نتایج جستجو برای: four classes of land use including cropland
تعداد نتایج: 21259755 فیلتر نتایج به سال:
Supplying food for the anticipated global population of over 9 billion in 2050 under changing climate conditions is one of the major challenges of the 21st century. Agricultural expansion and intensification contributes to global environmental change and risks the long-term sustainability of the planet. It has been proposed that no more than 15% of the global ice-free land surface should be con...
Sedimentation (primarily from human land use) is a major threat to runoff-fed wetlands of the Great Plains of North America (playas), but it is unknown how many playas are turbid, how prevalence of turbidity has changed over time, and how turbidity is related to surrounding land use. We used remotely sensed imagery to assess sedimentation in the waters of over 7700 playa basins in Texas on four...
A new 1 km global IIASA-IFPRI cropland percentage map for the baseline year 2005 has been developed which integrates a number of individual cropland maps at global to regional to national scales. The individual map products include existing global land cover maps such as GlobCover 2005 and MODIS v.5, regional maps such as AFRICOVER and national maps from mapping agencies and other organizations...
Net annual soil carbon change, fossil fuel emissions from cropland production, and cropland net primary production were estimated and spatially distributed using land cover defined by NASA's moderate resolution imaging spectroradiometer (MODIS) and by the USDA National Agricultural Statistics Service (NASS) cropland data layer (CDL). Spatially resolved estimates of net ecosystem exchange (NEE) ...
Irrigated croplands in Central Asia are highly prone to land degradation due to their environmentally fragile physical settings and intensive agricultural practices. This study: (i) assesses the state of croplands in irrigated areas in northern Uzbekistan, based on the time series of MODIS-NDVI imagery; (ii) analyzes relationships between the identified trend of cropland degradation and soil qu...
Land degradation has expanded in the Mediterranean region as a result of a variety of factors, including economic and population growth, land-use changes and climate variations. The level of land vulnerability to degradation and its growth over time are distributed heterogeneously over space, concentrating on landscapes exposed to high human pressure. The present study investigates the level of...
Specialized cash grain production, emergent in the midwestern United States during the post-WWII era, typifies the Upper Four Mile Creek watershed in southwestern Ohio. This style of agriculture intensifies cropland use, with consequent increases in soil erosion and stream sedimentation a serious problem in the lower reservoir, Acton Lake. Agricultural statistics and aerial photographs compiled...
Land cover type is a crucial parameter that is required for various land surface models that simulate water and carbon cycles, ecosystem dynamics, and climate change. Many land use/land cover maps used in recent years have been derived from field investigations and remote-sensing observations. However, no land cover map that is derived from a single source (such as satellite observation) proper...
The objectives of this paper were to determine the response of soil quality indicators and organic carbon (OC) distributions within different aggregate classes to changes in land use from desert soils to cropland occurring in the Abarkooh plain, Central Iran. Composite soil samples of the desert soil, wheat and alfalfa fields were taken from three different depths and soil quality indicators, i...
objective: the aim of this study is to provide a management plan for the sykan watershed of darre shahr city located in ilam province using gis in land use planning. methods: for land using of sykan watershed of ilam province with about 9 hectares area, map of classes, elevation, percent slope, geographical aspects, soil characteristics, vegetation density and the final map units were combined ...
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