Spectral Response Of Growth And Disaster Assessing For Rice Under Flooding And Waterlogging Stress

Flood disaster is an important type of disaster related to changes in global, it has seriousimpact on agricultural production and development of the national economy. Monitoringflood disaster and assessing the damage scientificly and rapidly has an important significancefor the development of insurance claims and compensation after disaster. Damage assessmentof existing research mainly concentrated on the aspects of population, infrastructure andsocial economy.Crop flood damage assessment is more complex, not only have to extractsubmerged area and duration of crop, but also must consider the crop variety, fertilizer,growth stage, soil texture and other factors, so the monitoring and evaluation of flood disasterfor rice is rarely involved, which lead to the lack of basic, theoretical and practicalresearchachievements.In this paper, the rice under flooding and waterlogging was the research object. With thesimulation experiment and field survey data, the paper conclude some major flood factorswhich influence the growth and development of rice, such as water depth, drowning duration,submerged area and sediment content, and the variation of Leaf Area Index(LAI), chlorophyllFluorescence Parameters(FPs) and yield loss at different stages and different flood stress wereanalyzed. Futhernore, via extracting spectral feature and constructing vegetation indices, therice canopy spectral characteristic under flood were discussed based on the red edgeparameters and continuum removal parameters, then the estimation models of LAI, FPs andyield were established by multiple linear regression, BP neural network and partial leastsquares(PLS)respectively.In addition, this study take the domestic HJ satellite images as theresearch data, extraction of submerged areaof rice were carried out by Change VectorAnalysis(CVS) method, then combined with Water Turbidity index(WTI) and PerpendicularVegetation Index(PVI) which extracted from themulti-temporal HJ satellite image data, the remote sensing evaluation method of disaster conditon and yield loss were put forward finally,which could be used for rapid assessment of the rice disaster loss.The main content of this paper is the mechanism of monitoring of rice growth and yieldby hyperspectral remote sensing under flood disaster,then two serious flood disaster in recentyears were used to evaluate large scale disaster loss of rice by remote sensing.This researchresults provide technical support and theoretical basis for the monitoring of disaster degree,growth conditions and yield loss of rice after flood disaster.