Measurement of vegetation coverage on a small scale is the foundation for the monitoring of changes in vegetation coverage and of the inversion model of monitoring vegetation coverage on a large scale by remote sensin...Measurement of vegetation coverage on a small scale is the foundation for the monitoring of changes in vegetation coverage and of the inversion model of monitoring vegetation coverage on a large scale by remote sensing. Using the object-oriented analytical software, Definiens Professional 5, a new method for calculating vegetation coverage based on high-resolution images （aerial photographs or near-surface photography） is proposed. Our research supplies references to remote sensing measurements of vegetation coverage on a small scale and accurate fundamental data for the inversion model of vegetation coverage on a large and intermediate scale to improve the accuracy of remote sensing monitoring of changes in vegetation coverage.展开更多
The upper and middle reaches of the Taoer River, a representative ecologically sensitive area, has experienced great climate change and rapid agricultural and industrial development since 1961. There is therefore an u...The upper and middle reaches of the Taoer River, a representative ecologically sensitive area, has experienced great climate change and rapid agricultural and industrial development since 1961. There is therefore an urgent need to evaluate the impact of climate change and human activities on stream flows to serve better the water resource management in this region. The nonparamet- ric Mann-Kendall test and moving t-test were used to identify trends and change points in stream flow, precipitation and potential evapotranspiration data series. A significant upward trend has been found in annual stream flow, with an abrupt change identified in 1985 at the Taonan station which is the station that controls the entire study area. The stream flow data was divided into a baseline period and a period of change. Both Fu and Zhang＇s functions were employed to evaluate the impacts of variation in climate and human activities on mean annual stream flow, based on precipitation and potential evaporation. Analysis of the increase in mean annual stream flow between the baseline and the period of change indicated that climate change accounted for about 45% of the total increase and human activities were responsible for about 55%.展开更多
基金funded by the National Natural Science Foundation of China(Grant No.40571029).
文摘Measurement of vegetation coverage on a small scale is the foundation for the monitoring of changes in vegetation coverage and of the inversion model of monitoring vegetation coverage on a large scale by remote sensing. Using the object-oriented analytical software, Definiens Professional 5, a new method for calculating vegetation coverage based on high-resolution images （aerial photographs or near-surface photography） is proposed. Our research supplies references to remote sensing measurements of vegetation coverage on a small scale and accurate fundamental data for the inversion model of vegetation coverage on a large and intermediate scale to improve the accuracy of remote sensing monitoring of changes in vegetation coverage.
基金supported by the National Natural Science Foundation of China titled Study on Mechanism and Quantitative Methods of Ecological Water Requirements in Typical Watersheds of Northeastern China (Grant No. 40571029)project (KZCX2-YW-Q06-1),Program of Knowledge Innovation,Chinese Academy of Sciences
文摘The upper and middle reaches of the Taoer River, a representative ecologically sensitive area, has experienced great climate change and rapid agricultural and industrial development since 1961. There is therefore an urgent need to evaluate the impact of climate change and human activities on stream flows to serve better the water resource management in this region. The nonparamet- ric Mann-Kendall test and moving t-test were used to identify trends and change points in stream flow, precipitation and potential evapotranspiration data series. A significant upward trend has been found in annual stream flow, with an abrupt change identified in 1985 at the Taonan station which is the station that controls the entire study area. The stream flow data was divided into a baseline period and a period of change. Both Fu and Zhang＇s functions were employed to evaluate the impacts of variation in climate and human activities on mean annual stream flow, based on precipitation and potential evaporation. Analysis of the increase in mean annual stream flow between the baseline and the period of change indicated that climate change accounted for about 45% of the total increase and human activities were responsible for about 55%.
