A tidal flat, the important potential land resource, is the sensitive area of intersection between the sea and the land. With Chinese HJ-1A/B remote sensing images of 2014 as data sources, based on the definition of a tidal flat, using DSAS software and Jenks Natural Breaks classification method synthetically, a more reasonable and accurate method of extracting tidal flat was imposed. In addition, the Bohai Rim was taken as an example to carry out investigation on the current situation of tidal flat. This paper can provide basic date and scientific evidence for rational utilization and sustainable development of tidal flat.
Reclamation caused a significant dynamic change in the coastal zone, the tidal flat zone is an unstable reserve land resource, it has important significance for its research. In order to realize the efficient extraction of the tidal flat area information, this paper takes Rudong County in Jiangsu Province as the research area, using the HJ1A/1B images as the data source, on the basis of previous research experience and literature review, the paper chooses the method of object-oriented classification as a semi-automatic extraction method to generate waterlines. Then waterlines are analyzed by DSAS software to obtain tide points, automatic extraction of outer boundary points are followed under the use of Python to determine the extent of tidal flats in 2014 of Rudong County, the extraction area was 55182hm2, the confusion matrix is used to verify the accuracy and the result shows that the kappa coefficient is 0.945. The method could improve deficiencies of previous studies and its available free nature on the Internet makes a generalization.
With 4 periods of remote sensing images as data sources, based on Geo-information TuPu analysis method, coastline change information mapping of Shandong province during the past 30 years is established using ArcGIS software, and then this kind of information was studied deeply. The conclusions are as follows: 1) During the past 30 years, coastline of Shandong province shows an increasing trend; the centre of increasing shifts eastward gradually; different areas have different increasing situations. 2) During the past 30 years, coastline change degree of Shandong province is basically stable, change fiercely areas concentrate on the Yellow River estuary while Zhaoyuan, Penglai and Longkou have a rather slow degree. 3) From 1980 to 1990, coastline of Shandong province retreats to land quickly, draws back slowly from 1990 to 2000 while advances to sea rapidly entering into 21st century; Dongying has a backward trace for 30 years, Zhaoyuan and Laiyang have been basically unchanged, Yantai, Rizhao and Jiaonan have a obvious trend of advancing to sea.
Proc. SPIE. 9221, Remote Sensing and Modeling of Ecosystems for Sustainability XI
KEYWORDS: Agriculture, Coastal modeling, Data modeling, Visualization, Remote sensing, Geographic information systems, Data acquisition, Information technology, Analytical research, Standards development
With 2 periods of standard false-color images as data sources, using remote sensing and GIS technology, dynamic change information extraction of the coastline and sea reclamation was completed in the region around Bohai through visual interpretation and artificial vectorization, and then this kind of information was studied deeply. The conclusions are as follows: 1) From 2000 to 2010, coastline of the region around Bohai shows an increasing trend, advancing to the sea rapidly; coastline change of the Beijing-Tianjin-Tangshan area is maximum; the advancing of coastlines of Liaoning and Shandong Province to the sea is obvious; human factors are key factors for the above change . 2) From 2000 to 2010, the sea reclamation area of the region around Bohai is rapidly increasing, the increase of Beijing-Tianjin-Tangshan region is the largest relatively and that of Shandong Province is the smallest; from the structure point of view, the area of sea reclamation for building ports is the largest and that of tideland reclamation is the smallest; different regions have different structures; social and natural factors together determine the evolution of sea reclamation. 3) To some extent, sea reclamation contributes to the increase in length of the coastline; different use types of sea reclamation have different influences on the coastline changes.
This paper extracted the spatial distribution of the continental coastline of Bohai Rim utilizing Remote Sensing and GIS spatial analysis techniques, and calculated the fractal dimension of the coastline by boxcounting method, with a time from 1990 to 2010. Moreover, we analyzed the characteristics of spatialtemporal variability of the coastline's length and fractal dimension, the relationship between the large scales length change and fractal dimension change. During the research period, the coastline length of the study area increased progressively and the most significant change in coastline length was found in Tianjin Municipality. Especially after 2000, the coastline length entered a period of rapid growth. In addition, the fractal dimension of the overall coastline of the study area was between the fractal dimensions of the regional coastlines and was close to the maximum fractal dimensions of these regional coastlines. The fractal dimension of the coastline in Bohai Rim was increasing during the research period, large scale project such as ports construction, reduced tortuous degree of the coastline.