Duan Hongtao, Zhang Yuanzhi, Zhang Bai, Song Kaishan, Wang Zongming
Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun 130012, China.
Environ Monit Assess. 2007 Jun;129(1-3):295-308. doi: 10.1007/s10661-006-9362-y. Epub 2006 Oct 21.
In this study, we present the digital evaluation of Landsat TM data and field spectral measurements for retrieving chlorophyll-a (chl-a) concentration and trophic state index in Lake Chagan of Northeast China. Chl-a concentration of the lake can be estimated from the band ratio (TM4/TM3) and the field spectral data at 670 nm (absorption peak) and at 700 nm (reflectance peak). The results show that the best determination coefficient (R (2)) is 0.67 from the TM data, by which chl-a distribution can be mapped. Based on chl-a determination from laboratory analysis, field spectral and TM data, the modified trophic state index (TSI(M)) was applied to assess the lake's trophic state. With the available data in Lake Chagan, each algorithm demonstrates the similar result for assessing the lake's chl-a and trophic state. Our results indicate that Landsat TM and field spectral data could be used effectively to determine chl-a concentration and evaluate the trophic state of Lake Chagan in the study.
在本研究中，我们展示了利用陆地卫星专题制图仪（Landsat TM）数据和野外光谱测量对中国东北查干湖叶绿素a（chl-a）浓度及营养状态指数进行数字评估的过程。湖泊的chl-a浓度可通过波段比值（TM4/TM3）以及670纳米（吸收峰）和700纳米（反射峰）处的野外光谱数据估算得出。结果表明，利用TM数据得出的最佳决定系数（R(2)）为0.67，据此可绘制chl-a分布图。基于实验室分析、野外光谱和TM数据确定的chl-a，应用修正的营养状态指数（TSI(M)）来评估湖泊的营养状态。利用查干湖现有的数据，每种算法在评估湖泊chl-a和营养状态方面都显示出相似的结果。我们的结果表明，陆地卫星TM数据和野外光谱数据可有效地用于确定查干湖的chl-a浓度并评估其营养状态。
