title: Assessment of chlorophyll-a concentration and trophic state for Lake Chagan using Landsat TM and field spectral data.
abstract: 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.
authors.affiliation: Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun 130012, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Duan
authors.forename: Yuanzhi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Bai
authors.initials: B
authors.lastname: Zhang
authors.forename: Kaishan
authors.initials: K
authors.lastname: Song
authors.forename: Zongming
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000465:Algorithms; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water / Q000032:analysis*; D045342:Light-Harvesting Protein Complexes / Q000032:analysis*; D011157:Population Dynamics; D017215:Satellite Communications
chemical_list: D045342:Light-Harvesting Protein Complexes