The pond’s sediment oxygen demand and the relationship with physical and chemical factors
The relationship of sediment oxygen demand (SOD) and physical and chemical factors (dissolved oxygen, temperature, pHt oxidation - reduction potential) of bottom water and sediment characteristics (sediment organic matter, sediment depths) in 10 fish ponds were studied by measuring sediment oxygen demand in situ. The results showed that-The average of SOD rate was 0. 91 g/( m2 ? D) in all ponds and the range of changes in different ponds were from 0. 76 to 1.09 g/(m2 ? D). Bivariate correlation analysis Bhowed that the relationship between the SOD rate and the physical and chemical factors of the ponds bottom water veried significantly (P <0.01) , and the Pearson correlation coefficient with DO was the highest (R=0.779), followed by temperature (R=0.587), pH (R =0.557) and ORP (R= -0.421). The correlation between SOD rate and sediment depth was significant {P <0.05). The partial correlation analysis results showed that the correlations of SOD rate and dissolved oxygen and temperature were highly significant (P <0.01), and other factors did not reach significant levels. The most important environmental factor affectting the SOD rate was dissolved oxygen, followed by temperature. Using BP neural network to analyze the physical and chemical factors influencing the SOD rate,dissolved oxygen, temperature, and sediment depth were regarded as the input variables to establish the BP neural network model and predict the SOD rate. The BP neural network model' s training and testing correlation coefficient were 0.911 and 0. 879, and the average relative error were 11. 6% and 10.4% , respectively. There were small differences in the predictive value and the true value, and the model had high accuracy. It can effectively predict the SOD rate.
pondsediment oxygen demandphysical and chemical factorscorrelation analysisBP neural network
NETL
NSTL
万方数据
维普
