湖泊是陆地生态系统的一个重要的组成部分,湖泊水域的变化对环境和人类的生产活动都有着重大的影响。鄱阳湖作为中国第一大淡水湖,近年来多次出现洪旱灾害现象,因此对鄱阳湖进行动态监测意义重大。文章以2000—2021年鄱阳湖175期Landsa...湖泊是陆地生态系统的一个重要的组成部分,湖泊水域的变化对环境和人类的生产活动都有着重大的影响。鄱阳湖作为中国第一大淡水湖,近年来多次出现洪旱灾害现象,因此对鄱阳湖进行动态监测意义重大。文章以2000—2021年鄱阳湖175期Landsat影像作为数据源,对比分析了归一化差异水体指数(normalized difference water index,NDWI)、改进的归一化差异水体指数(modified normalized difference water index,MNDWI)、自动水体提取指数(automated water extraction index,AWEI)、谱间关系法(spectrum photometric method,SPM)这4种水体提取方法,优选最适宜鄱阳湖的水体提取模型;利用175期面积数据分析了鄱阳湖2000—2021年面积的年际变化趋势,分析年内季节变化特征,同时结合2009—2013年和2017—2018年同时期的50组水位数据,建立面积-水位关系模型。结果表明:①AWEI模型提取水体精度优于其他3种,该文最终选用AWEI进行鄱阳湖水体提取;②鄱阳湖面积存在明显的季节性变化,且丰水季面积年际波动大,枯水季较平缓;③棠荫水位站湖泊面积-水位分段线性模型为最佳模型,从而可以根据鄱阳湖区域的实时水位观测值对水体覆盖面积进行预测,以弥补云雨天气时利用可见光遥感手段难以监测到湖泊水体淹没情况的不足。展开更多
By using remote sensing and GIS technologies, spatial analysis and statistic analysis, we calculated the water area and volume variations of the Nam Co Lake from 1971-2004, and discussed their influence factors from t...By using remote sensing and GIS technologies, spatial analysis and statistic analysis, we calculated the water area and volume variations of the Nam Co Lake from 1971-2004, and discussed their influence factors from the viewpoints of climatic change and water balance. Data source in this study includes bathymetric data of the lake, aerial surveyed topographic maps of 1970, remote sensing images of 1991 and 2004 in the lake catchment, meteorological data from 17 stations within 1971-2004 in the adjacent area of the lake catchment. The results showed that the lake area expanded from 1920 km2 to 2015 km2 during 1971 to 2004 with the mean annual increasing rate (MAIR) of 2.81 km2 a-1, and the lake volume augmented from 783.23×108 m3 to 863.77×108 m3 with the MAIR of 2.37×108 m3. Moreover, the MAIR of the lake area and volume are both higher during 1992 to 2004 (4.01 km2 a-1 and 3.61×108 m3 a-1) than those during 1971 to 1991 (2.06 km2 a-1 and 1.60×108 m3 a-1). Analyses of meteorological data indicated that the continue rising of air temperature conduced more glacier melting water. This part of water supply, together with the increasing precipitation and the descending evaporation, contributed to the enlargement of Nam Co Lake. The roughly water balance analyses of lake water volume implied that, in two study periods (1971-1991 and 1992-2004), the precipitation supplies (direct precipitations on the lake area and stream flow derived from precipitations) accounted for 63% and 61.92% of the whole supplies, while the glacier melting water supplies occupied only 8.55% and 11.48%, respectively. This showed that precipitations were main water supplies of the Nam Co Lake. However, for the reason of lake water increasing, the increased amount from precipitations accounted for 46.67% of total increased water supplies, while the increased amount from glacier melting water reached 52.86% of total increased water supplies. The ratio of lake evaporation and lake volume augment showed that 95.71% of total increased water suppl展开更多
文摘湖泊是陆地生态系统的一个重要的组成部分,湖泊水域的变化对环境和人类的生产活动都有着重大的影响。鄱阳湖作为中国第一大淡水湖,近年来多次出现洪旱灾害现象,因此对鄱阳湖进行动态监测意义重大。文章以2000—2021年鄱阳湖175期Landsat影像作为数据源,对比分析了归一化差异水体指数(normalized difference water index,NDWI)、改进的归一化差异水体指数(modified normalized difference water index,MNDWI)、自动水体提取指数(automated water extraction index,AWEI)、谱间关系法(spectrum photometric method,SPM)这4种水体提取方法,优选最适宜鄱阳湖的水体提取模型;利用175期面积数据分析了鄱阳湖2000—2021年面积的年际变化趋势,分析年内季节变化特征,同时结合2009—2013年和2017—2018年同时期的50组水位数据,建立面积-水位关系模型。结果表明:①AWEI模型提取水体精度优于其他3种,该文最终选用AWEI进行鄱阳湖水体提取;②鄱阳湖面积存在明显的季节性变化,且丰水季面积年际波动大,枯水季较平缓;③棠荫水位站湖泊面积-水位分段线性模型为最佳模型,从而可以根据鄱阳湖区域的实时水位观测值对水体覆盖面积进行预测,以弥补云雨天气时利用可见光遥感手段难以监测到湖泊水体淹没情况的不足。
基金supported by the National Basic Research Program of China (Grant No. 2005CB422002)National Natural Science Foundation of China (Grant No. 40871099)+1 种基金Innovation Project of Chinese Academy of Sciences (Grant No. KZCX2-YW-146)EU Sixth Frame-work Project (BRAHMATWINN, Grant No. FP6-036952)
文摘By using remote sensing and GIS technologies, spatial analysis and statistic analysis, we calculated the water area and volume variations of the Nam Co Lake from 1971-2004, and discussed their influence factors from the viewpoints of climatic change and water balance. Data source in this study includes bathymetric data of the lake, aerial surveyed topographic maps of 1970, remote sensing images of 1991 and 2004 in the lake catchment, meteorological data from 17 stations within 1971-2004 in the adjacent area of the lake catchment. The results showed that the lake area expanded from 1920 km2 to 2015 km2 during 1971 to 2004 with the mean annual increasing rate (MAIR) of 2.81 km2 a-1, and the lake volume augmented from 783.23×108 m3 to 863.77×108 m3 with the MAIR of 2.37×108 m3. Moreover, the MAIR of the lake area and volume are both higher during 1992 to 2004 (4.01 km2 a-1 and 3.61×108 m3 a-1) than those during 1971 to 1991 (2.06 km2 a-1 and 1.60×108 m3 a-1). Analyses of meteorological data indicated that the continue rising of air temperature conduced more glacier melting water. This part of water supply, together with the increasing precipitation and the descending evaporation, contributed to the enlargement of Nam Co Lake. The roughly water balance analyses of lake water volume implied that, in two study periods (1971-1991 and 1992-2004), the precipitation supplies (direct precipitations on the lake area and stream flow derived from precipitations) accounted for 63% and 61.92% of the whole supplies, while the glacier melting water supplies occupied only 8.55% and 11.48%, respectively. This showed that precipitations were main water supplies of the Nam Co Lake. However, for the reason of lake water increasing, the increased amount from precipitations accounted for 46.67% of total increased water supplies, while the increased amount from glacier melting water reached 52.86% of total increased water supplies. The ratio of lake evaporation and lake volume augment showed that 95.71% of total increased water suppl
