Temporal and spatial variation and influencing factors in fishery water of Tongxiang City
In Tongxiang City,there are many rivers which are used for aquaculture.In order to ascertain the water quality and their main influencing factors of rivers in Tongxiang City,we applied the water quality monitoring data in 2014-2022,determined pH value,the contents of dissolved oxygen(DO),total phosphorus(TP),total nitrogen(TN),ammonia nitrogen(NH3-N)in rivers and analyzed their temporal and spatial variation.The comprehensive pollution index method was used to evaluate the water quality.Combined with the quality of discharge water from freshwater aquaculture ponds,effects of aquaculture on water environment was discussed.Result showed that water quality of rivers in Tongxiang was generally stable from 2014 to 2022,and there was a certain degree of nitrogen and phosphorus pollution.The water quality in rivers had some seasonal and regional differences,which in northeast of Tongxiang was better than that in southwest.The evaluation result of water quality showed that there was pollution in the rivers,which was beyond the warning level.Correlation and principal component analysis showed that the water quality was mainly affected by the contents of nitrogen and phosphorus in rivers,the change of pH value and DO,and the organic contents in water,among which nitrogen and phosphorus were the main influencing factors.Quality of discharge water from freshwater aquaculture ponds up to standards,and there was no significant correlation between water quality comprehensive pollution index,aquaculture area and output of aquatic products.In conclusion,there was a certain degree of pollution risk in rivers of Tongxiang City,and discharge water from freshwater aquaculture ponds has little impact on water quality.It was suggested that the water in rivers should be pretreated for aquaculture,focusing on nitrogen and phosphorus pollution.
water in riversaquacultureinfluencing factorscorrelationprinciple component analysis
NETL
NSTL
万方数据
