黑龙滩水库氮磷平衡与富营养化评价

黑龙滩水库氮磷的输入包括东风渠、水面降水、农田径流、网箱养鱼、旅游、周围居民及地下水输入等。T N每年输入 10 76 .95t,T P每年输入 5 2 1.2t。T N的输入 ,农田径流、东风渠和网箱养鱼是主要输入源 ,其中农田径流占T N输入的 5 5 .41% ,东风渠占到 32 .8%。T P输入 ,主要由农田径流控制 ,占到 93.48%。黑龙滩水库氮磷支出有干渠输出 ,水库渗漏 ,网箱养鱼以及大水面捕获鱼所带出的氮磷量。T N每年输出 182 .82t,T P每年输出 13.0 3t。每年水库随水输出的氮磷量不大。大约有 893.99t的氮 ,5 0 8.17t的磷存留水库中 ,它们大部分以颗粒吸附态的形式沉积于水库底部、少部分溶解态N·P存留于库水中。基于水库中不同点连续 17个月采样的水质数据 ,选择SD、CODCr、T N、T P和Ch·a等五个水质指标进行富营养评价 ,得出黑龙滩水库处于中营养水平 ,有产生富营养化的潜在危险。与以前所测数据相比 ,水库的富营养化的趋势在加重。管理者应加强控制农田径流污染的工作 ,才能预防水库富营养化的发生

BALANCE OF N AND P IN THE INPUT AND OUTPUT IN HEILONGTAN RESERVOIR WITH THE ASSESSMENT OF ITS EUTROPHICATION

The amount of N and P in the input and output of Heilongtan Reservoir has been studied.The input amount of N and P is from Dongfeng Canal,field runoff,fish cage culture,touring,residents and groundwater.The amount of TN input is 1 076.95 t and TN input 521.2 t.The input of TN from field runoff is the main source of nitrogen,accounting for 55.41%,and the input water from canal is up to 32.8%.The input of TP from field runoff dominates all nonpoint pollution sources being up to 93.48%.The amount of N and P output is from canals,seepage,harvests of fish cage culture and fish from other parts of the reservoir.The amount of TN output is 182.92 t,and TP output is 13.03 t.The output amount of N and P is not large.About 893.99 t of N and 508.17 t of P have been detained in the reservoir.The form of partical phosphorus largely precipitates on the bottom of reservoir,and only a little part of P dissolves in the water.Based on the water monitoring data of Heilongtan Reservoir in the period of 17 months and on the 7 points,the eutrophication is discussed by using 5 indices,SD,COD cr,TN,TP and Ch.a.It has been showed that the eutrophication of reservoir is moderate at present and it will become serious in the future.From now on,field runoff pollution must be controlled.