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Showing items 1 through 9 of 10.
  1. Library Resource
    Journal Articles & Books
    December, 2011
    China

    The Geoscience Laser Altimeter System (GLAS) instrument onboard the Ice, Cloud and land Elevation Satellite (ICESat) provides elevation data with very high accuracy which can be used as ground data to evaluate the vertical accuracy of an existing Digital Elevation Model (DEM). In this article, we examine the differences between ICESat elevation data (from the 1064 nm channel) and Shuttle Radar Topography Mission (SRTM) DEM of 3 arcsec resolution (90 m) and map-based DEMs in the Qinghai-Tibet (or Tibetan) Plateau, China.

  2. Library Resource
    Journal Articles & Books
    December, 2011
    China

    Land managements and agricultural practices in China changed significantly during the past 25 years. Differences in soil fertility parameters between 1981 and 2006 in Jingzhou County, China were investigated, with the changes of land management and agricultural practices. The results showed that, from 1981 to 2006, soil pH and organic matter decreased by 3.35% and 32.2%, while total nitrogen (TN), available N (AN), available phosphorus (AP), and available potassium (AK) increased by 0.4 g kg⁻¹, 21 mg kg⁻¹, 8 mg kg⁻1, and 32 mg kg⁻¹, respectively.

  3. Library Resource
    Journal Articles & Books
    December, 2011
    China

    Grassland degradation not only results in soil degradation and severe decreases in land productivity, but also can promote the emission of soil carbon and nitrogen compounds as greenhouse gases into the atmosphere. The primary objective of this study was to characterize the impact of grassland degradation on carbon and nitrogen budgets in Inner Mongolia, China. We investigated the changes of total carbon, organic carbon, inorganic carbon and total nitrogen that occur in a grassland ecosystem (including vegetation and top 30 cm soil layer) in the course of grassland degradation.

  4. Library Resource
    Journal Articles & Books
    December, 2011
    China

    This article applies a nonlinear machine learning method, support vector regression (SVR), to construct empirical models retrieving water quality variables using remote sensing images. Based on in situ measurements and high-resolution multispectral SPOT-5 (Satellite Pour l'Observation de la Terre) data, a fittest nonlinear function between input and output was obtained from this method, and SVR model parameters were selected automatically using a genetic algorithm (GA).

  5. Library Resource
    Journal Articles & Books
    December, 2011
    China

    Agricultural soil quality is drastically affected in modern societies by human activities. This paper evaluates the anthropogenic influence on agricultural soil quality variation in Zhangjiagang County, China from 1980 to 2004 based on indicator selection and standard scoring function (SSF). The results indicated that after 24 years of anthropogenic influence, soil organic matter (SOM), total nitrogen (TN), cation exchange capacity (CEC) and available phosphorus (av-P) increased significantly and total phosphorus (TP) and available potassium (av-K) decreased slightly.

  6. Library Resource
    Journal Articles & Books
    December, 2011
    China

    With an increasing population and rapid development of the economy and society of the Yellow River Basin region, the Yellow River is at crisis point. The discrepancy between supply and demand of water resources is a key issue. In 2000–2006, the mean annual discharge of the Yellow River entering the delta was 13.2 billion m³, a reduction of 18.6 billion m³ compared with the 1980s, and 9 billion m³ less than in the 1990s. The water requirements of various sectors are increasing. Large amounts of water essential to maintain the health of the delta ecosystem have been diverted for other users.

  7. Library Resource
    Journal Articles & Books
    December, 2011
    China

    China's Horquin area in the northern farming–pastoral transition zone is undergoing rapid land degradation and rangeland modification that is impacting far broader areas as the source of material for dust storms. Multi-temporal Landsat images of the Horquin core area were used to generate a time series of land use covering about a 30-year period, 1975–2003. We show that the physical environment in Horquin deteriorated between 1975 and 2000, although this situation was more controlled after 2000.

  8. Library Resource
    Journal Articles & Books
    December, 2011
    China

    The Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra daily snow cover product MOD10A1 was compared with in situ climate station measurements and a snow map generated from Landsat Enhanced Thematic Mapper Plus (ETM+) data. Snow-covered area (SCA) dynamics were assessed using the MODIS 8-day snow cover composite product MOD10A2 for the 2001–2005 snow seasons in northern Xinjiang, China. The results indicate that the snow-mapping agreement between MODIS daily snow maps and surface observations is high at 94.6% over the four snow seasons under clear-sky conditions.

  9. Library Resource
    Journal Articles & Books
    December, 2011
    China

    Population is a key indicator of socioeconomic development, urban planning and environmental protection, particularly for developing countries like China. But, census data for any given area are neither always available nor adequately reflect the internal differences of population. The authors tried to overcome this problem by spatializing the population across China through utilizing integer night-time imagery (Defense Meteorological Satellite Program/Operational Linescan System, DMSP/OLS) and land-use data.

  10. Library Resource
    Journal Articles & Books
    December, 2011
    China, Asia

    This study aims to assess CO₂ levels in China, based on the dry air column-averaged mixing ratios of CO₂ measured by the Scanning Imaging Absorption spectrometer for Atmospheric CartograpHY (SCIAMACHY) instrument on board ENVISAT and emission inventories. A land cover and statistical data set, the Regional emission inventory in Asia (REAS), was also used in this study. The results show that the spatial variations of the CO₂ concentration in the whole of China are obvious, and with clear seasonal fluctuation during 2003–2005.

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