A method for evaluating and displaying the flood conveyance capacity of plain river networks based on heat maps

Abstract

The present invention discloses a method for evaluating and displaying the flood discharge capacity of plain river networks based on heatmaps. First, configure the evaluation period for the flood discharge capacity of the river network. Comprehensively consider the geometric, hydrological, and connectivity characteristics of the river network, and use the analytic hierarchy process and normalization processing to generate comprehensive flood discharge evaluation coefficients hierarchically from individual river channels to the entire river network, and dynamically and visually display the time series of heatmaps of the flood discharge capacity of the river network. Specifically, it includes data preparation, construction of flood discharge evaluation indicators, calculation of comprehensive flood discharge evaluation coefficients for river channels, calculation of comprehensive flood discharge evaluation coefficients for the river network, division of flood discharge evaluation levels, calculation of the time series of heatmaps of the flood discharge capacity of the river network, and dynamic display of flood discharge evaluation results. The present invention provides a scientific decision-making basis for flood control management by flexibly configuring the evaluation period for the flood discharge capacity of the river network, systematically analyzing and evaluating the flood discharge capacity of individual river channels and the entire river network, and dynamically and visually displaying the time series of evaluation heatmaps.

Description

Technical Field

[0001] The present invention relates to the technology of water conservancy and hydrological data processing, and particularly relates to a method for evaluating and displaying the flood conveyance capacity of plain river networks based on a heat map. Background Art

[0002] Accurately evaluating the flood conveyance capacity of plain river networks is crucial for flood control management and regional water resource allocation, directly affecting the prevention and control of flood disasters and the effective utilization of water resources. However, existing flood conveyance capacity evaluation methods mostly target single channels and fail to fully consider the connectivity and comprehensive effects of channels within the river network, making it difficult to comprehensively reflect the overall situation of the river network's flood conveyance capacity. Moreover, the evaluation period of the river network's flood conveyance capacity cannot be configured, and the evaluation results cannot be visually presented. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to solve the deficiencies existing in the prior art and provide a method for evaluating and displaying the flood conveyance capacity of plain river networks based on a heat map. By flexibly configuring the evaluation period of the river network's flood conveyance capacity, the present invention systematically analyzes and evaluates the flood conveyance capacity of individual channels and the overall river network, and dynamically and visually displays the time series of the evaluation heat map, providing a scientific decision-making basis for flood control management.

[0004] Technical Solution: A method for evaluating and displaying the flood conveyance capacity of plain river networks based on a heat map according to the present invention includes the following steps:

[0005] Step 1: Obtain and preprocess relevant data, which specifically includes the following content;

[0006] Set the start time for evaluating the flood conveyance capacity of the plain river network RN as T1, the end time as T2, and the evaluation interval as interval, then the total number T of the evaluation time series; the plain river network RN includes n channels {river}, and respectively obtain the geometric feature data, hydrological feature data, and connectivity feature data of these n channels;

[0007] RN = {river} = {river1, river2,..., river n};

[0008] river n refers to the nth channel in the plain river network RN; the geometric feature data includes the length data set {l}, width data set {b}, depth data set {d}, slope coefficient data set {s}, roughness coefficient data set {t}, and siltation rate data set {r} of the n channels; the hydrological feature data includes the flow data set {q}, water level data set {h}, and flow velocity data set {v} of the n channels within a preset evaluation period; the connectivity feature data includes the node connectivity coefficient data set {k} of the n channels within a preset evaluation period.

[0009] Step 2: Based on the relevant data obtained in Step 1, construct flood routing evaluation indicators, specifically including the following:

[0010] First, select flood routing evaluation indicators, including geometric feature indicators, hydrological feature indicators, and connectivity feature indicators, to obtain a flood routing capacity evaluation indicator system {l, b, d, s, t, r, q, h, v, k};

[0011] Then, perform normalization processing on the selected flood routing evaluation indicators to obtain a new flood routing capacity evaluation indicator system {l', b', d', s', t', r', q', h', v', k'};

[0012] Next, divide the weights of each normalized flood routing evaluation indicator, that is, use the analytic hierarchy process to calculate the weight {w} of each evaluation indicator within the preset evaluation period, and the weight calculation meets the consistency test requirements, with the CI value ≤ 0.1;

[0013]

[0014] {w l , w b , w d , w s , w t , w r , w q , w h , w v , w k} T is the length weight, width weight, depth weight, slope coefficient weight, roughness coefficient weight, siltation rate weight, flow rate weight, water level weight, flow velocity weight, and node connectivity coefficient weight of the T-th evaluation time series;

[0015] Step 3: Calculate the comprehensive flood routing evaluation coefficient of the river channel based on the evaluation indicator weights obtained in Step 2

[0016] First, calculate the comprehensive flood routing evaluation coefficient of a single river channel: For the m-th time series, based on the normalized index values and the corresponding index weights, calculate the comprehensive flood routing evaluation coefficient {C j} j of the j-th river channel river m , with a value range of [0, 1]. The higher the value, the stronger the flood routing capacity;

[0017] {C j} m = {w l ·l′ j + w b ·b′ j + w d ·d′ j + ws ·s' j +w t ·t' j +w r ·r′ j +w q ·q' j +w h ·h′ j +w v ·v' j +w k ·k′ j} m

[0018] Then, calculate the comprehensive flood discharge evaluation coefficients for all river channels: Traverse n river channels to obtain the comprehensive flood discharge evaluation coefficients {C} of n river channels in the m-th time series m ;

[0019] {C} m ={C1, C2,..., C n} m

[0020] Traverse T time series to obtain the comprehensive flood discharge evaluation coefficients {C} of the river channels within the preset evaluation period;

[0021]

[0022] Step 4: Calculate the comprehensive flood discharge evaluation coefficient of the entire river network

[0023] First, take the river channel length as the basis for weight division, and first calculate the contribution weights {w'} of all n river channels in the m-th time series to the flood discharge capacity of the entire river network m ;

[0024] {w'} m ={w′1, w'2,..., w' n} m

[0025]

[0026] Then traverse T time series to obtain the contribution weights {w’} of the flood discharge capacity of the river channels within the preset evaluation period;

[0027]

[0028] Next, calculate the comprehensive flood discharge evaluation coefficient of the entire river network. The specific method is: Based on the comprehensive flood discharge evaluation coefficient {C} of the river channels in the m-th time series m and the corresponding contribution weights {w’} of the flood discharge capacity m , calculate the comprehensive flood discharge evaluation coefficient {C of the river network through the weighted summation methodRN} m , with a value range of [0, 1]. The higher the value, the stronger the flood discharge capacity; {C RN} m = {w′1·C1 + w'2·C2 +..., + w' n ·C n} m ;

[0029] Traverse T time series to obtain the comprehensive river network flood discharge evaluation coefficient {C RN} within the preset evaluation period;

[0030]

[0031] Step 5: Based on the comprehensive river network flood discharge evaluation coefficient obtained in Step 4, divide the flood discharge evaluation levels;

[0032] Step 6: Calculate the time series of the flood discharge capacity heat map for the entire river network. The specific method is as follows:

[0033] Step (6.1): For the m-th time series, first calculate the flood discharge capacity heat map {HeatMap j} of a single river channel river j ; m ;

[0034] Step (6.2): Traverse n river channels to obtain the flood discharge capacity heat maps {HeatMap RN} of all n river channels in the m-th time series m ;

[0035] Step (6.3): Traverse T time series to calculate the time series of the flood discharge capacity heat map {HeatMap RN} of the entire river network;

[0036] Step 7: For the plain river network RN, dynamically display its flood discharge evaluation results {Result} in T time series. Among them, for the m-th time series, its flood discharge capacity evaluation result {Result} m includes the river network flood discharge capacity label {Label RN} m and the river network flood discharge capacity heat map {HeatMap RN}, and the river network flood discharge capacity label {Label m} RN} m displays the comprehensive river network flood discharge evaluation coefficient {C RN} m and the flood discharge capacity level of the plain river network RN through the label.

[0037] Further, in step 1, the detailed method for obtaining and preprocessing relevant data is as follows:

[0038] Step 1.1: Configure the evaluation period, including the start time T1, end time T2, and evaluation interval interval for the flood conveyance capacity evaluation of the plain river network; T = (T2 - T1) / interval;

[0039] T is the total number of evaluation time series.

[0040] Step 1.2: Obtain the basic data of the plain river network RN. The plain river network RN includes n rivers {river}, and the basic data includes the geometric feature data, hydrological feature data, and connectivity feature data of the n rivers;

[0041] The geometric feature data is obtained through on-site surveys and historical archive materials, including the lengths {l}, widths {b}, depths {d}, slope coefficients {s}, roughness coefficients {t}, and siltation rates {r} of the n rivers;

[0042] {l} = {l1, l2,..., l n}; {b} = {b1, b2,..., b n}; {d} = {d1, d2,..., d n}; {s} = {s1, s2,..., s n};

[0043] {t} = {t1, t2,..., t n}; {r} = {r1, r2,..., r n};

[0044] l n is the length of the nth river; b n is the width of the nth river; d n is the depth of the nth river; s n is the slope coefficient of the nth river; t n is the roughness coefficient of the nth river; r n is the siltation rate of the nth river;

[0045] The hydrological feature data is obtained through the deployed sensing monitoring devices (flow monitoring, water level monitoring, velocity monitoring), including the flow rates {q}, water levels {h}, and velocities {v} of the n rivers within the preset evaluation period;

[0046]

[0047]

[0048] {q1, q2, …, q n}} T is the flow data of n river channels in the T - th evaluation time series; {h1, h2, …, h n}} T is the water - level data of n river channels in the T - th evaluation time series; {v1, v2, …, v n}} T is the flow - velocity data of n river channels in the T - th evaluation time series;

[0049] The described connectivity characteristic data is obtained through the arranged perception monitoring devices (flow monitoring, water - level monitoring, flow - velocity monitoring) and historical archival materials, and includes the node connectivity coefficients {k} of n river channels within a preset evaluation period;

[0050]

[0051] {k1, k2, …, k n}} T is the node connectivity coefficient of n river channels in the T - th evaluation time series; k n is the node connectivity coefficient of the n - th river channel; f n is the connectivity weight of the upstream and downstream nodes of the n - th river channel; A n is the state parameter indicating whether the n - th river channel is connected. If it is connected, it is 1; otherwise, it is 0; η n is the resistance coefficient of the upstream and downstream nodes of the n - th river channel; q n is the flow of the n - th river channel; l n is the length of the n - th river channel; g n is the comprehensive regulation coefficient of the sluice and pumping station of the n - th river channel; t n is the roughness coefficient of the n - th river channel; s n is the slope coefficient of the n - th river channel.

[0052] Furthermore, the specific method for normalizing the flood - routing evaluation indexes {l, b, d, s, t, r, q, h, v, k} in step 2 is as follows:

[0053] To eliminate the unit and dimension differences between different evaluation indexes, the normalization process is carried out for each evaluation index of a single river channel, and all evaluation indexes are kept within the interval [0, 1];

[0054]

[0055] x i ’ is the normalized index value of the i - th index; x i is the original index value of the i - th index; x min and x max are the minimum and maximum values of the i - th index;

[0056] After normalization, the normalized evaluation indexes of n river channels within a preset evaluation period are obtained;

[0057] ① The formula for the normalized geometric feature index is as follows:

[0058] {l'} = {l′1, l'2,..., l′ n}

[0059] {b'} = {b′1, b′2,..., b′ n}

[0060] {d'} = {d′1, d′2,..., d' n}

[0061] {s '} = {s′1, s'2,..., s' n}

[0062] {t'} = {t′1, t'2,..., t' n}

[0063] {r '} = {r′1, r′2,..., r′ n}

[0064] l n ’ is the normalized length of the nth river channel; b n ’ is the normalized width of the nth river channel; d n ’ is the normalized depth of the nth river channel; s n ’ is the normalized slope coefficient of the nth river channel; t n ’ is the normalized roughness of the nth river channel; r n ’ is the normalized sedimentation rate of the nth river channel;

[0065] ② The formula for the normalized hydrological feature index is as follows:

[0066]

[0067]

[0068] {q′1, q'2,..., q' n} T is the normalized flow rate data of n river channels in the Tth evaluation time series; {h′1, h'2,..., h' n} T is the normalized water level data of n river channels in the Tth evaluation time series; {v′1, v'2,..., v' n} T is the normalized flow velocity data of n river channels in the Tth evaluation time series;

[0069] ③The formula for the normalized connectivity characteristic index is as follows:

[0070]

[0071] {k′1,k′2,...,k' n} T is the normalized node connectivity coefficient of n river channels in the T-th evaluation time series.

[0072] Furthermore, the specific content of step 5 for dividing the flood routing evaluation level is as follows:

[0073] Step 5.1: Divide the flood routing evaluation level of the river channel

[0074] According to the numerical value of the comprehensive flood routing evaluation coefficient {C} of the river channel, the flood routing capacity of the river channel is divided into three levels: level one, level two, and level three;

[0075] If 0.7 < {C} ≤ 1, the flood routing capacity level of the river channel is level one, indicating that the flood routing capacity of the river channel is good and the flood risk is low;

[0076] If 0.4 < {C} ≤ 0.7, the flood routing capacity level of the river channel is level two, indicating that the flood routing capacity of the river channel is average and there is a certain flood risk;

[0077] If 0 < {C} ≤ 0.4, the flood routing capacity level of the river channel is level three, indicating that the flood routing capacity of the river channel is poor and the flood risk is high;

[0078] Step 5.2: Divide the flood routing evaluation level of the entire river network

[0079] According to the numerical value of the comprehensive flood routing evaluation coefficient {C RN}, the flood routing capacity of the river network is divided into three levels: level one, level two, and level three;

[0080] If 0.7 < {C RN} ≤ 1, the flood routing capacity level of the river network is level one, indicating that the flood routing capacity of the river network is good and the flood risk is low;

[0081] If 0.4 < {C RN} ≤ 0.7, the flood routing capacity level of the river network is level two, indicating that the flood routing capacity of the river network is average and there is a certain flood risk;

[0082] If 0 < {C RN} ≤ 0.4, the flood routing capacity level of the river network is level three, indicating that the flood routing capacity of the river network is poor and the flood risk is high.

[0083] Furthermore, the specific method for step 6 to calculate the time series of the flood routing capacity heat map of the river network is as follows:

[0084] Step 6.1: Calculate the flood carrying capacity heat map of a single river channel;

[0085] For the m-th time series, based on the comprehensive flood carrying capacity evaluation coefficient {C j} j} m and the vector layer of the j-th river channel river j divide the flood carrying capacity level of river j If the flood carrying capacity level is level one, use the green color to display the vector layer of river j If the flood carrying capacity level is level two, use the blue color to display the vector layer of river j If the flood carrying capacity level is level three, use the red color to display the vector layer of river j to generate the flood carrying capacity heat map {HeatMap j} m ;

[0086] Step 6.2: Calculate the flood carrying capacity heat map of the entire river network;

[0087] Traverse n river channels to obtain the flood carrying capacity heat maps {HeatMap RN} m of the n river channels in the m-th time series;

[0088] {HeatMap RN} m = {HeatMap1, HeatMap2,..., HeatMap n} m

[0089] Step 6.3: Calculate the time series of the flood carrying capacity heat map of the entire river network;

[0090] Traverse T time series to obtain the time series {HeatMap RN} of the flood carrying capacity heat map of the river network within the preset evaluation period;

[0091]

[0092] Furthermore, the specific process of step 7 for dynamically displaying the flood evaluation result is as follows:

[0093] For the m-th time series, the flood carrying capacity evaluation result of the plain river network RN is set as {Result} m , {Result} m includes the river network flood carrying capacity label {Label RN} m and the river network flood carrying capacity heat map {HeatMapRN} m , through the flood discharge capacity label of the river network {Label RN} m Displays the comprehensive flood discharge evaluation coefficient {C of the plain river network RN RN} m and the flood discharge capacity level;

[0094] {Result} m = {Label RN , HeatMap RN} m ;

[0095] Traverse T time series and dynamically display the flood discharge capacity evaluation result {Result} of the river network RN within the preset evaluation period;

[0096]

[0097] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0098] (1). The present invention supports flexible configuration of the flood discharge capacity evaluation period of the river network and sets the start time and end time of the evaluation.

[0099] (2). The hydrological characteristic data of the river network of the present invention obtains the monitoring data within the preset evaluation period through the deployed sensing monitoring devices (flow monitoring, water level monitoring, flow velocity monitoring).

[0100] (3). The present invention evaluates the flood discharge capacity step by step and hierarchically from a single river channel to the entire river network, with comprehensive data and more accurate evaluation results.

[0101] (4). The present invention comprehensively considers the geometric characteristics, hydrological characteristics and connectivity characteristics of the river network, and uses the analytic hierarchy process and normalization processing, so that the flood discharge capacity evaluation result is more comprehensive and reasonable.

[0102] (5). The present invention dynamically displays the flood discharge evaluation results by calculating the time series of the flood discharge capacity heat map of the river network. Description of the Drawings

[0103] Figure 1 Is the flow chart of the method for evaluating and displaying the flood discharge capacity of the plain river network based on the heat map provided by the present invention;

[0104] Figure 2 Is the schematic diagram of the flood discharge evaluation result of the embodiment. Detailed Description of the Invention

[0105] The technical solution of the present invention will be described in detail below, but the protection scope of the present invention is not limited to the described embodiments.

[0106] Such asFigure 1 As shown in Figure 1 , the method for evaluating and displaying the flood discharge capacity of plain river networks based on heat maps according to the present invention includes the following steps:

[0107] Step 1: Obtain and preprocess relevant data, specifically including the following:

[0108] Set the start time of evaluating the flood discharge capacity of the plain river network RN as T1, the end time as T2, and the evaluation interval as interval, then the total number T of the evaluation time series; the plain river network RN includes n rivers {river}, and geometric feature data, hydrological feature data, and connectivity feature data of these n rivers are obtained respectively;

[0109] RN = {river} = {river1, river2,..., river n};

[0110] river n refers to the nth river in the plain river network RN; the geometric feature data includes the length data set {l}, width data set {b}, depth data set {d}, slope coefficient data set {s}, roughness coefficient data set {t}, and siltation rate data set {r} of the n rivers; the hydrological feature data includes the flow data set {q}, water level data set {h}, and flow velocity data set {v} of the n rivers within the preset evaluation period; the connectivity feature data includes the node connectivity coefficient data set {k} of the n rivers within the preset evaluation period;

[0111] Step 2: Construct flood discharge evaluation indicators based on the relevant data obtained in Step 1, specifically including the following:

[0112] First, select flood discharge evaluation indicators, including geometric feature indicators, hydrological feature indicators, and connectivity feature indicators, to obtain a flood discharge capacity evaluation indicator system {l, b, d, s, t, r, q, h, v, k};

[0113] Then, perform normalization processing on the selected flood discharge evaluation indicators to obtain a new flood discharge capacity evaluation indicator system {l', b', d', s', t', r', q', h', v', k'};

[0114] Next, divide the weights of each normalized flood discharge evaluation indicator, that is, use the analytic hierarchy process to calculate the weight {w} of each evaluation indicator within the preset evaluation period, and the weight calculation meets the consistency test requirement, CI value ≤ 0.1;

[0115]

[0116] {w l , w b , w d , w s , wt , w r , w q , w h , w v , w k} T are the length weight, width weight, depth weight, slope coefficient weight, roughness coefficient weight, siltation rate weight, discharge weight, water level weight, flow velocity weight, and node connectivity coefficient weight of the T-th evaluation time series;

[0117] Step 3: Calculate the comprehensive flood conveyance evaluation coefficient of the river channel based on the evaluation index weights obtained in Step 2

[0118] First, calculate the comprehensive flood conveyance evaluation coefficient of a single river channel: For the m-th time series, based on the normalized index values and the corresponding index weights, calculate the comprehensive flood conveyance evaluation coefficient {C j} j} m of the j-th river channel river, and the value range is [0, 1];

[0119] {C j} m = {w l · l′ j + w b · b′ j + w d · d′ j + w s · s' j + w t · t' j + w r · r′ j + w q · q' j + w h · h′ j + w v · v' j + w k · k′ j} m

[0120] Then, calculate the comprehensive flood conveyance evaluation coefficients of all river channels: Traverse n river channels to obtain the comprehensive flood conveyance evaluation coefficients {C} of the n river channels in the m-th time series m ;

[0121] {C} m = {C1, C2,..., C n} m

[0122] Traverse T time series to obtain the comprehensive flood conveyance evaluation coefficients {C} within the preset evaluation period;

[0123]

[0124] Step 4: Calculate the comprehensive flood conveyance evaluation coefficient of the entire river network

[0125] First, using the river channel length as the basis for weight division, calculate the contribution weights {w'} of all n river channels in the m-th time series to the flood conveyance capacity of the entire river network m ;

[0126] {w'} m ={w′1, w'2,..., w' n} m

[0127]

[0128] Then traverse the T time series to obtain the contribution weights {w’} of the river channel flood conveyance capacity within the preset evaluation period

[0129]

[0130] Next, calculate the comprehensive flood conveyance evaluation coefficient of the entire river network. The specific method is as follows: Based on the comprehensive flood conveyance evaluation coefficient {C} of the river channels in the m-th time series m and the corresponding contribution weights {w’} of the flood conveyance capacity m , calculate the comprehensive flood conveyance evaluation coefficient {C RN} m of the river network through the weighted summation method, with a value range of [0, 1]; {C RN} m ={w′1·C1 + w'2·C2 +..., + w' n ·C n} m ;

[0131] Traverse the T time series to obtain the comprehensive flood conveyance evaluation coefficient {C RN} of the river network within the preset evaluation period

[0132]

[0133] Step 5: Divide the flood evaluation level based on the comprehensive flood conveyance evaluation coefficient of the river network obtained in Step 4

[0134] Step 6: Calculate the time series of the flood conveyance capacity heat map of the entire river network. The specific method is as follows

[0135] Step (6.1): For the m-th time series, first calculate the flood conveyance capacity heat map {HeatMap j} j of a single river channel riverm ;

[0136] Step (6.2), traverse n river channels to obtain the flood carrying capacity heat map of all n river channels for the m-th time series {HeatMap RN} m ;

[0137] Step (6.3), traverse T time series and calculate the time series of the flood carrying capacity heat map of the entire river network {HeatMap RN};

[0138] Step 7, for the plain river network RN, dynamically display its flood evaluation results {Result} for T time series, where for the m-th time series, its flood carrying capacity evaluation results {Result} m include the flood carrying capacity label of the river network {Label RN} m and the flood carrying capacity heat map of the river network {HeatMap RN}; m The flood carrying capacity label of the river network {Label RN} m displays the comprehensive flood evaluation coefficient {C RN} m and the flood carrying capacity level of the plain river network RN through the label.

[0139] The detailed method for step 1 of this embodiment to obtain and preprocess relevant data is as follows:

[0140] Step 1.1, configure the evaluation period, including the start time T1, end time T2, and evaluation interval interval of the flood carrying capacity evaluation of the plain river network; T = (T2 - T1) / interval;

[0141] T is the total number of evaluation time series.

[0142] Step 1.2, obtain the basic data of the plain river network RN, where the plain river network RN includes n river channels {river}, and the basic data includes the geometric feature data, hydrological feature data, and connectivity feature data of the n river channels;

[0143] The geometric feature data is obtained through on-site surveys and historical archive materials, and includes the lengths {l}, widths {b}, depths {d}, slope coefficients {s}, roughness coefficients {t}, and siltation rates {r} of the n river channels;

[0144] {l} = {l1, l2,..., l n}; {b} = {b1, b2,..., b n}; {d} = {d1, d2,..., d n}; {s} = {s1, s2,..., s n};

[0145] {t} = {t1, t2,..., t n}; {r} = {r1, r2,..., r n};

[0146] l n is the length of the nth river channel; b n is the width of the nth river channel; d n is the depth of the nth river channel; s n is the slope coefficient of the nth river channel; t n is the roughness coefficient of the nth river channel; r n is the sedimentation rate of the nth river channel;

[0147] The hydrological characteristic data is obtained through the deployed sensing and monitoring devices, including the flow rate {q}, water level {h}, and flow velocity {v} of n river channels within a preset evaluation period;

[0148]

[0149] {q1, q2,…, q n} T is the flow rate data of n river channels in the Tth evaluation time series; {h1, h2,…, h n} T is the water level data of n river channels in the Tth evaluation time series; {v1, v2,…, v n} T is the flow velocity data of n river channels in the Tth evaluation time series;

[0150] The connectivity characteristic data is obtained through the deployed sensing and monitoring devices and historical archive materials, including the node connectivity coefficient {k} of n river channels within a preset evaluation period;

[0151]

[0152] {k1, k2,…, k n} T is the node connectivity coefficient of n river channels in the Tth evaluation time series; k n is the node connectivity coefficient of the nth river channel; f n is the connectivity weight of the upstream and downstream nodes of the nth river channel; A n is the state parameter indicating whether the nth river channel is connected. If it is connected, it is 1; otherwise, it is 0; η n is the resistance coefficient of the upstream and downstream nodes of the nth river channel; q n is the flow rate of the nth river channel; l n is the length of the nth river channel; gn is the comprehensive regulation coefficient of the sluice station for the nth river channel; t n is the roughness coefficient of the nth river channel; s n is the slope coefficient of the nth river channel.

[0153] The specific method for normalizing the flood routing evaluation indexes {l, b, d, s, t, r, q, h, v, k} in step 2 of this embodiment is as follows:

[0154] To eliminate the differences in units and dimensions between different evaluation indexes, the evaluation indexes of a single river channel are normalized, and all evaluation indexes are kept within the interval [0, 1];

[0155]

[0156] x i ’ is the normalized index value of the ith index; x i is the original index value of the ith index; x min and x max are the minimum and maximum values of the ith index;

[0157] After normalization, the normalized evaluation indexes of n river channels within the preset evaluation period are obtained;

[0158] ① The formula for normalizing geometric feature indexes is as follows:

[0159] {l'} = {l′1, l'2,..., l′ n}

[0160] {b'} = {b′1, b′2,..., b′ n}

[0161] {d'} = {d′1, d′2,..., d' n}

[0162] {s '} = {s′1, s'2,..., s' n}

[0163] {t'} = {t′1, t'2,..., t' n}

[0164] {r'} = {r′1, r′2,..., r′ n}

[0165] l n ’ is the normalized length of the nth river channel; b n ’ is the normalized width of the nth river channel; d n ’ is the normalized depth of the nth river channel; s n’ is the normalized slope coefficient of the nth river channel; t n ’ is the normalized roughness of the nth river channel; r n ’ is the normalized sedimentation rate of the nth river channel;

[0166] ② The formula for the normalized hydrological characteristic indexes is as follows:

[0167]

[0168]

[0169] {q′1, q'2,..., q' n} T is the normalized flow rate data of n river channels in the Tth evaluation time series; {h′1, h'2,..., h' n} T is the normalized water level data of n river channels in the Tth evaluation time series; {v′1, v'2,..., v' n} T is the normalized flow velocity data of n river channels in the Tth evaluation time series;

[0170] ③ The formula for the normalized connectivity characteristic indexes is as follows:

[0171]

[0172] {k′1, k′2,..., k' n} T is the normalized node connectivity coefficient of n river channels in the Tth evaluation time series.

[0173] The specific content of step 5 for dividing the flood routing evaluation level in this embodiment is as follows:

[0174] Step 5.1. Divide the flood routing evaluation level of the river channels

[0175] According to the numerical value of the comprehensive flood routing evaluation coefficient {C} of the river channels, the flood routing ability of the river channels is divided into three levels: level one, level two, and level three;

[0176] If 0.7 < {C} ≤ 1, the flood routing ability level of the river channel is level one, indicating that the flood routing ability of the river channel is good and the flood risk is low;

[0177] If 0.4 < {C} ≤ 0.7, the flood routing ability level of the river channel is level two, indicating that the flood routing ability of the river channel is average and there is a certain flood risk;

[0178] If 0 < {C} ≤ 0.4, the flood routing ability level of the river channel is level three, indicating that the flood routing ability of the river channel is poor and the flood risk is high;

[0179] Step 5.2: Classify the flood discharge evaluation levels for the entire river network

[0180] According to the value of the comprehensive flood discharge evaluation coefficient {C RN} of the river network, the flood discharge capacity of the river network is divided into three levels: level one, level two, and level three;

[0181] If 0.7 < {C RN} ≤ 1, the flood discharge capacity level of the river network is level one, indicating that the flood discharge capacity of the river network is good and the flood risk is low;

[0182] If 0.4 < {C RN} ≤ 0.7, the flood discharge capacity level of the river network is level two, indicating that the flood discharge capacity of the river network is average and there is a certain flood risk;

[0183] If 0 < {C RN} ≤ 0.4, the flood discharge capacity level of the river network is level three, indicating that the flood discharge capacity of the river network is poor and the flood risk is high.

[0184] The specific method for calculating the time series of the flood discharge capacity heat map of the river network in step 6 of this embodiment is as follows:

[0185] Step 6.1: Calculate the flood discharge capacity heat map of a single river channel;

[0186] For the m-th time series, based on the comprehensive flood discharge evaluation coefficient {C j} j and the vector layer of the j-th river channel river m , classify the flood discharge capacity level of river j . If the flood discharge capacity level is level one, use a green color to display the vector layer of river j . If the flood discharge capacity level is level two, use a blue color to display the vector layer of river j . If the flood discharge capacity level is level three, use a red color to display the vector layer of river j , and generate the flood discharge capacity heat map {HeatMap j} j} m ;

[0187] Step 6.2: Calculate the flood discharge capacity heat map of the entire river network;

[0188] Traverse n river channels to obtain the flood discharge capacity heat maps {HeatMap RN} m of the n river channels for the m-th time series;

[0189] {HeatMap RN} m={HeatMap1, HeatMap2,..., HeatMap n} m

[0190] Step 6.3: Calculate the time series of the flood carrying capacity heat map for the entire river network;

[0191] Traverse the T time series to obtain the time series of the flood carrying capacity heat map of the river network {HeatMap RN} within the preset evaluation period;

[0192]

[0193] The specific process of dynamically displaying the flood evaluation results in Step 7 of this embodiment is as follows:

[0194] For the m-th time series, the flood carrying capacity evaluation result of the plain river network RN is set as {Result} m , {Result} m includes the flood carrying capacity label of the river network {Label RN} m and the flood carrying capacity heat map of the river network {HeatMap RN} m , and display the comprehensive flood evaluation coefficient {C RN} m and the flood carrying capacity level of the plain river network RN through the flood carrying capacity label of the river network {Label RN} m ;

[0195] {Result} m ={Label RN , HeatMap RN} m ;

[0196] Traverse the T time series to dynamically display the flood carrying capacity evaluation result {Result} of the river network RN within the preset evaluation period;

[0197]

[0198] To verify the technical effect of the present invention, this embodiment further conducts a specific application on a typical plain river network with 50 river channels in a certain area in the south. The total length of the river channels in this plain river network is 58.44 km.

[0199] This embodiment specifically includes the following steps:

[0200] Step S1: Data preparation

[0201] (1) Evaluation period configuration

[0202] Configure the start time T1, end time T2, and evaluation interval interval for the flood discharge capacity evaluation of the plain river network.

[0203] T1 = 2023-11-02 10:00:00

[0204] T2 = 2023-11-02 18:00:00

[0205] interval = 10min

[0206] T = 48

[0207] (2) Acquisition of basic data

[0208] Based on the preset flood discharge capacity evaluation period of the plain river network, obtain the basic data of the plain river network RN through the deployed sensing and monitoring devices, on-site surveys, and historical archival materials to ensure its timeliness and reliability. The plain river network RN includes 50 river channels {river}, and the basic data includes the geometric feature data, hydrological feature data, and connectivity feature data of the 50 river channels.

[0209] RN = {river} = {river1, river2,..., river 50}

[0210] ① Geometric feature data

[0211] The geometric feature data is obtained through on-site surveys and historical archival materials, including the length {l}, width {b}, depth {d}, slope coefficient {s}, roughness coefficient {t}, and sedimentation rate {r} of the 50 river channels.

[0212] {l} = {l1, l2,..., l 50} = {1.80, 1.40,..., 0.78}

[0213] {b} = {b1, b2,..., b 50} = {27.64, 14.07,..., 19.71}

[0214] {d} = {d1, d2,..., d 50} = {7.80, 3.06,..., 3.51}

[0215] {s} = {s1, s2,..., s 50} = {0.08, 0.03,..., 0.08}

[0216] {t} = {t1, t2,..., t 50} = {0.07, 0.02,..., 0.09}

[0217] {r} = {r1, r2,..., r 50} = {0.21, 0.17,..., 0.03}

[0218] ② Hydrological characteristic data

[0219] The hydrological characteristic data is obtained through the deployed sensing and monitoring devices (flow monitoring, water level monitoring, velocity monitoring), including the flow {q}, water level {h}, and velocity {v} of 50 river channels within the preset evaluation period.

[0220]

[0221] Taking the first evaluation time series as an example (m = 1):

[0222] {q}1 = {168.25, 399.64,..., 316.67}1

[0223] {h}1 = {6.27, 9.46,..., 7.79}1

[0224] {v}1 = {0.15, 4.54,..., 0.51}1

[0225] ③ Connectivity characteristic data

[0226] The connectivity characteristic data is obtained through the deployed sensing and monitoring devices (flow monitoring, water level monitoring, velocity monitoring) and historical archive materials, including the node connectivity coefficient {k} of 50 river channels within the preset evaluation period.

[0227]

[0228] Taking the first evaluation time series as an example (m = 1):

[0229] {k}1 = {0.52, 0.15,..., 0.99}1

[0230] Step S2: Construction of flood routing evaluation index

[0231] (1) Selection of flood routing evaluation index

[0232] Comprehensively considering the basic data of the plain river network and the main influencing factors of flood routing capacity, a flood routing capacity evaluation index system {l, b, d, s, t, r, q, h, v, k} is constructed, including geometric characteristic indexes, hydrological characteristic indexes, and connectivity characteristic indexes.

[0233] ① Geometric characteristic indexes: river channel length l, width b, depth d, slope coefficient s, roughness coefficient t, and siltation rate r.

[0234] ② Hydrological characteristic indexes: river channel flow q, water level h, and velocity v.

[0235] ③ Connectivity characteristic index: channel node connectivity coefficient k.

[0236] (2) Normalization of flood discharge evaluation indexes

[0237] To eliminate the differences in units and dimensions between different evaluation indexes, the evaluation indexes of a single channel are normalized, and all evaluation indexes are kept within the range of [0, 1].

[0238]

[0239] x i ’ is the normalized index value of the i-th index; x i is the original index value of the i-th index; x min and x max are the minimum and maximum values of the i-th index.

[0240] After normalization, the normalized evaluation indexes of 50 channels within the preset evaluation period are obtained.

[0241] ① Normalized geometric characteristic indexes

[0242] {l'} = {l′1, l′2,..., l′ 50} = {0.89, 0.61,..., 0.17}

[0243] {b'} = {b′1, b'2,..., b′ 50} = {0.19, 0.04,..., 0.10}

[0244] {d'} = {d′1, d'2,..., d′ 50} = {0.78, 0.23,..., 0.28}

[0245] {s'} = {s′1, s'2,..., s' 50} = {0.77, 0.23,..., 0.79}

[0246] {t'} = {t′1, t'2,..., t' 50} = {0.68, 0,..., 0.88}

[0247] {r'} = {r′1, r′2,..., r′ 50} = {0.69, 0.56,..., 0.06}

[0248] ② Normalized hydrological characteristic indexes

[0249]

[0250] Taking the first evaluation time series as an example (m = 1):

[0251] {q'}1 = {0.32, 0.81,..., 0.64}1

[0252] {h'}1 = {0.58, 0.95,..., 0.76}1

[0253] {v'}1 = {0, 0.92,..., 0.07}1

[0254] ③ Normalized connectivity characteristic index

[0255]

[0256] Taking the first evaluation time series as an example (m = 1):

[0257] {k'}1 = {0.47, 0.05,..., 0.99}1

[0258] (3) Flood routing evaluation index weight division

[0259] The analytic hierarchy process is used to calculate the weight {w} of each evaluation index within the preset evaluation period, and the weight calculation meets the requirements of consistency test (CI value ≤ 0.1).

[0260]

[0261] Taking the first evaluation time series as an example (m = 1):

[0262] {w}1 = {0.07, 0.18, 0.14, 0.11, 0.03, 0.03, 0.01, 0.17, 0.12, 0.14}1

[0263] Step S3: Calculation of river comprehensive flood routing evaluation coefficient

[0264] (1) Calculation of single-river comprehensive flood routing evaluation coefficient

[0265] For the first time series, based on the normalized index values and the corresponding index weights, the comprehensive flood routing evaluation coefficient {C1}1 of the first river river1 is calculated by the weighted summation method. The value range is [0, 1], and the higher the value, the stronger the flood routing ability.

[0266] {C1}1 = 0.50

[0267] (2) Calculation of comprehensive flood routing evaluation coefficients of all rivers

[0268] Traverse 50 rivers to obtain the comprehensive flood routing evaluation coefficients {C}1 of the 50 rivers in the first time series.

[0269] {C}1 = {C1, C2, ..., C 50}1 = {0.50, 0.41, ..., 0.47}1

[0270] Traverse 48 time series to obtain the comprehensive flood discharge evaluation coefficient {C} of the river channel within the preset evaluation period.

[0271]

[0272] Step S4: Calculation of the comprehensive flood discharge evaluation coefficient of the river network

[0273] (1) Calculation of the contribution weights of the flood discharge capabilities of all river channels

[0274] Taking the river channel length as the basis for weight division, calculate the contribution weights {w’}1 of the 50 river channels in the first time series to the flood discharge capacity of the entire river network.

[0275] {w'} = {w′1, w'2, ..., w' 50}1 = {0.03, 0.02, ..., 0.01}1

[0276] Traverse 48 time series to obtain the contribution weights {w’} of the flood discharge capabilities of the river channels within the preset evaluation period.

[0277]

[0278] (2) Calculation of the comprehensive flood discharge evaluation coefficient of the river network

[0279] Based on the comprehensive flood discharge evaluation coefficient {C}1 of the river channels in the first time series and the corresponding contribution weights {w’}1 of the flood discharge capacity, calculate the comprehensive flood discharge evaluation coefficient {C RN}1, with a value range of [0, 1]. The higher the value, the stronger the flood discharge capacity.

[0280] {C RN}1 = 0.52

[0281] Traverse 48 time series to obtain the comprehensive flood discharge evaluation coefficient {C RN} of the river network within the preset evaluation period.

[0282]

[0283] Step S5: Division of flood discharge evaluation levels

[0284] (1) Division of flood discharge evaluation levels of river channels

[0285] According to the numerical value of the comprehensive flood discharge evaluation coefficient C of the river channel, divide the flood discharge capacity of the river channel into three levels: level one, level two, and level three.

[0286] If 0.7 < C ≤ 1, the flood conveyance capacity level of the river channel is Grade I, indicating good flood conveyance capacity of the river channel and low flood risk.

[0287] If 0.4 < C ≤ 0.7, the flood conveyance capacity level of the river channel is Grade II, indicating general flood conveyance capacity of the river channel and certain flood risk.

[0288] If 0 < C ≤ 0.4, the flood conveyance capacity level of the river channel is Grade III, indicating poor flood conveyance capacity of the river channel and high flood risk.

[0289] (2) Classification of flood conveyance evaluation levels of river networks

[0290] According to the value of the comprehensive flood conveyance evaluation coefficient C RN of the river network, the flood conveyance capacity of the river network is divided into three levels: Grade I, Grade II and Grade III.

[0291] If 0.7 < C RN ≤ 1, the flood conveyance capacity level of the river network is Grade I, indicating good flood conveyance capacity of the river network and low flood risk.

[0292] If 0.4 < C RN ≤ 0.7, the flood conveyance capacity level of the river network is Grade II, indicating general flood conveyance capacity of the river network and certain flood risk.

[0293] If 0 < C RN ≤ 0.4, the flood conveyance capacity level of the river network is Grade III, indicating poor flood conveyance capacity of the river network and high flood risk.

[0294] Step S6: Calculation of the time series of the flood conveyance capacity heat map of the river network

[0295] (1) Calculation of the flood conveyance capacity heat map of the river channel

[0296] For the first time series, based on the comprehensive flood conveyance evaluation coefficient {C1}1 of the first river river1 and the vector layer, divide the flood conveyance capacity level of river1. If the flood conveyance capacity level is Grade I, use green to display the vector layer of river1. If the flood conveyance capacity level is Grade II, use blue to display the vector layer of river1. If the flood conveyance capacity level is Grade III, use red to display the vector layer of river1, and generate the flood conveyance capacity heat map {HeatMap1}1 of river1.

[0297] (2) Calculation of the flood conveyance capacity heat map of the river network

[0298] Traverse 50 river channels to obtain the flood conveyance capacity heat maps {HeatMap RN}1 of the 50 river channels in the first time series.

[0299] {HeatMap RN}1 = {HeatMap1, HeatMap2,..., HeatMap 50}1

[0300] (3) Calculation of the time series of the heat map of the flood discharge capacity of the river network

[0301] Traverse 48 time series to obtain the time series of the heat map of the flood discharge capacity of the river network {HeatMap RN} within the preset evaluation period.

[0302]

[0303] Step S7: Dynamic display of the flood discharge evaluation results

[0304] For the first time series, dynamically display the flood discharge capacity evaluation results {Result}1 of the plain river network RN, including the flood discharge capacity label {Label RN}1 and the heat map of the flood discharge capacity of the river network {HeatMap RN}1. Display the comprehensive flood discharge evaluation coefficient {C RN}1 and the flood discharge capacity level of the plain river network RN through the flood discharge capacity label {Label RN}1.

[0305] {Result}1 = {Label RN , HeatMap RN}1

[0306] Traverse 48 time series to dynamically display the flood discharge capacity evaluation results {Result} of the river network RN within the preset evaluation period.

[0307]

[0308] Taking the first evaluation time series as an example (m = 1):

[0309] The flood discharge capacity evaluation results {Result}1 of the plain river network RN are as Figure 2 shown, including the flood discharge capacity label {Label RN}1 and the heat map of the flood discharge capacity of the river network {HeatMap RN}1.

[0310] The comprehensive flood discharge evaluation coefficient C RN = 0.52, which satisfies 0.4 < C RN ≤ 0.7. The flood discharge capacity level is secondary, indicating that the flood discharge capacity of the plain river network RN is average, there is a certain flood risk, and it is necessary to strengthen the dredging and renovation of key river channels to improve the flow rate and connectivity.

Claims

1. A method for evaluating and displaying the flood conveyance capacity of plain river networks based on heat maps, characterized in that, It includes the following steps: Step 1: Obtain and preprocess relevant data, which specifically includes the following: Set the start time as T1, the end time as T2, and the evaluation interval as interval for evaluating the flood discharge capacity of the plain river network RN. Then the total number T of the evaluation time series; the plain river network RN includes n rivers {river}, and respectively obtain the geometric feature data, hydrological feature data, and connectivity feature data of these n rivers; RN = {river} = {river1, river2,..., river n}; river n It refers to the nth river channel in the plain river network RN; the geometric feature data includes the length data set {l}, width data set {b}, depth data set {d}, slope coefficient data set {s}, roughness coefficient data set {t}, and sedimentation rate data set {r} of the n river channels; the hydrological feature data includes the flow rate data set {q}, water level data set {h}, and flow velocity data set {v} of the n river channels within a preset evaluation period; the connectivity feature data includes the node connectivity coefficient data set {k} of the n river channels within a preset evaluation period; Step 2: Construct flood discharge evaluation indicators based on the relevant data obtained in Step 1, which specifically includes the following: First, select flood discharge evaluation indicators, including geometric feature indicators, hydrological feature indicators, and connectivity feature indicators, to obtain a flood discharge capacity evaluation indicator system {l, b, d, s, t, r, q, h, v, k}; Then, perform normalization processing on the selected flood discharge evaluation indicators to obtain a new flood discharge capacity evaluation indicator system {l', b', d', s', t', r', q', h', v', k'}; Next, divide the weights of each flood discharge evaluation indicator after normalization, that is, use the analytic hierarchy process to calculate the weight {w} of each evaluation indicator within the preset evaluation period, and the weight calculation meets the consistency test requirements, with the CI value ≤ 0.1; {w l ,w b ,w d ,w s ,w t ,w r ,w q ,w h ,w v ,w k} T are the length weight, width weight, depth weight, slope coefficient weight, roughness weight, sedimentation rate weight, discharge weight, water level weight, flow velocity weight, and node connectivity coefficient weight of the T-th evaluation time series; Step 3: Calculate the comprehensive flood discharge evaluation coefficient of the river channel based on the evaluation indicator weights obtained in Step 2 First, calculate the comprehensive flood discharge evaluation coefficient for a single river channel: For the m-th time series, based on the normalized index values and the corresponding index weights, calculate the comprehensive flood discharge evaluation coefficient {C j} j} m of the j-th river channel river through the weighted summation method, and the value range is [0, 1]; {C j} m = {w l · l' j + w b · b' j + w d · d' j + w s · s' j + w t · t' j + w r · r' j + w q · q' j + w h · h' j + w v · v' j + w k · k' j} m Then, calculate the comprehensive flood discharge evaluation coefficient for all river channels: Traverse n river channels to obtain the comprehensive flood discharge evaluation coefficient {C} of n river channels in the m-th time series m ; {C} m = C1, C2,..., C n} m Traverse the T time series to obtain the comprehensive flood discharge evaluation coefficient {C} of the river channel within the preset evaluation period; Step 4: Calculate the comprehensive flood discharge evaluation coefficient of the entire river network First, taking the river channel length as the weight division basis, calculate the contribution weights {w'} of all n river channels in the m-th time series to the flood discharge capacity of the entire river network m ; {w'} m = {w'1, w'2,..., w' n} m Then traverse the T time series to obtain the contribution weight {w’} of the flood discharge capacity of the river channel within the preset evaluation period; Next, calculate the comprehensive flood discharge evaluation coefficient of the entire river network. The specific method is as follows: Based on the channel comprehensive flood discharge evaluation coefficient {C} of the m-th time series m and the corresponding flood discharge capacity contribution weight {w’} m , calculate the comprehensive flood discharge evaluation coefficient {C RN} m of the river network by the weighted summation method, and the value range is [0, 1]; {C RN} m = {w'1·C1 + w'2·C2 +..., + w' n ·C n} m ; Traverse T time series to obtain the comprehensive flood discharge evaluation coefficient {C RN} of the river network within the preset evaluation period; Step 5: Divide the flood evaluation level based on the comprehensive flood discharge evaluation coefficient of the river network obtained in Step 4; Step 6: Calculate the time series of the flood discharge capacity heat map of the entire river network. The specific method is: Step (6.1): For the m-th time series, first calculate the flood carrying capacity heat map {HeatMap j} j of a single river, river m ; Step (6.2), traverse n river channels to obtain the flood carrying capacity heat map {HeatMap of all n river channels in the m-th time series RN} m ; Step (6.3), traverse the T time series, and calculate the time series of the flood carrying capacity heat map of the entire river network {HeatMap RN}; Step 7. For the plain river network RN, dynamically display the flood routing evaluation results {Result} in T time series. For the m-th time series, the flood routing capacity evaluation result {Result} m includes the river network flood routing capacity label {Label RN} m and the river network flood routing capacity heat map {HeatMap RN} m , and the river network flood routing capacity label {Label RN} m displays the comprehensive flood routing evaluation coefficient {C RN} m of the plain river network RN and the flood routing capacity level through the label.

2. The method for evaluating and displaying the flood conveyance capacity of plain river networks based on heat maps according to claim 1, wherein, In the above Step 1, the detailed method for obtaining and preprocessing relevant data in Step 1 is: Step 1.1: Configure the evaluation period, including the start time T1, the end time T2, and the evaluation interval interval for the flood discharge capacity evaluation of the plain river network; T = (T2 - T1) / interval; T is the total number of the evaluation time series; Step 1.2: Obtain the basic data of the plain river network RN. The plain river network RN includes n rivers {river}, and the basic data includes the geometric feature data, hydrological feature data, and connectivity feature data of the n rivers; The geometric feature data is obtained through on-site surveys and historical archive materials, including the length {l}, width {b}, depth {d}, slope coefficient {s}, roughness coefficient {t}, and siltation rate {r} of the n rivers; {l} = {l1, l2,..., l n}; {b} = {b1, b2,..., b n}; {d} = {d1, d2,..., d n}; {s} = {s1, s2,..., s n}; {t} = {t1, t2,..., t n}; {r} = {r1, r2,..., r n}; l n is the length of the nth river channel; b n is the width of the nth river channel; d n is the depth of the nth river channel; s n is the slope coefficient of the nth river channel; t n is the roughness coefficient of the nth river channel; r n is the sedimentation rate of the nth river channel; The hydrological feature data is obtained through the deployed sensing monitoring devices, including the flow rate {q}, water level {h}, and flow velocity {v} of the n rivers within the preset evaluation period; {q1, q2, …, q n} T are the flow rate data of n river channels in the T-th evaluation time series; {h1, h2, …, h n} T are the water level data of n river channels in the T-th evaluation time series; {v1, v2, …, v n} T are the flow velocity data of n river channels in the T-th evaluation time series; The connectivity feature data is obtained through the deployed sensing monitoring devices and historical archive materials, including the node connectivity coefficient {k} of the n rivers within the preset evaluation period; {k1, k2, …, k n} T is the node connectivity coefficient of n river channels in the T-th evaluation time series; k n is the node connectivity coefficient of the n-th river channel; f n is the connectivity weight of the upstream and downstream nodes of the n-th river channel; A n is the state parameter indicating whether the n-th river channel is connected. If it is connected, it is 1; otherwise, it is 0; η n is the resistance coefficient of the upstream and downstream nodes of the n-th river channel; q n is the flow rate of the n-th river channel; l n is the length of the n-th river channel; g n is the comprehensive regulation coefficient of the sluice and pumping station of the n-th river channel; t n is the roughness coefficient of the n-th river channel; s n is the slope coefficient of the n-th river channel.

3. The method for evaluating and displaying the flood carrying capacity of plain river networks based on heat maps according to claim 1, characterized in that, The specific method for normalizing the flood discharge evaluation indicators {l, b, d, s, t, r, q, h, v, k} in Step 2 is: To eliminate the differences in units and dimensions between different evaluation indicators, the normalization process is carried out for each evaluation indicator of a single river channel, and all evaluation indicators are kept within the range of [0, 1]; x i ’ is the normalized index value of the i-th index; x i is the original index value of the i-th index; x min and x max are the minimum and maximum values of the i-th index; After the normalization process, the normalized evaluation indicators of n river channels within the preset evaluation period are obtained; ① The formula for the normalized geometric feature index is as follows: {l'}＝{l'1,l'2,...,l' n} {b'} = {b'1, b'2,..., b' n} {d'} = {d'1, d'2,..., d' n} {s'} = {s'1, s'2,..., s' n} {t'} = {t'1, t'2,..., t' n} {r'}＝{r'1,r'2,...,r' n} l n ’ is the normalized length of the nth river channel; b n ’ is the normalized width of the nth river channel; d n ’ is the normalized depth of the nth river channel; s n ’ is the normalized slope coefficient of the nth river channel; t n ’ is the normalized roughness of the nth river channel; r n ’ is the normalized sedimentation rate of the nth river channel; ② The formula for the normalized hydrological feature index is as follows: {q'1,q'2,...,q' n} T is the normalized flow rate data of n river channels in the T-th evaluation time series; {h'1,h'2,...,h' n} T is the normalized water level data of n river channels in the T-th evaluation time series; {v'1, v'2,...,v' n} T is the normalized flow velocity data of n river channels in the T-th evaluation time series; ③ The formula for the normalized connectivity feature index is as follows: {k'1,k'2,...,k' n} T is the normalized node connectivity coefficient of n river channels in the T-th evaluation time series.

4. The method for evaluating and displaying the flood discharge capacity of plain river networks based on heat maps according to claim 1, characterized in that, The specific content of step 5 for dividing the flood routing evaluation level is as follows: Step 5.1: Divide the flood routing evaluation level of the river channel According to the numerical value of the comprehensive flood routing evaluation coefficient {C} of the river channel, the flood routing capacity of the river channel is divided into three levels: level one, level two, and level three; If 0.7 < {C} ≤ 1, the flood routing capacity level of the river channel is level one, indicating that the flood routing capacity of the river channel is good and the flood risk is low; If 0.4 < {C} ≤ 0.7, the flood routing capacity level of the river channel is level two, indicating that the flood routing capacity of the river channel is average and there is a certain flood risk; If 0 < {C} ≤ 0.4, the flood routing capacity level of the river channel is level three, indicating that the flood routing capacity of the river channel is poor and the flood risk is high; Step 5.2: Divide the flood routing evaluation level of the entire river network According to the value of the comprehensive flood discharge evaluation coefficient {C RN} of the river network, the flood discharge capacity of the river network is divided into three levels: level one, level two, and level three; If 0.7 < {C RN} ≤ 1, the flood conveyance capacity level of the river network is Class I, indicating that the flood conveyance capacity of the river network is good and the flood risk is low; If 0.4 < {C RN} ≤ 0.7, the flood conveyance capacity level of the river network is grade II, indicating that the flood conveyance capacity of the river network is average and there is a certain flood risk; If 0 < {C RN} ≤ 0.4, the flood conveyance capacity level of the river network is level three, indicating that the flood conveyance capacity of the river network is poor and the flood risk is high.

5. The method for evaluating and displaying the flood carrying capacity of plain river networks based on heat maps according to claim 1, characterized in that The specific method for step 6 to calculate the time series of the flood routing capacity heat map of the river network is as follows: Step 6.1: Calculate the flood routing capacity heat map of a single river channel; For the m-th time series, based on the comprehensive flood discharge evaluation coefficient {C j} j and the vector layer of the j-th river, divide the flood discharge capacity level of the river. If the flood discharge capacity level is level one, use the green vector layer of the river to display it. If the flood discharge capacity level is level two, use the blue vector layer of the river to display it. If the flood discharge capacity level is level three, use the red vector layer of the river to display it, and generate the flood discharge capacity heat map {HeatMap m} j of the river j ; j j j j m ​​​​​ Step 6.2: Calculate the flood routing capacity heat map of the entire river network; Traverse n river channels to obtain the heat map of the flood discharge capacity of n river channels in the m-th time series {HeatMap RN} m ; {HeatMap RN} m ={HeatMap1, HeatMap2,..., HeatMap n} m Step 6.3: Calculate the time series of the flood routing capacity heat map of the entire river network; Traverse T time series to obtain the time series of the heat map of the flood conveyance capacity of the river network {HeatMap RN} within the preset evaluation period; 6. The method for evaluating and displaying the flood conveyance capacity of plain river networks based on heat maps according to claim 1, wherein The specific process of step 7 for dynamically displaying the flood routing evaluation result is as follows: For the m-th time series, the flood discharge capacity evaluation result of the plain river network RN is set as {Result} m , {Result} m includes the river network flood discharge capacity label {Label RN} m and the river network flood discharge capacity heat map {HeatMap RN} m . Through the river network flood discharge capacity label {Label RN} m , the comprehensive flood discharge evaluation coefficient {C RN} m of the plain river network RN and the flood discharge capacity level are displayed; {Result} m ={Label RN ,HeatMap RN} m ; Traverse T time series and dynamically display the flood routing capacity evaluation result {Result} of the river network RN within the preset evaluation period;

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