Search results | Land Portal

Search results

Showing items 1 through 9 of 141.
  1. 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).

  2. Library Resource
    Conference Papers & Reports
    May, 2011
    China

    Chinas’ successfully increased food production during the last 30 years has causedsignificant negative external impacts and subsequent escalating environmental costs (Ashand Edmonds, 1998). This dilemma has recently become a popular issue and thegovernment attaches great importance towards a more sustainable agricultural production(UNDP, 2006).

  3. Library Resource
    Conference Papers & Reports
    September, 2011
    China

    Using a panel dataset from Zhejiang province in China over the period 1995-2002, wepropose a two-step estimation procedure to investigate the links between land lease activityand production efficiency. We find that the output elasticity with respect to land, the scaleeffect and the technical efficiency are higher for farmers involved in land-lease activities.

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

    Oil exploitation and road development have strongly fragmented the coastal landscapes, leading to profound ecological consequences. The dynamic relationships between oil wells, roads, and landscape fragmentation indices in the Yellow River Delta, China were explored. Oil wells, roads and land cover were mapped from TM images in 1992, 2000, 2006, and 2009, respectively. Changes and relationships were compared among three selected typical sections using linear regression models.

  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

    The relationships between water yields of tributaries and coverage of different vegetation types in the corresponding sub-watersheds were investigated during the wet season in the Heishui River Valley, located in the upper portion of the Yangtze River in western China. Stable isotope analysis was used to calculate the relative contributions of the tributaries to water yield in the main stem of the Heishui River, while relative coverages of the different vegetation types were calculated from classified Landsat 7 TM satellite images of the study area.

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

    Impervious surfaces are the result of urbanization that can be explicitly quantified, managed and controlled at each stage of land development. It is a very useful environmental indicator that can be used to measure the impacts of urbanization on surface runoif, water quality, air quality, biodiversity and microclimate. Therefore, accurate estimation of impervious surfaces is critical for urban environmental monitoring, land management, decision-making and urban planning.

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

    Soil carbon stocks and sequestration have been given a lot of attention recently in the study of terrestrial ecosystems and global climate change. This review focuses on the progress made on the estimation of the soil carbon stocks of China, and the characterization of carbon dynamics of croplands with regard to climate change, and addresses issues on the mineralization of soil organic carbon in relation to greenhouse gas emissions.

  9. 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.

  10. 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.

Land Library Search

Through our robust search engine, you can search for any item of the over 64,800 highly curated resources in the Land Library. 

If you would like to find an overview of what is possible, feel free to peruse the Search Guide


Share this page