CN104535125A - Stream flow monitoring device and stream flow computing method - Google Patents

Abstract

The invention belongs to the technical field of flow monitoring, in particular to a river flow monitoring device and a river flow calculation method. The device includes a flow velocity measurement module, a water level measurement module, a microprocessor module, a storage module, a keyboard display module, a GPRS module and a power supply module; the flow velocity measurement module adopts an ultrasonic transducer, and the ultrasonic velocity difference method is used to calculate the river flow velocity; The water level measurement module uses an ultrasonic transducer to calculate the water level, and then calculates the cross-sectional area of the river; thereby calculating the river flow; the GPRS module can realize remote data transmission and real-time control. The invention can realize real-time monitoring of river flow and remote transmission of data, and has the advantages of simple installation, little impact on equipment, high accuracy and remote transmission by adopting non-contact measurement, and is very suitable for monitoring river flow of small hydropower stations in mountainous areas of my country.

Description

A river flow monitoring device and a river flow calculation method

technical field

The invention belongs to the technical field of flow monitoring, in particular to a river flow monitoring device and a river flow calculation method.

Background technique

Small hydropower is widely distributed in mountainous areas far away from large power grids due to its small scale, simple engineering, short construction period, quick returns, full use of natural resources, and good ecological benefits. It is an important part of rural energy in my country. In the process of small hydropower generation, river flow is an important factor affecting the benefits of small hydropower generation. Accurate and real-time monitoring of river flow can take timely measures in wet/dry seasons to ensure the effective power supply of small hydropower, and it is also the key to rationalize rural electricity consumption. links. Therefore, real-time monitoring of river flow in the process of small hydropower generation is of great significance to control the efficiency of small hydropower generation and the rational use of electricity in rural areas.

The current flow monitoring is mostly used in pipeline sewage, pipeline energy transmission and simple flow measurement, and few people monitor the flow of mountain rivers. Moreover, the situation of natural rivers is complex, and it is difficult to arrange the liquid level sensor. Most flow monitoring devices directly install the liquid level sensor in the measured medium. It is easy to be corroded after long-term use, the accuracy is not high, and remote transmission is not possible.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a river flow monitoring device and a river flow calculation method, thereby solving the shortcomings of existing equipment that are difficult to arrange, easy to corrode, low in accuracy, and unable to be remotely transmitted.

The technical scheme adopted in the present invention is:

The river flow monitoring device includes a flow velocity measurement module, a water level measurement module, a microprocessor module, a storage module, a keyboard display module, a GPRS module and a power supply module, and is characterized in that: the flow velocity measurement module, the water level measurement module, the storage module , keyboard display module, GPRS module and power supply module are respectively connected with the microprocessor module;

The flow velocity measurement module is provided with two ultrasonic transducers, and adopts the ultrasonic velocity difference method to measure the river flow velocity;

The water level measurement module uses an ultrasonic transducer to measure the water level;

The GPRS module realizes remote transmission of data.

The flow rate measurement module includes a time measurement circuit, a first CPLD chip, a first ultrasonic transducer drive circuit, a first transducer, a second transducer, a first transceiver timing control circuit, and a first signal processing circuit; the first The CPLD chip is respectively connected with the first ultrasonic transducer drive circuit, the time measurement circuit, and the first transceiver sequence control circuit, and the first ultrasonic transducer drive circuit is respectively connected with the first transducer and the second transducer, and the first transducer Both the device and the second transducer are connected with the first transceiver timing control circuit, the first transceiver timing control circuit is connected with the first signal processing circuit, and the first signal processing circuit is connected with the first CPLD chip; the time measurement circuit and the first CPLD The chips are respectively connected with the microprocessor modules.

The water level measurement module includes a second CPLD chip, a second ultrasonic transducer drive circuit, a third transducer, a second transceiver timing control circuit, and a second signal processing circuit; the second CPLD chip and the second ultrasonic transducer drive circuit 1. The second transceiver timing control circuit is connected, the second ultrasonic transducer drive circuit is connected with the third transducer, the third transducer is connected with the second transceiver timing control circuit, and the second transceiver timing control circuit is connected with the second signal processing circuit connected, the second signal processing circuit is connected with the second CPLD chip; the second CPLD chip is connected with the microprocessor module.

A river flow calculation method of the river flow monitoring device provided by the present invention comprises the following steps:

Step (1): The flow velocity of the river is measured by the flow velocity measurement module through the ultrasonic velocity difference method;

Step (2): measure the river water level by the water level measurement module, which is divided into a regular river channel shape measurement method and an irregular river channel shape measurement method;

The method for measuring the shape of the regular river channel is as follows:

The ultrasonic transducer sends out a bunch of pulses to the return time T, and calculates the distance between the ultrasonic transducer and the measured water surface Therefore, the river water level H=H ₀ -H ₁ , where H ₀ is the distance between the ultrasonic transducer and the lowest position at the bottom of the river, and V is the speed of sound wave propagation;

The irregular channel shape measurement method is as follows:

The ultrasonic transducer sends out a bunch of pulses to the return time T, and calculates the distance between the ultrasonic transducer and the measured water surface Divide a number of uniformly distributed measuring points along the bottom of the channel section, divide the channel section into n sections, and measure the vertical distance A _i between the ultrasonic transducer and these measuring points respectively. Therefore, the river at each measuring point The water level is a _i =A _i -H ₁ , where V is the speed of sound wave propagation, and i is a positive integer not greater than n-1;

Step (3): Calculate the river cross-sectional area S according to the water level data measured in step (2);

Step (4), measuring river water flow: Q=S×V.

In the step (3), when the channel cross-section is parabolic, the channel cross-sectional area S is: Among them, ε is the smallest integrable constant;

When the cross-section of the channel is trapezoidal, the cross-sectional area S of the channel is: Among them, L is the width of the river bottom, α is the angle between the river bottom and the embankment;

When the channel cross-section is irregular, the channel cross-sectional area S is: Among them, l is the distance between two adjacent measurement points at the bottom of the channel section, and n is a positive integer greater than 1.

It also includes the step of storing the measured data in the storage module, and transmitting the measured river velocity, river water level and river flow data to the remote wireless terminal equipment through the GPRS module.

The beneficial effects of the present invention are:

The flow velocity measurement module uses an ultrasonic transducer, and the ultrasonic velocity difference method is used to calculate the river flow velocity; the water level measurement module uses an ultrasonic water level sensor to measure the water level. The flow measurement module and water level measurement module use ultrasonic transducers, which improves the data measurement accuracy and the service life of the equipment; the GPRS module can transmit the measured river flow velocity, river water level, and river flow information to remote wireless terminal equipment in real time. The river flow monitoring device is easy to deploy in practice, supports small hydropower river flow monitoring, and can remotely transmit river flow velocity, river water level, and river flow data to wireless terminal equipment, and has the advantages of simple installation and low impact on equipment by adopting non-contact measurement. The advantages of small size, high accuracy, and remote transmission are very suitable for monitoring the flow of small hydropower rivers in mountainous areas of our country.

Description of drawings

Fig. 1 is a schematic structural view of a river flow monitoring device in an embodiment of the present invention;

Fig. 2 Schematic diagram of parabolic channel shape;

Fig. 3 is the schematic diagram of trapezoidal channel shape;

Fig. 4 is a schematic diagram of the shape of an irregular river channel;

Figure 5 is a flow chart of river flow calculation.

Detailed ways

The present invention provides a river flow monitoring device and a river flow calculation method. The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

The river flow monitoring device is shown in Figure 1. The river flow monitoring device includes a flow velocity measurement module, a water level measurement module, a microprocessor module, a storage module, a keyboard display module, a GPRS module and a power module, and is characterized in that: the flow velocity measurement module, the water level measurement module, the storage module, the keyboard The display module, the GPRS module and the power supply module are respectively connected with the microprocessor module. The GPRS module realizes the remote transmission of data.

The flow rate measurement module includes a time measurement circuit, a first CPLD chip, a first ultrasonic transducer drive circuit, a first transducer, a second transducer, a first transceiver timing control circuit, and a first signal processing circuit; A CPLD chip is respectively connected with the first ultrasonic transducer drive circuit, the time measurement circuit, and the first transceiver sequence control circuit, the first ultrasonic transducer drive circuit is respectively connected with the first transducer and the second transducer, and the first transducer Both the transducer and the second transducer are connected with the first transceiver timing control circuit, the first transceiver timing control circuit is connected with the first signal processing circuit, and the first signal processing circuit is connected with the first CPLD chip; the time measurement circuit and the first The CPLD chip is respectively connected with the microprocessor module. The flow velocity measurement module uses the ultrasonic velocity difference method to measure the river flow velocity.

The water level measurement module includes a second CPLD chip, a second ultrasonic transducer drive circuit, a third transducer, a second transceiver timing control circuit, and a second signal processing circuit; the second CPLD chip and the second ultrasonic transducer drive circuit 1. The second transceiver timing control circuit is connected, the second ultrasonic transducer drive circuit is connected with the third transducer, the third transducer is connected with the second transceiver timing control circuit, and the second transceiver timing control circuit is connected with the second signal processing circuit connected, the second signal processing circuit is connected with the second CPLD chip; the second CPLD chip is connected with the microprocessor module.

Using the above-mentioned river flow calculation method of the river flow monitoring device, the steps are as follows:

Step (1): The flow velocity of the river is measured by the flow velocity measurement module through the ultrasonic velocity difference method;

Step (2): The water level of the river is measured by the water level measurement module, which is divided into a regular river channel shape measurement method and an irregular river channel shape measurement method;

The method for measuring the shape of the regular river channel is as follows:

The ultrasonic transducer with a fixed height sends a beam of pulses to return time T, and calculates the distance between the ultrasonic transducer and the measured water surface Therefore, the river water level H=H ₀ -H ₁ , where H ₀ is the distance between the ultrasonic transducer and the lowest position at the bottom of the river, and V is the speed of sound wave propagation, which is 344m/s;

The irregular channel shape measurement method is as follows:

The ultrasonic transducer with a fixed height sends a beam of pulses to return time T, and calculates the distance between the ultrasonic transducer and the measured water surface Divide a number of uniformly distributed measuring points along the bottom of the channel section, divide the channel section into n sections, and measure the vertical distance A _i between the ultrasonic transducer and these measuring points respectively. Therefore, the river at each measuring point The water level is a _i =A _i -H ₁ , where V is the speed of sound wave propagation, and i is a positive integer not greater than n-1;

Step (3): Calculate the river cross-sectional area S according to the water level data measured in step (2);

Channel sections are usually divided into regular shapes (such as parabola and trapezoid) and irregular shapes. Taking these three cases as examples, the calculation methods for the cross-sectional area S of the channel are given respectively:

As shown in Figure 2, when the cross-section of the channel is parabolic, the cross-sectional area S of the channel is: Among them, ε is the smallest integrable constant;

As shown in Figure 3, when the channel cross-section is trapezoidal, the channel cross-sectional area S is:

Among them, L is the width of the river bottom, α is the angle between the river bottom and the embankment;

As shown in Figure 4, when the channel cross-section is irregular, the channel cross-sectional area S is: Among them, l is the distance between two adjacent measurement points at the bottom of the channel section, and n is a positive integer greater than 1.

Still taking Figure 4 as an example, 11 measuring points are set, and the cross section of the river is divided into 12 equal parts. Among them, the water level of the middlemost measuring point is recorded as a ₁ , and the water level of the measuring points from the middlemost measuring point to the left is sequentially recorded as are a ₂ , a ₃ , a ₄ , a ₅ , and a ₆ , and the water levels of the measuring points from the middlemost measuring point to the right are recorded as a ₇ , a ₈ , a ₉ , a ₁₀ , and a ₁₁ in turn, and the water levels of each section of the river course The cross-sectional area of is denoted as S _j , 1≤j≤12, we get:

${\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 5</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 6</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>$

${\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 6</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 6</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 7</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 7</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 8</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 8</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 7</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 9</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 9</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 8</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 10</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 10</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 9</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>$

${\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 10</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ;</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; l</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ;</span>$

Then you can get: $S=\underset{1}{\overset{12}{\mathrm{\&Sigma;}}}{S}_i=\underset{1}{\overset{12}{\mathrm{\&Sigma;}}}{a}_i\&times;l.$

Step (4), calculating the river flow: Q=S×V.

In this embodiment, the known river parameters can be input into the microprocessor module through the keyboard, thereby judging the shape of the river, selecting a suitable calculation formula to calculate the cross-sectional area, and simultaneously calculating the river with the product of the river flow velocity obtained by using the ultrasonic propagation velocity difference method. Flow, the calculation process is shown in Figure 5.

Further, the river velocity, river water level, and river flow obtained by the calculation method are stored in the storage module, and the river flow is displayed on the LCD; at the same time, the river velocity, the river water level, and the river flow data obtained by the calculation method are passed through the GPRS The module transmits to the remote wireless terminal equipment.

The above-mentioned embodiments are only used to illustrate the invention patent, but not to limit the invention patent. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications or equivalent replacements of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all should cover Within the scope of the claims of the present invention.

Claims (6)

1. a river discharge monitoring device, comprise fluid-velocity survey module, level measuring module, microprocessor module, memory module, keyboard display module, GPRS module and power module, it is characterized in that: described fluid-velocity survey module, level measuring module, memory module, keyboard display module, GPRS module are connected with microprocessor module respectively with power module;

Described fluid-velocity survey module installation two ultrasonic transducers, adopt ultrasonic velocity difference method to measure river flow;

Described level measuring module adopts a ultrasonic transducer to measure water level;

Described GPRS module realizes the remote transmission of data.

2. a kind of river discharge monitoring device according to claim 1, it is characterized in that, described fluid-velocity survey module comprises time measuring circuit, a CPLD chip, the first ultrasonic transduction driving circuit, the first transducer, the second transducer, the first transmitting-receiving sequential control circuit and the first signal processing circuit; One CPLD chip is received and dispatched sequential control circuit with the first ultrasonic transduction driving circuit, time measuring circuit, first respectively and is connected, first ultrasonic transduction driving circuit is connected with the first transducer, the second transducer respectively, first transducer, the second transducer are are all received and dispatched sequential control circuit with first and are connected, first transmitting-receiving sequential control circuit is connected with the first signal processing circuit, and the first signal processing circuit is connected with a CPLD chip; Time measuring circuit is connected with microprocessor module respectively with a CPLD chip.

3. a kind of river discharge monitoring device according to claim 1, it is characterized in that, described level measuring module comprises the 2nd CPLD chip, the second ultrasonic transduction driving circuit, the 3rd transducer, the second transmitting-receiving sequential control circuit and secondary signal treatment circuit; 2nd CPLD chip is received and dispatched sequential control circuit with the second ultrasonic transduction driving circuit, second and is connected, second ultrasonic transduction driving circuit is connected with the 3rd transducer, 3rd transducer and second is received and dispatched sequential control circuit and is connected, second transmitting-receiving sequential control circuit is connected with secondary signal treatment circuit, and secondary signal treatment circuit is connected with the 2nd CPLD chip; 2nd CPLD chip is connected with microprocessor module.

4., based on river discharge computing method for river discharge monitoring device described in claim 1, it is characterized in that, comprise the following steps:

Step (1): measure acquisition river flow by ultrasonic velocity difference method by fluid-velocity survey module;

Step (2): measure river level by level measuring module, be divided into regular stream shape measuring method and irregular stream shape measuring method;

Described regular stream shape measuring method is as follows:

It is T that ultrasonic transducer sends a beam pulse to time of return, calculates the distance of ultrasonic transducer apart from the tested water surface therefore, river level H=H ₀-H ₁, wherein, H ₀for the distance of ultrasonic transducer distance bottom of river channel extreme lower position, V is acoustic wave propagation velocity;

Described irregular stream shape measuring method is as follows:

It is T that ultrasonic transducer sends a beam pulse to time of return, calculates the distance of ultrasonic transducer apart from the tested water surface bottom along cross section, river course marks off several equally distributed measurement points, and cross section, river course is divided into n section, measures the vertical range A between ultrasonic transducer and these measurement points respectively _i, therefore, the river level of each measurement point is a _i=A _i-H ₁, wherein, V is acoustic wave propagation velocity, and i is the positive integer being not more than n-1;

Step (3): measure according to step (2) waterlevel data obtained and calculate river course cross-sectional area S;

Step (4), measures river discharge: Q=S × V.

5. river discharge computing method according to claim 4, is characterized in that, in described step (3), when river course xsect is parabolical, river course cross-sectional area S is: wherein, ε is minimum integrable constant;

When river course xsect is trapezoidal, river course cross-sectional area S is: wherein, L is river bed width, and α is river bed and river levee angle;

When river course xsect is irregular shape, river course cross-sectional area S is: wherein, l is the spacing of adjacent two measurement points in the bottom in cross section, river course, n be greater than 1 positive integer.

6. river discharge computing method according to claim 4, it is characterized in that, also comprise and be stored into memory module by measuring the data obtained, and river flow measurement obtained, river level, river discharge data are sent to the step of remote wireless terminal equipment by GPRS module.