Europe

The European forest carbon balance studied by various methods shows different results. We compared the regional and national net primary production (NPP) estimated by the forest inventory-based model EFISCEN and the climate-based terrestrial ecosystem models (TEMs: BIOME-BGC, ORCHIDEE, and JULES), and single forests NPP derived from the international network of eddy-covariance towers (FLUXNET). In addition, the paper presents the net ecosystem production (NEP) and the net biome production (NBP) calculated with EFISCEN and discusses the influence of forest management onto carbon fluxes.

Greenhouse gas emissions from rice crop with different tillage permutations in rice–wheat system

Journal Articles & Books
Décembre, 2012
Global

Global agriculture lies in intersection of two inescapable issues of the present times, viz. keeping pace with growing food demand and participating in climate change mitigation efforts. Rice cultivation is a major emitter of greenhouse gases (GHGs) and no tillage of soil is becoming popular due to low economic investments with improved soil conditions. However, how these arrangements will affect GHG emissions need to be quantified.

Identification of hydrologic and geochemical pathways using high frequency sampling, REE aqueous sampling and soil characterization at Koiliaris Critical Zone Observatory, Crete

Journal Articles & Books
Décembre, 2011

Koiliaris River watershed is a Critical Zone Observatory that represents severely degraded soils due to intensive agricultural activities and biophysical factors. It has typical Mediterranean soils under the imminent threat of desertification which is expected to intensify due to projected climate change. High frequency hydro-chemical monitoring with targeted sampling for Rare Earth Elements (REE) analysis of different water bodies and geochemical characterization of soils were used for the identification of hydrologic and geochemical pathways.

Assessing strategic water availability using remote sensing, GIS and a spatial water budget model: case study of the Upper Ing Basin, Thailand

Journal Articles & Books
Décembre, 2011
Thaïlande

This paper assesses strategic water availability and use under different development pathways on a basin scale using remote sensing (RS), geographical information systems (GIS) and a spatial water budget model (SWBM). The SWBM was applied to the Upper Ing Basin in northern Thailand to investigate the spatial and temporal variations in the location of streams and water yields from different parts of the basin. The base simulation was carried out for the years 1998–2007 using a DEM and actual land-use data at 100-m resolution.

restricted range of the Ethiopian Bush-crow Zavattariornis stresemanni is a consequence of high reliance on modified habitats within narrow climatic limits

Journal Articles & Books
Décembre, 2012
Éthiopie
Afrique

We attempt to describe and explain the peculiarly restricted distribution of the globally threatened Ethiopian Bush-crow Zavattariornis stresemanni. At a regional scale, models containing only correlates of land cover suggested a far wider distribution of suitable habitat in north-east Africa than the area actually occupied. However, models including only climate variables predicted the known distribution almost perfectly, and suggested that the species’ area of occupancy is delimited by a pocket of climate that is cooler, dryer and more seasonal than surrounding areas.

Sink or source—The potential of coffee agroforestry systems to sequester atmospheric CO₂ into soil organic carbon

Journal Articles & Books
Décembre, 2013
Nicaragua
Costa Rica

Current carbon accounting methodologies often assume interactions between above-ground and below-ground carbon, without considering effects of land management. We used data from two long-term coffee agroforestry experiments in Costa Rica and Nicaragua to assess the effect on total soil organic carbon (SOC) stocks of (i) organic versus conventional management, (ii) higher versus moderate agronomic inputs, (iii) tree shade types. During the first nine years of coffee establishment total 0–40cm depth SOC stocks decreased by 12.4% in Costa Rica and 0.13% in Nicaragua.

Supporting conservation with biodiversity research in sub-Saharan Africa’s human-modified landscapes

Journal Articles & Books
Décembre, 2014
Afrique

Protected areas (PAs) cover 12� % of terrestrial sub-Saharan Africa. However, given the inherent inadequacies of these PAs to cater for all species in conjunction with the effects of climate change and human pressures on PAs, the future of biodiversity depends heavily on the 88� % of land that is unprotected. The study of biodiversity patterns and the processes that maintain them in human-modified landscapes can provide a valuable evidence base to support science-based policy-making that seeks to make land outside of PAs as amenable as possible for biodiversity persistence.