OLCI-based remote sensing estimation method for cyanobacteria biomass ratio of inland eutrophic lakes

Abstract

The invention discloses an OLCI-based remote sensing estimation method for cyanobacteria biomass ratio of inland eutrophic lakes. The method comprises steps of: extracting a research area of inland eutrophic lakes from OLCI remote sensing image data, and preprocessing and obtaining remote sensing reflective rate of a corresponding water body in the area; resolving a ratio of remote sensing reflective rates of a sixth wave band to a tenth wave band, if the ratio is greater than a preset threshold, recording the ratio as an extremely high gradient, and outputting a result; if the ratio is less than the threshold, acquiring backscatter value at 778 nanometer, absorption coefficients at 620 nanometer and 665 nanometer, and absorption coefficient of chlorophyll a at 665 nanometer; creating a normalized difference index representing cyanobacteria biomass ratio at current image element; and performing above steps on each image element in the research area, so as to obtain space distribution of cyanobacteria biomass ratios of inland eutrophic lakes. The method greatly improves cyanobacteria detection efficiency and scale, providing reference for warning cyanobacteria bloom.

Description

technical field [0001] The invention belongs to the technical field of remote sensing, in particular to an OLCI-based remote sensing method for estimating the proportion of cyanobacteria biomass in inland eutrophic lake water. Background technique [0002] Eutrophication of lakes can cause a series of environmental problems, among which cyanobacterial blooms are the most studied and most polluted. Cyanobacterial blooms not only cause water quality deterioration, water body function decline, ecosystem disorder and other consequences, but also have great harm to human health. [0003] Algae bloom is an instantaneous "outbreak" from the appearance, but its essence is a slow process of the gradual increase of algae biomass in the water body, rather than the continuous rapid growth of algae in a short period of time. (Kong Fanxiang, Gao Guang. Reflections on the Formation Mechanism of Cyanobacteria Blooms in Large Shallow Water Eutrophic Lakes[J]. Acta Ecologica Sinica, 2005,25(...

AI Technical Summary

Problems solved by technology

At present, there are relatively few studies on the proportion of algae biomass. Most of them cultivate several pure algae indoors, configure them into two-component or multi-component mixed algae, and use empirical methods to invert the proportion of one of the algae. There are relatively few studies on the abundance of a certain class of algae in the wild, such as the ratio of cyanobacterial biomass, which is often indicated by PC:Chla (Hunter et al. 2008, 2009, Shikun et al. When the concentration of suspended solids exceeds 25mg / L, the model is not suitable to use PC:Chla to indicate the proportion of cyanobacteria biomass, and the parameters of the model need to be re-calibrated according to the area

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