使用遥测水位数据与使用实测水位数据计算过闸流量的对比实验

1、使用遥测水位数据与使用实测水位数据计算过闸流量的对比实验黄河水利委员会信息中心 赵阳 宋涛 刘鹏 史婧摘要自黄河下游引黄涵闸监控系统2004年建设以来，积累了大量的引黄涵闸运用的遥测数据资料，成为一笔宝贵的财富。对自动监测系统遥测的水位闸位数据和对实测水位闸位数据进行的流量计算对比，是深化使用这笔财富的第一步。本文采用监控站目前使用的流量计算经验系数公式、水文局重新率定的多种流量计算公式，分别对监测数据和遥测数据计算出的流量进行了比较。结果表明，重新率定的流量计算公式虽然有适应性限制，在精度上比原公式稍有提高，而影响流量计算精度最大的因素，在于水位计量的准确性。1 背景黄河下游引黄涵闸监控系统

2、是涵盖了委调度中心、河南山东两局、各地市、县以及涵闸现地的五级监控系统，自2004年建设以来，在黄河水资源调度、黄河防断流工作中取得了巨大成果3 ，积累了大量的引黄涵闸运用的遥测数据资料，成为一笔宝贵的财富。如何利用这些数据以进一步提高闸门控制操作效能、提升水资源管理调度手段成为摆在闸门控制操作、水量调度人员的一个问题。2004年，河南黄河水文勘测设计院陆续对黄河下游引黄涵闸站进行流量比测和泄流曲线的分析率定工作，人工实测水位（利用水尺）和闸门开度数据，通过流量系数率定分析、水位流量关系曲线分析等对这些涵闸的流量计算公式进行了重新率定。在这次测算中，发现人工水尺和用于遥测的超声波水位计的安装位

3、置不同。对大多数涵闸来说，二者的测量数据基本呈线性相关。利用设计院的测量计算结果与监测系统的数据做对比试验是对监测数据进行利用的第一步。2 试验试验目标：在监控系统的运行中发现，监控系统计算的流量数据与实测流量数据有差异，有些差异较大，为了分析产生差异的原因（是由于监控系统的流量计算公式不精确还是水位测量不精确亦或兼而有之），对遥测水位数据和实测水位数据分别利用监控系统的流量计算公式和重新率定的流量计算公式进行计算和比较，试图找到差异产生的原因，在以后对监控系统的升级改造中做到有的放矢。试验数据：2007年，选取了旧城、刘楼、邢庙（这三座闸提供了完整的遥测水位计水位和人工水尺水位的相互转换公式

4、，并且这三座闸提供的实测资料的时间段，与遥测数据的时间段互相重合。）等数个典型涵闸在小范围内对监控系统的流量计算与河南水文设计院提供的数据进行了对比，其时间段分别为2006-1-282006-6-22（旧城）、2006-2-222006-4-28（刘楼）、2006-4-12006-4-7（邢庙）。遥测数据的时间与实测数据的时间不完全重合，尽量选取相靠近的时间。流量计算公式：流量计算公式分别为（见表1）：表1：旧城、刘楼、邢庙的流量计算公式水尺与遥测水位关系：重新率定的流量计算方法使用人工观测水位（水尺水位），所采取的观测点位置与自动监测的超声波水位计的位置有所不同，闸上、闸下水尺水位和遥测水位

5、的差异在0.100.50m之间，一般遥测水位较高，闸上、闸下变幅基本一样，因此可对大部分引黄涵闸建立闸上、闸下水尺水位与遥测水位的线性关系。由于有了这种关系，便可以使用重新率定的流量计算方法计算遥测水位得到流量。三座闸的水尺与遥测水位的关系如表2。表2：旧城、刘楼、邢庙的水尺与遥测水位关系试验步骤：首先使用遥测水位进行流量计算。由于第一次比较后结果差别较大，为了探明差别的原因，对水文局提供的实测水位进行了流量计算的对比。3 试验结果3.1采用遥测水位的结果与分析（1） 旧城由左图可得，当流量大于10m/s时（此时总开高30cm左右），Bez1/2值将>2，超出其允许范围，经验系数公式出现

6、较大误差。（2） 刘楼由左图可得，新的水位流量关系法不适应该系列数据，而新的水位指数公式与监控系统原公式表现良好。（3） 邢庙由左图可得，新的公式计算结果不适应该系列数据。3.2采用实测水位的结果与分析（1） 旧城由图可得，当流量大于15m/s时（此时总开高50cm左右），Bez1/2值将>2，超出其允许范围，新的经验系数法公式出现较大误差。（2） 刘楼由图可得，当流量大于7m/s时（此时总开高70cm左右），Bez1/2值将>2，超出其允许范围，出现小幅误差。（3） 邢庙由图可得，经验系数法2与实测流量较符，在Bez1/2其允许范围4内，经验系数法2计算出的流量可达到其闸门设计流

7、量15m/s。其最大总开高大致在120cm左右。4 结论与建议通过这个比较，发现经验系数法的计算结果最为接近实测数据，对不同的流态也具有最大的适应性，水位流量关系法适应性较小，误差较大，不适合作为自动监控系统的流量计算方法，经验系数法则居于两者之间；不管是哪种计算方法，在Bez1/2超过限度后，都会发生急剧增大的误差；从这个实验中可以看到，水位数据的选取对于计算结果造成的影响很大，使用遥测水位和水尺水位的计算结果差异明显，造成这一点的原因首先在于所选取的遥测时间，并不完全与实测数据时间相吻合，其次并不排除遥测水位计量精度存在问题。这一点也再次说明了在涵闸过流量计算的过程中，必须保证遥测水位的计

8、量精确。建议扩大试验规模，为更多的涵闸进行该项试验；使用更多、更长系列的实测数据以与更大范围的遥测数据进行对比；更为重要的是，复测超声波水位计的精度，或者，建立直接基于超声波水位计的流量计算公式。5 参考资料1李民东，2007，“黄河下游引黄涵闸监控系统在山东水量调度中的作用与意义”，第三节黄河国际论坛论文汇编Comparison Examination on Sluice Gates Discharge Calculations with Automatic Measured Data and Manual Measured DataInformation Center of YRCC Zh

9、ao Yang, Song Tao, Liu Peng, Shi Liang AbstractSince The Control System of Sluice Gates in Lower Yellow River was started up in 2004, a large amount of automatic measured water lever data and gates operation data has been accumulated, meanwhile, depended on them discharge data has been calculated. I

10、n order to verify the quality of the data and seek more accurate calculation methods for discharge, it is used some new discharge formula and the present formula being used in control system to recalculate both the automatic measured water level data and manual measured water level data at the nearl

11、y same time. The comparison results show that accuracy of the measured water level data is the decisive factor which affect the discharge accuracy, and although somehow the new formula are more complex they are still inflexible on some special cases. 6 BackgroundThe Control System of Sluice Gates in

12、 Lower Yellow River is a large scale control system which covers 84 sluice gates in the Lower YR reach and five administrative organizations of YRCC. Since the construction of this system in 2004 it has played big role in the program of “Zero Flow Prevention for Lower YR” (Li, 2007) and accumulated

13、innumerous automatic measured data which is now a huge wealth. So far how to utilize these measured data to improve the accuracy of sluice gates control and enhance the water resources management is questionfor us.From 2004, the Henan Hydrological Design Institution started to validate the sluice ga

14、tes of Lower YR and analyze their discharge chart, and through it, some new discharge formulas are verified. It is also found in this validation that the location of the manual measuring meter is different from the ultrasonic meter which is used in the control system. For most gates, there is linear

15、 relationship between the manual and ultrasonic meter.It is the first step of utilizing the automatic measured data to make the examination to compare the Design Institution data and automatic measured data with the new validated formulas and the present formula being used in control system.7 Examin

16、ationObjectives: In the running of The Control System of Sluice Gates in Lower Yellow River it is found there are diversity between the automatic measured data and the manual measured data which are reported by the local gates officers, some of them are huge. In order to probe which factor leads to

17、the diversity (e.g. the inaccuracy of the calculation formula or the inaccuracy of the measured data or both), both the automatic and manual measured data are used to be calculated by the new validated formulas and the present formula being used in the system. The results of this examination are sup

18、posed to be useed in the later update of the control system.Data: In 2007, the data of three sluice gates (Jiucheng, Liulou,and Xingmiao) are selected as the sample data, for the conversion equations from automatic measured water level to manual water lever are provided in these gates, and there are

19、 time overlap for the both automatic and manual measured data, which is Jan. 28, 2006 to June 22, 2006 for Jiucheng, Feb 22, 2006 to Apr. 28 , 2006 for Liulou and Apr. 1, 2006 to Apr. 7, 2006 for Xingmiao. The measure time of the automatic and manual data series are not exact consistent, so in many

20、cases we can only select the nearby data .Discharge calculation formulas: The formulas used in the examination are shown in the Table 1 ：Table 1: Discharge calculation formulas in Jiucheng, Liulou and XingmiaoThe relationship of manual and ultrasonic meter: The manual measuring meters are located di

21、fferent site from the ultrasonic meter site, and the difference is between 0.10 to 0.50 meter for both up gate and down gate water level. Generally, the data measured by ultrasonic meter is larger than the manual meter, but the difference along time is nearly equal so that linear relationship betwee

22、n data series measured by manual and ultrasonic meter is verified. In this way, we can treat the automatic data by the new validated formula by converting them from based on the ultrasonic meter to the manual meter. The relationships of meters in three gate are shown in Table 2.Table 2：Relationships

23、 of manual and ultrasonic meter in Jiucheng, Liulou, and XingmiaoProgram: Firstly the automatic measured data are calculated. For the diversity is quite large, the manual measured data are calculated to compare.8 Examination Results3.1 With automatic measured data(1) JiuchengFrom the left graph, it

24、is shown that while discharge is bigger than 10m/s, the value of Bez1/2 would be bigger than 2 which is too large for this gate, and then the new experiential coefficient formula would brought large error.(2) LiulouFrom the left graph, the new water lever & discharge relationship formula is not

25、suitable to this data series while the new experiential exponent formula and the control system one are quite good.(3) XingmiaoFrom the left graph, the new formulas are not suitable to this data series3.2 With manual measured data(1) JiuchengFrom the graph, while discharge is bigger than 15m/s, the

26、value of Bez1/2 would be bigger than 2 which is too large for this gate, and then the new experiential coefficient formula would brought large error.(2) LiulouFrom the graph, while discharge is bigger than 7m/s, the value of Bez1/2 would be bigger than 2, and the error is slightly raised up.(3) Xing

27、miaoFrom the graph, all Bez1/2 is less than 4 which is permitted by this gate, and all formulas get satisfatory results.9 Conclusions and RecommendationBy this examination, it is found that the experiential exponent formulas (both the present control system formula and the new validated) are the mos

28、t accuracy methods and flexible to most flow regime, while water lever & discharge relationship formula is the one with least accuracy and the experiential coefficient formula is in the middle. However, there are always a particular range in which each formula is not suitable, e.g. while Bez1/2 is too large. And also from the examination, it is clear that the chosen of water level data serie