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Effects of salinity and sodicity on some soil physical properties

Policy Papers & Briefs
декабря, 2007
Turkey

Effects of salinity and sodicity on some soil physical properties were discussed in this article. Effects of salinity and sodicity on floculation, dispersion, infiltration, hydraulic conductivity, runoff and seal formation were taken into consideration in assessment. In many studies it is indicated that high natrium concentration of soil decreases infiltration and hydraulic conductivity values and stimulates crust formation and dispersion occurrence associated with many factors such as texture, structure, Ca and Mg concentration in solution.

Interactions entre systèmes fourragers et systèmes de grandes cultures à l'échelle d'un territoire. Intérêts pour l'environnement

Journal Articles & Books
декабря, 2007

In certain regions where mixed farming prevails, the specialization of the farms (with the progressive disappearance of livestock) has brought about uniform methods of land occupation which run counter the environmental functions of farming. For that matter, grasslands and perennial covers have beneficial effects, but their insertion or their maintenance have to be thought out at the territorial scale.

regression tree-based method for integrating land-cover and land-use data collected at multiple scales

Journal Articles & Books
декабря, 2007

As data sets of multiple types and scales proliferate, it will be increasingly important to be able to flexibly combine them in ways that retain relevant information. A case in point is Amazonia, a large, data-poor region where most whole-basin data sets are limited to understanding land cover interpreted through a variety of remote sensing techniques and sensors. A growing body of work, however, indicates that the future state of much of Amazonia depends on the land use to which converted areas are put, but land use in the tropics is difficult to assess from remotely sensed data alone.

Land use change and land degradation in China from 1991 to 2001

Journal Articles & Books
декабря, 2007
China

China has long been experiencing intense land use/cover changes (LUCC). Undesirable land use/cover changes have resulted in widespread land degradation. This study examines the temporal and spatial dynamics of land use change and land degradation as evident from land use survey datasets (1991-2001). Six prominent land degradation processes were identified, namely: desertification, secondary salinisation, loss of agricultural use, deforestation, grassland degradation and loss of wetland. Rates of conversion were calculated and distribution patterns were mapped with the aid of GIS.

Modeling Linkages Between Climate Policy and Land Use: An Overview

Policy Papers & Briefs
декабря, 2007

Agriculture and forestry play an important role in emitting and storing greenhouse gases. For an efficient and cost-effective climate policy it is therefore important to explicitly include land use, land use change, and forestry (LULUCF) in economy-climate models. This paper gives an overview and assessment of existing approaches to include land use, land-use change, and forestry into climate-economy models or to link economy-climate models to land-use models.

Application of GIS and logistic regression to fossil pollen data in modelling present and past spatial distribution of the Colombian savanna

Journal Articles & Books
декабря, 2007
Colombia

Climate changes affect the abundance, geographic extent, and floral composition of vegetation, which are reflected in the pollen rain. Sediment cores taken from lakes and peat bogs can be analysed for their pollen content. The fossil pollen records provide information on the temporal changes in climate and palaeo-environments. Although the complexity of the variables influencing vegetation distribution requires a multi-dimensional approach, only a few research projects have used GIS to analyse pollen data.

Global Attention to Turkey Due to Desertification

Journal Articles & Books
декабря, 2007
Turkey
Europe
Western Asia
Global

Desertification has recognized as an environmental problem by many international organizations such as UN, NATO and FAO. Desertification in Turkey is generally caused by incorrect land use, excessive grazing, forest fires, urbanization, industry, genetic erosion, soil erosion, salinization, and uncontrolled wild type plants picking. Due to anthropogenic destruction of forest, steppe flora gradually became dominant in Anatolia. In terms of biodiversity, Turkey has a significant importance in Europe and Middle East.

Land cover change 2002-2005 in Borneo and the role of fire derived from MODIS imagery

Journal Articles & Books
декабря, 2007

Borneo has experienced heavy deforestation and forest degradation during the past two decades. In this study the Moderate Resolution Imaging Spectroradiometer was used to monitor land cover change in Borneo between 2002 and 2005 in order to assess the current extent of the forest cover, the deforestation rate and the role of fire. Using Landsat and ground observation for validation it was possible to discriminate 11 land cover classes. In 2002 57% of the land surface of Borneo was covered with forest of which 74% was dipterocarp and more than 23% peat swamp forest.