An in-situ measuring device for studying the sediment connectivity under the influence of hydrological processes in wetlands

Abstract

The application discloses an in-situ measuring device for studying the connection of sediments under the influence of wetland hydrological processes, which comprises at least two traps, the upper end of each of the traps is open for the entry of silt, and the inside of each of the traps is designed with a partition plate, the partition plate divides the inside of the trap into a plurality of separate chambers, the partition plate in different traps is provided with a plurality of holes, and the number and / or size of the holes on the partition plate in different traps are different. The device is simple in structure and convenient to use, the separate chambers are separately arranged, each layer is provided with a first pore water collecting bottle, the separate chambers are divided by the holes, and the size and number of the holes of the partition plate are used to simulate the influence of the hydrological connection process on the migration and transformation of chemical elements in the sediments.

Description

Technical Field

[0001] The invention relates to the technical field of ecohydrological research, and in particular to an in-situ measuring device for studying sediment connectivity under the influence of wetland hydrological processes. Background Art

[0002] Wetland hydrological connectivity is a hot topic in ecohydrology. Beyond conceptual and theoretical modeling, in situ experiments to quantify sediment connectivity and the associated chemical connectivity characteristics under changing hydrological processes remain a key challenge in international hydrology, geography, ecology, and environmental science. Previous studies of hydrological, sediment, and chemical connectivity have mostly relied on field sampling of water and sediment, followed by laboratory measurements of sediment content, nutrient content, or isotopic concentrations of biogenic elements to roughly quantify their spatial distribution patterns. Based on these distribution patterns, the absolute change between points is calculated using the Euclidean distance algorithm. Simulations are then performed using mathematical models to match the observed data and predict connectivity. However, this crude sampling approach fails to fully capture the dynamics of each spatial point and makes it difficult to quantify the interplay between water, sediment, and chemical elements. This challenge has become a major obstacle to the development of refined models for hydrological connectivity research. Summary of the Invention

[0003] To address these issues, the present invention provides an in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes. By placing the device on-site, the natural settling characteristics of sediments (silt, debris, plant and animal remains, etc.) are utilized to quantify the spatiotemporal distribution of sediment flux, thus avoiding the potential for sampling discontinuities and interference caused by human factors and weather over short periods of time, which can lead to unreliable experimental results. Therefore, by deploying a vertical sediment trap, combined with isotopic analysis of the collected samples, the sedimentary characteristics of the sediments within the study area can be quantitatively revealed.

[0004] The technical solution adopted by the present invention to solve its technical problems is: an in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes, comprising at least two traps, each of which has an opening at the upper end, for allowing silt / sediment to settle by itself during the process of being carried by water flow to achieve the purpose of collection, and a partition is designed inside each of the traps, which divides the inside of the trap into several separation chambers, and some of the partitions in different traps may be provided with first holes, and the number and / or size of the first holes on the partitions in different traps are different. Finally, the contents of sediments and elements in different traps are compared to deeply study the influence of different hydrological connectivity processes on sediment connectivity processes, as well as the occurrence form, migration and transformation laws of key chemical elements in sediments.

[0005] Preferably, the trap is multi-layered, with several interlayers arranged vertically. The sidewalls of the trap are provided with hinged openings corresponding to each interlayer. The hinges are opened by rotating or pulling out the hinges, allowing sampling from different layers. This multi-layered arrangement can be used to determine the composition and content of nutrients in soil and pore water across different sediment layers, as well as the stratified variations in sediment particle size and pore water content within the sediment.

[0006] Preferably, a first pore water collection bottle is provided in each interlayer. A first filter membrane of different pore sizes will be installed at the mouth of the first pore water collection bottle as needed to allow water to enter but prevent the entry of sediment. The first pore water collection bottle is used to sample sediment pore water within a certain period of time and to determine the N and P elements in the pore water. At the same time, the concentration difference between each layer can be quantified based on the concentration of nutrient elements N and P in the sediment pore water in the collector, so as to indirectly reflect the difference in nutrient elements in the sediment pore water of each layer. When collecting layered soil samples, the entire device is removed from the sediment, and by manually pulling the loose-leaf, each layer of sediment is collected and placed in a sediment storage bag, and then brought back to the laboratory for analysis and determination of sediment deposition amount, biogenic elements C, N, S and P and other element contents. The changes between different layers can be used to reveal the effects of vertical hydrological connectivity on the sediment deposition process and the exchange flux of biogenic elements at the interfaces of different layers. The presence or absence of holes in the septa can be used to illustrate the effects of lateral hydrological connectivity on the sediment deposition and the flux exchange of biogenic elements between different compartments.

[0007] Preferably, each of the collectors is also connected to a collection tube, the top of the collection tube is exposed to the ground at a height of about 2m, the bottom of the collection tube is connected to the collector through an elbow, and a number of water inlet holes are provided at different heights along the upper edge of the collection tube for collecting mud and suspended sand from the water body (sediment in the water body above the surface), that is, for determining the content of sediment, organic matter and debris in the water body.

[0008] Preferably, a second pore water collection bottle is also connected to the bottom of the elbow, and a second filter membrane for filtering mud and sand is provided at the upper seal of the second pore water collection bottle to prevent mud and sand from entering the bottle (the second pore water collection bottle is the same as the first pore water collection bottle in the collector, but is slightly larger in size).

[0009] Preferably, the collection tube is also provided with a scale, which can be used to directly observe the water level during sampling. The collection tube is used to install a water level meter to monitor the water level change pattern within a time period.

[0010] Preferably, the collector and the collection tube are made of stainless steel, or PVC, organic glass, etc.

[0011] Preferably, a human-controllable electronic device can be set up at a specific location as needed; an experimental control program can also be set up, a mobile phone app can be established, and connected to a mobile phone for real-time monitoring and management.

[0012] The beneficial effects of the present invention are as follows: the device has a simple structure and is easy to use. By setting up separate collection chambers, providing a first pore water collection bottle on each layer, adopting the method of segmenting the collection chambers with or without pore connectivity, and adjusting the size and number of pores in the segmentation sheets, the effect of hydrological connectivity on the migration and transformation of chemical elements in sediments can be simulated and studied. The device is placed on site, and the natural settling characteristics of sediments (silt, debris, plant and animal remains, etc.) are used to quantify the spatiotemporal distribution pattern of sediment flux, thus avoiding the unreliability of experimental results caused by sampling discontinuity and interference due to human factors and weather in a short period of time. Therefore, by deploying a vertical sediment trap and combining it with isotope analysis of the collected samples, the sedimentary characteristics of the sediments in the study area can be quantitatively revealed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0014] Figure 2 It is a schematic diagram of the structure of a single collector of the present invention;

[0015] Figure 3 for Figure 2 The structural diagram marked with 1 in the figure;

[0016] Figure 4 for Figure 2 Schematic diagram of the structure marked 10. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] like Figures 1-4 As shown, an in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes includes at least two traps (such as Figure 2As shown, in this embodiment, three collectors A, B, and C are taken as examples, and more collector combinations can also be used. The upper end of each of the collectors is opened for the entry of mud and sand. A separator 1 is designed inside each of the collectors 1. The separator 1 divides the interior of the collector into several separation chambers. The separators 1 in different collectors may or may not have the first holes 10 (that is, the separators 1 in some of the collectors have the first holes 10, and some do not). The number of the first holes 10 and / or the size of the first holes on the separators 1 in different collectors may be different. The sizes of the first holes 10 are different (i.e., the number and / or size of the first holes on the separator 1 in the A trap, the B trap, and the C trap are different). The bottom of the trap is fully open, fully closed, or blocked, but with a second hole (the number or size can be adjusted according to experimental requirements) to simulate the influence of vertical hydrological connectivity on various sediment parameters. The interior of the trap adopts a multi-layer arrangement, and a plurality of interlayers are provided in the vertical direction. The side wall of the trap is provided with a hinge opening 2 corresponding to each of the interlayers. The hinge opening 2 is opened by rotating or pulling out the hinge, thereby completing the sampling activities of different layers. A first pore water collection bottle 3 is provided in each interlayer. The mouth of the first pore water collection bottle 3 will be installed with a first filter membrane of different pore sizes as needed to allow water to enter but prevent the entry of sediment. The first pore water collection bottle 3 is used to sample sediment pore water within a certain period of time and to determine the N and P elements in the pore water. At the same time, the concentration difference between each layer can be quantified based on the concentration of the nutrient elements N and P in the sediment pore water in the collector, thereby indirectly reflecting the difference in nutrient elements in the sediment pore water of each layer. Each of the traps is also connected to a collection tube 4, the top of which is about 2 meters above the ground surface. The bottom of the collection tube 4 is connected to the trap via an elbow, and a barrier glass 40 is installed on the elbow. Several water inlet holes 41 are provided at different heights along the upper edge of the collection tube to collect mud and suspended sand from the water body (mud and sand in the water body above the surface), that is, to measure the content of mud, organic matter and debris in the water body. A second pore water collection bottle 5 is also connected to the bottom of the elbow. The upper end of the second pore water collection bottle 5 is sealed with a second filter membrane 51 for filtering mud and sand to prevent mud and sand from entering the bottle. When collecting layered soil samples, the entire device is removed from the sediment, and each layer of sediment is collected and placed into a sediment collection bag by manually pulling the loose-leaf device. The bag is then taken back to the laboratory for analysis and determination of the sediment deposition amount and the content of biogenic elements such as C, N, S and P.The changes between the layers can be used to reveal the effects of vertical hydrological connectivity on the sediment deposition process and the exchange flux of biogenic elements at the interfaces of the layers. The presence or absence of holes in the spacers can be used to illustrate the effects of lateral hydrological connectivity on sediment deposition and the flux exchange of biogenic elements between compartments. Finally, the contents of sediments and elements in different traps are compared to further study the effects of different hydrological connectivity processes on the sediment connectivity process and the occurrence, migration, and transformation patterns of key chemical elements in the sediment. The multi-layer setting can be used to determine the differences in the composition and content of nutrient elements in the soil and pore water of different sedimentary layers, as well as the stratified variation characteristics of the sediment particle size and interstitial water content in the sediment. The adjacent layers and internal compartments are used to measure the differences between the compartments in order to achieve quantitative calculations of lateral and vertical connectivity. The calculations are mainly obtained by taking the difference between the materials or elements in adjacent or different layers.

[0019] Preferably, the collection tube is also provided with a scale, which can be used to directly observe the water level during sampling. The collection tube is used to install a water level meter to monitor the water level change pattern within a time period.

[0020] Preferably, the collector and the collection tube are made of stainless steel, or PVC, organic glass, etc.

[0021] The above is only a preferred embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. In other words, any simple equivalent changes and modifications made according to the scope of the patent application and the content of the invention description are still within the scope of the patent of the present invention.

Claims

1. An in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes, characterized in that: The invention comprises at least two collectors, each of which has an opening at the upper end for the entry of mud and sand. A partition is designed inside each of the collectors, and the partition divides the interior of the collector into several separation chambers. In each of the collectors, some of the partitions are provided with first holes, while some of the partitions are not provided with first holes. The number of the first holes and / or the size of the holes on the partitions in different collectors are different. The bottom of the collector is fully open, fully closed, or blocked but with a second hole.

2. The in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes according to claim 1, characterized in that: A plurality of interlayers are arranged in the upper and lower directions inside the collector, and a hinged opening corresponding to each of the interlayers is arranged on the side wall of the collector.

3. The in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes according to claim 2, characterized in that: A first interstitial water collection bottle is provided in each interlayer, and a first filter membrane is installed at the bottle mouth of the first interstitial water collection bottle.

4. The in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes according to claim 1, characterized in that: Each of the collectors is also connected to a collection pipe, the top of the collection pipe is exposed to the ground surface, the bottom of the collection pipe is connected to the collector through an elbow, and a plurality of water inlet holes are provided at different height positions along the collection pipe.

5. The in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes according to claim 4, characterized in that: The bottom of the elbow is also connected to a second interstitial water collection bottle, and a second filter membrane is provided at the upper sealing end of the second interstitial water collection bottle.

6. The in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes according to claim 4, characterized in that: The collection tube is also provided with a scale.

7. The in-situ measurement device for studying sediment connectivity under the influence of wetland hydrological processes according to claim 4, characterized in that: The trap and the collection tube are made of stainless steel, PVC or organic glass.

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