Method for analyzing overwater capacity of karst depression based on monitoring of waterlogging inundation depth

Abstract

The present application belongs to the technical field of hydraulic engineering, and particularly relates to a karst depression water-passing capacity analysis method based on waterlogging submerged water depth monitoring. As the connecting place of surface water and groundwater in karst areas, the karst depression exchanges frequently with surface and groundwater, and rainstorm in flood season easily causes waterlogging disaster in the karst depression. Therefore, analyzing the water-passing capacity of the karst depression is of great significance to reveal the disaster-causing mechanism of waterlogging in the karst depression. In the present application, the karst depression water-passing system composed of fissures, solution fissures and pipes is generalized as a virtual reservoir, a karst depression waterlogging monitoring station network is arranged, hydrological data such as submerged water depth in the waterlogging process is collected, a virtual reservoir model of the karst depression water-passing system is constructed based on the water balance equation, the uneven distribution of the karst water-passing system medium at each elevation of the karst depression is considered, a calculation method of the storage-discharge process of the karst depression water-passing system to the inflow flood under different waterlogging submerged water depths is proposed, and the water-passing capacity of the karst depression water-passing system is analyzed. The analysis method has clear physical meaning, and the hydrological elements are easy to monitor and require less data, so it can be applied to the water-passing capacity analysis of various types of karst depressions and provide technical support for the water depth process prediction and early warning of karst depression waterlogging.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water conservancy engineering, and particularly relates to a karst depression water passing capacity analysis method based on waterlogging submerged water depth monitoring. BACKGROUND

[0002] The water-bearing medium in karst areas has strong heterogeneity, the underlying surface geomorphology and hydrology effect is complex, and the surface and underground water exchange frequently. The depression is the connection of surface water and underground water in karst areas, and the underground karst fissure, solution fissure and pipeline in the depression develop together to form a depression water passing system. The unique binary three-dimensional spatial structure system of the karst water-bearing system makes the karst basin water cycle and runoff more complex than the non-karst basin, and the flood generated by the rainstorm in the flood season will enter the karst water storage system such as underground cave and underground river through the depression water passing system. When the water quantity entering the water storage system exceeds the water passing capacity, the waterlogging disaster in the depression is easily caused. Therefore, analyzing the karst depression water passing capacity has important significance for the simulation and prediction of the hydrological process of the mountain slope and depression system in karst areas, ecological protection, water resource utilization and flood control.

[0003] The karst depression geomorphology condition is complex, and the underground pipeline and cave develop generally. At present, it is difficult to directly measure the depression water passing flow, and most of the karst depressions have neither measured flow nor water level monitoring data of waterlogging. Therefore, the depression water passing capacity is often calculated by an indirect generalization method, and some scholars analyze the karst depression water passing capacity by referring to the idea of flood routing. According to the special geological conditions in karst areas, Zhang Zulian's "Qingjiang Lichuan Waterfall Hole Water Passing Capacity Analysis" regards the flood storage area formed in front of the waterfall hole as "a reservoir", and regards the waterfall hole as "a flood discharge structure of the reservoir", directly takes the water level-flow curve of the waterfall hole adjacent to the hydrological station corrected as the discharge curve of the waterfall hole, and combines the historical measured submerged water level to determine the water passing capacity of the Qingjiang Lichuan Waterfall Hole according to the reservoir flood routing principle. Cai Guizhen et al's "Flood Routing of Karst Depression in Reservoir Influenced Area" uses the hydraulic formula (Q = K*H^1.5) of the pressure tunnel to calculate the water passing capacity of the karst depression in the reservoir influenced area. Q is the karst conduit discharge, μ is the flow coefficient, W is the karst conduit cross-sectional area, and ΔH is the approximate conduit inlet and outlet water level difference describing the karst depression conduit discharge (flow) capacity. Combined with the design storm flood hydrograph and the depression storage curve, the maximum flow capacity of the underground karst channel in Qianshijing karst depression was obtained by trial calculation using flood regulation calculation principles. The above research regards the karst depression as a reservoir and the underground karst channel as the flood discharge structure of the reservoir. The karst depression flow capacity curve is calculated using simple hydraulic formulas or by transferring the water level-flow relationship curve of the hydrological station near the depression. Only the idea of flood regulation calculation is used to verify the rationality of the karst depression flow process and the correctness of the predefined flow capacity curve. In karst landforms, fissures, karst caves, and conduits all have flow capacity, so the structure of the karst depression flow system is relatively complex. Only the sinkhole and conduit are considered as the karst depression flow passage, which does not completely match the actual situation. Most of the water flow in the karst depression flow system is conduit flow, which is characterized by complex hydrodynamic properties. The current theory for accurately describing the karst underground conduit water flow mechanism is not perfect, and the karst geometric properties and water flow path are difficult to determine. Therefore, the results of the karst cave and conduit flow process obtained by trial calculation using simple hydraulic pressure tunnel calculation formulas have a high degree of uncertainty, and it is also impossible to analyze the seepage flow process in the karst depression fissure. Li Dacheng et al. "Research on Karst Depression Discharge Capacity Based on Water Balance" proposed a method for determining the discharge (flow) capacity of the Tiangehaizi karst depression conduit in Anlong County, Guizhou Province, using flood season runoff data and the water balance equation. However, the assumption that the discharge (flow) capacity increases uniformly with the increase of the elevation in the karst depression does not match the actual situation. The karst depression flow capacity at a certain elevation (submerged water depth) depends on the distribution of flow media such as fissures, karst fissures, and conduits below that elevation. Therefore, the change in flow capacity of the karst depression corresponding to the change in elevation is not uniform. Li Wenxing et al. "Physical (Mathematical) Simulation of Karst Submergence Inundation Disaster" aimed at the karst depression inundation disaster in the reservoir area of the Hongshuihe cascade hydropower stations, including Bailongtan and Yantan. The underground river conduit was considered as the karst depression flow site, and a physical (mathematical) model was constructed to simulate the variation of the karst depression inundation water level under different atmospheric precipitation and different underground river outlet water levels. Guang Yaohua "Preliminary Study on Karst Submergence Inundation Disaster" and "Research on Karst Submergence Inundation in Yantan Hydropower Station Reservoir" considered that the restriction of the karst underground conduit structure is the internal cause of the karst depression inundation. The design storm flood hydrograph was used as the karst depression inflow process, and the difference between the valley inflow and the underground river discharge was calculated based on the water balance method to obtain the underground river discharge capacity in the Banag Valley of Guangxi.However, the above studies only analyzed the underground river discharge capacity during the receding process of waterlogging disasters in karst depressions, without considering the regulation and storage effect of the karst water flow system on the inflow flood process throughout the entire waterlogging process in the depression; and only the maximum water flow capacity of the depression was analyzed, lacking curves of water flow capacity of depressions at different inundation depths. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for analyzing the water-passing capacity of karst depressions based on monitoring inundation depth during urban flooding. The specific technical solution is as follows:

[0005] The method for analyzing the water carrying capacity of karst depressions based on water depth monitoring of waterlogging includes the following steps: Step S1, setting up a network of waterlogging monitoring stations in the karst depressions of the monitoring area to monitor the water depth change process of waterlogging in the karst depressions of the monitoring area, obtaining the relationship between the water depth Z of waterlogging in the karst depressions of the monitoring area for each time period (e.g., 1 hour) and the corresponding time t, that is, the water depth process line of waterlogging in the karst depressions of the monitoring area Z~t, and also monitoring the rainfall and water surface evaporation data of the karst depressions for each time period (e.g., 1 hour);

[0006] Step S2: Collect high-precision DEM data of karst depressions in the monitoring area;

[0007] Step S3: Based on the high-precision DEM data of the monitoring area, determine the water storage capacity V of the karst depression corresponding to each flood inundation depth Z in the monitoring area, thereby obtaining the relationship curve V ~ Z between flood inundation depth and water storage capacity of the karst depression in the monitoring area, and further obtain the functional relationship V = f(Z) between the water storage capacity V of the karst depression in the monitoring area and the flood inundation depth Z in the depression.

[0008] Step S4: Using the time-period (e.g., 1-hour) rainfall data and water surface evaporation data obtained in Step S1, the hydrological model is driven to calculate the inflow flood hydrograph of the depression, i.e., the inflow rate Q of the karst depression in the monitoring area. 入 The curve Q of the relationship with time t 入 ~t;

[0009] Step S5: Treat the karst depression water flow system in the monitoring area as a virtual reservoir, and consider the uneven distribution of the karst water flow system medium at various elevations in the depression. Based on the water balance equation, use the inflow flood process line Q of the karst depression in the monitoring area. 入 By combining the inundation depth process line Z~t of the karst depression in the monitoring area obtained in step S1, the outflow process line q of the virtual reservoir can be calculated. 过 ~t, this process is the water-carrying capacity curve q of the karst depression water-carrying system in the monitoring area. 过 ~t;

[0010] Step S6, based on the water flow capacity curve q of the karst depression water flow system in the monitoring area obtained in step S5.过 ~t obtains the water-carrying capacity q of the karst depression water-carrying system in the monitoring area at time t. 过，t Based on the water depth Z of the karst depression in the monitoring area at time t, t The relationship curve between water depth and water carrying capacity in the karst depression of the monitoring area can be plotted (Z~q). 过 Z~q obtained by piecewise fitting and plotting 过 The curve is used to extract the corresponding functional expression q. 过 =f(Z); and further utilize the relationship curve V~Z between the flood inundation depth and water storage capacity of the karst depression in the monitoring area obtained in step S3 to establish the real-time water storage capacity V of the karst depression in the monitoring area at time t. t The water flow capacity q of the karst depression water flow system in the monitoring area 过，t The relationship between the real-time water storage capacity V of the karst depressions in the monitoring area and the corresponding inundation depth Z was obtained through interpolation. Then, the real-time water storage capacity V of the karst depressions in the monitoring area and the corresponding water flow capacity q of the water flow system of the karst depressions in the monitoring area were plotted. 过 Relationship curve V~q 过 Then, the corresponding functional relationship expression q is extracted by piecewise curve fitting. 过 =f(V), and the water flow capacity of the karst depression in the monitoring area is obtained through this analysis.

[0011] Preferably, the urban flooding monitoring network in step S1 includes several water level gauges, remote terminal units, rainfall telemetry stations, evaporation telemetry stations, and a server; the water level gauges are respectively installed at the water-reducing points at the bottom of the karst depressions in the monitoring area and at the main control points; the remote control terminal is connected to the water level gauges and is used to upload the monitoring data of the water level gauges to the server in real time; the rainfall and evaporation telemetry stations are respectively used to monitor the hourly (e.g., 1 hour) rainfall and water surface evaporation data of the karst depressions in the monitoring area;

[0012] The server interacts with the rain gauge station, evaporation telemetry station, and remote control terminal to analyze the relationship between the flooding depth Z in the karst depression of the monitoring area and the corresponding time t based on the monitoring data of several water level gauges, and to obtain the rainfall, flooding depth, and water surface evaporation data of the karst depression in the area for each time period (e.g., 1 hour).

[0013] Preferably, in step S3, determining the water storage capacity V of the karst depression in the monitoring area corresponding to each flooding depth Z in the karst depression specifically involves: calling the batch processing functions of the null function tool and the surface volume tool in ArcGIS software, and extracting the water storage capacity V of the karst depression in the monitoring area corresponding to each flooding depth Z in the karst depression in the monitoring area at intervals of a certain change in flooding depth ΔH (e.g., 0.1m).

[0014] Preferably, the hydrological model in step S4 can be a distributed hydrological model or a lumped hydrological model suitable for simulating runoff processes in karst basins. The accuracy of the inflow flood forecasting scheme based on the hydrological model meets the requirements of Class B or above accuracy in the current "Hydrological Information Forecasting Specification". The forecasting scheme parameters are calibrated using measured inflow flood data from karst depressions. If measured inflow flood data from karst depressions is lacking, the forecasting scheme parameters are calibrated using measured flood data from adjacent small karst basins.

[0015] Preferably, in step S5, the outflow process curve q of the virtual reservoir is calculated. 过 Specifically, t is as follows: V t =f(Z) t );

[0016] ΔV=V t -V t-1 =f(Z) t )-f(Z t-1 );

[0017]

[0018] Among them, Z t Z represents the real-time flooding depth in the karst depression of the monitoring area, obtained from the water level gauges of the flooding monitoring network at time t. t-1 V represents the real-time flooding depth in the karst depression of the monitoring area, obtained from the water level gauges of the flooding monitoring network at time t-1; t V represents the real-time water storage capacity of the karst depression in the monitoring area at time t, calculated from the relationship curve V:Z between the flood inundation depth and water storage capacity in the karst depression. t-1 Q is the real-time water storage capacity of the karst depression in the monitoring area, calculated from the water depth-storage capacity relationship curve V~Z at time t-1; Δt is the unit time period; ΔV is the change in water storage capacity of the karst depression in the monitoring area within the unit time period; 入,t E represents the real-time inflow rate of the karst depression in the monitoring area calculated by the karst hydrological model at time t. t Let q be the real-time water surface evaporation in the karst depression area monitored by the evaporation telemetry stations of the urban flooding monitoring network at time t; 过,t The water flow capacity of the karst depression water flow system in the monitoring area at time t.

[0019] The beneficial effects of the present application are: compared with the prior art, the present application adopts a water level gauge to monitor the change process of the waterlogging submerged water depth in the depression in real time, combines the waterlogging submerged water depth-storage capacity relationship curve, considers the uneven distribution of the karst overwater system medium at each elevation of the depression, and directly calculates the overwater quantity of the depression at each period according to the water balance principle, which can effectively avoid the error in the trial calculation of the overwater capacity of the underground pipeline in the depression by indirectly generalizing the simple hydraulics method, reduces the uncertainty of the calculation result, and thus more directly and accurately calculates the overwater capacity of the depression; on the other hand, the method has relatively low data requirement degree, is simple and easy to implement, and can be applied to the overwater capacity analysis of various types of karst depressions, thereby providing technical support for the prediction and early warning of the waterlogging disaster process in the karst depression. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art, the drawings needed to be used in the specific embodiments or the prior art description will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0021] Figure 1 It is a schematic diagram of the principle of the present application;

[0022] Figure 2 It is a waterlogging submerged water depth-storage capacity relationship curve of a karst depression;

[0023] Figure 3 It is a schematic diagram of a calculation and analysis method of the flood regulation and discharge process of a virtual reservoir of a karst depression overwater system based on a water balance equation;

[0024] Figure 4 It is a schematic diagram of a calculation method of the overwater capacity of a depression at a period based on the measured waterlogging submerged water depth and the simulated inflow data;

[0025] Figure 5 It is a schematic diagram of a waterlogging submerged water depth-overwater capacity relationship curve of a karst depression;

[0026] Figure 6 It is a flowchart for deriving the waterlogging submerged water depth-overwater capacity relationship of a karst depression;

[0027] Figure 7 It is a principle diagram of a waterlogging monitoring station network of the present application. DETAILED DESCRIPTION

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0030] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0031] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0032] like Figure 1 As shown, a specific embodiment of the present invention provides a method for analyzing the water-passing capacity of karst depressions based on monitoring the inundation depth during urban flooding, comprising the following steps:

[0033] Step S1: Set up a network of waterlogging monitoring stations in the karst depressions of the monitoring area to monitor the changes in the water depth of the karst depressions in the monitoring area, and obtain the relationship between the water depth Z of the karst depressions in the monitoring area for each time period (e.g., 1 hour) and the corresponding time t, that is, the water depth process line of the karst depressions in the monitoring area Z~t. At the same time, monitor the rainfall and water surface evaporation data of the karst depressions for each time period (e.g., 1 hour).

[0034] Among them, such as Figure 7 As shown, the urban flooding monitoring network includes several water level gauges, remote terminal units (RTUs), rainfall telemetry stations, evaporation telemetry stations, and a server. The water level gauges are respectively installed at the water-reducing points at the bottom of the karst depressions in the monitoring area and at the main control points. The remote control terminals are connected to the water level gauges and are used to upload the monitoring data of the water level gauges to the server in real time. The rainfall and evaporation telemetry stations are used to monitor the rainfall (e.g., 1 hour) and water surface evaporation data of the karst depressions in the monitoring area.

[0035] The server interacts with the rain gauge station, evaporation telemetry station, and remote control terminal to analyze the relationship between the flooding depth Z in the karst depression of the monitoring area and the corresponding time t based on the monitoring data of several water level gauges, and to obtain the rainfall, flooding depth, and water surface evaporation data of the karst depression in the area for each time period (e.g., 1 hour).

[0036] Step S2: Collect DEM data of karst depressions in the monitoring area from an open-source database and download high-precision DEM data from NASA EARTHDATA ALOS with a spatial resolution of 12.5m.

[0037] Step S3: Based on the high-precision DEM data collected in Step S2, the batch processing functions of the null function tool and surface volume tool in ArcGIS software are called. Using a certain interval of water depth change ΔH (0.1m can be selected in this implementation), the water storage capacity V of the karst depressions in the monitoring area corresponding to each water depth Z is extracted. This yields the water depth-water storage capacity relationship curve V~Z of the karst depressions in the monitoring area. Furthermore, the functional relationship V = f(Z) between the water storage capacity V and the water depth Z of the karst depressions in the monitoring area is obtained. Figure 2 As shown.

[0038] Step S4: Using the rainfall data and water surface evaporation data obtained in Step S1 for each time period within the karst depression, the hydrological model is driven to calculate the inflow flood hydrograph of the depression, i.e., the inflow rate Q of the karst depression in the monitoring area. 入 The curve Q of the relationship with time t 入 ~t. The hydrological model can be a distributed hydrological model or a lumped hydrological model suitable for simulating runoff processes in karst basins. The accuracy of the inflow flood forecasting scheme for depressions based on the hydrological model should meet the accuracy level of Class B or above in the current "Hydrological Information Forecasting Specification". The forecasting scheme parameters should be calibrated using measured inflow flood data from karst depressions. If measured inflow flood data for karst depressions is lacking, the forecasting scheme parameters should be calibrated using measured flood data from adjacent small karst basins.

[0039] Step S5: Treat the karst depression water flow system in the monitoring area as a virtual reservoir, and consider the uneven distribution of the karst water flow system medium at various elevations in the depression. Based on the water balance equation, such as... Figures 3-4 As shown, when floodwaters enter the karst depression in the monitoring area, the floodwater depth (water level) within the karst depression is level with the inlet of the water flow system at the bottom of the karst depression. Q 入 ~t represents the inflow flood process in the karst depression of the monitoring area, q 过~t is the overwater process of the karst depression overwater system in the monitoring area, and Z~t is the change process of the water depth of the waterlogging inundation in the karst depression in the monitoring area. The flood regulation and storage process of the karst depression overwater system in the monitoring area can be divided into the following three stages: ① the moment t0 when the flood enters the karst depression in the monitoring area corresponds to the initial moment in the process of reservoir flood regulation and discharge, at this time, the "initial water level" Z0 corresponds to the elevation of the entrance of the overwater system at the bottom of the karst depression in the monitoring area being submerged, and the overwater quantity q 过，0 of the karst depression overwater system in the monitoring area 洞 , q 洞 is the overwater capacity of the main sinkhole at the bottom of the depression itself, which is related to the diameter and position of the sinkhole and can be determined according to the field measurement data; ② during the period of t0~t2, since Q 入，t > q 过，t , the karst depression in the monitoring area is always in a water storage state, the waterlogging inundation water depth Z t continuously rises, and the overwater quantity q 过 of the karst depression overwater system in the monitoring area also increases accordingly. At the moment t2, Q 入，2 = q 过，2 , at this time, the karst depression in the monitoring area reaches the maximum waterlogging inundation water depth Z2 and the maximum flood storage capacity, and the overwater quantity of the karst depression overwater system in the monitoring area also reaches the maximum; after the moment t2, since Q 入，t < q 过，t , the flood temporarily stored in the last period is gradually discharged to the underground karst water storage system through the karst depression overwater system in the monitoring area, the waterlogging inundation water depth Z t of the karst depression in the monitoring area gradually decreases, and the discharge quantity q 过，t of the overwater system also decreases accordingly. At the moment t4, the waterlogging water level of the karst depression in the monitoring area decreases to the elevation of the bottom water sink being submerged, and the regulation and discharge process ends.

[0040] Using the inflow flood hydrograph Q 入 ~t of the karst depression in the monitoring area and the waterlogging inundation water depth hydrograph Z~t of the karst depression in the monitoring area obtained in step S1 at the same period, the outflow hydrograph q 过 ~t of the virtual reservoir can be obtained, which is the overwater process curve q 过 ~t of the karst depression overwater system in the monitoring area; the specific process is as follows:

[0041] V t = f(Z t );

[0042] ΔV = V t - V t-1 = f(Z t ) - f(Z t-1 );

[0043]

[0044] Among them, Z t Z represents the real-time flooding depth (in meters) of the karst depression in the monitoring area, obtained from the water level gauges of the flooding monitoring network at time t. t-1 V represents the real-time flooding depth (m) of the karst depression in the monitoring area, obtained from the water level gauges of the flooding monitoring network at time t-1. t Let t be the real-time water storage capacity of the karst depression in the monitoring area, calculated from the V:Z curve of the relationship between the inundation depth and water storage capacity at time t, in m. 3 V t-1 The real-time water storage capacity of the karst depression in the monitoring area at time t-1 is calculated from the V:Z curve of the relationship between the inundation depth and water storage capacity in the karst depression in the monitoring area, in meters. 3 Δt represents the unit time period, in seconds; ΔV represents the change in water storage in the karst depression within the monitoring area within the unit time period, in meters. 3 Q 入，t Let t be the real-time inflow rate (m) of the karst depression in the monitoring area calculated by the karst hydrological model at time t. 3 / s;E t Let q be the real-time water surface evaporation in the karst depression area monitored by the evaporation telemetry stations of the urban flooding monitoring network at time t, expressed in m; 过，t Let m be the flow rate of the karst depression water system in the monitoring area at time t. 3 / s.

[0045] Step S6, as follows Figures 5-6 As shown, based on the water flow process curve q of the karst depression water flow system in the monitoring area obtained in step S5... 过 ~t obtains the flow rate q of the water-passing system in the karst depression monitoring area at time t. 过，t Based on the water depth Z of the karst depression in the monitoring area at time t, t The relationship curve between water depth and water carrying capacity in the karst depression of the monitoring area can be plotted (Z~q). 过 Z~q obtained by piecewise fitting and plotting 过 The curve is used to extract the corresponding functional expression q. 过 =f(Z); and further utilize the relationship curve V~Z between the flood inundation depth and water storage capacity of the karst depression in the monitoring area obtained in step S4 to establish the real-time water storage capacity V of the karst depression in the monitoring area at time t. t The flow rate q of the water flow system in the karst depression of the monitoring area 过，t The relationship between the real-time water storage V of the karst depressions in the monitoring area and the corresponding inundation depth Z was obtained through interpolation. Then, the real-time water storage V of the karst depressions in the monitoring area and the corresponding flow rate q of the water flow system of the karst depressions in the monitoring area were plotted. 过 Relationship curve V~q 过 Then, the corresponding functional relationship expression q is extracted by piecewise curve fitting. 过= f(V), thus the analysis obtains the overwater capacity of the karst depression in the monitoring area.

[0046] The present application generalizes the overwater system of the karst depression, which is composed of fissures, solution fissures and pipelines, as a virtual reservoir, sets up a monitoring station network for the karst depression, collects hydrological data such as the submerged water depth during the waterlogging, constructs a virtual reservoir model of the karst depression overwater system based on the water balance equation, considers the uneven distribution of the karst overwater system medium at each elevation of the depression, proposes a calculation method for the regulation and discharge process of the karst depression overwater system to the inflow flood under different waterlogging submerged water depths, and analyzes the overwater capacity of the karst depression overwater system.

[0047] In view of the problem that the existing technology uses limited historical rainfall marks of the depression to calculate the overwater capacity of the depression, which is not representative, the present application sets up water level gauges, remote terminal units, rainfall telemetry stations and evaporation telemetry stations in the karst depression in the monitoring area according to the topographic features of the karst depression, constructs a waterlogging monitoring station network, collects measured rainfall-waterlogging submerged water depth data of important infrastructure such as houses, farmlands and roads in the depression, and provides high-precision real-time basic data for subsequent analysis and calculation.

[0048] Those skilled in the art can realize that the units of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware, computer software or a combination of both, and the components of each example have been described in the above description in general terms in terms of functions in order to clearly illustrate the interchangeability of hardware and software. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0049] In the embodiments provided in the present application, it should be understood that the division of the units is only a logical function division, and there can be another division manner in actual implementation, for example, a plurality of units can be combined as one unit, one unit can be split into a plurality of units, or some features can be ignored, etc.

[0050] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

Claims

1. A method for analyzing the water passing capacity of a karst depression based on monitoring the water depth of waterlogging, characterized in that, Comprise the following steps: Step S1, setting a waterlogging monitoring station network in the karst depression of the monitoring area, monitoring the water depth change process of the waterlogging in the karst depression of the monitoring area, and obtaining the waterlogging water depth of the karst depression of the monitoring area in each time interval The relationship between the waterlogging water depth of the karst depression of the monitoring area at the corresponding moment , that is, the waterlogging water depth process line of the karst depression of the monitoring area Meanwhile, the rainfall and water surface evaporation data of the karst depression in each time interval are also monitored. Step S2, collect monitoring area karst depression high-precision DEM data; Step S3, determining the water depth of each karst depression in the monitoring area based on the high-precision DEM data of the monitoring area The corresponding water storage capacity of the karst depression , thereby obtaining the relationship curve between the water depth of the karst depression in the monitoring area and the water storage capacity , and further obtaining the water storage capacity of the karst depression in the monitoring area and the water depth of the depression ; the function relationship ; Step S4, using the karst depression in step S1 obtained by time period rainfall data and water evaporation data driving hydrological model, using hydrological model to calculate the depression inflow hydrograph, that is, the monitoring area karst depression inflow With the relationship curve of time ;​ Step S5, the karst depression overwater system in the monitoring area is regarded as a virtual reservoir, and the inflow flood hydrograph of the karst depression in the monitoring area is obtained based on the water balance equation and the corresponding monitoring area karst depression waterlogging submerged water depth hydrograph in the same period obtained in step S1 , that is, the outflow hydrograph of the virtual reservoir can be obtained , and the process is the overwater capacity curve of the karst depression overwater system in the monitoring area ; Step S6: Based on the water flow capacity curve of the karst depression water flow system in the monitoring area obtained in step S5. get The water flow capacity of the karst depression water flow system in the monitoring area is constantly monitored. According to the corresponding time period The water depth of the karst depression in the monitoring area at any given time. The relationship curve between water depth and water carrying capacity in the karst depression of the monitoring area can be plotted. Piecewise fitting point plotting Extract the corresponding functional expression from the curve. Furthermore, the relationship curve of water depth-storage capacity in the karst depression of the monitoring area obtained in step S3 is used. Establish Real-time water storage in karst depressions under constant monitoring Water flow capacity of the karst depression water flow system in the monitoring area The relationship was used to obtain the inundation depth of each karst depression in the monitoring area through interpolation. Real-time water storage in the corresponding karst depressions of the monitoring area Then, the real-time water storage of the karst depressions in the monitoring area was plotted. The water flow capacity of the corresponding karst depression water flow system in the monitoring area Relationship curve Then, the corresponding functional relationship expression is extracted by piecewise curve fitting. The water flow capacity of the karst depressions in the monitoring area was obtained through analysis.

2. The karst depression overwater capacity analysis method based on waterlogging inundation water depth monitoring according to claim 1, characterized in that, The step S1 in the waterlogging monitoring station network includes several water level gauges and remote terminal units, rainfall telemetry stations, evaporation telemetry stations, servers; several water level gauges are respectively arranged at the bottom of the monitoring area karst depression and the main control point; the remote terminal unit is connected with several water level gauges respectively, and is used for uploading the monitoring data of several water level gauges to the server in real time; the rainfall telemetry station and the evaporation telemetry station are respectively used for monitoring the rainfall of the monitoring area karst depression in each time period and the water surface evaporation data; The server respectively carries out data interaction with the rainfall telemetry station, the evaporation telemetry station and the remote terminal unit, is used for obtaining the relationship between the waterlogging submerged water depth Z in the monitoring area karst depression and the corresponding time moment t according to the monitoring data of several water level gauges, and obtaining the rainfall in each time period in the area karst depression, the waterlogging water submerged water depth and the water surface evaporation data.

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4. The method for analyzing the water-passing capacity of karst depression based on monitoring of water depth submerged by waterlogging according to claim 1, characterized in that, ​ 5. The method for analyzing the water-passing capacity of karst depression based on monitoring water depth submerged by waterlogging according to claim 1, characterized in that, In step S5, the outflow hydrograph of the virtual reservoir is calculated The specific process is as follows: ； ； wherein, is the real-time waterlogging submerged water depth of the karst depression in the monitoring area obtained by the water level gauge of the waterlogging monitoring station network at the moment; is the real-time waterlogging submerged water depth of the karst depression in the monitoring area obtained by the water level gauge of the waterlogging monitoring station network at the moment; is the real-time waterlogging submerged water depth of the karst depression in the monitoring area obtained by the water level gauge of the waterlogging monitoring station network at the moment; is the real-time water storage capacity of the karst depression in the monitoring area calculated by the water level gauge of the waterlogging monitoring station network at the moment; is the real-time water storage capacity of the karst depression in the monitoring area calculated by the water level gauge of the waterlogging monitoring station network at the moment; is the real-time water storage capacity of the karst depression in the monitoring area calculated by the water level gauge of the waterlogging monitoring station network at the moment; is a unit time period; is the change amount of the water storage capacity of the karst depression in the monitoring area in a unit time period; is the real-time inflow of the karst depression in the monitoring area calculated by the karst hydrological model at the moment; is the real-time water surface evaporation of the karst depression in the monitoring area obtained by the evaporation telemetry station of the waterlogging monitoring station network at the moment; is the water passing capacity of the water passing system of the karst depression in the monitoring area at the moment.

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