| 摘要: |
| 青海湖是我国最大的内陆水体,它及其流域的生态环境近来一直倍受广泛关注. 其水位下降、湖水面积缩小、湖体分离等更是研究的热点问题. 本文针对这些问题展开遥感调查与研究,收集了多时相、多种信息源的影像数据;分析了1975年至2000年25年以来湖泊的变迁及成因,湖岸变化及湖体分离状况;用遥感方法反推25年以来湖水位的变化;计算了1975、2000年两个年份的湖水面积,并遥感分析了湖水面积萎缩的原因. 此外,对青海湖进行了实地调查与水深测量,建立了该湖泊水深反演模型. |
| 关键词: 青海湖 湖泊变迁 水位 湖水面积 水深 遥感调查 反演 |
| DOI：10.18307/2003.0401 |
| 分类号: |
| 基金项目: |
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| Remote Sensing Investigation and Survey of Qinghai Lake in the Past 25 Years |
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SHEN Fang1,2, KUANG Dingbo1
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1.Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, P. R. China;2.State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, P. R. China
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| Abstract: |
| Qinghai Lake is the largest one of inland lakes in China. Some issues about water level drop, lake area shrinking and lake separateies have brought to broad attentions in recent years. Remote sensing researches for these issues were discussed in this paper. Landsat MSS, TM, ETM+ images and Chinese FY-1C, FY-1D, HY-1A satellitic data from 1975 to 2002 were applied to this study. Furthermore, we collected some useful data including relief map, water depth map and hydrological data. Those satellitic data, combined with useful data, were processed and analyzed, some results revealed that the lakeshore physiognomy have greatly changed from 1975 to 2000. The region changed mostly located in the west shore near the Bird Island and Buha River, in the north shore-Shaliu River and the east shore-Sha Island and Haiyan Bay. Due to rich land-carriage materials from Buha River and lake currents action, the west shore of lake is progressing towards lake. The famous Bird Island and Haisepi Island become the part of land; Also, the east shore was accumulated eroded by the removal of sand dune. Shadao Lake and Haiyanwan Lake were gradually separated from Qinghai Lake. On basis of lakeshore line change, we estimated that lake water level dropped about 2 m from 1975 to 2000, by the approach to matching two images and contrasting water depth data. This numeric value estimated was close to hydrological observation value 1.71 m. Also, this study estimated that the area of Qinghai Lake was 4405.64 km2 in 1975, and was 4256.04 km2 in 2000. FY-1D image on June, 2002 and field investigating results revealed that Haiyanwan Lake with an area or 100 km2 has been separated from Qinghai Lake. Water level drop and lake variation were the main cause of lake shrinking. In addition, we carried through field investigating and lake water depth measuring in the south-easters lakeshore of Qinghai Lake in Sep., 2002. The study indicated that the relativity of the grey scale of TM1 band image and water depth was very high in this lake. As a result, the water depth retrieval model was established. |
| Key words: Qinghai Lake lake variation water level water area water depth remote sensing investigating retrieval model |
