Riverside zone range defining method and system

Abstract

The invention relates to a riverside zone range defining method and system, and relates to the technical field of hydrogeology, and the method comprises the following steps: obtaining the landform characteristics, hydrogeologic structure, river channel form, soil property, vegetation distribution characteristics and other index data in a drainage basin; monitoring water level dynamic change data of the river and the riverside groundwater, analyzing a conversion relation between the river and the groundwater, and dividing different river-groundwater conversion modes. A two-dimensional profile river-underground water conversion kinetic model perpendicular to the river channel is established, and the conversion flux of the river and the underground water at the river bank and the moisture contribution amount extending to the two sides of the river bank by different distances are calculated. And determining an effective influence space range of river-underground water conversion based on the water contribution amount of a set threshold value. On the basis of the influence space range of river-underground water conversion, various index data obtained in the first step are superposed, and the river basin riverside zone range is defined.

Description

Technical Field

[0001] The present invention relates to the field of hydrogeological technology, and in particular to a method and system for defining a riverside zone. Background Art

[0002] The riverside is a corridor centered on the river. It is an interlaced area where the water system and the land system interact. Compared with the area of ​​the basin, the area of ​​the riverside is very small, but it is the area with the largest exchange of water, matter and energy between the river and groundwater. It is also the area with the most concentrated natural plants, the highest level of biodiversity and the largest habitat gradient in the basin, and plays an important ecological barrier function in the basin. Against the background of climate warming and increasing human activities, the ecological environment in some water-scarce areas is deteriorating. The protection and management of the riverside is crucial to the healthy and sustainable development of the basin ecosystem.

[0003] At the watershed scale, the transformation of rivers and groundwater within the riparian zone plays a leading role and has an impact on the ecosystems on both sides. However, there is no unified definition of the riparian zone so far. Strengthening the research on the riparian zone and demarcating the physical boundaries of the riparian zone will help to formulate reasonable riparian zone ecological protection and management strategies, which is of great significance to maintaining the stability of the basin ecosystem.

[0004] In the prior art, many researchers have defined the scope of the riverside zone by investigating the topography, landforms, plant populations, soil physical and chemical properties, etc. of river sections and both sides of the river, and using statistical methods to find mutation points of topography, plant populations or soil physical and chemical properties, thereby making different definitions of the riverside zone boundary. However, in arid and semi-arid areas with scarce precipitation, strong evaporation and fragile ecosystems, rivers and groundwater frequently transform into each other, and dynamic hydrological changes determine the evolution of the riverside ecosystem. If the scope of the riverside zone is simply defined based on mutations in topography or plant populations, it is not accurate enough, and the ecological protection and management of the riverside zone are difficult. There is currently no effective solution to the problem of how to accurately define the boundary of the riverside zone. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art in how to accurately define the boundaries of the riverside zone, the main purpose of the present invention is to provide a method and system for defining the scope of the riverside zone based on the river-groundwater conversion relationship.

[0006] To achieve the above object, the present invention adopts the following technical scheme to provide a method for defining the scope of a riverside zone based on the river-groundwater conversion relationship, the method comprising the following steps:

[0007] Obtain water level change data of rivers and groundwater adjacent to the rivers, compare the water level and riverbed elevation data of rivers and groundwater adjacent to the rivers, and combine the transformation relationship between rivers and groundwater to obtain analysis results. According to the analysis results, classify the analysis results to obtain a variety of different river-groundwater transformation types;

[0008] According to the hydrogeological structure, river channel morphology, soil properties, dynamic change characteristic data of river and groundwater levels, combined with the various types of river-groundwater conversion, boundary ranges, hydrogeological parameters, initial conditions and boundary conditions are set to construct a river-groundwater conversion dynamics model;

[0009] Based on the river-groundwater conversion dynamics model, the conversion flux between river and groundwater at the river bank and the water contribution at different distances extending to both sides of the river bank are obtained;

[0010] Based on the moisture contribution of the set threshold, the effective spatial scope of river-groundwater conversion is determined, and the scope of the riverside zone is confirmed by combining the multiple geographical indicator data obtained on the surface.

[0011] The moisture contribution amount of the set threshold is that the contribution of groundwater to the river is greater than 15%.

[0012] The geographical indicators include geomorphic features, hydrogeological structure, river channel morphology, soil properties, and vegetation distribution characteristics.

[0013] The landforms include mountainous areas, piedmont alluvial fan areas, alluvial fine soil plain areas, aeolian plain areas and lacustrine plain areas;

[0014] The hydrogeological structure includes the structure of aquifers and aquitards, and the distribution characteristics of groundwater;

[0015] The river channel morphology includes the geometric shape of the river channel, the flow direction and slope of the riverbed, and the geomorphic features of the riverbed and riverbank;

[0016] The soil properties include texture, bulk density, porosity, and permeability;

[0017] The vegetation distribution characteristics include plant diversity, distribution type, and coverage.

[0018] The transformation relationship between rivers and groundwater includes permanent disconnected river recharge of groundwater, seasonal river recharge of groundwater, alternating transformation between rivers and groundwater, and groundwater recharge of river water:

[0019] The permanent disconnected river recharges groundwater when the groundwater level is far lower than the river level all year round, an unsaturated zone exists under the riverbed, the river is disconnected from the groundwater, and there is no unified infiltration surface;

[0020] The seasonal river recharges groundwater when there is no water in the river during the dry season, the groundwater level is lower than the lowest point of the river, and there is no hydraulic connection between the river and the groundwater. During the flood season, the river infiltrates and recharges the groundwater, and the river and the groundwater have a unified infiltration surface.

[0021] The alternating transformation between river and groundwater is that when the river is interrupted during the dry season, the groundwater level is higher than the river level, and the groundwater replenishes the river; when the river flow in the river is large during the flood season, the river infiltrates to replenish the groundwater, and the river and the groundwater have a unified infiltration surface;

[0022] The groundwater replenishes river water: when the groundwater level is higher than the river level all year round, the groundwater overflows to replenish the river.

[0023] A system for riparian zone scoping method based on river-groundwater transformation relationship, comprising:

[0024] The data processing module is used to obtain the water level change data of the river and the groundwater adjacent to the river, and obtain the analysis results by comparing the water level and riverbed elevation data of the river and the groundwater adjacent to the river, and combining the transformation relationship between the river and the groundwater. According to the analysis results, the analysis results are classified to obtain a variety of different river-groundwater transformation types;

[0025] The conversion model construction module is used to set the boundary range, hydrogeological parameters, initial conditions and boundary conditions according to the hydrogeological structure, river channel morphology, soil properties, dynamic change characteristic data of river and groundwater levels, combined with the various types of river-groundwater conversion, to construct a river-groundwater conversion dynamic model;

[0026] The scope definition module, based on the river-groundwater conversion dynamics model, obtains the conversion flux between river and groundwater at the river bank, as well as the water contribution at different distances extending to both sides of the river bank; based on the water contribution of the set threshold, determines the effective spatial scope of the river-groundwater conversion, and confirms the scope of the riverside zone by combining the obtained multiple geographic indicator data of the surface.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: it is carried out based on the river-groundwater conversion characteristics, by dividing the river-groundwater conversion mode, and defining the riverside zone with the water contribution of the set threshold as a constraint, to achieve classified definition, and propose differentiated protection and management needs for the riverside zone, which is more targeted and goal-oriented; the boundary is determined based on geological, hydrological, groundwater, soil, vegetation and other conditions, which is more scientific and specific; the scope is defined by combining quantitative and qualitative analysis, and numerical simulation is used as the main means of operation, which is more scientific and operational. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0029] Figure 1 It is a schematic diagram of the process of the method for defining the scope of the riverside zone of the present invention;

[0030] Figure 2 This is a comprehensive schematic diagram of the hydrogeological structure in the embodiment of the present invention.

[0031] Figure 3 This is a comprehensive schematic diagram of the river channel morphology in the embodiment of the present invention.

[0032] Figure 4 is a comprehensive schematic diagram of river groundwater interaction type one in an embodiment of the present invention;

[0033] Figure 5 is a comprehensive schematic diagram of the second type of river-groundwater interaction in an embodiment of the present invention;

[0034] Figure 6 is a comprehensive schematic diagram of the third type of river-groundwater interaction in an embodiment of the present invention;

[0035] Figure 7 1 is a comprehensive schematic diagram of the fourth type of river-groundwater interaction in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In the prior art, many researchers have defined the scope of the riverside zone by investigating the topography, landforms, plant populations, soil physical and chemical properties, etc. of river sections and both sides of the river, and using statistical methods to find mutation points of topography, plant populations or soil physical and chemical properties, thereby making different definitions of the riverside zone boundary. However, in arid and semi-arid areas with scarce precipitation, strong evaporation and fragile ecosystems, rivers and groundwater frequently transform into each other, and dynamic hydrological changes determine the evolution of the riverside ecosystem. If the scope of the riverside zone is simply defined based on mutations in topography or plant populations, it is not accurate enough, and the ecological protection and management of the riverside zone are difficult. There is currently no effective solution to the problem of how to accurately define the boundary of the riverside zone.

[0037] In order to overcome the shortcomings of the above-mentioned prior art in how to accurately define the boundaries of the riverside zone, the main purpose of the present invention is to provide a method and system for defining the scope of the riverside zone based on the river-groundwater conversion relationship.

[0038] Obtain water level change data of rivers and groundwater adjacent to the rivers, compare the water level and riverbed elevation data of rivers and groundwater adjacent to the rivers, and combine the transformation relationship between rivers and groundwater to obtain analysis results. According to the analysis results, classify the analysis results to obtain a variety of different river-groundwater transformation types;

[0039] According to the hydrogeological structure, river channel morphology, soil properties, dynamic change characteristic data of river and groundwater levels, combined with the various types of river-groundwater conversion, boundary ranges, hydrogeological parameters, initial conditions and boundary conditions are set to construct a river-groundwater conversion dynamics model;

[0040] Based on the river-groundwater conversion dynamics model, the conversion flux between river and groundwater at the river bank and the water contribution at different distances extending to both sides of the river bank are obtained;

[0041] Based on the water contribution of the set threshold, the effective spatial scope of river-groundwater conversion is determined, and the scope of the riverside zone is confirmed by combining multiple surface geographical indicator data obtained. The water contribution of the set threshold is that the contribution of groundwater to the river is greater than 15%.

[0042] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0043] Embodiment 1:

[0044] The following is a specific embodiment, a method for defining the scope of the riverside zone based on the river-groundwater conversion relationship, which specifically includes the following steps:

[0045] Step 1: Data acquisition:

[0046] Obtain the water level change data of a river in the past year. The data comes from the river's automatic monitoring station.

[0047] The data on changes in groundwater levels along the river are collected through groundwater monitoring wells set up on both sides of the river.

[0048] Obtain riverbed elevation data by combining river Geographic Information System (GIS) data with field measurements.

[0049] Step 2: Analyze the transformation relationship between rivers and groundwater

[0050] Compare river water level and groundwater level data and analyze their seasonal changes and interrelationships.

[0051] Combined with riverbed elevation data, the spatial relationship between river water level and riverbed is analyzed.

[0052] Through analysis, it was found that rivers recharge groundwater in flood seasons and rely on groundwater recharge in dry seasons, thus obtaining the analysis results of the conversion relationship between rivers and groundwater.

[0053] The analysis results were classified into the following transformation types: river-groundwater recharge type in flood season, groundwater-river recharge type in dry season, and seasonal dynamic balance type.

[0054] Step 3: Construct river-groundwater conversion dynamics model

[0055] The model boundary range is set based on the hydrogeological structure map, river morphology, soil properties and water level dynamic change characteristic data, combined with the above-mentioned conversion types.

[0056] Determine hydrogeological parameters such as permeability, porosity, etc.

[0057] Set the initial conditions and boundary conditions of the model, such as the initial water levels of rivers and groundwater, the flow boundary of rivers, etc.

[0058] Numerical simulation software such as MODFLOW was used to construct a river-groundwater transformation dynamics model.

[0059] Step 4: Simulation and Analysis

[0060] Run the model to obtain the transformation flux data between river and groundwater at the river bank.

[0061] Calculate the water contribution at different distances, for example every 10 meters, extending to both sides of the river bank.

[0062] Step 5: Determine the extent of the riverside zone

[0063] According to the simulation results, it was found that the moisture contribution within 30 meters from the river bank was greater than 15%.

[0064] Thirty meters was determined as the effective spatial range of influence of river-groundwater conversion.

[0065] The specific scope of the riverside zone is further confirmed by combining multiple geographical indicator data of the surface, such as vegetation coverage, soil moisture, terrain slope, etc.

[0066] The riverside zone was finally determined to be a 30-meter strip area on each side of the river, and corresponding ecological protection and restoration measures were implemented within this range.

[0067] This example demonstrates how to determine the extent of the riparian zone through data analysis, model building, and simulation results to support river ecological protection and water resource management.

[0068] Embodiment 2:

[0069] like Figure 1As shown in the figure, a riparian zone scoping method based on the river-groundwater transformation relationship includes the following steps:

[0070] S1. Obtain data on topographic features, hydrogeological structure, river channel morphology, soil properties, vegetation distribution characteristics, etc. within the basin, including: Figure 2 As shown, Figure 2 It is a comprehensive schematic diagram of the hydrogeological structure, showing the different landform types and hydrogeological structures that the river passes through from upstream to downstream, passing through mountainous areas, alluvial fans, overflow zones, alluvial plains, aeolian plains, and lacustrine plains.

[0071] The topography and landforms include mountainous areas, piedmont alluvial fans, alluvial fine soil plains, aeolian plains and lacustrine plains; the hydrogeological structure includes the structure of aquifers and weak permeable layers, and the distribution characteristics of groundwater; the river channel morphology includes the geometry of the river channel, the direction and slope of the riverbed, and the landform characteristics of the riverbed and riverbank; soil properties include texture, bulk density, porosity, permeability, etc.; vegetation distribution characteristics include plant diversity, distribution type, coverage, etc.

[0072] S2. Monitor the dynamic change data of river and riverside groundwater levels, analyze the transformation relationship between rivers and groundwater, and classify different river-groundwater transformation modes;

[0073] S21. Dynamic change characteristics of river and groundwater levels are monitored by the following method: multiple transverse sections perpendicular to the river are selected, and six groundwater automatic monitoring points are arranged on one side of the river bank along each transverse section, which are 10m, 50m, 100m, 200m, 500m, and 2000m away from the center of the river, respectively, and a river water level monitoring point is arranged in the center of the river;

[0074] S22. According to the dynamic changes and mutual influence characteristics of rivers and groundwater, the river-groundwater transformation relationship is divided into the following four modes: Figure 4As shown: ① Permanently disconnected river recharges groundwater: When the groundwater level is far lower than the river level all year round, there is an unsaturated zone under the riverbed, the river and groundwater are disconnected, there is no unified infiltration surface, and the river recharges groundwater in the form of unsaturated flow. This situation usually occurs in mountainous areas and piedmont alluvial fan areas; ② Seasonal river recharges groundwater: When there is no water in the river channel during the dry season, the river and groundwater have no hydraulic connection. During the flood season, the river infiltrates to recharge the groundwater, and the river and groundwater have a unified infiltration surface. This situation usually occurs in aeolian plains ③ Alternation of river and groundwater: when the river is interrupted during the dry season, the groundwater level is higher than the river level, and the groundwater replenishes the river. When the river flow in the river is large during the flood season, the river infiltration replenishes the groundwater, and the river and groundwater have a unified infiltration surface. The river and groundwater alternately transform. This situation usually occurs in alluvial and diluvial plains with shallow groundwater levels; ④ Groundwater replenishes river water: when the groundwater level is higher than the river level all year round, the groundwater overflows to replenish the river. This situation usually occurs in the edge of alluvial and diluvial fans and lacustrine plains;

[0075] S3. Establish a two-dimensional cross-section river-groundwater conversion dynamic model perpendicular to the river channel to calculate the conversion flux between river and groundwater at the river bank and the water contribution at different distances extending to both sides of the river bank;

[0076] S31. Based on the data of hydrogeological structure, river channel morphology, soil properties, dynamic characteristics of river and groundwater levels, etc., a two-dimensional cross-sectional hydrodynamic model of river-groundwater coupling was constructed using Hydrogeosphere software to simulate and calculate the river-groundwater conversion process in different modes;

[0077] S32. Based on the dynamic model, the conversion flux between river and groundwater at the river bank and the water contribution at different distances extending to both sides of the river bank are simulated and calculated;

[0078] S4. According to previous research results, when the contribution of groundwater to rivers is less than 15%, the rivers will be disconnected from the groundwater. Therefore, the effective spatial range of river-groundwater conversion is determined with a water contribution greater than 15% as a constraint.

[0079] S5. Based on the spatial scope of the impact of river-groundwater conversion, superimpose the various indicator data obtained in step 1 to define the scope of the riverside zone in the basin.

[0080] The present invention provides a method for defining the scope of a riverside zone based on the relationship between rivers and groundwater. The method is carried out on the basis of the river-groundwater conversion characteristics, divides the river-groundwater conversion modes, and defines the riverside zone with a 15% moisture contribution as a constraint, thereby achieving classified definition and proposing differentiated protection and management requirements for the riverside zone, which is more targeted and objective; the boundary is determined based on geological, hydrological, groundwater, soil, vegetation and other conditions, which is more scientific and specific; the scope definition is analyzed by combining quantitative and qualitative analysis, and numerical simulation is used as the main means for operation, which is more scientific and operational.

[0081] It should be noted that, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0082] The above embodiments are merely examples of the present invention and do not limit the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A method for defining a riverside zone, characterized in that: The following steps are involved: Obtain water level change data of rivers and groundwater adjacent to the river, compare the water level and riverbed elevation data of rivers and groundwater adjacent to the river, and combine the transformation relationship between rivers and groundwater to obtain a variety of different types of river-groundwater transformation; According to the hydrogeological structure, river channel morphology, soil properties, dynamic change characteristic data of river and groundwater levels, combined with the various types of river-groundwater conversion, boundary ranges, hydrogeological parameters, initial conditions and boundary conditions are set to construct a river-groundwater conversion dynamics model; Based on the river-groundwater conversion dynamics model, the conversion flux between river and groundwater at the river bank and the water contribution at different distances extending to both sides of the river bank are obtained; Based on the moisture contribution of the set threshold, the effective spatial scope of river-groundwater conversion is determined, and the scope of the riverside zone is confirmed by combining the multiple geographical indicator data obtained on the surface.

2. The method for defining the riverside area according to claim 1, characterized in that: The moisture contribution amount of the set threshold is that the contribution of groundwater to the river is greater than 15%.

3. The method for defining the scope of a riverside zone according to claim 1, characterized in that: The geographical indicators include geomorphic features, hydrogeological structure, river channel morphology, soil properties, and vegetation distribution characteristics.

4. The method for defining the scope of a riverside zone according to claim 3, characterized in that: The landforms include mountainous areas, piedmont alluvial fan areas, alluvial fine soil plain areas, aeolian plain areas and lacustrine plain areas; The hydrogeological structure includes the structure of aquifers and aquitards, and the distribution characteristics of groundwater; The river channel morphology includes the geometric shape of the river channel, the flow direction and slope of the riverbed, and the geomorphic features of the riverbed and riverbank; The soil properties include texture, bulk density, porosity, and permeability; The vegetation distribution characteristics include plant diversity, distribution type, and coverage.

5. The method for defining the riparian zone as claimed in claim 1, characterized in that: The transformation relationship between rivers and groundwater includes permanent disconnected rivers replenishing groundwater, seasonal rivers replenishing groundwater, alternating transformation between rivers and groundwater, and groundwater replenishing river water: The permanent disconnected river recharges groundwater when the groundwater level is lower than the river level, an unsaturated zone exists under the riverbed, the river is disconnected from the groundwater, and there is no unified infiltration surface; The seasonal river recharges groundwater when there is no water in the river during the dry season, the groundwater level is lower than the lowest point of the river, and there is no hydraulic connection between the river and the groundwater. During the flood season, the river infiltrates and recharges the groundwater, and the river and the groundwater have a unified infiltration surface. The alternating transformation between river and groundwater is that when the river is interrupted during the dry season, the groundwater level is higher than the river level, and the groundwater replenishes the river; when the river flow in the river is large during the flood season, the river infiltrates and replenishes the groundwater, and the river and the groundwater have a unified infiltration surface; The groundwater replenishes the river water: when the groundwater level is higher than the river level, the groundwater overflows to replenish the river.

6. A system for defining the riparian zone as claimed in claim 1, characterized in that: include: The data processing module is used to obtain the water level change data of the river and the groundwater adjacent to the river, and obtain the analysis results by comparing the water level and riverbed elevation data of the river and the groundwater adjacent to the river, and combining the transformation relationship between the river and the groundwater. According to the analysis results, the analysis results are classified to obtain a variety of different river-groundwater transformation types; The conversion model construction module is used to set the boundary range, hydrogeological parameters, initial conditions and boundary conditions according to the hydrogeological structure, river channel morphology, soil properties, dynamic change characteristic data of river and groundwater levels, combined with the various types of river-groundwater conversion, to construct a river-groundwater conversion dynamic model; The scope definition module, based on the river-groundwater conversion dynamics model, obtains the conversion flux between river and groundwater at the river bank, as well as the water contribution at different distances extending to both sides of the river bank; based on the set threshold contribution, determines the effective spatial scope of river-groundwater conversion, and confirms the scope of the riverside zone by combining the obtained multiple geographic indicator data of the surface.

7. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

8. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method described in any one of claims 1 to 5 is implemented.

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