Research On Spatial And Temporal Variation Of China Mainland Coastline And Coastal Engineering

For coastal zone monitoring, coastline extraction in various times is a fundamental work. Coastline mapping and coastline change detection become critical to coastal resource management, coastal environment protection, sustainable coastal development, and planning. This paper focuses mainly on spatial-temporal variation of china mainland coastline and coastal engineering since China’s Reform and Opening. In this study, these changes were examined by using satellite images(Landsat MSS, TM, ETM+ and O LI) from collected between 1980 and 2015. This paper retrieved categorical mainland coastline information in mainland C hina in the year of 1980, 1990, 2000, 2010 and 2015. The spatial-temporal variation of C hina mainland coastline was analyzed systematically in the aspects of the spatial distribution of coastal types, length changes, changes in shape and spatial change utilizing Remote Sensing and GIS technologies. The utilization of China mainland coastline was analyzed systematically in the aspects of improved utilization intensity, coastline type change and land use change over the past 35 years. Then the spatial-temporal characteristics of coastal engeering of aquaculture pond, salt field and seaport and its impact on the coastline changes were analyzed combined with social-economic data and typical area. The main conclusions were as follows:(1)During the research period, the length of C hina’s mainland coastline increased continuously and the rising intensity cincreased progressively. The types of coastline changed significantly. The amount of artificial coastlines increased continuously and dramatically, while the length of the natural coastlines decreased acutely.(2) The variation of C hina mainland coastlines showed notable temporal and spatial heterogeneity. The coastline length entered a period of rapid growth after 2000. Areas that had coastlines that changed significantly were concentrated in Bohai Bay, the south and west bank of Laizhou Bay, the north bank of Liaodong Bay, the south of Jiangsu Province, Yangtze River Delta, the south bank of Hangzhou Bay and Pearl River Delta.(3)The fractal dimension of the overall coastline was increased steadily, whose change trend was consistent with the length of the coastline, indicating that the geometry of the coastline of the study area became more complex.(4)The coastline mainly expanded seaward and coastal engineering construction were the leading factor in coastal evolution.(5)The unutilized coastlines and heavily utilized coastlines are the major components of China mainland coastline. After 1990, the utilization intensity of mainland coastlines showed an increasing trend. The dividing line of the regional utilization intensity was in the Hangzhou bay, the regional utilization intensity of the northern coastlines were higher than the shouther coastal area.(6) The variation of reclamation of aquaculture pond, salt field and seaport showed significant temporal heterogeneity. Before 2000, coastal development was predominantly constituted by reclamation of aquaculture pond, salt fields; while after 2000, the seaports had entered a stage of rapid development with the problems of a certain blindness and constructing in advance.The innovation points: 1) This paper retrieved categorical mainland coastline information and analyzed its spatial- temporal variation based on the national scale long term series. 2) The utilization of C hina mainland coastline was analyzed systematically in the aspects of improved utilization intensity, coastline type change and land use change over the past 35 years. 3) The spatial- temporal characteristics of coastal development and its impact on the coastline changes were analyzed in the aspects of single coastal engineering, combined with social and economic data.