水文预报课程设计.doc

四川大学水利水电学院水文水资源工程专业 课程名称：水文预报老师：*姓名：*学号：*课程设计流域背景介绍上犹江发源于湖南省汝城县诸广山的东南麓，干流称为古亭水。上犹江水库位于江西省上犹县，水库建于古亭水之上。水库入库站麟潭站控制面积1067km2，干流河长93km。流域地貌属低山丘陵区，以低山分布为主，相对高差多在500m左右。上游部分地区分布有原始森林, 森林植被以松树、杉树、竹类为主，灌木次之；山间盆地种植农作物，流域植被率在80%以上。土壤多为红色砂壤土,间有亚粘土层。山坡残积坡积一般厚度为12m,最厚者约45m。在山麓坡积层与基岩接触面上，或河流下切至接触部位时，常有泉水出露、涌水量较大者可达每秒数升左右。流域气候温暖湿润，年降雨量为1700mm左右。汛期49月降雨量约占全年降雨量的73%左右；冬季有降雪，但量不大。地下水位一般较高,且季节性变幅较小,因此,一般情况下，土壤含水量较大。洪水流量过程线极不对称，涨洪历时仅数小时至十多小时,而洪水退水历时可达数日至十余日。洪水退水尾部的底水与起涨点比较明显抬高,说明洪水期潜水和壤中流补给十分丰富。图2 预报流域水系示意图一、退水曲线分析我们已知十四场洪水的退水过程，绘制这十四场洪水的退水曲线图，可得如下图所示曲线簇。通过分析其曲线簇，可知退水规律符合指数函数的形式。即Qt=Q0e-t/k由相邻时段的流量关系绘制QtQt+1关系线组，得到如下图所示曲线簇。由于其下部大致重合，且近于直线，反映了地下径流退水特性，因此，我们采用下包线将其概括。其斜率倒数定义为C=Qt+1/Qt 即消退系数 取为0.984因为Qt+1=Qte-1/K 现将e-1/K 取为0.984并由此绘制流域的标准Qtt退水线，如下图所示。得到如上标准Qtt退水线后，可根据微积分用计算机软件绘制出QR关系线，如下图所示。二、 次洪量划分计算计算67701次洪量R:绘制67701的洪水过程线,进行分割，分别以起涨点和与起涨点流量大致相等的退水点分割，有计算机软件计算可得出本次洪水的次洪量为56.4mm,其中，地面径流为45.46mm，地下径流为11.38mm同理可得出73728洪水的次洪量为88.7mm，其中地面径流量为52.29mm，地下径流量为31.81mm。三、次雨的面平均雨量计算由67701和73728洪水的降雨资料可求得影响这两次洪水的次雨面平均雨量。采用泰森多边形法求解，权重系数为K益=0.17、K丰=0.42、K麟=0.42，并认为起涨点之后的降雨量为次雨。则其计算结果如下表所示：67701的时段面平均雨量计算P麟P丰P益平均雨量权重系数0.170.420.4114.53.77.16.9348.657.243.850.24429.480.730.851.5215.314.912.513.9844.96.35.75.8160.41.21.81.313.97.47.56.846雨量总和136.6573628的时段面平均雨量计算P麟P丰P益平均雨量权重系数0.170.420.411.81.51.71.6330.51.32.61.69740.75061.152.9738.835.230.133.72141.634.236.336.3192.71.91.11.708雨量总和128.048四 、次洪的前期土壤蓄水量（初始土壤蓄水量）W0计算1、由假定的的Wm=120mm、b=0.42，计算降雨径流(RW0Pe)关系曲线节点原理：由Wm=120mm， WMM=(1+b)WM=170.4,且A=WMM1-(1-W/WM)1/(1+b)计算A+PE,进行判断若A+PE<WMM或A+PE=WMM，R=PE+W-WM+WM1-(PE+A)/WMMb+1若A+PE>WMM,R= PE+W-WM按照以上原理进行计算，得到下表（降雨径流关系节点表）.降雨径流节点关系表W00102030405060708090100110120RP100.10.40.711.31.622.533.64.45.610200.51.11.62.22.93.64.45.36.47.79.31220301.122.83.84.85.97.18.610.212.3151030402.13.24.45.778.610.312.214.617.521.62040503.34.76.27.99.611.613.816.419.523.5303050604.86.58.410.412.615.117.921.225.230.6404060706.68.710.913.4161922.526.631.740505070808.811.213.916.719.923.527.732.840506060809011.314.117.220.624.328.633.740.2506070709010014.217.52124.929.334.440.7506070808010011017.521.225.329.83541.250607080909011012021.325.530.135.441.6506070809010010012013025.530.335.741.9506070809010011011013014030.435.842.1506070809010011012012014015035.942.2506070809010011012013013015016042.35060708090100110120130140140160170506070809010011012013014015015017018060708090100110120130140150160160180.由两次洪水的日降雨和蒸发资料，且其处于较湿润地区，采用一层蒸发模式计算其蒸发量，由水量平衡原理计算土壤含水量，一般取主雨前15天作为计算时期，进行计算，求得主雨开始时的土壤含水量。一层蒸发模式计算公式：，WM=120mm水量平衡方程：式中，Rt由初步产流方案(RW0Pe)理论关系曲线查算，P为流域面积内的平均降雨，由泰森多边形法求得。67701次洪水计算表日 期P麟P丰P益EmW0peR(由上表查）年月日(mm)(mm)(mm)(mm)(mm)(mm)(mm)(mm)676150004.7380.0 1.5 0160004.836.5 0.0 1.5 0170004.135.0 0.0 1.2 0180.21.40.64.233.80.8 1.2 0.1191.20.91.14.633.3 1.1 1.3 0.1200.1004.233.0 0.0 1.2 0210.40.80.84.731.9 0.6 1.2 0.12220.31821231.1 19.5 0.5 2.2233.73.65.32.447.9 3.9 1.0 0.6240005.250.3 0.0 2.2 0250005.448.1 0.0 2.2 026012.612.24.445.9 7.4 1.7 1.12738.90.82.350.5 5.1 1.0 0.828000453.8 0.0 1.8 0290004.752.0 0.0 2.0 030122.7179.1111.24.450.0 144.4 1.8 74.4由R可知起涨点是1967、6、30，当日8：00 （测量要求） W0=50.0，所以进行小时段分段计算，取t=3h,即Em =4.4*3/24=0.55P麟P丰P益EmW0peR(由上表查）时间段(mm)(mm)(mm)(mm)(mm)(mm)(mm)(mm)10000.55500.0 0.2 020000.5549.8 0.0 0.2 030000.5549.5 0.0 0.2 0414.53.77.10.5549.3 6.93 0.2 1.4548.657.243.80.5556.4 W0 =56.4（初始时刻土壤含水量）同理可得73628号洪水计算表如下：日 期P麟P丰P益EmW0peR(由上表查）年月日(mm)(mm)(mm)(mm)(mm)(mm)(mm)(mm)7361210.815.43.52.49011.51.84.2130002.695.502.10140003.793.402.90150.20.20.80.490.50.30.30.116002.72.390.40.51.70.217000.34.2890.13.101814.426.212.63.485.919.12.46.7197.82.553.495.85.12.72200004.596.203.60210003.892.602.9022000489.7030230004.286.703024000.13.983.602.702521.29.28.94.480.914.134.4263.44.972.587.64.61.81.52753.456.872.52.98958.12.128.52883.171.167.50.7116.4 由R可知，73628次洪水号洪水起涨点是6月27日，同上可得73628次洪水开始前土壤含水量计算表格。P麟P丰P益EmW0peR(由上表查）日时(mm)(mm)(mm)(mm)(mm)(mm)(mm)(mm)2780000.725890.0 0.5 0140000.72588.5 0.0 0.5 0201.81.51.70.72587.9 1.633 0.5 0.62820.51.32.60.72588.5 1.697 0.5 0.4588.7 即W0 =88.7mm五、由下表（降雨径流数据表）对降雨径流节点关系表进行检验，如下图：由次雨量P（忽略雨期蒸发）查(RW0Pe)理论关系曲线得R计，按规范规定评定误差。误差评定标准如下:点据合格标准 并且 =3mm方案合格率 编号洪号PW0R实R查|a|合格否16640835.29717.417.20.20.20.01149425326762325.960.37.361.31.30.17808219237040161.7107.749.150-0.90.90.01832993947041723.910513.212.80.40.40.0303030357041815.510511.97.64.34.30.36134453867042050.5109.542.3402.32.30.05437352277050638.9112.434.8322.82.80.0804597787052444.9118.144.7431.71.70.0380313297080738.762.810.6100.60.60.056603774107151174.160.930.124.95.25.20.172757475117191243.192.118.721-2.32.30.122994652127242935110.225.225.2000137250766.2109.95755220.035087719147281987.274.242.4402.42.40.0566037741572101216.1845.35.4-0.10.10.0188679251672110975.671.428.830.1-1.31.30.045138889177352013.611510.79.31.41.40.130841121187461460.19029.531-1.51.50.050847458197470438.2113.130.931.3-0.40.40.012944984207491340.585.217.6170.60.60.034090909217550425.911221.317.93.43.40.159624413227560519.9108.210.311.3-110.097087379237560774.511166.165.50.60.60.009077156247580850.5100.831.731.30.40.40.0126182972575100445.3101.327.326.70.60.60.0219780222675100669.3115.565.664.80.80.80.012195122277652715.599.510.173.13.10.3069306932864529115.86967.464.82.62.60.038575668296460229.3117.124.525-0.50.50.020408163306462295.7102.3887513130.147727273316551025.496.511.811.40.40.40.033898305326552555.5100.136.335.60.70.70.019283747336562617.511512.312.5-0.20.20.0162601633467701136.6556.456.874.9-18.118.10.3186619723573628128.0588.78586-110.011764706合格率=29/35=82.9六 水源划分1 由计算洪峰距直接径流中止点的时距，N=0.8*10670.2=3.2d=24*3.2= 76.8d，绘制66701及77828洪水的洪水过程线进行分割，使用软件计算得到66701洪水的地面径流为45.46mm，地下径流为11.38mm，88728洪水的地面径流量为52.29mm，地下径流量为31.81mm。2用制作好的产流方案，根据67701、73728号洪水的时段雨量Pt查算两场洪水对应的时段产流量Rt(忽略雨期蒸发量)。并由此计算稳渗率Fc，则对其中有直接径流产生的时段的净雨量按照面积平均求得。67701计算结果如下：月日时段面雨量W0REr/pFc范围Fc630206.9356.41.600.18 11.62.54 2350.24463.515.300.30 1.662.25 71251.5299.630.800.60 513.98412014.701.00 85.8161205.601.00 111.31120101.00 146.846120601.00 136.657512.6673628计算结果如下：月日时段面雨量W0REr/pFc范围Fc628852.9788.721.700.45 2.121.712.84 1133.721115.130.900.86 1436.31912037.601.00 171.7081202.101.00 128.04892.3323、将这两场洪水的经验点据加入已有资料编号洪号fc（mm/h）(mm/3h)编号洪号fc（mm/h）(mm/3h)编号洪号fc（mm/h）(mm/3h)1645291.56.62646021.912.83655100.7104656260.86.15675272.711.76676230.837704011.046.18704200.866.79705242.21110724291.79.711725072.311.812728191.77.5137211091.69.514746142.813157510042.310.416765272.711.7177362812.843218677012.2512.66由67701、73728号洪水计算的各相应时段产流量Rt由初定的关系线查算各次洪水的时段值,再按公式Rg、计=逐时段计算地下径流量Rg、计，则次洪直接径流计算值Rs、计=67701月日时段PRR/PFCRgRS630206.931.60.23 0.370.26 2350.2415.30.30 3.152.88 71251.5230.80.60 5.539.92 513.9814.71.05 3.049.59 85.8165.60.96 1.253.61 111.3110.76 0.230.53 146.84660.88 1.333.50 总和136.77530.27 44.73 经检验，精度合格！73728 月日时段PRR/PFCRgRS628848.121.70.454.235.73 1135.830.90.865.5514.36 1437.637.616.3218.96 172.12.110.481.44 总和123.592.340.4951.81经检验，精度合格！经评定，曲线精度符合要求。采用马斯京根线性水库演算法作地下径流汇流方案。取 ；C是流域退水系数,可由流域地下水退水曲线分析。由马斯京根法演算公式取为0,可用水源划分计算的演算出次洪地下径流过程。各时段汇流计算按时段净雨量R和降雨量P的下述条件选用单位线:A.当R4mm时 .如果 P益、权0.5P , 用型单位线。 .如果 P益、权0.5P , 用型单位线。B.当R4mm时： 用型单位线。按照单位线出流进行计算：单位线如下所示：表7 型、型、型单位线分析成果 计算时段：t=3h单位：10mm 型型型时段q时段q时段q0000001115175115227022429031953152318041104120412057059051006556706807437557658328418509239309401017102110351114111711311212121412281310131213251471410142015515915181641681615173177171218218618111921951910202204208211213217221223226231232235240242245251254261264271273281283290292302311321330使用条件：R4mm且 P益、权0.5 P使用条件：R4mm且 P益、权0.5 P使用条件：R4mm误差评定（附于直接径流汇流表中）校核67701、63728号两场洪水过程，由次洪地下径流流量过程、次洪直接径流流量过程、前期洪水退水流量过程叠加得出预报流量过程。将实测流量过程和预报流量过程绘制在同一图上比较。对67701、63728号洪水按规范规定标准评定预报精度。洪峰QM预报精度评定标准:洪峰QM允许误差 洪水过程预报精度评定标准:洪水过程允许误差 洪峰QM滞时预报精度评定标准:洪峰QM滞时允许误差Tp·30%；并以一个计算时段为下限。Tp指发布预报洪峰QM、预的时间至洪峰QM、实出现的时距。67701地下水退水过程计算表时 间月日时6308136.6575111417206.931.60.370.20.032350.24415.33.152.810.070.020.0371251.5230.85.539.990.070.060.09513.98414.73.049.130.030.10.1385.8165.61.253.740.010.130.14111.3110.2310.010.140.14146.84661.333.990.140.1517 0.150.1520 0.150.15230.150.15220.150.1550.140.1580.140.14110.140.14140.140.14170.140.14200.140.14230.140.14320.130.1450.130.1380.130.13110.130.13140.130.13170.130.13200.130.13230.120.13420.120.1250.120.1280.120.12110.120.12140.120.12170.120.12200.120.11230.110.11420.110.1150.110.1180.110.11110.110.11140.110.11170.110.11200.110.173728地下水退水过程计算表时 间m3/s月日时6278128.0592.311141720232821.63 0.60.140.15051.70 0.40.090.090.048#21.74.235.730.170.020.0411#30.95.5514.40.360.110.1914#37.66.32190.230.330.47171.71 2.10.481.4400.50.55200.520.5230.50.522920.50.550.50.580.490.511