A method for setting up a natural degassing river channel for stalactite conservation

Abstract

This invention discloses a method for constructing a natural deaerated river channel for travertine conservation, relating to the field of river channel construction technology. The method includes the following steps: S1, determining the water quality at the river's starting and ending points, and determining the target SIc index improvement based on water quality parameters; S2, conducting river topographic measurements, designing the river's direction and slope, ensuring the slope is no greater than 10°; S3, dividing the river into a rapid deaeration section (thin-layer flow section) and a normal deaeration section (thick-layer flow section) based on water quality parameters and design targets. This invention utilizes existing natural topographic conditions, controlling the river's slope, width, bed conditions, and micro-landforms such as waterfalls, to construct, renovate, or expand the river channel, forming a natural river with high carbon dioxide deaeration capacity within a given length. At the river outlet, a landscape water body with macroscopic travertine deposition capacity (SIc > 1) is formed. After the water body enters the conservation area in a dispersed flow, it can form a blue-green colored pool.

Description

Technical Field

[0001] This invention relates to the field of river channel construction technology, specifically a natural deaeration river channel construction method for travertine conservation. Background Technology

[0002] When the external environment changes significantly, such as narrowing of the river channel, slowing or stagnating of the water flow, excessive vegetation cover, or insufficient sunlight leading to lower water temperature, the deaeration capacity of the travertine is weakened, the formation of new travertine ceases or even erosion occurs, the blue-green hue of the water disappears, and the travertine pond degenerates into an ordinary pond with sediment accumulation. Summary of the Invention

[0003] This invention provides a method for constructing naturally deaerated river channels for travertine conservation, which can effectively solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for constructing naturally deaerated river channels for travertine conservation, comprising the following steps:

[0005] S1. Determine the water quality at the beginning and end points of the river channel, and determine the target SIc index improvement range based on the water quality parameters;

[0006] S2. Conduct river topographic surveys, design river course direction and slope, and ensure that the river slope does not exceed 10°.

[0007] S3. Based on water quality parameters and design objectives, the river channel is divided into rapid deaeration section, thin-layer flow section, ordinary deaeration section, and thick-layer flow section. The segment length and SIc lifting capacity of each section are determined through field tests.

[0008] S4. Design the riverbed roughness to enhance the degassing effect. The roughness should be 2-4 mm, and the uneven gaps between the unfinished gravel should be used as the site for enhanced degassing.

[0009] S5. Set up drop structures at appropriate locations, adjust the drop height according to the elevation difference of the river channel, and optimize the degassing effect of the drop sections so that the SIc index increase reaches the predetermined target.

[0010] S6. Construct a deaerated river channel and add erosion control dikes on both sides to prevent silt from entering the river channel. The height of the dikes shall not be less than 20cm, and native moss or other suitable vegetation shall be used.

[0011] S7. Conduct river monitoring on the constructed river channel to assess the degassing effect and stability of the river channel;

[0012] S8. Adjust the channel design and structure to ensure that the SIc index of the outlet water reaches greater than 1.0, thereby enabling travertine deposition.

[0013] S9. After the water flows into the area to be restored, the water flow thins out, and the SIc index rapidly increases to greater than 1.2, forming a strong deposition zone, which promotes the deposition and conservation of travertine.

[0014] According to the above technical solution, the design water layer thickness of the S3 rapid degassing river section is less than 5cm and the flow velocity is no more than 1m / s, so as to maximize the degassing capacity of the water body.

[0015] The drop design of S5 ensures that the river channel elevation difference is ≤2 meters and that the SIc index increases by no less than 0.1 when the elevation difference is ≥1.0m.

[0016] The erosion control dike of S6 is constructed using native moss, and the height of the dike is not less than 20cm.

[0017] The monitoring period for the S7 river channel is at least one hydrological year to ensure the stability of the degassing process and the sustained improvement of water quality.

[0018] According to the above technical solution, the carbon dioxide degassing capacity of S8 is enhanced by controlling the water flow thickness and velocity in the river channel and by setting up waterfalls and riverbed roughness, thereby effectively improving the SIc index of the water body and forming a landscape water body with travertine deposition capacity.

[0019] According to the above technical solution, the length of the river channel in S2 can be controlled to be around 100 meters, and the specific length can be adjusted according to the flow rate and the application of degassing enhancement methods.

[0020] The setting of the rapid degassing section and the ordinary degassing section of S3 is based on the water quality conditions and water flow characteristics.

[0021] According to the above technical solution, the setting of the riverbed roughness in S4 includes the following specific measures:

[0022] The surface of the riverbed is uniformly laid with natural or artificial materials such as quartz sand, crushed stone, and gravel with a particle size of 2-4mm, without surface smoothing, so that there are naturally formed uneven gaps between the sand and gravel.

[0023] The rough bed material is fixed to the riverbed substrate by bonding or curing to ensure stability and prevent it from falling off under the scouring of natural water flow;

[0024] The length and location of the riverbed roughness section are scientifically arranged based on the actual water flow velocity, water layer thickness, and water quality.

[0025] According to the above technical solution, the specific structure of the waterfall includes setting up stepped waterfalls, steep slopes, drop slopes or artificial small waterfalls in the middle or outlet of the river channel by artificial or natural terrain, and reasonably selecting single-stage or multi-stage waterfall methods according to the longitudinal elevation difference of the river channel and the water flow rate, with the height of each waterfall controlled between 0.5 and 2 meters, and the total elevation difference not exceeding 2 meters.

[0026] According to the above technical solution, the structure and materials of the erosion control dike are constructed by mixing in-situ soil with native moss and ground cover plants. The height of the dike is set at 20-30cm, and the width is adjusted according to the scale of the river channel and the characteristics of the water flow.

[0027] The construction of erosion control dikes takes into full account the fluctuations in river water levels and includes permeable structures or spillways when necessary.

[0028] According to the above technical solution, the river monitoring includes the deployment of multi-parameter water quality monitoring equipment, flow monitoring sections and video monitoring devices, which can collect key parameters such as flow rate, water level, flow velocity, water temperature, pH value, conductivity, calcium ions, bicarbonate ions, carbon dioxide partial pressure and calcite saturation index in real time or periodically during the operation of the river.

[0029] It connects to the back-end data management system via wireless data transmission, and the monitoring results are used to guide the adjustment of river operation parameters, structural optimization, and degassing effect evaluation.

[0030] According to the above technical solution, the river structure can be flexibly adjusted according to changes in river water volume, seasonal hydrological fluctuations and changes in water quality parameters, including increasing or decreasing the length of the deaerated river section, adjusting the number and height of the waterfalls, and appropriately widening the river or adding branches.

[0031] At the same time, reasonable river maintenance and management measures should be implemented to prevent river siltation, blockage, and excessive vegetation cover.

[0032] Based on the above technical solution, personalized designs are made according to different terrain, geomorphological conditions and existing river structure, including the use of single river channel, double river channel or multi-branch river channel parallel degassing methods, respectively corresponding to application scenarios with different flow rates and river widths.

[0033] In areas with high flow rates or wide channels, a composite structure with multiple branches, localized drop structures, and multi-stage rough bed reinforcement is adopted.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention has a scientific and reasonable structure, is safe and convenient to use, and relies on the existing natural terrain conditions to control the river channel slope, width, bed conditions, and micro-landforms of waterfalls, etc., to build, renovate, or expand river channels, forming natural river channels with high carbon dioxide degassing capacity within a given length, and forming a landscape water body with macroscopic travertine deposition capacity (SIc>1) at the river channel outlet. After the water body enters the conservation area to be restored in a decentralized manner, the index rapidly increases to SIc>1.2, forming a strong deposition zone. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0036] In the attached diagram:

[0037] Figure 1 This is a flowchart of the method of the present invention;

[0038] Figure 2 This is a schematic diagram illustrating the decrease in partial pressure of carbon dioxide in water along the path according to the present invention;

[0039] Figure 3 This is a schematic diagram illustrating the increase of the SIc exponent along the path in this invention;

[0040] Figure 4 This is a schematic diagram of the degassing situation (during the high water season) along the natural degassing river SIc of Lianhuatai in Shenxianchi, Sichuan Province, according to the present invention.

[0041] Figure 5 This is a schematic diagram of the PCO2 degassing situation along the natural degassing river channel of Lianhuatai in Shenxianchi, Sichuan (during the high water season).

[0042] Figure 6 This is a schematic diagram of the degassing situation (dry season) along the natural degassing river SIc of Shenxianchi Lotus Terrace in Sichuan Province, according to the present invention.

[0043] Figure 7 This is a schematic diagram of the PCO2 degassing situation along the natural degassing river channel of Lianhuatai in Shenxianchi, Sichuan (dry season) according to the present invention;

[0044] Figure 8 This is a schematic diagram illustrating the relationship between PCO2, SIc, and pH during natural degassing along the Huanglong Zhuanhuachi River in Sichuan Province, as described in this invention. Detailed Implementation

[0045] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0046] Example 1:

[0047] like Figure 1-3 As shown, the present invention provides a technical solution: a method for constructing naturally deaerated river channels for travertine conservation, comprising the following steps:

[0048] S1. Determine the water quality at the beginning and end points of the river channel, and determine the target SIc index improvement range based on the water quality parameters;

[0049] S2. Conduct topographic surveys of the proposed river channel, design the river channel direction and slope, and ensure that the river channel slope is no greater than 10°.

[0050] S3. Based on water quality parameters and design objectives, the river channel is divided into a rapid deaeration section (thin-layer flow section) and a normal deaeration section (thick-layer flow section), and the segment length and SIc lifting capacity of each section are determined through field tests.

[0051] S4. Design the riverbed roughness to enhance the degassing effect. The roughness should be 2-4 mm, and the uneven gaps between the unfinished gravel should be used as the site for enhanced degassing.

[0052] S5. Set up drop structures at appropriate locations, adjust the drop height according to the elevation difference of the river channel, and optimize the degassing effect of the drop sections so that the SIc index increase reaches the predetermined target.

[0053] S6. Construct a deaerated river channel and add erosion control dikes on both sides to prevent silt from entering the river channel. The height of the dikes shall not be less than 20cm, and native moss or other suitable vegetation shall be used.

[0054] S7. Conduct river monitoring on the constructed river channel to assess the degassing effect and stability of the river channel;

[0055] S8. Adjust the channel design and structure to ensure that the SIc index of the outlet water reaches greater than 1.0, thereby enabling travertine deposition.

[0056] S9. After the water flows into the area to be restored, it can directly form a blue-green water body (depth not less than 30cm) after entering the colored pool. After the water flow spreads out, the SIc index increases rapidly to more than 1.2, forming a strong sedimentation zone, which promotes the deposition and conservation of travertine.

[0057] According to the above technical solution, the influence of the river slope on degassing in the slope design of S2 is relatively limited. From 5° to 30°, the overall lifting range is about 0.03 (Table 1). According to general application requirements, the slope design value is usually ≤10°, and the lifting capacity of SIc per meter is ≤0.06. At the same time, it is ensured that the river water flow velocity is not too fast to avoid the problem of large amount of sediment transport.

[0058] Table 1. Influence of channel slope on SIc lifting capacity

[0059]

[0060] The design water layer thickness of the S3 rapid degassing section is less than 5cm and the flow velocity is no more than 1m / s to ensure that the degassing capacity of the water body is maximized.

[0061] Based on the degassing capacity along the flow path, due to the influence of turbulence during the flow of the landscape water, the partial pressure of carbon dioxide in the water continuously and rapidly decreases, while SIc continuously increases. Figure 2 , Figure 3 As the flow rate increases, degassing weakens, and the increase in SIc decreases. Figure 3 );

[0062] Under a typical slope of 10° and a flow velocity not exceeding 1 m / s, when the water layer is extremely thin at low flow rates, the turbulent boundary layer is fully developed, resulting in relatively thorough deaeration. The average SIc lifting capacity is approximately 0.04–0.06 / m. At higher flow rates, the average SIc lifting capacity decreases to approximately 0.01–0.03 / m. Under normal conditions, when the water layer thickness is >5 cm, the average SIc lifting capacity decreases by one order of magnitude, to approximately 0.001–0.007 / m. The basic channel design is based on baseline values ​​and deaeration lengths for both rapid deaeration sections (thin-layer flow sections) and ordinary deaeration sections (thick-layer flow sections).

[0063] The drop design of S5 ensures that the river channel elevation difference is ≤2 meters and that the SIc index increases by no less than 0.1 when the elevation difference is ≥1m.

[0064] In cascade design, sections of the river channel with elevation differences will form cascades, increasing the SIc index. As the elevation difference increases, the impact of the cascade on deaeration increases (Table 3). In cascade environments with elevation differences ≤ 2 meters, the SIc index increase is generally 0.1-0.2, and can reach 0.3 at extremely low flow rates. When using cascades, utilizing wide river channels and thin water flow results in better deaeration efficiency.

[0065] Table 3. Degassing effect of water droplet

[0066]

[0067] The erosion control dike of S6 is constructed using native moss, and the height of the dike is no less than 20cm.

[0068] The monitoring period for the S7 river channel is at least one hydrological year to ensure the stability of the degassing process and the sustained improvement of water quality.

[0069] According to the above technical solution, the carbon dioxide degassing capacity of S8 is enhanced by controlling the water flow thickness and velocity in the river channel, as well as by setting up waterfalls and riverbed roughness, thereby effectively improving the SIc index of the water body and forming a landscape water body with travertine deposition capacity.

[0070] According to the above technical solution, the length of the S2 river channel can be controlled at around 100 meters, and the specific length will be adjusted according to the flow rate and the application of degassing enhancement methods.

[0071] The design of the rapid degassing section and the ordinary degassing section of S3 is based on water quality conditions and water flow characteristics. The length and water flow layer thickness of each section are scientifically designed to ensure effective degassing and improve the SIc index in each section.

[0072] According to the above technical solution, the specific measures for setting the riverbed roughness of S4 include the following:

[0073] The surface of the riverbed is uniformly covered with natural or artificial materials such as quartz sand, crushed stone, and gravel with a particle size of 2-4 mm, without surface smoothing. This creates naturally formed uneven voids between the sand and gravel, which can significantly increase the contact area between water and gas, improve the degree of boundary layer turbulence, and promote the release of carbon dioxide and degassing efficiency.

[0074] The rough bed material is fixed to the riverbed base by bonding or curing to ensure that it is stable and does not fall off under the scouring of natural water flow, while not affecting the overall structural safety of the riverbed;

[0075] The length and location of the riverbed roughness section are scientifically arranged according to the actual water flow velocity, water layer thickness and water quality to achieve the best deaeration enhancement effect. It can also be adjusted and optimized based on river operation monitoring data to improve the overall travertine conservation efficiency.

[0076] Based on the basic river channel, by increasing the riverbed roughness and the river channel drop, the ability of the SIc index to be improved in local sections is further enhanced, so that the outlet water body can reach the level of SIc>1.

[0077] In riverbed roughness design, when the roughness and water flow thickness are on the same order of magnitude, the rough surface has a better secondary enhancement effect on degassing. The greater the roughness, the better the degassing and the better the SIc index improvement effect (Table 2). It is recommended to use a roughness of 2-4 mm, which can achieve a better degassing enhancement effect on the one hand, and facilitate in-situ application on the other hand. Under this condition, the relative enhancement of the rough surface can generally reach 100%-200% for a relatively smooth riverbed surface. To ensure the application effect, it is necessary to construct a section of riverbed in-situ, solidify the bottom and adhere quartz sand, etc., and not smooth the surface. The uneven gaps between the gravel are the main places for degassing enhancement.

[0078] Table 2. Effect of riverbed roughness on degassing:

[0079]

[0080] According to the above technical solution, the specific structure of the waterfall includes setting up stepped waterfalls, steep slopes, drop slopes or artificial small waterfalls in the middle or outlet of the river channel through artificial or natural terrain, and reasonably selecting single-stage or multi-stage waterfall methods according to the longitudinal elevation difference of the river channel and the water flow rate. The height of each waterfall is controlled between 0.5 and 2 meters, and the total elevation difference is not greater than 2 meters.

[0081] A buffer pool or energy reduction structure is set downstream of the drop section to prevent the water flow from scouring and eroding the downstream riverbed and banks. At the same time, the surface of the drop structure can be made of rough and uneven materials to further enhance the degassing effect.

[0082] Waterfall structures can be combined with river landscape design for beautification and ecological treatment, achieving degassing while enhancing the ecological and landscape value of the river and surrounding areas.

[0083] According to the above technical solution, the structure and materials of the erosion control dike are constructed by mixing in-situ soil with native moss and ground cover plants. The height of the dike is set at 20-30cm, and the width is adjusted according to the scale of the river and the characteristics of the water flow. It can effectively block the silt and runoff on both sides from entering the main channel area of ​​the river, prevent lateral erosion of the river and sediment pollution, and the vegetation on the outer edge of the dike can play multiple roles in soil stabilization and slope protection, ecological restoration and environmental beautification.

[0084] The construction of erosion control dikes takes into full account the fluctuations in river water levels, ensuring that the dikes do not break or overflow during periods of high water levels and floods. When necessary, permeable structures or spillways are installed to ensure the overall safety and ecological connectivity of the river system.

[0085] According to the above technical solution, river monitoring includes deploying multi-parameter water quality monitoring equipment, flow monitoring sections, and video monitoring devices, which can monitor flow rate, water level, flow velocity, water temperature, pH value, conductivity (TDS), and calcium ion concentration (Ca) during river operation. 2+ ), bicarbonate ions (HCO3) - Key parameters such as partial pressure of carbon dioxide (PCO2) and calcite saturation index (SIc) are collected in real time or periodically.

[0086] It connects to the back-end data management system via wireless data transmission to achieve remote monitoring, data analysis, and result visualization; the monitoring results are used to guide the adjustment of river operation parameters, structural optimization, and degassing effect evaluation, providing a scientific basis for subsequent travertine conservation and restoration.

[0087] According to the above technical solution, the river structure can be flexibly adjusted according to changes in river water volume, seasonal hydrological fluctuations and changes in water quality parameters. This includes increasing or decreasing the length of the deaerated river section, adjusting the number and height of the drop levels, appropriately widening the river channel or adding branches, improving the system's adaptability and regulation capacity, ensuring that the SIc value of the outlet water body is greater than 1.0 during the wet season, dry season and sudden hydrological events, and ensuring that the travertine deposition capacity is not affected.

[0088] At the same time, reasonable river maintenance and management measures can be implemented to prevent river siltation, blockage, and excessive vegetation cover, thus maintaining the long-term effectiveness of river degassing and travertine conservation functions.

[0089] Based on the above technical solutions, personalized designs are made according to different terrain, geomorphological conditions and existing river structure, including the use of single-channel, double-channel or multi-branch channel parallel degassing methods, corresponding to application scenarios with different flow rates and river widths; in high-flow or wide-channel areas, a composite structure of multi-branch diversion, local cascades and multi-stage rough bed reinforcement is adopted to improve overall degassing efficiency and travertine deposition capacity.

[0090] In damaged or degraded waterways, ecological restoration measures, such as vegetation transplantation, riverbank reinforcement, and water regulation, can be combined to achieve a comprehensive improvement in waterway function and effective protection of the landscape of the World Natural Heritage site.

[0091] Example 2:

[0092] like Figure 4-7 As shown, the original natural deaeration channel of Lianhuatai in Shenxianchi, Sichuan, was damaged by debris flow, with a width of less than 1 meter and completely covered by shrubs. The carbon dioxide deaeration effect was extremely weak, and the SIc index of the outlet water was about 0, with no travertine deposition capacity. The Lianhuatai area has been continuously degraded since 1976. A 145-meter-long natural deaeration channel was reconstructed, with a channel width of 1-3 meters. Single-channel deaeration was adopted, with a basic SIc increase of 0.005 per meter. Two new waterfalls were added, with SIc increases of 0.1 and 0.17 respectively; the 6-meter thin-layer water flow section had an increase of 0.12.

[0093] The SIc index of the rough bed section is raised to 0.11 in 10 meters, and the SIc index at the outlet is 1.01. The SIc index of the entire river channel is raised by an average of 0.007 per meter, and can reach a maximum of 0.009 during the dry season. After the water enters the area to be restored, the water flow thins out, and the SIc index increases rapidly to 1.2-1.3 (exceeding 1.5 during the dry season). White and golden travertine forms rapidly, forming layers in about 7 days. The beach and colored pools are restored within 1 month.

[0094] Example 3:

[0095] like Figure 8As shown, the natural deaeration channel of Zhuanhuachi in Huanglong, Sichuan, has suffered from severe deaeration due to the extensive expansion of alpine willow shrubs and the narrowing of the channel. After the spring water overflows the surface, the runoff in the forest leads to insufficient deaeration. The water entering the Five-Colored Pool lacks the capacity for travertine deposition, resulting in numerous gray-brown pools with siltation and a dull water color, thus damaging the scenic value of the Five-Colored Pool. Since 2000, this area has continuously degraded. The original channel's average SIc index improvement capacity was approximately 0.003 / m. After using a dual-channel synergistic deaeration method, a 126-meter-long naturally deaerated channel was reconstructed, with an average pH of approximately 0.008 / m. The channel width is 1-4 meters. During the flow, the pH increases approximately linearly with the channel length. SIc showed a linear relationship with pH, ​​while PCO2 showed an exponential decreasing relationship with pH. The newly established thin-layer water flow section (section 1) was 12 meters long, and SIc increased by 0.19; the thin-layer water flow section (section 2) was 16 meters long, and SIc increased by 0.27 to 0.34; there was one waterfall, and SIc increased by 0.12. The overall SIc index of the outlet water body increased by about 0.6. The macro-deposition line of travertine (SIc=1) appeared on the southern edge of the Five-Colored Pool (shifted 15 to 50 meters south from the middle and upper part of the Five-Colored Pool). More new travertine was formed near and north of this line, and the color tone of the Five-Colored Pool landscape was improved. The application of this method has curbed the degradation phenomenon that has been occurring in the Five-Colored Pool of Huanglong for nearly 30 years.

[0096] When the water flow thickness is large (>20cm), deaeration along the way is weak, and SIc will remain at a certain level. Pools with greater water depth (>1.5m) in the river channel will cause a more obvious reverse deaeration effect, that is, SIc decreases, PCO2 increases, and the water body's travertine deposition capacity decreases. When it is necessary to curb the excessive increase of SIc, these two methods can be considered.

[0097] When using this method to reconstruct degassing channels, multiple branch channels need to be used in parallel for larger flows. Under normal circumstances, the channel length can be controlled to about 100 meters, and if the degassing enhancement measures are well applied, it can be controlled to about 50 meters.

[0098] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the construction of a naturally degassing river channel for the conservation of tufa, characterized in that: Includes the following steps: S1. Determine the water quality at the beginning and end points of the river channel, and determine the target SIc index improvement range based on the water quality parameters; S2. Conduct river topographic surveys, design river course direction and slope, and ensure that the river slope does not exceed 10°. S3. Based on water quality parameters and design objectives, the river channel is divided into rapid deaeration section, thin-layer flow section, ordinary deaeration section, and thick-layer flow section. The segment length and SIc lifting capacity of each section are determined through field tests. S4. Design the riverbed roughness to enhance the degassing effect. The roughness should be 2-4 mm, and the uneven gaps between the unfinished gravel should be used as the site for enhanced degassing. S5. Set up drop structures at appropriate locations, adjust the drop height according to the elevation difference of the river channel, and optimize the degassing effect of the drop sections so that the SIc index increase reaches the predetermined target. S6. Construct a deaerated river channel and add erosion control dikes on both sides to prevent silt from entering the river channel. The height of the dikes shall not be less than 20cm, and native moss or other suitable vegetation shall be used. S7. Conduct river monitoring on the constructed river channel to assess the degassing effect and stability of the river channel; S8. Adjust the channel design and structure to ensure that the SIc index of the outlet water is greater than 1.0, thereby enabling travertine deposition. S9. After the water flow enters the area to be restored, the water flow thins out, and the SIc index rapidly increases to greater than 1.2, forming a strong deposition zone, which promotes the deposition and conservation of travertine. The design water layer thickness of the S3 rapid degassing section is less than 5cm and the flow velocity is no more than 1m / s to ensure that the degassing capacity of the water body is maximized. The drop design of S5 ensures that the river channel elevation difference is ≤2 meters and that the SIc index increases by no less than 0.1 when the elevation difference is ≥1.0m. The monitoring period for the S7 river channel is at least one hydrological year to ensure the stability of the degassing process and the sustained improvement of water quality. The specific measures for setting the riverbed roughness in S4 include the following: The surface of the riverbed is uniformly laid with natural or artificial materials such as quartz sand, crushed stone, and gravel with a particle size of 2-4mm, without surface smoothing, so that there are naturally formed uneven gaps between the sand and gravel. The rough bed material is fixed to the riverbed substrate by bonding or curing to ensure stability and prevent it from falling off under the scouring of natural water flow; The length and location of the riverbed roughness section are scientifically arranged based on the actual water flow velocity, water layer thickness, and water quality.

2. The method for constructing a naturally deaerated river channel for travertine conservation according to claim 1, characterized in that, The erosion control dike of S6 is constructed using native moss, and its height is not less than 20cm.

3. The method for constructing a naturally deaerated river channel for travertine conservation according to claim 1, characterized in that, The carbon dioxide degassing capacity of the S8 is enhanced by controlling the water flow thickness and velocity in the river channel, as well as by setting up waterfalls and riverbed roughness, thereby effectively increasing the SIc index of the water body and forming a landscape water body with travertine deposition capacity.

4. The method for constructing a naturally deaerated river channel for travertine conservation according to claim 1, characterized in that, The rapid degassing section and the ordinary degassing section of S3 are set according to the water quality conditions and water flow characteristics.

5. A method for constructing naturally deaerated river channels for travertine conservation according to claim 1, characterized in that, The specific structure of the waterfall includes setting up stepped waterfalls, steep slopes, drop slopes, or artificial small waterfalls in the middle or at the outlet of the river channel through artificial or natural terrain. Based on the longitudinal elevation difference of the river channel and the water flow, a single-stage or multi-stage waterfall method is reasonably selected, with the height of each stage controlled between 0.5 and 2 meters, and the total elevation difference not exceeding 2 meters.

6. A method for constructing naturally deaerated river channels for travertine conservation according to claim 1, characterized in that, The structure and materials of the erosion control dike are constructed by mixing in-situ soil with native moss and ground cover plants. The height of the dike is set at 20-30cm, and the width is adjusted according to the scale of the river channel and the characteristics of the water flow. The construction of the erosion control dike takes into full account the fluctuations in river water level.

7. A method for constructing naturally deaerated river channels for travertine conservation according to claim 1, characterized in that, The river monitoring includes the deployment of multi-parameter water quality monitoring equipment, flow monitoring sections, and video monitoring devices, which can collect key parameters such as flow rate, water level, flow velocity, water temperature, pH value, conductivity, calcium ions, bicarbonate ions, carbon dioxide partial pressure, and calcite saturation index in real time or periodically during river operation. It connects to the back-end data management system via wireless data transmission, and the monitoring results are used to guide the adjustment of river operation parameters, structural optimization, and degassing effect evaluation.

8. A method for constructing naturally deaerated river channels for travertine conservation according to claim 1, characterized in that, The river structure is flexibly adjusted according to changes in river water volume, seasonal hydrological fluctuations, and changes in water quality parameters, including increasing or decreasing the length of deaerated river sections, adjusting the number and height of waterfalls, and appropriately widening the river channel or adding branches. At the same time, reasonable river maintenance and management measures should be implemented to prevent river siltation, blockage, and excessive vegetation cover.

9. A method for constructing naturally deaerated river channels for travertine conservation according to claim 1, characterized in that, Personalized designs are made based on different terrain, geomorphological conditions and existing river structure, including the use of single-channel, double-channel or multi-branch channel parallel degassing methods, corresponding to application scenarios with different flow rates and river widths. In areas with high flow rates or wide channels, a composite structure with multiple branches, localized drop structures, and multi-stage rough bed reinforcement is adopted.

Images