1、一一. . 统计参数初估方法统计参数初估方法 1 1 矩法矩法 2 2 经验关系法经验关系法 3 3 三点法三点法 4 4 权函数法权函数法 5 5 概率权重矩法概率权重矩法矩法svCCx,3321)3()1(1)1(1visivniiCnKCnKCxnx经验法三点法3321)3()1(1)1(1visivniiCnKCnKCxnx)1()1()1(332211vvvCxxCxxCxx（3-22）参数计算公式311331xxx 133131xxxxCv 312313123122xxxxx（3-24）（3-25）（3-23）),(PCfSsS 表S012345678900 0.290.3270.
2、10.364 0.650.6870.20.723 1.011.0420.31.217 0.4 0.5 0.62.133 0.72.529 0.83.009 0.93.714 附录附录C P-III曲线三点法曲线三点法 S 与与 Cs 关系表关系表P = 5 50 95%求参步骤 据据(3-25)(3-25)式左端计算得式左端计算得S S值，且已知值，且已知P P1,1,P P2,2,P P3,3,查查 附录附录C,C,求得参数求得参数Cs； 据据Cs查附录查附录B,B,得得p p1 1、p p2 2，代入，代入(3-23)(3-23)、 (3-24)(3-24)式式, ,求得求得 。适线法sv
3、CCx, 二二. . 适线法适线法1步骤 表格 实际计算水文频率时，通过制表完成上述的步骤实际计算水文频率时，通过制表完成上述的步骤 。经验频率及统计参数计算表经验频率及统计参数计算表理论线 表 项项 P%Cv/Cs 目目0.010.010.10.11 15 51010 9595999999.999.91Xp= (1+Cvp)2Xp= (1+Cvp)3Xp= (1+Cvp) xxxppp例题100%1mpn年份年份最大流量最大流量Q(m3/s)序号序号m递减排序递减排序Q(m3/s)模比系数模比系数KiKi1(Ki1)2(1)(2)(3)(4)(5)(6)(7)(8)1965980012750
4、02.4171.4172.00883.7041966109002239002.1011.1011.21197.4071967154003186001.6350.6350.403211.111968105004174001.5290.530.280314.811969186005154001.3530.3540.125118.521970114006152001.3360.3360.112922.22197198007127001.1160.1160.013525.931972275008126001.1080.1080.011529.63197376209121001.0630.0640.00
5、4033.3319742390010120001.0550.0550.003037.0419751210011114001.0020.0024.4E-0640.7419761270012109000.958-0.040.001744.4419771200013105000.923-0.080.005948.1519781740014105000.923-0.080.005951.85197988301598000.861-0.140.019255.561980126001698000.861-0.140.019259.26198140801788300.776-0.220.050162.961
6、982105001885000.747-0.250.063966.671983152001979400.698-0.30.091270.37198448302076200.669-0.330.109074.07198579402167700.595-0.40.163977.78198667702260100.528-0.470.222581.48198760102358000.510-0.490.240285.19198858002451000.448-0.550.304388.89198985002548300.424-0.580.331192.59199051002640800.358-0.640.411396.3总计总计29578029578026.000.006.2145 图三点法配线矩法配线经验点年最大洪峰流量Q频率P()120000.180003（m /s)1600020000240002800015 1020 30 40 50 60 70 8090 95994000Q5%Q50%Q95%经验法经验法优化法End21( )( , ) niiiSxf P( )min ( )SS0S (3-26)(3-27)(3-28)
