Method for evaluating and displaying flood discharge capacity of plain river network based on thermodynamic diagram

Abstract

The invention discloses a thermodynamic diagram-based plain river network flood discharge capacity evaluation and display method, which comprises the following steps of: firstly, configuring a river network flood discharge capacity evaluation period, comprehensively considering geometric characteristics, hydrological characteristics and connectivity characteristics of a river network, and generating comprehensive flood discharge evaluation coefficients from a single river channel to the whole river network in a hierarchical manner by applying an analytic hierarchy process and normalization processing; and dynamically and visually displaying the time sequence of the thermodynamic diagram of the flood discharge capacity of the river network. The method specifically comprises the steps of data preparation, flood discharge evaluation index construction, river comprehensive flood discharge evaluation coefficient calculation, river network comprehensive flood discharge evaluation coefficient calculation, flood discharge evaluation grade division, river network flood discharge capacity thermodynamic diagram time sequence calculation and flood discharge evaluation result dynamic display. According to the method, the river network flood discharge capacity evaluation cycle is flexibly configured, the flood discharge capacity of a single river channel and the overall river network is systematically analyzed and evaluated, the evaluation thermodynamic diagram time sequence is dynamically and visually displayed, and a scientific decision basis is provided for flood control management.

Description

Technical Field

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

[0002] Accurately assessing the flood-carrying capacity of plain river networks is crucial for flood control management and regional water resources allocation, and directly affects the prevention and control of flood disasters and the effective use of water resources. However, existing flood-carrying capacity evaluation methods are mostly targeted at a single river channel, and fail to fully consider the connectivity and comprehensive effects of the river channels within the river network, making it difficult to fully reflect the overall status of the river network's flood-carrying capacity. In addition, the evaluation cycle of the river network's flood-carrying capacity cannot be configured, and the evaluation results cannot be visualized. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to solve the deficiencies in the prior art and to provide a method for evaluating and displaying the flood-carrying capacity of a plain river network based on a heat map. The present invention flexibly configures the evaluation cycle of the flood-carrying capacity of the river network, systematically analyzes and evaluates the flood-carrying capacity of a single river channel and the entire river network, and dynamically and visually displays the evaluation heat map time series, providing a scientific decision-making basis for flood control management.

[0004] Technical solution: A method for evaluating and displaying flood discharge capacity of a plain river network based on a heat map of the present invention comprises the following steps:

[0005] Step 1: Obtain and preprocess relevant data, including the following contents:

[0006] The start time of evaluating the flood discharge capacity of the plain river network RN is set as T1, the end time is set as T2, and the evaluation interval is set as interval, then the total number of evaluation time series is T; the plain river network RN includes n rivers {river}, and the geometric characteristic data, hydrological characteristic data and connectivity characteristic data of the n rivers are obtained respectively;

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

[0008] river n Refers to the nth river channel in the plain river network RN; the geometric feature data include the length data set {l}, width data set {b}, depth data set {d}, slope coefficient data set {s}, roughness data set {t} and sedimentation rate data set {r} of the n rivers; the hydrological feature data include 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 include the node connectivity coefficient data set {k} of the n rivers within the preset evaluation period;

[0009] Step 2: Construct flood discharge evaluation indicators based on the relevant data obtained in step 1, including the following:

[0010] Firstly, the flood discharge evaluation indicators are selected, including geometric characteristic indicators, hydrological characteristic indicators and connectivity characteristic indicators, and the flood discharge capacity evaluation index system {l, b, d, s, t, r, q, h, v, k} is obtained;

[0011] Then, the selected flood discharge evaluation indexes are normalized to obtain a new flood discharge capacity evaluation index system {l', b', d', s', t', r', q′, h', v', k'};

[0012] Next, the normalized weights of each flood discharge evaluation index are divided, that is, the weight {w} of each evaluation index within the preset evaluation period is calculated using the hierarchical analysis method. The weight calculation meets the consistency test requirements, and the CI value is ≤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 The length weight, width weight, depth weight, slope coefficient weight, roughness weight, siltation rate weight, flow weight, water level weight, flow velocity weight, and node connectivity coefficient weight of the Tth evaluation time series;

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

[0016] First, the comprehensive flood discharge evaluation coefficient of a single river is calculated: for the mth time series, based on the normalized index value and the corresponding index weight, the weighted summation method is used to calculate the jth river j The comprehensive flood discharge evaluation coefficient {C j} m , the value range is [0,1], the higher the value, the stronger the flood discharge 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, the comprehensive flood discharge evaluation coefficient of all rivers is calculated by traversing n rivers and obtaining the comprehensive flood discharge evaluation coefficient of n rivers in the mth time series {C} m ;

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

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

[0021]

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

[0023] First, the length of the river channel is used as the basis for weight division, and the contribution weight {w′} of all n river channels in the mth time series to the flood discharge capacity of the entire river network is calculated. m ;

[0024]

[0025] Then traverse T time series to obtain the river flood discharge capacity contribution weight {w'} within the preset evaluation period;

[0026]

[0027] Next, the comprehensive flood discharge evaluation coefficient of the entire river network is calculated. The specific method is: based on the river comprehensive flood discharge evaluation coefficient {C} of the mth time series m and the corresponding flood discharge capacity contribution weight {w'} m , the river network comprehensive flood discharge evaluation coefficient {C RN} m , the value range is [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 ;

[0028] Traverse T time series and obtain the river network comprehensive flood discharge evaluation coefficient {C RN};

[0029]

[0030] Step 5: Divide the flood assessment level based on the river network comprehensive flood assessment coefficient obtained in step 4;

[0031] Step 6: Calculate the time series of the heat map of the flood discharge capacity of the entire river network. The specific method is:

[0032] Step (6.1), for the mth time series, first calculate a single river j HeatMap j} m ;

[0033] Step (6.2), traverse n rivers and obtain the heat map of flood discharge capacity of all n rivers in the mth time series {HeatMap RN} m ;

[0034] Step (6.3), traverse T time series and calculate the heat map time series of the flood discharge capacity of the entire river network {HeatMap RN};

[0035] Step 7: For the plain river network RN, dynamically display its flood discharge evaluation results {Result} in T time series, where the flood discharge capacity evaluation result {Result} for the mth time series m Including river network flood capacity label {Label RN} m HeatMap RN} m , and the river network flood capacity label {Label RN} m The comprehensive flood discharge evaluation coefficient of the plain river network RN is displayed through labels {C RN} m and flood discharge capacity level.

[0036] Furthermore, in step 1, the detailed method of obtaining and preprocessing relevant data in step 1 is:

[0037] Step 1.1, configure the evaluation cycle, including the start time T1, end time T2 and evaluation interval interval of the flood discharge capacity evaluation of the plain river network; T = (T2-T1) / interval;

[0038] T is the total number of evaluation time series.

[0039] Step 1.2, obtaining basic data of a plain river network RN, wherein the plain river network RN includes n rivers {river}, and the basic data includes geometric feature data, hydrological feature data, and connectivity feature data of the n rivers;

[0040] The geometric characteristic data are obtained through field surveys and historical archive data, including the length {l}, width {b}, depth {d}, slope coefficient {s}, roughness {t} and siltation rate {r} of n river channels;

[0041] {l}={l1,l2,...,l n}; {b} = {b1, b2, ..., b n}; {d} = {d1, d2, ..., d n}; {s} = {s1,s2,...,s n};

[0042] {t}={t1,t2,...,t n}; {r} = {r1, r2, ..., r n};

[0043] 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 of the nth river channel; r n is the sedimentation rate of the nth river channel;

[0044] The hydrological characteristic data are obtained through the deployed sensing monitoring equipment (flow monitoring, water level monitoring, flow velocity monitoring), including the flow {q}, water level {h} and flow velocity {v} of n rivers within a preset evaluation period;

[0045]

[0046]

[0047] {q1,q2,…,q n} T is the flow data of n rivers in the Tth evaluation time series; {h1,h2,…,h n}T is the water level data of n rivers in the Tth evaluation time series; {v1,v2,…,v n} T is the flow velocity data of n rivers in the Tth evaluation time series;

[0048] The connectivity characteristic data is obtained through the deployed sensing monitoring equipment (flow monitoring, water level monitoring, flow velocity monitoring) and historical archive data, including the node connectivity coefficients {k} of n rivers within a preset evaluation period;

[0049]

[0050] {k1,k2,…,k n} T k is the node connectivity coefficient of n rivers in the Tth evaluation time series; n is the node connectivity coefficient of the nth river; f n A is the connectivity weight of the upstream and downstream nodes of the nth river; n is the state parameter of 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; l n is the length of the nth river; g n is the comprehensive control coefficient of the sluice station of the nth river; t n is the roughness of the nth river channel; s n is the slope coefficient of the nth river channel.

[0051] Furthermore, the specific method of normalizing the flood discharge evaluation index {l, b, d, s, t, r, q, h, v, k} in step 2 is:

[0052] In order to eliminate the differences in units and dimensions among different evaluation indicators, each evaluation indicator of a single river channel was normalized, and all evaluation indicators were kept in the interval [0,1];

[0053]

[0054] 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 is the minimum and maximum value of the i-th indicator;

[0055] After normalization, the normalized evaluation indexes of n rivers within the preset evaluation period are obtained;

[0056] ①The formula of normalized geometric characteristic index is as follows:

[0057] {l'}={l'1,l'2,...,l' n}

[0058] {b'}={b'1,b'2,...,b' n}

[0059] {d′}={d'1,d'2,...,d' n}

[0060] {s'}={s'1,s'2,...,s' n}

[0061] {t'}={t'1,t'2,...,t' n}

[0062] {r'}={r'1,r'2,...,r' n}

[0063] l n ' is the normalized length of the nth river; 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;

[0064] ②The formula for normalized hydrological characteristic index is as follows:

[0065]

[0066]

[0067] {q'1,q'2,...,q' n} T is the normalized flow data of n rivers in the Tth evaluation time series; {h'1,h'2,...,h' n} T is the normalized water level data of n rivers in the Tth evaluation time series; {v'1,v'2,...,v' n} T is the normalized velocity data of n rivers in the Tth evaluation time series;

[0068] ③The formula of normalized connectivity feature index is as follows:

[0069]

[0070] {k'1,k'2,...,k' n} T is the normalized node connectivity coefficient of the n rivers in the Tth evaluation time series.

[0071] Furthermore, the specific contents of the flood discharge evaluation level classification in step 5 are as follows:

[0072] Step 5.1: Classify the flood discharge evaluation level of the river channel

[0073] According to the value of the comprehensive flood discharge evaluation coefficient C of the river channel, the flood discharge capacity of the river channel is divided into three levels: level one, level two and level three;

[0074] If 0.7<C≤1, the flood-carrying capacity of the river is level 1, indicating that the flood-carrying capacity of the river is good and the flood risk is low;

[0075] If 0.4<C≤0.7, the river channel flood discharge capacity level is level 2, indicating that the river channel flood discharge capacity is average and there is a certain flood risk;

[0076] If 0<C≤0.4, the river channel flood discharge capacity level is level 3, indicating that the river channel flood discharge capacity is poor and the flood risk is high;

[0077] Step 5.2: Classify the flood discharge evaluation level of the entire river network

[0078] According to the comprehensive flood discharge evaluation coefficient C of the river network RN The numerical value of is used to divide the flood discharge capacity of the river network into three levels: primary, secondary and tertiary.

[0079] If 0.7<C RN ≤1, the river network flood discharge capacity level is level 1, indicating that the river network has good flood discharge capacity and low flood risk;

[0080] If 0.4<C RN ≤0.7, the river network flood discharge capacity level is level 2, indicating that the river network flood discharge capacity is average and there is a certain flood risk;

[0081] If 0<C RN ≤0.4, the river network’s flood-carrying capacity is level three, indicating that the river network’s flood-carrying capacity is poor and the flood risk is high.

[0082] Furthermore, the specific method of calculating the time series of the heat map of the river network flood discharge capacity in step 6 is:

[0083] Step 6.1, calculate the heat map of flood discharge capacity of a single river channel;

[0084] For the mth time series, based on the jth river j The comprehensive flood discharge evaluation coefficient {C j}m And vector layer, divide the river j If the flood discharge capacity level is level 1, the river will be displayed in green. j If the flood discharge capacity level is level 2, the river is displayed in blue. j If the flood discharge capacity level is level 3, the river is displayed in red. j Vector layer of the river j HeatMap j} m ;

[0085] Step 6.2, calculate the flood discharge capacity heat map of the entire river network;

[0086] Traverse n rivers and obtain the heat map of flood discharge capacity of n rivers in the mth time series {HeatMap RN} m ;

[0087] {HeatMap RN} m ={HeatMap1,HeatMap2,...,HeatMap n} m

[0088] Step 6.3, calculate the time series of the heat map of flood discharge capacity of the entire river network;

[0089] Traverse T time series to obtain the heat map time series of river network flood discharge capacity in the preset evaluation period {HeatMap RN};

[0090]

[0091] Furthermore, the specific process of step 7 dynamically displaying the flood discharge evaluation result is as follows:

[0092] For the mth time series, the flood discharge capacity evaluation result of the plain river network RN is set to {Result} m , {Result} m Including river network flood capacity label {Label RN} m HeatMap RN} m , through the river network flood capacity label {Label RN} m The comprehensive flood discharge evaluation coefficient of the plain river network RN is shown in RN} m and flood discharge capacity level;

[0093] {Result} m ={Label RN ,HeatMap RN} m ;

[0094] Traverse T time series and dynamically display the flood discharge capacity evaluation results {Result} of the river network RN within the preset evaluation period;

[0095]

[0096] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0097] (1) The present invention supports flexible configuration of the river network flood discharge capacity evaluation cycle and setting of the evaluation start time and end time.

[0098] (2) The hydrological characteristic data of the river network of the present invention is obtained through the deployed sensing monitoring equipment (flow monitoring, water level monitoring, flow velocity monitoring) to obtain monitoring data within a preset evaluation period.

[0099] (3) The present invention evaluates the flood discharge capacity step by step and in layers from a single river channel to the entire river network, with comprehensive data and more accurate evaluation results.

[0100] (4) The present invention comprehensively considers the geometric characteristics, hydrological characteristics and connectivity characteristics of the river network, and uses hierarchical analysis method and normalization processing to make the flood discharge capacity evaluation result more comprehensive and reasonable.

[0101] (5) The present invention dynamically displays the flood discharge evaluation results by calculating the time series of the heat map of the river network's flood discharge capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] Figure 1 A flow chart of the method for evaluating and displaying the flood discharge capacity of a plain river network based on a heat map provided by the present invention;

[0103] Figure 2 Schematic diagram of flood discharge evaluation results of the embodiment. DETAILED DESCRIPTION

[0104] The technical solution of the present invention is described in detail below, but the protection scope of the present invention is not limited to the embodiments.

[0105] like Figure 1 As shown, the method for evaluating and displaying the flood discharge capacity of a plain river network based on a heat map of the present invention comprises the following steps:

[0106] Step 1: Obtain and preprocess relevant data, including the following contents:

[0107] The start time of evaluating the flood discharge capacity of the plain river network RN is set as T1, the end time is set as T2, and the evaluation interval is set as interval, then the total number of evaluation time series is T; the plain river network RN includes n rivers {river}, and the geometric characteristic data, hydrological characteristic data and connectivity characteristic data of the n rivers are obtained respectively;

[0108] RN={river}={river1,river2,...,river n};

[0109] river n Refers to the nth river channel in the plain river network RN; the geometric feature data include the length data set {l}, width data set {b}, depth data set {d}, slope coefficient data set {s}, roughness data set {t} and sedimentation rate data set {r} of the n rivers; the hydrological feature data include 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 include the node connectivity coefficient data set {k} of the n rivers within the preset evaluation period;

[0110] Step 2: Construct flood discharge evaluation indicators based on the relevant data obtained in step 1, including the following:

[0111] Firstly, the flood discharge evaluation indicators are selected, including geometric characteristic indicators, hydrological characteristic indicators and connectivity characteristic indicators, and the flood discharge capacity evaluation index system {l, b, d, s, t, r, q, h, v, k} is obtained;

[0112] Then, the selected flood discharge evaluation indexes are normalized to obtain a new flood discharge capacity evaluation index system {l′, b′, d′, s′, t′, r′, q′, h′, v′, k′};

[0113] Next, the normalized weights of each flood discharge evaluation index are divided, that is, the weight {w} of each evaluation index within the preset evaluation period is calculated using the hierarchical analysis method. The weight calculation meets the consistency test requirements, and the CI value is ≤0.1;

[0114]

[0115] {w l ,w b ,w d ,w s ,w t ,w r ,w q ,w h ,w v ,w k} TThe length weight, width weight, depth weight, slope coefficient weight, roughness weight, siltation rate weight, flow weight, water level weight, flow velocity weight, and node connectivity coefficient weight of the Tth evaluation time series;

[0116] Step 3: Calculate the comprehensive flood discharge evaluation coefficient of the river channel based on the evaluation index weights obtained in step 2

[0117] First, the comprehensive flood discharge evaluation coefficient of a single river is calculated: for the mth time series, based on the normalized index value and the corresponding index weight, the weighted summation method is used to calculate the jth river j The comprehensive flood discharge evaluation coefficient {C j} m , the value range is [0,1];

[0118] {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

[0119] Then, the comprehensive flood discharge evaluation coefficient of all rivers is calculated by traversing n rivers and obtaining the comprehensive flood discharge evaluation coefficient of n rivers in the mth time series {C} m ; {C} m ={C1,C2,...,C n} m

[0120] Traverse T time series to obtain the comprehensive flood discharge evaluation coefficient {C} of the river within the preset evaluation period;

[0121]

[0122] Step 4: Calculate the comprehensive flood discharge evaluation coefficient of the entire river network

[0123] First, the length of the river is used as the basis for weight division, and the contribution weight {w'} of all n rivers in the mth time series to the flood discharge capacity of the entire river network is calculated. m ;

[0124] {w'} m ={w'1,w'2,...,w' n} m

[0125]

[0126] Then traverse T time series to obtain the river flood discharge capacity contribution weight {w'} within the preset evaluation period;

[0127]

[0128] Next, the comprehensive flood discharge evaluation coefficient of the entire river network is calculated. The specific method is: based on the river comprehensive flood discharge evaluation coefficient {C} of the mth time series m and the corresponding flood discharge capacity contribution weight {w'} m , the river network comprehensive flood discharge evaluation coefficient {C RN} m , the value range is [0,1]; {C RN} m ={w'1·C1+w'2·C2+...,+w' n ·C n} m ;

[0129] Traverse T time series and obtain the river network comprehensive flood discharge evaluation coefficient {C RN};

[0130]

[0131] Step 5: Divide the flood assessment level based on the river network comprehensive flood assessment coefficient obtained in step 4;

[0132] Step 6: Calculate the time series of the heat map of the flood discharge capacity of the entire river network. The specific method is:

[0133] Step (6.1), for the mth time series, first calculate a single river j HeatMap j} m ;

[0134] Step (6.2), traverse n rivers and obtain the heat map of flood discharge capacity of all n rivers in the mth time series {HeatMap RN} m ;

[0135] Step (6.3), traverse T time series and calculate the heat map time series of the flood discharge capacity of the entire river network {HeatMap RN};

[0136] Step 7: For the plain river network RN, dynamically display its flood discharge evaluation results {Result} in T time series, where the flood discharge capacity evaluation result {Result} for the mth time series m Including river network flood capacity label {Label RN} m HeatMap RN} m , and the river network flood capacity label {Label RN} m The comprehensive flood discharge evaluation coefficient of the plain river network RN is displayed through labels {C RN} m and flood discharge capacity level.

[0137] The detailed method of obtaining and preprocessing relevant data in step 1 of this embodiment is as follows:

[0138] Step 1.1, configure the evaluation cycle, including the start time T1, end time T2 and evaluation interval interval of the flood discharge capacity evaluation of the plain river network; T = (T2-T1) / interval;

[0139] T is the total number of evaluation time series.

[0140] Step 1.2, obtaining basic data of a plain river network RN, wherein the plain river network RN includes n rivers {river}, and the basic data includes geometric feature data, hydrological feature data, and connectivity feature data of the n rivers;

[0141] The geometric characteristic data are obtained through field surveys and historical archive data, including the length {l}, width {b}, depth {d}, slope coefficient {s}, roughness {t} and siltation rate {r} of n river channels;

[0142] {l}={l1,l2,...,l n}; {b}={b1,b2,...,b n}; {d}={d1,d2,...,d n}; {s} = {s1,s2,...,s n};

[0143] {t}={t1,t2,...,t n}; {r} = {r1, r2, ..., r n};

[0144] 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 of the nth river channel; r n is the sedimentation rate of the nth river channel;

[0145] The hydrological characteristic data are obtained through the deployed sensing monitoring equipment, including the flow {q}, water level {h} and flow velocity {v} of n rivers within a preset evaluation period;

[0146]

[0147] {q1,q2,…,q n} T is the flow data of n rivers in the Tth evaluation time series; {h1,h2,…,h n} T is the water level data of n rivers in the Tth evaluation time series; {v1,v2,…,v n} T is the flow velocity data of n rivers in the Tth evaluation time series;

[0148] The connectivity characteristic data is obtained through the deployed sensing monitoring equipment and historical archive data, including the node connectivity coefficients {k} of n rivers within a preset evaluation period;

[0149]

[0150] {k1,k2,…,k n} T k is the node connectivity coefficient of n rivers in the Tth evaluation time series; n is the node connectivity coefficient of the nth river; f n A is the connectivity weight of the upstream and downstream nodes of the nth river; n is the state parameter of 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; l n is the length of the nth river; g n is the comprehensive control coefficient of the sluice station of the nth river; t n is the roughness of the nth river channel; s n is the slope coefficient of the nth river channel.

[0151] The specific method for normalizing the flood discharge evaluation index {l, b, d, s, t, r, q, h, v, k} in step 2 of this embodiment is:

[0152] In order to eliminate the differences in units and dimensions among different evaluation indicators, each evaluation indicator of a single river channel was normalized, and all evaluation indicators were kept in the interval [0,1];

[0153]

[0154] 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 is the minimum and maximum value of the i-th indicator;

[0155] After normalization, the normalized evaluation indexes of n rivers within the preset evaluation period are obtained;

[0156] ①The formula of normalized geometric characteristic index is as follows:

[0157]

[0158] l n ' is the normalized length of the nth river; 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;

[0159] ②The formula for normalized hydrological characteristic index is as follows:

[0160]

[0161]

[0162] {q'1,q'2,...,q' n} T is the normalized flow data of n rivers in the Tth evaluation time series; {h'1,h'2,...,h' n} T is the normalized water level data of n rivers in the Tth evaluation time series; {v'1,v'2,...,v' n} T is the normalized velocity data of n rivers in the Tth evaluation time series;

[0163] ③The formula of normalized connectivity feature index is as follows:

[0164]

[0165] {k'1,k'2,...,k' n} T is the normalized node connectivity coefficient of the n rivers in the Tth evaluation time series.

[0166] The specific contents of the classification of flood discharge evaluation levels in step 5 of this embodiment are as follows:

[0167] Step 5.1: Classify the flood discharge evaluation level of the river channel

[0168] According to the value of the comprehensive flood discharge evaluation coefficient C of the river channel, the flood discharge capacity of the river channel is divided into three levels: level one, level two and level three;

[0169] If 0.7<C≤1, the flood-carrying capacity of the river is level 1, indicating that the flood-carrying capacity of the river is good and the flood risk is low;

[0170] If 0.4<C≤0.7, the river channel flood discharge capacity level is level 2, indicating that the river channel flood discharge capacity is average and there is a certain flood risk;

[0171] If 0<C≤0.4, the river channel flood discharge capacity level is level 3, indicating that the river channel flood discharge capacity is poor and the flood risk is high;

[0172] Step 5.2: Classify the flood discharge evaluation level of the entire river network

[0173] According to the comprehensive flood discharge evaluation coefficient C of the river network RN The numerical value of is used to divide the flood discharge capacity of the river network into three levels: primary, secondary and tertiary.

[0174] If 0.7<C RN ≤1, the river network flood discharge capacity level is level 1, indicating that the river network has good flood discharge capacity and low flood risk;

[0175] If 0.4<C RN ≤0.7, the river network flood discharge capacity level is level 2, indicating that the river network flood discharge capacity is average and there is a certain flood risk;

[0176] If 0<C RN ≤0.4, the river network’s flood-carrying capacity is level three, indicating that the river network’s flood-carrying capacity is poor and the flood risk is high.

[0177] The specific method of calculating the time series of the heat map of the river network flood discharge capacity in step 6 of this embodiment is:

[0178] Step 6.1, calculate the heat map of flood discharge capacity of a single river channel;

[0179] For the mth time series, based on the jth river j The comprehensive flood discharge evaluation coefficient {C j} m And vector layer, divide the river j If the flood discharge capacity level is level 1, the river will be displayed in green. j If the flood discharge capacity level is level 2, the river is displayed in blue. j If the flood discharge capacity level is level 3, the river is displayed in red. j Vector layer of the river j HeatMap j} m ;

[0180] Step 6.2, calculate the flood discharge capacity heat map of the entire river network;

[0181] Traverse n rivers and obtain the heat map of flood discharge capacity of n rivers in the mth time series {HeatMap RN} m ;

[0182] {HeatMap RN} m ={HeatMap1,HeatMap2,...,HeatMap n} m

[0183] Step 6.3, calculate the time series of the heat map of flood discharge capacity of the entire river network;

[0184] Traverse T time series to obtain the heat map time series of river network flood discharge capacity in the preset evaluation period {HeatMap RN};

[0185]

[0186] The specific process of step 7 of this embodiment to dynamically display the flood discharge evaluation result is as follows:

[0187] For the mth time series, the flood discharge capacity evaluation result of the plain river network RN is set to {Result} m , {Result} m Including river network flood capacity label {Label RN} m HeatMap RN} m , through the river network flood capacity label {Label RN}m The comprehensive flood discharge evaluation coefficient of the plain river network RN is shown in RN} m and flood discharge capacity level;

[0188] {Result} m ={Label RN ,HeatMap RN} m ;

[0189] Traverse T time series and dynamically display the flood discharge capacity evaluation results {Result} of the river network RN within the preset evaluation period;

[0190]

[0191] In order to verify the technical effect of the present invention, this embodiment is further applied to a typical plain river network containing 50 rivers in a certain area in the south, and the total length of the rivers in the plain river network is 58.44 km.

[0192] The implementation specifically includes the following steps:

[0193] Step S1: Data preparation

[0194] (1) Evaluation cycle configuration

[0195] Configure the start time T1, end time T2 and evaluation interval interval of the plain river network flood discharge capacity evaluation.

[0196] T1 = 2023-11-02 10:00:00

[0197] T2 = 2023-11-02 18:00:00

[0198] interval=10min

[0199] T=48

[0200] (2) Basic data acquisition

[0201] Based on the preset flood discharge capacity evaluation cycle of the plain river network, the basic data of the plain river network RN is obtained through the deployment of sensing monitoring equipment, field surveys and historical archives to ensure its timeliness and reliability. The plain river network RN includes 50 rivers, and the basic data includes the geometric feature data, hydrological feature data and connectivity feature data of the 50 rivers.

[0202] RN={river}={river1,river2,...,river 50}

[0203] ①Geometric feature data

[0204] The geometric characteristic data were obtained through field surveys and historical archives, including the length {l}, width {b}, depth {d}, slope coefficient {s}, roughness {t} and siltation rate {r} of 50 river channels.

[0205] {l}=l1,l2,...,l 50}={1.80,1.40,...,0.78}

[0206] {b}={b1,b2,...,b 50}={27.64,14.07,...,19.71}

[0207] {d}={d1,d2,...,d 50}={7.80,3.06,...,3.51}

[0208] {s}={s1,s2,...,s 50}={0.08,0.03,...,0.08}

[0209] {t}={t1,t2,...,t 50}={0.07,0.02,...,0.09}

[0210] {r}={r1,r2,...,r 50}={0.21,0.17,...,0.03}

[0211] ②Hydrological characteristic data

[0212] The hydrological characteristic data are obtained through the deployed sensing monitoring equipment (flow monitoring, water level monitoring, flow velocity monitoring), including the flow {q}, water level {h} and flow velocity {v} of 50 rivers within the preset evaluation period.

[0213]

[0214] Take the first evaluation time series as an example (m=1):

[0215] {q}1={168.25,399.64,...,316.67}1

[0216] {h}1={6.27,9.46,...,7.79}1

[0217] {v}1={0.15,4.54,...,0.51}1

[0218] ③Connectivity feature data

[0219] The connectivity characteristic data are obtained through the deployed sensing monitoring equipment (flow monitoring, water level monitoring, flow velocity monitoring) and historical archive data, including the node connectivity coefficients {k} of 50 rivers within the preset evaluation period.

[0220]

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

[0222] {k}1={0.52,0.15,...,0.99}1

[0223] Step S2: Construction of flood discharge evaluation index

[0224] (1) Selection of flood discharge evaluation indicators

[0225] Taking into account the basic data of plain river network and the main influencing factors of flood discharge capacity, a flood discharge capacity evaluation index system {l, b, d, s, t, r, q, h, v, k} is constructed, including geometric characteristic indicators, hydrological characteristic indicators and connectivity characteristic indicators.

[0226] ① Geometric characteristic indicators: river channel length l, width b, depth d, slope coefficient s, roughness t and siltation rate r.

[0227] ②Hydrological characteristic indicators: river flow q, water level h and flow velocity v.

[0228] ③Connectivity characteristic index: river node connectivity coefficient k.

[0229] (2) Normalization of flood discharge evaluation indicators

[0230] In order to eliminate the differences in units and dimensions among different evaluation indicators, the evaluation indicators of a single river channel were normalized, and all evaluation indicators were kept in the interval [0,1].

[0231]

[0232] 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 is the minimum and maximum value of the i-th indicator.

[0233] After normalization, the normalized evaluation indicators of 50 rivers within the preset evaluation period were obtained.

[0234] ① Normalized geometric feature index

[0235] {l'}={l'1,l'2,...,l' 50}={0.89,0.61,...,0.17}

[0236] {b'}={b'1,b'2,...,b' 50}={0.19,0.04,...,0.10}

[0237] {d'}={d'1,d'2,...,d' 50}={0.78,0.23,...,0.28}

[0238] {s'}={s'1,s'2,...,s' 50}={0.77,0.23,...,0.79}

[0239] {t'}={t'1,t'2,...,t' 50}={0.68,0,...,0.88}

[0240] {r'}={r'1,r'2,...,r' 50}={0.69,0.56,...,0.06}

[0241] ②Normalized hydrological characteristic index

[0242]

[0243] Take the first evaluation time series as an example (m=1):

[0244] {q′}1={0.32,0.81,...,0.64}1

[0245] {h′}1={0.58,0.95,...,0.76}1

[0246] {v′}1={0,0.92,...,0.07}1

[0247] ③Normalized connectivity feature index

[0248]

[0249] Take the first evaluation time series as an example (m=1):

[0250] {k′}1={0.47,0.05,...,0.99}1

[0251] (3) Weight division of flood discharge evaluation indicators

[0252] The analytic hierarchy process is used to calculate the weight {w} of each evaluation indicator within the preset evaluation period, and the weight calculation meets the consistency test requirements (CI value ≤ 0.1).

[0253]

[0254] Take the first evaluation time series as an example (m=1):

[0255] {w}1={0.07,0.18,0.14,0.11,0.03,0.03,0.01,0.17,0.12,0.14}1

[0256] Step S3: Calculation of river comprehensive flood discharge evaluation coefficient

[0257] (1) Calculation of comprehensive flood discharge evaluation coefficient for a single river channel

[0258] For the first time series, based on the normalized index value and the corresponding index weight, the comprehensive flood discharge evaluation coefficient {C1}1 of the first river river1 is calculated by the weighted summation method. The value range is [0,1]. The higher the value, the stronger the flood discharge capacity.

[0259] {C1}1=0.50

[0260] (2) Calculation of comprehensive flood discharge evaluation coefficients for all rivers

[0261] Traverse 50 rivers and obtain the comprehensive flood discharge evaluation coefficient {C}1 of the 50 rivers in the first time series.

[0262] {C}1={C1,C2,...,C 50}1={0.50,0.41,...,0.47}1

[0263] By traversing 48 time series, the comprehensive flood discharge evaluation coefficient {C} of the river within the preset evaluation period is obtained.

[0264]

[0265] Step S4: Calculation of river network comprehensive flood discharge evaluation coefficient

[0266] (1) Calculation of contribution weights of all river flood discharge capacity

[0267] Taking the length of the river channel as the basis for weight division, the contribution weight {w'}1 of the 50 rivers in the first time series to the flood discharge capacity of the entire river network is calculated.

[0268] {w′}={w′1,w′2,...,w′ 50}1={0.03,0.02,...,0.01}1

[0269] By traversing 48 time series, the contribution weight {w'} of the river flood discharge capacity within the preset evaluation period is obtained.

[0270]

[0271] (2) Calculation of river network comprehensive flood discharge evaluation coefficient

[0272] Based on the comprehensive flood discharge evaluation coefficient {C}1 of the first time series and the corresponding flood discharge capacity contribution weight {w'}1, the comprehensive flood discharge evaluation coefficient {C}1 of the river network is calculated by weighted summation method. RN}1, the value range is [0,1]. The higher the value, the stronger the flood discharge capacity.

[0273] {C RN}1=0.52

[0274] Traversing 48 time series, the river network comprehensive flood discharge evaluation coefficient {C RN}.

[0275]

[0276] Step S5: Flood discharge evaluation level classification

[0277] (1) Classification of river flood discharge evaluation levels

[0278] According to the numerical value of the comprehensive flood discharge evaluation coefficient C of the river, the flood discharge capacity of the river is divided into three levels: level one, level two and level three.

[0279] If 0.7<C≤1, the river’s flood-carrying capacity level is level one, indicating that the river’s flood-carrying capacity is good and the flood risk is low.

[0280] If 0.4<C≤0.7, the river's flood-carrying capacity level is level two, indicating that the river's flood-carrying capacity is average and there is a certain flood risk.

[0281] If 0<C≤0.4, the river flood-carrying capacity level is level three, indicating that the river flood-carrying capacity is poor and the flood risk is high.

[0282] (2) Classification of river network flood discharge evaluation levels

[0283] According to the comprehensive flood discharge evaluation coefficient C of the river network RN The numerical value of the river network is used to divide the flood-carrying capacity of the river network into three levels: level one, level two, and level three.

[0284] If 0.7<C RN ≤1, the river network’s flood-carrying capacity is level one, indicating that the river network has good flood-carrying capacity and low flood risk.

[0285] If 0.4<C RN ≤0.7, the river network’s flood-carrying capacity is level 2, indicating that the river network’s flood-carrying capacity is average and there is a certain flood risk.

[0286] If 0<CRN ≤0.4, the river network’s flood-carrying capacity is level three, indicating that the river network’s flood-carrying capacity is poor and the flood risk is high.

[0287] Step S6: Calculation of time series of heat map of river network flood discharge capacity

[0288] (1) Calculation of thermal diagram of river flood discharge capacity

[0289] For the first time series, based on the comprehensive flood discharge evaluation coefficient {C1}1 and the vector layer of the first river river1, the flood discharge capacity level of river1 is divided. If the flood discharge capacity level is level one, the vector layer of river1 is displayed in green. If the flood discharge capacity level is level two, the vector layer of river1 is displayed in blue. If the flood discharge capacity level is level three, the vector layer of river1 is displayed in red, and the flood discharge capacity heat map {HeatMap1}1 of river1 is generated.

[0290] (2) Calculation of thermal diagram of river network flood discharge capacity

[0291] Traverse 50 rivers and obtain the heat map of flood discharge capacity of 50 rivers in the first time series {HeatMap RN}1.

[0292] {HeatMap RN}1={HeatMap1,HeatMap2,...,HeatMap 50}1

[0293] (3) Calculation of time series of heat map of river network flood discharge capacity

[0294] Traversing 48 time series, we can obtain the heat map time series of river network flood discharge capacity in the preset evaluation period. RN}.

[0295]

[0296] Step S7: Dynamic display of flood discharge evaluation results

[0297] For the first time series, the evaluation results of the flood discharge capacity of the plain river network RN are dynamically displayed, including the river network flood discharge capacity label {Label RN}1HeatMap RN}1. Through the river network flood capacity label {Label RN}1Show the comprehensive flood discharge evaluation coefficient of the plain river network RN{C RN}1 and flood discharge capacity level.

[0298] {Result}1={Label RN ,HeatMap RN}1

[0299] Traverse 48 time series and dynamically display the flood discharge capacity evaluation results {Result} of the river network RN within the preset evaluation period.

[0300]

[0301] Take the first evaluation time series as an example (m=1):

[0302] Evaluation results of flood discharge capacity of plain river network RN Figure 2 As shown, including the river network flood capacity label {Label RN}1HeatMap RN}1.

[0303] Comprehensive flood discharge evaluation coefficient C RN =0.52, satisfying 0.4<C RN ≤0.7, the flood-carrying capacity level is Level 2, indicating that the flood-carrying capacity of the plain river network RN is average, with certain flood risks. It is necessary to strengthen the dredging and regulation of key river channels to improve flow and connectivity.

Claims

1. A method for evaluating and displaying flood discharge capacity of plain river network based on heat map, characterized in that: The following steps are involved: Step 1: Obtain and preprocess relevant data, including the following contents: The start time of evaluating the flood discharge capacity of the plain river network RN is set as T1, the end time is set as T2, and the evaluation interval is set as interval, then the total number of evaluation time series is T; the plain river network RN includes n rivers {river}, and the geometric characteristic data, hydrological characteristic data and connectivity characteristic data of the n rivers are obtained respectively; RN={river}={river1,river2,...,river n }; river n Refers to the nth river channel in the plain river network RN; the geometric feature data include the length data set {l}, width data set {b}, depth data set {d}, slope coefficient data set {s}, roughness data set {t} and sedimentation rate data set {r} of the n rivers; the hydrological feature data include 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 include the node connectivity coefficient data set {k} of the n rivers within the preset evaluation period; Step 2: Construct flood discharge evaluation indicators based on the relevant data obtained in step 1, including the following: Firstly, flood discharge evaluation indicators are selected, including geometric characteristic indicators, hydrological characteristic indicators and connectivity characteristic indicators, to obtain the flood discharge capacity evaluation index system {l, b, d, s, t, r, q, h, v, k}; Then, the selected flood discharge evaluation indexes are normalized to obtain a new flood discharge capacity evaluation index system {l′, b′, d′, s′, t′, r′, q′, h′, v′, k′}; Next, the normalized weights of each flood discharge evaluation index are divided, that is, the weight {w} of each evaluation index within the preset evaluation period is calculated using the hierarchical analysis method. The weight calculation meets the consistency test requirements, and the CI value is ≤0.1; {w l , w b , w d , w s , w t , w r , w q , w h , w v , w k } T The length weight, width weight, depth weight, slope coefficient weight, roughness weight, siltation rate weight, flow weight, water level weight, flow velocity weight, and node connectivity coefficient weight of the Tth evaluation time series; Step 3: Calculate the comprehensive flood discharge evaluation coefficient of the river channel based on the evaluation index weights obtained in step 2 First, the comprehensive flood discharge evaluation coefficient of a single river is calculated: for the mth time series, based on the normalized index value and the corresponding index weight, the weighted summation method is used to calculate the river j The comprehensive flood discharge evaluation coefficient {C j } m , 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, the comprehensive flood discharge evaluation coefficient of all rivers is calculated by traversing n rivers and obtaining the comprehensive flood discharge evaluation coefficient of n rivers in the mth time series {C} m ; {C} m ={C1,C2,...,C n } m Traverse T time series to obtain the comprehensive flood discharge evaluation coefficient {C} of the river within the preset evaluation period; Step 4: Calculate the comprehensive flood discharge evaluation coefficient of the entire river network First, the length of the river is used as the basis for weight division, and the contribution weight {w′} of all n rivers in the mth time series to the flood discharge capacity of the entire river network is calculated. m ; {In'} m ={w′1,w′2,...,w′ n } m Then traverse T time series to obtain the river flood discharge capacity contribution weight {w'} within the preset evaluation period; Next, the comprehensive flood discharge evaluation coefficient of the entire river network is calculated. The specific method is: based on the river comprehensive flood discharge evaluation coefficient {C} of the mth time series m and the corresponding flood discharge capacity contribution weight {w'} m , the river network comprehensive flood discharge evaluation coefficient {C RN } m , the value range is [0, 1]; {C RN } m ={w′1·C1+w′2·C2+...,+w′ n ·C n } m ; Traverse T time series and obtain the river network comprehensive flood discharge evaluation coefficient {C RN }; Step 5: Divide the flood assessment level based on the river network comprehensive flood assessment coefficient obtained in step 4; Step 6: Calculate the time series of the heat map of the flood discharge capacity of the entire river network. The specific method is: Step (6.1), for the mth time series, first calculate a single river j HeatMap j } m ; Step (6.2), traverse n rivers and obtain the heat map of flood discharge capacity of all n rivers in the mth time series {HeatMap RN } m ; Step (6.3), traverse T time series and calculate the heat map time series of the flood discharge capacity of the entire river network {HeatMap RN }; Step 7: For the plain river network RN, dynamically display its flood discharge evaluation results {Result} in T time series, where the flood discharge capacity evaluation result {Result} for the mth time series m Including river network flood capacity label {Label RN } m HeatMap RN } m , and the river network flood capacity label {Label RN } m The comprehensive flood discharge evaluation coefficient of the plain river network RN is displayed through labels {C RN } m and flood discharge capacity level.

2. The method for evaluating and displaying flood discharge capacity of a plain river network based on a heat map according to claim 1 is characterized in that: In step 1, the detailed method of obtaining and preprocessing relevant data in step 1 is: Step 1.1, configure the evaluation cycle, including the start time T1, end time T2 and evaluation interval interval of the flood discharge capacity evaluation of the plain river network; T = (T2-T1) / interval; T is the total number of evaluation time series; Step 1.2, obtaining basic data of a plain river network RN, wherein the plain river network RN includes n rivers {river}, and the basic data includes geometric feature data, hydrological feature data, and connectivity feature data of the n rivers; The geometric characteristic data are obtained through field surveys and historical archive data, including the length {l}, width {b}, depth {d}, slope coefficient {s}, roughness {t} and siltation rate {r} of n river channels; {l}={l1,l2,...,l n };{b}={b1,b2,...,b n };{d}={d1,d2,...,d n };{s}={s1,s2,...,s n }; {t}={t1t2,...,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 of the nth river channel; r n is the sedimentation rate of the nth river channel; The hydrological characteristic data are obtained through the deployed sensing monitoring equipment, including the flow {q}, water level {h} and flow velocity {v} of n rivers within a preset evaluation period; {q1, q2, ..., q n } T is the flow data of n rivers in the Tth evaluation time series; {h1, h2, ..., h n } T is the water level data of n rivers in the Tth evaluation time series; {v1, v2, ..., v n } T is the flow velocity data of n rivers in the Tth evaluation time series; The connectivity characteristic data is obtained through the deployed sensing monitoring equipment and historical archive data, including the node connectivity coefficients {k} of n rivers within a preset evaluation period; {k1,k2,…,k n } T k is the node connectivity coefficient of n rivers in the Tth evaluation time series; n is the node connectivity coefficient of the nth river; f n A is the connectivity weight of the upstream and downstream nodes of the nth river; n is the state parameter of 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; l n is the length of the nth river; g n is the comprehensive control coefficient of the sluice station of the nth river; t n is the roughness of the nth river channel; s n is the slope coefficient of the nth river channel.

3. The method for evaluating and displaying flood discharge capacity of a plain river network based on a heat map according to claim 1 is characterized in that: The specific method of normalizing the flood discharge evaluation index {l, b, d, s, t, r, q, h, v, k} in step 2 is: In order to eliminate the differences in units and dimensions among different evaluation indicators, each evaluation indicator of a single river channel was normalized, and all evaluation indicators were kept in the interval [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 is the minimum and maximum value of the i-th indicator; After normalization, the normalized evaluation indexes of n rivers within the preset evaluation period are obtained; ①The formula of normalized geometric characteristic 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; 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; ②The formula for normalized hydrological characteristic index is as follows: {q′1,q′2,...,q′ n } T is the normalized flow data of n rivers in the Tth evaluation time series; {h′1,h′2,...,h′ n } T is the normalized water level data of n rivers in the Tth evaluation time series; {v′1,v′2,...,v′ n } T is the normalized velocity data of n rivers in the Tth evaluation time series; ③The formula of normalized connectivity feature index is as follows: {k′1,k′2,...,k′ n } T is the normalized node connectivity coefficient of the n rivers in the Tth evaluation time series.

4. The method for evaluating and displaying flood discharge capacity of a plain river network based on a heat map according to claim 1 is characterized in that: The specific contents of the flood discharge evaluation level classification in step 5 are as follows: Step 5.1: Classify the flood discharge evaluation level of the river channel According to the value of the comprehensive flood discharge evaluation coefficient C of the river channel, the flood discharge capacity of the river channel is divided into three levels: level one, level two and level three; If 0.7<C≤1, the flood-carrying capacity of the river is level 1, indicating that the flood-carrying capacity of the river is good and the flood risk is low; If 0.4<C≤0.7, the river channel flood discharge capacity level is level 2, indicating that the river channel flood discharge capacity is average and there is a certain flood risk; If 0<C≤0.4, the river channel flood discharge capacity level is level 3, indicating that the river channel flood discharge capacity is poor and the flood risk is high; Step 5.2: Classify the flood discharge evaluation level of the entire river network According to the comprehensive flood discharge evaluation coefficient C of the river network RN The numerical value of is used to divide the flood discharge capacity of the river network into three levels: primary, secondary and tertiary. If 0.7<C RN ≤1, the river network flood discharge capacity level is level 1, indicating that the river network has good flood discharge capacity and low flood risk; If 0.4<C RN ≤0.7, the river network flood discharge capacity level is level 2, indicating that the river network flood discharge capacity is average and there is a certain flood risk; If 0<C RN ≤0.4, the river network’s flood-carrying capacity is level three, indicating that the river network’s flood-carrying capacity is poor and the flood risk is high.

5. The method for evaluating and displaying flood discharge capacity of a plain river network based on a heat map according to claim 1 is characterized in that: The specific method of calculating the time series of the heat map of the river network flood discharge capacity in step 6 is: Step 6.1, calculate the heat map of flood discharge capacity of a single river channel; For the mth time series, based on the jth river j The comprehensive flood discharge evaluation coefficient {C j } m And vector layer, divide the river j If the flood discharge capacity level is level 1, the river will be displayed in green. j If the flood discharge capacity level is level 2, the river is displayed in blue. j If the flood discharge capacity level is level 3, the river is displayed in red. j Vector layer of the river j HeatMap j } m ; Step 6.2, calculate the flood discharge capacity heat map of the entire river network; Traverse n rivers and obtain the heat map of flood discharge capacity of n rivers in the mth time series {HeatMap RN } m ; {HeatMap RN } m ={HeatMap1,HeatMap2,...,HeatMap n } m Step 6.3, calculate the time series of the heat map of flood discharge capacity of the entire river network; Traverse T time series to obtain the heat map time series of river network flood discharge capacity in the preset evaluation period {HeatMap RN }; 6. The method for evaluating and displaying flood discharge capacity of plain river network based on heat map according to claim 1 is characterized in that: The specific process of step 7 dynamically displaying the flood discharge evaluation result is as follows: For the mth time series, the flood discharge capacity evaluation result of the plain river network RN is set to {Result} m , {Result} m Including river network flood capacity label {Label RN } m HeatMap RN } m , through the river network flood capacity label {Label RN } m The comprehensive flood discharge evaluation coefficient of the plain river network RN is shown in RN } m and flood discharge capacity level; {Result} m ={Label RN ,HeatMap RN } m ; Traverse T time series and dynamically display the flood discharge capacity evaluation results {Result} of the river network RN within the preset evaluation period;

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