2.4 永定河水系河流水质评价
根据北三河水系2001—2014年河流水质评价资料,分别计算不同年份各类水河长。表6-15为永定河水系河流水质评价表。
表6-15 永定河水系河流水质概况评价表
年份评价河长
/km分类河长/kmⅠ类Ⅱ类Ⅲ类Ⅳ类Ⅴ类>Ⅴ类2001541.000147.035.0150.0209.02002496.000286.0014.0196.02003496.00277.030.035.048.0106.02004541.00241.0101.000199.02005541.00261.045.0050.0185.02006541.000296.010.014.0221.02007541.0091.020.0245.00185.02008541.0076.010.0234.034.0187.02009541.00110.0230.063.09.0129.02010541.035.0132.056.0259.0059.02011551.000286.079.017.0169.02012561.035.034.0251.0085.0156.02013561.0035.0302.075.00.0149.020145610103219810158
根据永定河水系2001—2014年水质评价结果,分别计算各河长占评价河长的比例。通过 ...... (共1007字) [阅读本文]>>