Study On Extraction Methods Of Cyanophytes Bloom Based On HJ-1

Along with the rapid economic development and the degree of industrialization and the influence of intensifying human life, Lakes pollution and eutrophication problem is getting worse. Distribution in the eastern plains by a series of large shallow lake eutrophication influence, Algal blooms that cyanobacteria disasters appears. The Cyanobacteria bloom for current research become one of the hot point int case 2 water research.Currently most of the research is to establish a model of chlorophyll a concentration or blue protein concentration algae are calculated to monitor cyanobacteria bloom in taihu distribution characteristics of the algae. The complexity of the prototype, applicability, and the accuracy of model was restricted by estimating the scope of application of important factors.Using the 680nm China Envirormental Satellite 1(HJ-1) CCD visual band and 790nm near-infrared wavelengths and IRS 800nm near-infrared wavelengths of 1720nm and short-wave infrared bands in tai lake area, for, a method of cyanobacteria bloom algae extracted CAI (cyanobacteria bloom algae index). Through quantitative extraction model, with such vegetation index NDVI extract cyanobacteria bloom method of comparative analysis, the result shows:CAI can better remove air, observation environment influence, stable extraction algae.Through researchs of the paper, the following conclusions are concluded(1) Through introducing the FAI extraction method of afloating algae which is application on case 1 water,inproved and fixed the model,constructedthe model of CAI(cyanobacteria algae index) based on HJ-1, applied in inland lake-taihu lake water to detect cyanobacteria blooms.This method can better purify air and observation environmental impact.the method detectting cyanobacteria blooms has physical meaning and geometric meaning,can applied on HJ-1,and is the extraction methods of cyanobacteria blooms whick is compliant for long time series(2) HJ-1 included two Near-infrared wavelength of 790nm and 800nm.The two bands are on CCD and IRS remote sensor., With different time, space, radiation resolution. And near-infrared wavelengths are most important features bands of the CAI method.Through of the two bands respectively and band combination comparative analysis,the results showed 790nm band for high levels of cyanobacteria blooms has higher sensitivity,but 800nm band for low levels of cyanobacteria blooms has lower sensitivity. Both have very similar to water the response characteristics,800nm and 790nm bands combination method can better integrated these two band features, are More stable and can better distinguish different level of cyanobacteria bloom.(3) This paper compared several methods such as the quantitative estimation chlorophyll-a concentration, NDVI and CAI, evaluated the stability and applicability of several methods,nalyzed their respective characteristics and applicable range. CAI is better than the others in the stability of the two methods, and can be a very good distinguish with clean water cyanobacteria algae, suitable for long time series cyanobacteria algal extracted.(4) Using CAI cyanobacteria bloom extraction method,verified Taihu lake and Chaohu lake. Results show that:CAI method Cyanobacteria bloom extracted in spatial distribution or explosion extent accuracy is higher, and the method is not dependent on research to study, the regional has very good applicability. Finally using CAI method from different time scales the space distribution features of algal research, gathering area, season for dynamic evolution characteristics, such as real-time monitoring of cyanobacteria algae bloom in taihu to provide the reference.