River and lake ecological blue-green space water supplement amount accounting method based on multidisciplinary crossing theory

Abstract

The invention relates to the technical field of hydrology and water resources, in particular to a river-lake ecological blue-green space water replenishing amount accounting method based on a multidisciplinary crossing theory, which integrates theoretical basis of hydrology, soil hydrodynamics, water supply and drainage and the like, and eliminates errors and uncertainty by applying a statistical method. The urban river and lake leakage loss amount can be accurately checked, scientific, quantitative and fine scientific support is provided for managers and decision makers, the water resource management cost is remarkably reduced, the water resource utilization efficiency is improved, and reasonable allocation of water resources is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of hydrology and water resources, and in particular to a method for calculating water replenishment in blue-green space of river and lake ecology based on multidisciplinary cross-theory. Background Art

[0002] Urban river and lake water systems are the cornerstone of urban water security and an important carrier of the water ecological environment. In order to support sufficient water surface, suitable water flow, good water quality, and diverse ecology in urban rivers and lakes, it is necessary to first meet the ecological water demand of urban rivers and lakes. However, due to the special time of the flood season, water resources are very uneven. To keep urban rivers and lakes with water all year round and beautiful landscapes, at least a large amount of water resources must be supplemented during the dry season, which requires accurate calculation of the ecological water demand of urban rivers and lakes.

[0003] The ecological water demand of urban rivers and lakes generally includes three aspects: evaporation and leakage loss, water source renewal water demand and riverside ecological landscape water demand. The calculation methods of water surface evaporation are relatively mature. One is the conversion from evaporation pan to water surface evaporation, and the other is the calculation of water surface evaporation based on potential evaporation. The main difficulty in leakage is that due to the high heterogeneity of soil, the soil properties in different regions and depths vary greatly. The leakage observation based on point scale is difficult to expand to the regional scale, which makes it difficult to estimate the river leakage loss. From the water source renewal water demand, the calculation method of water surface evaporation is relatively mature. One is the conversion from evaporation pan to water surface evaporation, and the other is the calculation of water surface evaporation based on potential evapotranspiration. The main difficulty in leakage is that due to the high heterogeneity of soil, the soil properties in different regions and depths vary greatly. The leakage observation based on point scale is difficult to expand to the regional scale, which makes it difficult to estimate the river leakage loss. From the perspective of quantity, fresh water sources are added to form a certain water dynamics with the goal of increasing dissolved oxygen in water bodies, improving water self-purification capacity, and inhibiting algae outbreaks. There is currently no consensus on the calculation method for this part of the quantity; from the perspective of the water demand of the riparian ecological landscape, the banks of urban rivers and lakes are generally ornamental vegetation, which generally require irrigation to supplement the water shortage of vegetation. The calculation method for the ecological water demand of vegetation of a single species is relatively mature, but the calculation of the water demand of regional riparian vegetation landscape considering the growth needs of different types of vegetation still requires a set of calculation methods.

[0004] In view of the above problems, the actual observation process in the existing technology is affected by a series of uncertainties such as wind and waves, instrument signals and accuracy, the technical level of instrument monitoring personnel, and on-site artificial water extraction and irrigation. Even continuous observation for a year is difficult to obtain relatively stable and reliable leakage data. Under actual working conditions, soil infiltration is divided into vertical leakage and lateral leakage. The existing soil column experiment is also difficult to reflect the actual situation of regional soil infiltration. In addition, there are certain technical and economic problems in "electricity for water". Different water source water levels and water receiving area water levels have different water lifting heads and different operating powers of pump stations. That is, the water consumption may not be the same under the same power consumption. In addition, there are peak and valley electricity prices for electricity consumption, and the electricity charges used for electricity consumption in different periods are also inconsistent, which brings certain uncertainties to the deduction of leakage loss using pump station electricity consumption.

[0005] Therefore, when calculating the seepage loss of urban rivers and lakes from the perspectives of hydrology, soil hydrodynamics, water supply and drainage, etc., there are certain disciplinary theoretical foundations and practical uncertainties. The amount of water resources required for ecological replenishment throughout the year directly affects the urban river and lake operation and maintenance expenses (water and electricity charges). The observation errors at the point will produce an error amplification effect when used to calculate the overall water accounts of the regional river and lake systems.

[0006] Therefore, it is necessary to design a method for calculating the water replenishment of the blue-green space of river and lake ecology based on multidisciplinary cross-theory, integrating the theoretical basis of hydrology, soil hydrodynamics, water supply and drainage and other disciplines, integrating the existing theoretical advantages, making full use of various types of observation data and extracting effective information from them, and using statistical methods to eliminate uncertainty, so as to achieve the purpose of accurate calculation, provide scientific, quantitative and precise scientific support for managers and decision makers, significantly reduce the cost of water resources management, improve the efficiency of water resources utilization, and promote the rational allocation of water resources. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for calculating the water replenishment of the blue-green space of river and lake ecology based on multidisciplinary cross-theory, integrating the theoretical basis of hydrology, soil hydrodynamics, water supply and drainage and other disciplines, integrating the existing theoretical advantages, making full use of various types of observation data and extracting effective information therefrom, and using statistical methods to eliminate uncertainty, so as to achieve the purpose of accurate calculation, provide scientific, quantitative and precise scientific support for managers and decision makers, significantly reduce the cost of water resource management, improve the efficiency of water resource utilization, and promote the rational allocation of water resources.

[0008] In order to achieve the above object, the present invention provides a method for calculating the water replenishment amount of the blue-green space of river and lake ecology based on multidisciplinary cross-theory:

[0009] The blue-green space includes the blue space of rivers and lakes and the green space within the blue line of the river; the water replenishment calculation includes the calculation of the water demand for evaporation and leakage of the blue space, the calculation of the water demand for water source renewal in the blue space, and the calculation of the water demand for irrigation in the green space.

[0010] Among them, the calculation of the evaporation and leakage water demand of the blue space is selected from any one of the evaporation and leakage water demand calculation based on historical literature research, the evaporation and leakage water demand calculation based on in-situ observation tests, and the evaporation and leakage water demand calculation based on the power consumption of the water replenishment pump station.

[0011] S1, the blue space in the blue-green space refers to the space where rivers and lakes have water, specifically:

[0012] The amount of water lost due to evaporation and leakage is used to maintain the water level of rivers and lakes at normal levels all year round and to maintain the water area; the amount of water retained for water source renewal means that the water quality meets the functional requirements of the water body while maintaining the flow of the water body;

[0013] The calculation of evaporation and leakage water demand based on historical literature research is as follows:

[0014] Calculation of water surface evaporation loss:

[0015] When the precipitation is greater than the evaporation of the water surface, the evaporation water requirement of the water surface is considered to be 0;

[0016] When the precipitation is less than the evaporation of the water surface, the calculation formula is:

[0017] Q 蒸发 =(EP)×A÷10;

[0018] Among them, Q 蒸发 The water demand for evaporation from the water surface, unit: 10,000 m 3 ; E is the evaporation of water surface, unit: mm; P is the precipitation, unit: mm; A is the water surface area of ​​the river, unit: km 2 ;

[0019] in, Evaporation from water surface E Calculated based on the city's average annual precipitation over many years and the water surface evaporation conversion coefficient;

[0020] Calculation of water demand due to leakage loss:

[0021] The empirical formula was confirmed by comprehensive analysis of groundwater dynamics method, river infiltration simulation experimental method and empirical formula:

[0022] Q 渗漏 =K 渗漏 ×A×100;

[0023] Where Q 渗漏 is the leakage water demand, unit: 10,000 m 3 ; K 渗漏 is the river leakage coefficient, unit: m / year; A is the river surface area, unit: km 2 ;

[0024] Where K 渗漏 Based on the monitoring of river infiltration simulation experiments, or the hydrogeological survey results of regional geotechnical engineering survey reports, as well as the relevant literature survey of the basin where the study area is located;

[0025] The K 渗漏 In typical plain river network areas, it is 1.93 mm / d, or 0.7 m / a.

[0026] When the surface layer below the ground surface is silty clay, silt or silty fine sand, the K 渗漏 They are 0.1mm / d~5.2mm / d, 5.2mm / d~52mm / d, and 52mm / d~104mm / d respectively.

[0027] The calculation of evaporation leakage water demand based on in-situ observation test is as follows:

[0028] Evaporation leakage calculation:

[0029] Referring to the calculation formula of evaporation and seepage water demand, under the premise of known river evaporation and seepage capacity, the calculation formula of water system evaporation and seepage loss can be simplified as follows: Q 蒸发渗漏 =K 蒸发渗漏 ×A×100; where Q 蒸发渗漏 The water demand due to evaporation and leakage, unit: 10,000 m 3 ; K 蒸发渗漏 is the evaporation leakage coefficient, unit: m / year; A is the river surface area, unit: km 2 ;

[0030] Evaporation leakage coefficient K 蒸发渗漏 The determination method is:

[0031] Taking the evaporation and leakage law of the target water system as the goal, the data of the in-situ observation time, field condition control, observation point, index, frequency and instrument use are recorded to obtain the target water system evaporation and leakage law. The ...

[0032] Calculate the evaporation leakage coefficient K for each observation 蒸发渗漏 :

[0033] Where: ΔH i is the observed change value of the water level of the target water body during the i-th in-situ observation period, unit: m; T i is the duration of the i-th in-situ observation, in s;

[0034] Calculate the average value of the evaporation leakage coefficient Where n is the number of valid observations; the sample standard deviation T is calculated using the Bessel formula:

[0035]

[0036] Determine and remove outliers:

[0037] use As a criterion, if a K 蒸发渗漏 satisfy It is considered as an outlier and should be eliminated. The number of samples after eliminating the outlier is counted, n′;

[0038] Recalculate the average evaporation leakage coefficient K 蒸发渗漏 :

[0039]

[0040] Among them, K 蒸发渗漏 ′ is the evaporation leakage coefficient of each observation after removing abnormal values;

[0041] Determine the range of evaporation leakage [K min , K max ]:

[0042] From the data set after removing outliers, take the minimum value K min and the maximum value K max As the range of values ​​for evaporation leakage.

[0043] Evaporation leakage coefficient K 蒸发渗漏 The correction method needs to take into account evaporation, leakage and groundwater level rise, and the correction methods are:

[0044] Method 2: Evaporation: The annual distribution law of river evaporation is calculated based on the monthly water surface evaporation conversion coefficient. The specific calculation method is as follows:

[0045] Collect monthly water surface evaporation data for many years:

[0046] Obtain the multi-year average monthly evaporation data E for the target water system area i , where i = 1, 2, ..., 12 represents the month;

[0047] Calculate the monthly evaporation conversion factor:

[0048] Calculate the total evaporation for the year:

[0049] Calculate the evaporation conversion factor k for each month 蒸发,i :

[0050]

[0051] Corrected evaporation during the observation period:

[0052] The evaporation during the observation period is corrected according to the conversion coefficient corresponding to the observation month:

[0053]

[0054] Where: n is the number of observations; E j is the evaporation of the jth observation; m j is the month corresponding to the j-th observation;

[0055] Method 2: Leakage: The annual distribution pattern of river leakage is calculated based on the rainfall distribution pattern and groundwater level in the area;

[0056] Collect monthly rainfall and groundwater level data:

[0057] Get the multi-year average monthly rainfall P of the target area i and monthly average groundwater depth G i , where i is the month;

[0058] Calculate the monthly leakage conversion factor:

[0059] According to rainfall and groundwater level, establish the leakage conversion coefficient k for each month 渗漏,i The empirical formula of linear regression is as follows

[0060] k 渗漏,i =a×P i +b×G i +c;

[0061] Among them, a, b, and c are unknown coefficients, which are determined by fitting historical data;

[0062] Corrected leakage during the observation period:

[0063] The leakage during the observation period is corrected according to the conversion coefficient corresponding to the observation month:

[0064] L=L 观测 ×k 渗漏,i ;

[0065] Where: L 观测 is the observed leakage;

[0066] Method 3: Coefficient correction for future groundwater level rise background:

[0067] Based on the monitoring data of shallow groundwater depth in the target area, the groundwater level changes are analyzed, and the future groundwater evolution trend is predicted and reasonable corrections are made. By collecting the groundwater level monitoring data of the target area over the years, the groundwater level change curve is drawn, and its long-term change trend and periodicity are analyzed. The linear fitting method is used to determine the future groundwater level estimate.

[0068] The specific calculation of evaporation leakage water demand based on the power consumption of the water replenishment pump station is:

[0069] A liquid level meter is installed in the water pump room to monitor the water level in the pump station. The amount of water replenishment is determined by the accumulated water volume measured by the electromagnetic flow meter installed on the outlet pipe. The water consumption of other pump stations is excluded and converted into the power consumption of the pump station, which is calculated in the form of electricity to water conversion.

[0070] The calculation of the irrigation water demand of the green space in the blue-green space is the irrigation demand to maintain the life needs of the grassland and forest bank vegetation ecology within the width of the river blue line. It is calculated using the irrigation quota method, and the formula is:

[0071] Q 绿化 =C 绿化 ×S×100;

[0072] Where Q 绿化 The water requirement for greening irrigation, unit: 10,000 m 3 ; C 绿化 It is the greening irrigation quota, unit: m 3 / (m 2 a) 0.3~0.9m 3 / (m 2 a); S is the green area on both sides of the river, unit: km 2 ;

[0073] The irrigation quota for green space is set according to the Water Use Quota standard. Generally speaking, the irrigation quota for green space is 0.6 m per year. 3 / (m 2 a);

[0074] The irrigation times of the green space are specifically set as:

[0075] The green space is irrigated 10 times per month from June to September, 6 times per month in April, May and October, 3 times per month in February, March and November. January and December are frozen periods and no irrigation is required. Based on the above irrigation cycles, the annual irrigation times are 67 times.

[0076] Compared with the prior art, the present invention has the following beneficial effects:

[0077] The present invention integrates the theoretical foundations of hydrology, soil hydrodynamics, water supply and drainage and other disciplines, integrates the existing theoretical advantages, makes full use of various types of observation data and extracts effective information therefrom, and uses statistical methods to eliminate uncertainty, thereby achieving the purpose of accurate accounting, providing managers and decision makers with scientific, quantitative and precise scientific support, significantly reducing the cost of water resource management, improving the efficiency of water resource utilization, and promoting the rational allocation of water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is a schematic diagram of the ecological water demand accounting framework for the blue-green space of urban river and lake systems in the present invention. DETAILED DESCRIPTION

[0079] The present invention will now be further described with reference to the accompanying drawings.

[0080] See also Figure 1The present invention provides a method for calculating the water replenishment of the blue-green space of river and lake ecology based on multidisciplinary cross-theory. The blue-green space of urban river and lake water systems mainly includes the river and lake water space and the green space within the blue line of the river.

[0081] like Figure 1 As shown in the figure, blue space guarantee is essentially to have enough water. First, it can make up for the loss caused by evaporation and leakage so that the river can maintain a normal water level all year round and maintain a certain water surface area. Second, it can leave enough water for water source renewal so that the river water can flow while ensuring that the water quality meets the functional requirements of the water body. Green space guarantee is essentially to maintain the basic life needs of the shore vegetation ecology such as grassland and forests within the ideal river blue line width.

[0082] (1) Water demand for evaporation and leakage in blue space

[0083] The evaporation and leakage conditions of river and lake systems vary greatly, such as soil compactness, groundwater depth, and the soundness of the water ecosystem. The estimation of water consumption due to evaporation and leakage in the water system is very complicated. Based on three methods, namely historical literature data survey, in-situ observation test of evaporation and leakage in the water system, and water replenishment scheduling data of pumping stations, the evaporation and leakage water demand of the blue space of the water system is estimated.

[0084] 1) Calculation of water demand for evaporation and leakage based on historical literature research

[0085] Calculation of water surface evaporation loss: Part of the river's water demand comes from replenishing the evaporation loss of the water surface. The amount of evaporation from the water surface is not only related to the water surface area and temperature, but also directly affected by precipitation. When the precipitation is small and insufficient to replenish the evaporation consumption, the extra net water consumed by evaporation is provided by the river itself, which is also called the water demand for evaporation from the water surface. When the precipitation is greater than the evaporation from the water surface, the evaporation demand from the water surface is considered to be 0, and the calculation formula is:

[0086] Q 蒸发 =(EP)×A÷10;

[0087] Where: Q 蒸发 —Water demand for evaporation from water surface, 10,000 / m 3 ; E—water surface evaporation, mm; P—precipitation, mm; A—river water surface area, km 2 .

[0088] Generally speaking, water surface evaporation is estimated based on the multi-year average (1956-2016) annual precipitation in typical urban areas and the water surface evaporation conversion coefficient.

[0089] Calculation of water demand for leakage loss: When the river water level is higher than the groundwater level on both sides, the river water level, under the action of gravity, replenishes the groundwater in the form of seepage, which is river leakage.

[0090] The water demand for river leakage is related to the soil permeability coefficient of the riverbed and the hydraulic gradient of the river, and can be calculated using the Darcy formula. Considering that the soil permeability coefficient under natural conditions is affected by multiple factors such as water level, soil type and river morphology, it is generally determined by groundwater dynamics or field experiments of river channel permeability simulation. The river channel leakage loss can be calculated based on the empirical formula, which is:

[0091] Q 渗漏 =K 渗漏 ×A×100;

[0092] Where: Q 渗漏 : Leakage water demand, 10,000 m 3 ; K 渗漏 : River leakage coefficient, m / year; A: River surface area, km 2 .

[0093] The value of the river channel leakage coefficient is related to the location of the river and the river's leakage reduction situation. The geological lithology of the riverbed determines the infiltration capacity. When the riverbed lithology is sandy soil, the river leakage is large; when the riverbed lithology is clay soil, the river leakage is small. Generally, the permeability coefficient can be obtained based on the hydrogeological survey results of the regional geotechnical engineering survey report, or by consulting relevant literature on the study area, its adjacent areas or its basin. The surface layer below the surface is mainly silty clay, silt and fine silt sand, and the corresponding permeability coefficients are 0.1mm / d~5.2mm / d for silty clay, 5.2mm / d~52mm / d for silt, and 52mm / d~104mm / d for fine silt sand.

[0094] The leakage coefficient of rivers in plain river network areas is usually 1.93mm / d, that is, 0.7m / a. During the water resources survey and evaluation in Tianjin, the leakage intensity of the river channel was calculated by analyzing the flow measurement data of the upstream and downstream sections of the river during the non-agricultural irrigation period and the Yellow River diversion period. The leakage coefficient is generally 1mm / d~2.6mm / d, that is, 0.365m / a~0.949m / a. The soil layer in the riverbed of the Yongding River in Tianjin is extremely micro-micro permeable, and the groundwater is buried at a depth of about 2.0m. Referring to the experimental data of nearby rivers, the leakage coefficient of the Yongding River is about 2.0mm / d, which is equivalent to 0.73m / a. The theoretical leakage coefficient of the bentonite waterproof blanket technology is 6.6×10 -7 cm / s, that is 0.21m / a.

[0095] 2) Calculation of water demand for evaporation and leakage based on in-situ observation tests

[0096] Calculation of evaporation and leakage: The in-situ observation experiment measures the total amount of evaporation and leakage. Therefore, referring to the calculation formula of evaporation and leakage water demand, under the premise of known river evaporation and leakage capacity, the calculation formula of water system evaporation and leakage loss can be simplified to:

[0097] Q 蒸发渗漏 =K 蒸发渗漏 ×A×100;

[0098] Where: Q 蒸发渗漏 : Water loss due to evaporation and leakage, 10,000 m 3 ; K 蒸发渗漏 : Evaporation leakage coefficient, m / year; A: River surface area, km 2 .

[0099] Determination method of evaporation leakage coefficient based on in-situ observation: The prototype observation test aims to study the evaporation and leakage laws of the target water system. By observing the water level data, the evaporation and leakage conditions of the water system are analyzed to provide a basis for calculating the water demand for evaporation and leakage of the water system.

[0100] When the water system is not replenished, the time series of evaporation and leakage analysis of each river section varies due to the subsequent opening time of the replenishment pump station or the control culvert gate.

[0101] Data with abnormal data fluctuations were removed. The initial water level of the first point on the water replenishment path was the highest, and the initial water levels of points along the way decreased. Without water replenishment, the river water level at each monitoring point showed a stable decreasing trend due to evaporation and leakage. If there were slight fluctuations in the data chain of some points, it was mainly related to manual observation errors.

[0102] All external interferences that may affect the observation experiment are eliminated, such as strong winds, upstream water replenishment, irrigation water intake, etc. It can be considered that the water level changes in each river channel are caused by evaporation and leakage.

[0103] Based on the water level changes during the observation period of each river section, the evaporation seepage is calculated. After eliminating invalid data, the evaporation seepage of different river sections in a certain observation experiment sequence can be obtained. The evaporation seepage data at different points may be different. The arithmetic mean is taken as the average evaporation seepage, and the minimum and maximum values ​​are taken as the interval of evaporation seepage values.

[0104] Correction method of evaporation leakage coefficient considering observation period and groundwater level change: According to the evaporation leakage test, the evaporation leakage coefficient of different river sections of the water system is calculated. Considering that the evaporation leakage coefficient of the river channel is related to the observation period, the operation status of the river channel construction, the height of the groundwater level, etc., in order to obtain a reasonable evaporation leakage coefficient, the evaporation leakage coefficient measured this time should be corrected in combination with the actual situation. For example, in recent years, the North China Plain has implemented ecological water replenishment and groundwater pressure extraction, and the groundwater level has shown an upward trend. The impact of groundwater level changes on river leakage should be considered.

[0105] Coefficient correction considering the influence of observation period:

[0106] Affected by factors such as annual rainfall, temperature and groundwater, evaporation and leakage have seasonal variability. The data observed in a certain season is significantly different from the annual average evaporation and leakage coefficient, and the evaporation and leakage coefficient needs to be corrected.

[0107] ① Evaporation: The annual distribution pattern of river evaporation is calculated based on the monthly water surface evaporation conversion coefficient.

[0108] ② Leakage: The annual distribution of river leakage is closely related to the rainfall distribution in the area and the groundwater level. In places where rainfall is unevenly distributed, the annual distribution of river leakage will also be uneven. In the dry season, the groundwater level is relatively low, the river flow is generally relatively small, and the river leakage will also be relatively small. In the flood season, the river flow gradually increases, and the leakage will also increase accordingly. However, as the groundwater is gradually replenished, the groundwater level on both sides of the river rises, and the river leakage will gradually decrease.

[0109] Coefficient correction considering the background of future groundwater level rise:

[0110] When the groundwater level is buried deep, the seepage can infiltrate freely and the leakage is large; when the groundwater level is buried shallow, the groundwater level supports the infiltration and the leakage decreases. The leakage amount is linearly related to the leakage intensity.

[0111] Consider the impact of groundwater pressure extraction and river ecological water replenishment in the northern region. According to the monitoring data of the shallow groundwater depth in the study area, analyze the changes in groundwater levels and predict the future evolution of groundwater. It can be considered that the leakage coefficient observed by the present invention is greater than the leakage coefficient after the groundwater rises. When predicting the future leakage coefficient, it is necessary to make reasonable corrections based on the future changes in groundwater levels.

[0112] 3) Calculation of evaporation and leakage water demand based on power consumption of water replenishment pump station

[0113] For river and lake systems in northern cities, ecological water replenishment is usually carried out by gates or pumping stations to maintain landscape waters. For river and lake systems that use pumping stations for water replenishment, the power consumption of the pumping stations is one of the important bases for water consumption calculation. When using the electricity-to-water method to calculate evaporation and leakage, pay attention to the elimination of other influencing factors, such as irrigation water intake. For example, a water replenishment channel uses 3 pumps, and the design flow rate of each pump is Q = 1800m 3 / h, design head H = 8m, power N = 55kW, water is replenished through 2 DN800 pressure pipes, and 2 electromagnetic flow meters are installed on the outlet pipes. An ultrasonic level meter is installed in the pump room, and the start and stop of the water pump is mainly manually controlled according to the water situation. If the water level in the pump station is lower than 5.5m, the water pump is forced to stop. All the replenishment water is pumped and discharged through the pump station, so the replenishment amount can be determined by the cumulative water volume measured by the electromagnetic flow meter.

[0114] (2) Water demand for blue space water source renewal

[0115] For rivers controlled by sluice gates and dams, water source renewal is usually required to maintain the self-purification capacity and hydrodynamics of the river. Drawing on the calculation method of lake water source renewal, the importance of the river in the starting area, the water source situation and other factors are comprehensively considered, and the water demand is determined according to a certain number of water source renewals and the storage capacity of the river channel.

[0116] Q 水源更新 =K 水源更新 ×q;

[0117] Where: Q 水源更新 :Water source renewal water demand, 10,000 m 3 ; K 水源更新 : Water source renewal times, times / year; q: Water source renewal river channel storage capacity, 10,000 m 3 .

[0118] The water source renewal cycle or frequency should be maintained within a reasonable range. If the cycle is too short, nitrogen and phosphorus in the sediment are easily released, and frequent water replacement is not conducive to biological growth, reducing the interception of non-point source pollutants and water purification service functions. If the cycle is too long, it is not conducive to the increase of water DO concentration and the growth of organisms with strong adaptability to dynamic disturbances, and it is easy to cause eutrophication of water bodies. Under natural conditions, the renewal cycle of river water is 16 days, so the water source renewal frequency is considered to be twice a month.

[0119] Considering that the long-term water replenishment source for general urban rivers is mainly recycled water, the temperature is high in summer and blue algae are prone to outbreaks, the residence time of recycled water should not be too long. Therefore, in summer, it is necessary to supplement the internal water circulation of the river to increase the fluidity of the water body, ensure that the recycled water enters and exits quickly, shorten the residence time, and prevent blue algae outbreaks and water quality deterioration. Because the temperature in winter (December to February of the following year) is low (the average temperature from 1961 to 2005 is -1.7℃), the river is mostly frozen, so the water source is not renewed. In summary, the long-term water source renewal period is spring, summer and autumn, the renewal frequency is twice a month, and the annual water source renewal frequency is at least 18 times.

[0120] (3) Water demand for green space irrigation

[0121] The calculation scope of green space water demand this time only includes the green space within the blue line on both sides of the river and lake systems in northern cities. The water demand of other park green spaces is not within this scope.

[0122] The water demand for greening irrigation is calculated using the quota method, and the calculation formula is as follows: Q 绿化 =C 绿化 ×S×100

[0123] Where: Q 绿化 The water requirement for greening irrigation, 10,000 m 3 ; C 绿化is the greening irrigation quota, m 3 / (m 2 a) Generally 0.3~0.9m 3 / (m 2 a); S is the green area on both sides, km 2 .in:

[0124] Green irrigation area: The green area on both sides of the river is determined based on the width of the blue line of the river.

[0125] Comprehensive irrigation quota: According to the provincial local standard "Water Use Quota" (DB**) (each province has its own local water use quota standard), generally speaking, the annual comprehensive irrigation quota for park green space is 0.6m 3 / (m 2 a).

[0126] Greening irrigation frequency: determined by comprehensive analysis based on local actual conditions. For example, in a city in the North China Plain, the green space is irrigated 10 times per month from June to September, 6 times per month in April, May and October, and 3 times per month in February, March and November. January and December are frozen periods and no irrigation is required. Based on the above irrigation cycle, the annual irrigation frequency is 67 times.

[0127] The above are only preferred embodiments of the present invention, which are only used to help understand the method and core idea of ​​the present application. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the idea of ​​the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

[0128] The present invention solves the problems encountered in the prior art in the actual working conditions and applications of the evaporation and leakage loss, the water source renewal water demand and the riverbank ecological landscape water demand. The soil is highly heterogeneous, and the point-scale leakage observation is difficult to expand and estimate due to the large difference in properties. The calculation method for increasing the dissolved oxygen in the water body, the self-purification of the water body and the inhibition of algae is inconsistent. The problem of difficulty in obtaining stable and reliable data for evaporation observation, the lack of the true situation of vertical and lateral leakage in the soil column experiment and the cost uncertainty caused by the conversion of electricity to water. By integrating the theoretical basis of hydrology, soil hydrodynamics, water supply and drainage and other disciplines, the statistical method is used to eliminate errors and uncertainties, so as to achieve accurate verification of the leakage loss of urban rivers and lakes, provide scientific, quantitative and precise scientific support for managers and decision makers, significantly reduce the cost of water resource management, improve the efficiency of water resource utilization, and promote the rational allocation of water resources.

Claims

1. A method for calculating water replenishment of blue-green space in river and lake ecology based on multidisciplinary cross-theory, characterized in that: The blue-green space includes the blue space of rivers and lakes and the green space within the blue line of the river; the water replenishment calculation includes the calculation of the water demand for evaporation and leakage of the blue space, the calculation of the water demand for water source renewal in the blue space, and the calculation of the water demand for irrigation of the green space; Among them, the calculation of the evaporation and leakage water demand of the blue space is selected from any one of the evaporation and leakage water demand calculation based on historical literature research, the evaporation and leakage water demand calculation based on in-situ observation tests, and the evaporation and leakage water demand calculation based on the power consumption of the water replenishment pump station.

2. The method for calculating water replenishment of river and lake ecological blue-green space based on multidisciplinary cross-theory according to claim 1 is characterized in that: The calculation of evaporation leakage water demand based on historical literature research is as follows: Calculation of water surface evaporation loss: When the precipitation is greater than the evaporation of the water surface, the evaporation water requirement of the water surface is considered to be 0; When the precipitation is less than the evaporation of the water surface, the calculation formula is: Q 蒸发 =(E-P)×A÷10; Among them, Q 蒸发 The water demand for evaporation from the water surface, unit: 10,000 m 3 ; E is the evaporation of water surface, unit: mm; P is the precipitation, unit: mm; A is the water surface area of ​​the river, unit: km 2 ; in, Evaporation from water surface E Calculated based on the city's average annual precipitation and water surface evaporation conversion coefficient; Calculation of water demand for leakage loss: The empirical formula was confirmed by comprehensive analysis of groundwater dynamics method, river infiltration simulation experimental method and empirical formula: Q 渗漏 =K 渗漏 ×A×100; Where Q 渗漏 is the leakage water demand, unit: 10,000 m 3 ; K 渗漏 is the river leakage coefficient, unit: m / year; A is the river surface area, unit: km 2 ; Where K 渗漏 Based on the monitoring of river infiltration simulation experiments, or the hydrogeological survey results of regional geotechnical engineering survey reports, as well as the relevant literature survey of the basin where the study area is located; The K 渗漏 In typical plain river network areas, it is 1.93 mm / d, or 0.7 m / a.

3. The method for calculating water replenishment of river and lake ecological blue-green space based on multidisciplinary cross-theory according to claim 2 is characterized in that: When the surface layer below the ground surface is silty clay, silt or silty fine sand, the K 渗漏 They are 0.1mm / d~5.2mm / d, 5.2mm / d~52mm / d, and 52mm / d~104mm / d respectively.

4. The method for calculating water replenishment of river and lake ecological blue-green space based on multidisciplinary cross-theory according to claim 1 is characterized in that: The calculation of the evaporation leakage water demand based on the in-situ observation test is specifically as follows: Evaporation leakage calculation: Referring to the calculation formula of evaporation and seepage water demand, under the premise of known river evaporation and seepage capacity, the calculation formula of water system evaporation and seepage loss can be simplified as follows: Q 蒸发渗漏 =K 蒸发渗漏 ×A×100; Q 蒸发渗漏 The water demand due to evaporation and leakage, unit: 10,000 m 3 ; K 蒸发渗漏 is the evaporation leakage coefficient, unit: m / year; A is the river surface area, unit: km 2 ; Evaporation leakage coefficient K 蒸发渗漏 The determination method is: Taking the evaporation and leakage law of the target water system as the goal, the data of the in-situ observation time, field condition control, observation point, index, frequency and instrument use are recorded to obtain the target water system evaporation and leakage law. The ... Calculate the evaporation leakage coefficient K for each observation 蒸发渗漏 : Where: ΔH i is the observed change value of the water level of the target water body during the i-th in-situ observation period, unit: m; T i is the duration of the i-th in-situ observation, in s; Calculate the average value of the evaporation leakage coefficient Where n is the number of valid observations; Use Bessel's formula to calculate the sample standard deviation T: Determine and remove outliers: use As a criterion, if a K 蒸发渗漏 satisfy It is considered as an outlier and should be eliminated. The number of samples after eliminating the outlier is counted, n′; Recalculate the average evaporation leakage coefficient K 蒸发渗漏 : Among them, K 蒸发渗漏 ′ is the evaporation leakage coefficient of each observation after removing abnormal values; Determine the range of evaporation leakage [K min , K max ]: From the data set after removing outliers, take the minimum value K min and the maximum value K max As the range of values ​​for evaporation leakage.

5. The method for calculating water replenishment of river and lake ecological blue-green space based on multidisciplinary cross-theory according to claim 1 is characterized in that: The calculation of the evaporation leakage water demand based on the in-situ observation test is specifically as follows: Evaporation leakage calculation: Referring to the calculation formula of evaporation and seepage water demand, under the premise of known river evaporation and seepage capacity, the calculation formula of water system evaporation and seepage loss can be simplified as follows: Q 蒸发渗漏 =K 蒸发渗漏 ×A×100; Q 蒸发渗漏 The water demand due to evaporation and leakage, unit: 10,000 m 3 ; K 蒸发渗漏 is the evaporation leakage coefficient, unit: m / year; A is the river surface area, unit: km 2 ; Evaporation leakage coefficient K 蒸发渗漏 The determination method is: Taking the evaporation and leakage law of the target water system as the goal, the data of the in-situ observation time, field condition control, observation point, index, frequency and instrument use are recorded to obtain the target water system evaporation and leakage law. The ... Calculate the evaporation leakage coefficient K for each observation 蒸发渗漏 : Where: ΔH i is the observed change value of the water level of the target water body during the i-th in-situ observation period, unit: m; T i is the duration of the i-th in-situ observation, in s; Calculate the average value of the evaporation leakage coefficient Where n is the number of valid observations; Use Bessel's formula to calculate the sample standard deviation T: Determine and remove outliers: use As a criterion, if a K 蒸发渗漏 satisfy It is considered as an outlier and should be eliminated. The number of samples after eliminating the outlier is counted, n′; Recalculate the average evaporation leakage coefficient K 蒸发渗漏 : Among them, K 蒸发渗漏 ′ is the evaporation leakage coefficient of each observation after removing abnormal values; Determine the range of evaporation leakage [K min , K max ]: From the data set after removing outliers, take the minimum value K min and the maximum value K max As the range of values ​​for evaporation leakage.

6. The method for calculating water replenishment of river and lake ecological blue-green space based on multidisciplinary cross-theory according to claim 1 is characterized in that: The calculation of the evaporation leakage water demand based on the power consumption of the water replenishment pump station is specifically as follows: A liquid level meter is installed in the water pump room to monitor the water level in the pump station. The amount of water replenishment is determined by the accumulated water volume measured by the electromagnetic flow meter installed on the outlet pipe. The water consumption of other pump stations is excluded and converted into the power consumption of the pump station, which is calculated in the form of electricity to water.

7. The method for calculating water replenishment of river and lake ecological blue-green space based on multidisciplinary cross-theory according to claim 1 is characterized in that The calculation of the irrigation water demand of the green space in the blue-green space is the irrigation demand to maintain the life needs of the grassland and forest bank vegetation ecology within the width of the river blue line. The irrigation quota method is used for calculation, and the formula is: Q 绿化 =C 绿化 ×S×100; Where Q 绿化 The water requirement for greening irrigation, unit: 10,000 m 3 ; C 绿化 It is the greening irrigation quota, unit: m 3 / (m 2 a) 0.3~0.9m 3 / (m 2 a); S is the green area on both sides of the river, unit: km 2 ; The irrigation quota for green space is set according to the Water Use Quota standard. Generally speaking, the irrigation quota for green space is 0.6 m per year. 3 / (m 2 a); The irrigation times of the green space are specifically set as: The green space is irrigated 10 times per month from June to September, 6 times per month in April, May and October, 3 times per month in February, March and November. January and December are frozen periods and no irrigation is required. Based on the above irrigation cycles, the annual irrigation times are 67 times.

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