| Constructions of large-scale water conservancy projects may cause changes of water level and periodical flooding of areas near the reservoir, which lead to the construction of reservoir riparian zone. As an essential ecologic land areas located between terrestrial and aquatic ecosystems, riparian zone is characterized by its fragile and sensitive features. It also serves as the last ecological barrier in the prevention of pollution flooding into the water. Due to its effectiveness in the indication of environment factors, ecological processes, and vegetation communities, riparian zone is essential in the conservation of biological diversity, protection of ecological security, and maintenance of ecosystem services. Remote Sensing can be used in the study of reservoir riparian zone in light of its effectiveness and timeliness. Determining the avaliable buffer areas of raparian zone in Guanting reservoir and assessing its health condition with numerous ecological factors in the context of long-term water storage and seasonal water level changes controls the natural flow of water can be essential in the monitoring of riparian zone eco-system, which also serves as a reliable scientific basis for the future planning and development of the study area. This study also has some important application value and practical significance.In this paper, raparian zone of Guanting reservoir was the study area, used the band of near infrared that the medium resolution of the Landsat-TM5Satellite Imagery to edge detection which be used Sobel operator, Roberts operator and Laplacian operator, then used object-oriented classification method to high-resolution satellite remote sensing images WorldView-II to determine the riparian zone, finally to choose the best operator. Combined with the statistical data on water level, determined the high flow period and low flow period, then usd MSS, TM, WorldView-II satellite data resources to dectect the effective range in raparian zone of Guanting reservoir from1983to2013. Applicated PSR(Pressure-State-Response) model, with interpret remote sensing data, statistical monitoring data and19highly concentrated evaluation of representative, used AHP (analytic hierarchy process) method to determine the index weight, used multi-fuzzy comprehensive evaluation method to evaluate the ecosystem health of raparian zone of Guanting reservoir. Main contents and conclusions are as follows: (1)Used the visual observation as a qualitative discriminant analysis method, Laplacian operator has extracted the vast majority edge, and the edge positioning accuracy was relatively high.Calculated the relative error as quantified identificate method, Laplacian operator which relatively error in area, shoreline length and mean values were minimal, so that Laplacian operator as the best edge detection operator.(2) Applied remote sensing method to detecte raparian zone of Guanting reservoir from1983to2013. April1983to July1993as the first decade, April1993to July2003as the second decade and April2003to July2013as the third decade. From the first decade to the second decade, raparian zone of Guanting reservoir showed an increasing trend about34.9955km2, and its landscape indices showed a downward trend, which centroid moved about0.559km and35.14°in the southeast direction. From the second decade to the third decade, Guanting reservoir riparian zone showed an decreasing trend, dropped to41.5195km2, landscape indices showed an upward trend, which centroid moved about1.202km and33.67°in the northeast direction.(3)Applicated PSR(Pressure-State-Response) model, raparian zone of Guanting reservoir evaluated ecosystem health. Which pressure index was in the second level, state indicators index was in the second level, response index was in the second level. According to the evaluation results, combined with the right to index layers, raparian zone of Guanting reservoir ecosystem health was in the second level in2013. |
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