The Research On The Prediction Method Of The Growth Trend Of Pyropia Based On The Dominant Factors Under The Data Absence Condition

Pyropia is one of the most important species of large cultivated seaweed in China which has high nutritional value,economic value and environmental value.However,there are still many problems in the cultivation process,such as lack of seeds,rot disease and its yield reduction because of environmental changes are always happen.Research the prediction method of the growth trend of pyropia have contribute to improve the yield.The lack of observation data of pyropia,and the combined effect of various factors during the growth process and the different degree of influence of various factors on different stages will bring a series of difficulties to predicting the growth of pyropia.In order to predict the growth trend of pyropia,this dissertation analyzed the whole growth stage of Porphyra and its influence factors.Different data completing methods were used according to the data characteristics based on the real but discontinuous environmental factor data and the area data.Considering the strong spatial characteristics of the influence factors,the Kriging-three cubic spline interpolation method was proposed to recovery its data integrity.Considering the different degrees influence of various environmental factors on the area data of Porphyra,the SVR piecewise area interpolation method was proposed to recovery integrity of the area.Built the SVM weight calculation model to analyze the weight change of influence factors and obtain the dominant factors.Combining with the complete area data,compared and analyzed dominant factors'weight intersections and the whole growth stage,their change regulation in different stages was summarized,and a prediction method of the growth trend of Porphyra based on the dominant factors was provided.Providing a reference method of predicting growth of Porphyra and a new method for solving other marine related problems.The main research contents and results are as follows:?1?Considering the influence factors will influence the growth process of Porphyra and analyzed its growth mechanism,the influence factors include PH,chemical oxygen demand?COD?,dissolved oxygen?DO?,water depth?D?,water temperature?T?,salinity?SAL?was obtained,which provided an experimental basis for building of the prediction model of Porphyra.?2?Considering the loss,discontinuity,and lack of regulation of the influence factors,the Kriging-three spline interpolation was proposed to recovery its timing continuity based on its'spatial characteristics.Verified the result of interpolation,and the relative error range is 0-12.5%which showed the environment factor data recovered by the Kriging-three spline interpolation model is reliable,this model has high accuracy of recovering data with serious missing and spatial characteristics.?3?Considering the loss,discontinue and irregular of the area data,and combined with the different degrees influence of various environmental factors on the area data,the SVR piecewise area interpolation method was used to recovery integrity of area data.Comparing the results with the result of the non-piecewise SVR interpolation model showed this model is more consistent with the growth characteristics of Porphyra,and this interpolation algorithm is more practical and instructive.?4?Considering the growth of Porphyra is complex and related to many environmental factors,the SVM dynamic weight analysis method was used to calculate the dynamic weight change sequence of each factor in the growth process,obtained W_PH?W_COD?W_DO?W_D?W_T?W_SAL.The conclusions are as follows:The effect of salinity,PH and depth on the whole stage is big compared to other factors.Due to salinity,depth and PH all had larger weight in the whole process,and they all use to be the biggest weighted factors,they are the dominant factors that need to be monitored in the process of cultivation.?5?Comparing the dominant factors'weight intersections and the whole growth process of Porphyra,we concluded that the weight node has the meaning of stage node,and summarized the regulation of the dominant factors,the prediction method of growth trend of Porphyra based on dominant factors are follows:In the rapid growth phase,the ratio of salinity and depth is of 0 to 6,the ratio of depth and PH is of 0 to 1;In the stationary phase,the ratio of salinity and depth is of 5 to 8,the ratio of depth and PH is of 1 to 2;In the decline phase,the ratio of salinity and depth is of 0 to 5,the ratio of depth and PH is of 0 to 1.Providing a reference method for the prediction of the growth trend of Porphyra.?6?Combined with the Porphyra and related observation data are seriously absence and discontinuity,the growth process is complex and has a nonlinear relationship with environmental factors.The design and establishment of the growth trend prediction system of Porphyra which based on the data interpolation and the dominant factors analysis was finished,which provided a new reference for other marine problems and cultivation problems.