CN210198672U - An artificial watershed suitable for studying the relationship between rainfall and stratified runoff - Google Patents

Abstract

The utility model relates to an artificial drainage basin, especially the artificial drainage basin who is fit for studying rainfall-layering runoff relation, including the triplex: the artificial watershed comprises a main body part, an input part and an output part. The main body part comprises a watershed boundary (1), an experimental soil body (2), a longitudinal collecting ditch (3) and a transverse collecting ditch (4); the input part comprises an artificial rainfall system and a measuring station network. The output part refers to an observation chamber (7) of the artificial watershed, and layered flow measurement weirs (9) are arranged according to the number of the flow collection grooves and are provided with water sample collection points of the system. For the research of utilizing natural experiment basin rainfall-layering runoff relation in the traditional meaning, the utility model discloses can be at tripartite precision measurement hydrology key element such as input, output and internal variable to analyze the isotopic composition and the water chemistry index of water sample, utilize the tracer effect of these indexes to study basin hydrology mechanism.

Description

Artificial drainage basin suitable for researching rainfall-stratified runoff relation

Technical Field

The utility model relates to an artificial drainage basin, especially the artificial drainage basin who is fit for studying rainfall-layering runoff relation belongs to hydrology experiment technical field.

Background

The rainfall-runoff relation is a basic problem in hydrology and hydrology experiments and is also the main content of hydrology simulation. At present, the rainfall-runoff relation of a drainage basin is researched, basically, rainfall is measured to serve as an input variable of the drainage basin, total runoff is measured to serve as an output variable of the drainage basin at an outlet section of the drainage basin, the rainfall-runoff relation of the drainage basin is researched in a black box type mode, the water motion rule inside the drainage basin cannot be deeply disclosed, and new theoretical support cannot be provided for development of hydrological models and hydrology. Therefore, a brand-new hydrological experimental facility is necessary to be designed and constructed to study the rainfall-runoff relation of the drainage basin, a new method, new data and a new theory are provided for the development of hydrological models and hydrology, and the method has important scientific significance and application value.

SUMMERY OF THE UTILITY MODEL

The utility model provides a technical problem be: an artificial drainage basin is constructed, the input quantity, the output quantity and the internal variable of the drainage basin are comprehensively obtained, and the artificial drainage basin is used for researching the rainfall-layered runoff relation of the drainage basin.

In order to solve the technical problem, the utility model provides a technical scheme is: an artificial drainage basin suitable for researching rainfall-stratified runoff relation is designed and constructed, and comprises three parts: the artificial watershed comprises a main body part, an input part and an output part.

The main body part comprises a basin boundary (1), an experimental soil body (2), a longitudinal collecting ditch (3) and a transverse collecting ditch (4). The basin boundary (1) is formed by constructing a water-resisting boundary by using concrete from an upstream boundary, two side boundaries and a bottom boundary, the shape of the peripheral boundary is a natural basin boundary such as a leaf shape, a fan shape and the like, regular boundaries such as a rectangle and the like are not adopted, and the basin area is 100-10000 m-²Within the range; the bottom boundary is divided into two pieces by a middle line, and the two pieces are collected at the middle line by an inclination angle of 5-20 degrees; the lower boundary has a longitudinal inclination of 5-20 degrees from upstream to downstream of the basin. The area above the longitudinal collecting ditch is not ditched and is used as an independent flow generating area, namely a ditch-free area. And in the boundary (1) of the flow field, filling soil with the thickness of 1-5 m as an experimental soil body (2) in a layered manner. Excavating a longitudinal flow collecting ditch (3) with the width of 30-100cm in the center of an experimental soil body, arranging transverse flow collecting ditches (4) at the outlet boundary of a flow field, and erecting a plurality of layers of flow collecting ditches in the ditches at intervals of 30-60cm, wherein each layer of flow collecting ditches comprises a layer of flow collecting ditch (25) for directly collecting rainfall, a layer of flow collecting ditch (26) for collecting surface runoff and a plurality of layers of flow collecting ditches (27) for collecting subsurface runoff. Layered panels (21) with the length of 10-20cm on two sides of the collecting groove are directly cut into the experimental soil body (2) and are used for separating runoff generated by different layers of soil.

The water-proof bottom plate of the watershed boundary (1) is built on a hard foundation rock surface, and soil and a weathered layer above the foundation rock surface are removed before construction.

The material of the flow collecting groove (25) for directly collecting rainfall, the material of the flow collecting groove (26) for collecting surface runoff, the material of the flow collecting grooves (27) for collecting subsurface runoff and the material of the flat plates (21) on the two sides of the flow collecting groove (27) for collecting subsurface runoff are 304 stainless steel plates, and the thickness of the stainless steel plates is 2-5 mm.

A reverse filtering quartz sand layer (24) is arranged among the longitudinal collecting ditch (3), the transverse collecting ditch (4) and the experimental soil body (2), so that the produced flow in the soil body can smoothly enter the collecting ditch, and soil loss is prevented. The interface between the reverse-filtering quartz sand layer (24) and the experimental soil body (2) is separated by a nylon net (23), and the reverse-filtering quartz sand layer is separated from the longitudinal collecting ditch (3) and the transverse collecting ditch (4) by a stainless steel net (22). The width of the reverse filtering quartz sand layer is 10-20cm, the half part close to the nylon net (23) is fine sand (the diameter is 0.5-1mm), and the half part close to the stainless steel net (22) is coarse sand (the diameter is 1-2 mm).

The experimental soil body (2) is provided with a soil moisture profile tachymeter (16) to monitor the change of the soil moisture content; an underground water well (15) is arranged, a pressure type water level meter is arranged in the underground water well to monitor the underground water level, and meanwhile, a water suction pipe is preset to be used for extracting an underground water sample; a transmitter (19) and a receiver (20) of a large-aperture or small-aperture scintillator are respectively arranged at two points outside the drainage basin to monitor the evapotranspiration amount of the drainage basin; argil heads (17) are embedded at different depths of an experimental soil body in the flow field and are used for extracting a soil water sample.

The input part comprises an artificial rainfall system and a measuring station network. The artificial rainfall system comprises a plurality of movable travelling crane nozzle groups (5), the arrangement quantity is determined according to the condition that the whole artificial drainage basin can be covered, and the controllable rainfall intensity of the artificial rainfall system is within the range of 6-240 mm/h. When an artificial rainfall experiment needs to be performed, the artificial rainfall system is moved to the artificial drainage basin through the travelling track (6); when the artificial rainfall experiment is not performed, the artificial rainfall system is moved out of the artificial flow area so as to avoid influencing the measurement of the natural rainfall. The rain gauge station network is provided with enough rain gauges (18) according to the area and the shape of the drainage basin, and the artificial rainfall and the natural rainfall are monitored in real time.

The rain gauge (12) can adopt a tipping bucket rain gauge or a weighing rain gauge to measure the rainfall process, and can also adopt a standard rain gauge to measure the total amount of rainfall in a field.

The output part refers to an observation chamber (7) of the artificial watershed, layered flow measurement weirs (9) are arranged in the observation chamber according to the number of the flow collection grooves, and the longitudinal flow collection grooves (3), the transverse flow collection grooves (4) and the flow measurement weirs (9) are connected through bent flow guide grooves (8). After passing through the layered runoff weir, each layered runoff is collected into a buffer pool (10), and a total runoff weir (11) is arranged at the outlet of the buffer pool.

The layered flow measuring weir (9) and the total runoff flow measuring weir (11) can adopt a triangular weir, a rectangular weir or a logarithmic weir and a combination thereof according to the flow.

And layered runoff sampling points (28) are distributed between the diversion trench (8) and the flow measurement weir (9) and are used for collecting layered runoff water samples.

The observation room (7) is provided with a rainfall sampler, which comprises a rain bearing device (12), a water storage bottle (13) and a connecting pipe (14) arranged between the rain bearing device and the water storage bottle.

Has the advantages that:

for the research of the rainfall-runoff relation of utilizing the natural experiment basin in the traditional meaning, the utility model discloses can be at tripartite accurate measurement hydrology key element such as input, output and internal variable: in the aspect of input variables, the total amount, process and distribution of natural rainfall or artificial rainfall input into the drainage basin can be accurately measured; in the aspect of output variables, surface runoff at an outlet of a drainage basin and subsurface runoff generated by soil at different depths can be monitored, wherein the layered runoff cannot be obtained by adopting a traditional total runoff measuring mode and structure), and the evapotranspiration of the surface; in the aspect of internal variables, the soil moisture content and the underground water level can be synchronously monitored.

The utility model discloses except the accurate measurement that can realize the water yield, still be equipped with the sampling equipment of rainfall, layering runoff, soil water and groundwater, can gather high time resolution's water sample at rainfall-runoff in-process, carry out the isotopic composition and the water chemistry index of analysis water sample, utilize the tracer effect of these indexes to study basin hydrology mechanism.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a cross-sectional view of the collecting channel of the present invention.

Fig. 3 is a schematic view of the design in the observation room of the present invention.

Fig. 4 is a diagram showing an example of rainfall process measured in a hydrographic mountain.

Fig. 5 is an example graph of a layered runoff process measured in a hydrographic mountain.

FIG. 6 is an example graph of the water chemistry ion process in stratified runoff measured in hydrographic mountains.

In the figure: 1-artificial watershed boundaries; 2-experimental soil body; 3-longitudinal collecting channels; 4-transverse collecting channels; 5-artificial rainfall traveling crane spray head group; 6-orbit; 7-observation room; 8-a diversion trench; 9-layered flow measurement weir; 10-a buffer pool; 11-total runoff measuring weir; 12-a rain bearing device; 13-a water collecting bottle; 14-a connecting tube; 15-underground water well; 16-soil moisture content profile tachymeter; 17-embedding clay heads; 18-a rain gauge; 19-a transmitter of a small aperture scintillator; 20-receiver of small aperture scintillation detector; 21-a layered panel of a launder; 22-stainless steel mesh; 23-nylon mesh; 24-reverse filtering the quartz sand; 25-a collecting groove for collecting rainfall, 26-a collecting groove for collecting surface runoff and 27-a collecting groove for collecting subsurface runoff; 28-stratified runoff sampling point

Detailed Description

The technical solution of the present invention will be further described in detail with reference to the accompanying drawings.

Example (b):

by adopting the technical scheme of the utility model, an artificial watershed-hydrology mountain experimental watershed (hereinafter referred to as 'hydrology mountain') suitable for researching rainfall-layered runoff relation is constructed in Chuzhou experimental base of Nanjing Water conservancy science research institute. The hydrology mountain is built near the exit of the flower mountain watershed in the west of Chuzhou city on a hill slope with an inclination angle of about 14 degrees (118 degrees 12 '34.68' E, 32 degrees 17 '25.75' N). Before the water wenshan is built, soil and weathered layers on the surface layer of a hillside are removed to expose a fresh rocky basement rock surface, then a bottom plate of the water wenshan is poured on the basement rock surface by using concrete and serves as an underwater isolation boundary, the longitudinal inclination angle of the bottom plate is 14 degrees, and two sides of the center line of the bottom plate are converged on the center line in an opposite mode by two slopes with the inclination angles of 10 degrees. Concrete is poured into the periphery of the water-proof side wall with the height of 130cm (except for the drainage basin outlet) of the water-proof mountain. Taking soil from nearby farmland, backfilling the soil layer by layer into the hydrological mountain, wherein the average thickness of the soil is about 100 cm. The slope surface area of the whole drainage basin is 512m²The projected area on the horizontal plane is 490m²。

And excavating a collecting ditch with the width of about 40cm to the bottom plate at the center and the outlet of the drainage basin. Five layers of stainless steel collecting grooves with the width of 40cm are erected in the collecting grooves, and the uppermost layer is 5cm higher than the ground and is used for collecting rainfall; the second layer is flush with the ground, surface runoff is collected and recorded as RC; the stainless steel panels of the lower three layers of the collecting grooves are respectively cut into soil with the depth of 30cm, 60cm and 100cm, and the subsurface runoff generated by the soil layers with the depth of 0cm to 30cm, 30cm to 60cm and 60cm to 100cm is respectively collected and is respectively marked as R30, R60 and R100.

A mobile artificial rainfall system is erected above a drainage basin and comprises five groups of artificial rainfall traveling cranes, wherein each group of the traveling cranes is provided with 26 large, medium and small sprayers, and the total number of the sprayers is 390. The rainfall area formed by spraying is 656m²The whole water wenshan can be effectively covered. By controlling the opening and the pressure of the large, medium and small spray heads, the artificial rainfall with the rain intensity of 10-200mm/h can be manufactured.

And carrying out hydrological full factor (water quantity plus water quality) observation on the hydrological mountain. In the aspect of rainfall observation, 5 rain gauges and 12 rain gauges are installed, and the model of the rain gauge is JQH-2; the rain gauge adopts two 1mm tipping bucket rain gauges (JDZ10-1, Nanjing institute of Water conservancy Automation) and 3 0.1mm tipping bucket rain gauges (SL3-1, Shanghai weather instrumentation and plant), and the measurement time resolution is 1 minute. In the aspect of runoff observation, each layer of runoff is guided to the observation chamber through a connecting groove with the length of 6 meters between the artificial watershed and the observation chamber, and then the flow is measured by utilizing a triangular-logarithmic weir. The trough surface, the 30cm, the 60cm and the 100cm runoff were distributed from left to right in the observation room. In terms of soil moisture content observation, 31-section soil moisture content tacheometers (PR2, Delta, uk) were installed to measure soil moisture content at depths of 10, 20, 30, 40, 60 and 100 cm. In the aspect of underground water level observation, 22 steel pipes penetrating through a soil layer to a concrete bottom plate are arranged in a hydrological mountain area to serve as underground water wells, openings are formed in the bottoms of the steel pipes by 20cm, pressure type water level gauges (LEV01, ADCON, Austria) are installed in the underground water wells to monitor the underground water level, and data are sent to a base server through a remote measuring terminal. In the aspect of evapotranspiration observation, two sets of systems are adopted to measure the evapotranspiration and adopt a small-aperture scintillation spectrometer. In the aspect of water sample collection, the hydrographic mountain rainfall sampling can be through two kinds of modes water sample collection: firstly, the 'groove surface' of the uppermost layer of the layered radial-flow groove is used as a large-scale rain gauge to guide rainfall into an observation room for collection; and secondly, a rainfall sampler with the diameter of 40cm is installed on the top of the observation room, and rainfall is guided into the observation room through a pipeline to be collected. The hydrology mountain runoff sampling adopts the layering runoff sampling system, and the system can rapidly and synchronously collect runoff water samples of all layers. The water sample collection point is arranged in front of the flow measurement weir water tank, so that the influence of the old water in the water tank is avoided. 9, 12 and 10 argil heads are respectively buried in 15 cm, 45 cm and 85cm deep soil of the hydrographic mountains as soil water collecting points, after the hydrographic mountains are installed at an early stage, the water pumping effect is good, and in a later stage, because the argil heads are blocked, the water pumping effect is poor, the argil heads need to be distributed in an important mode. A hard air pipe with the inner diameter of 3mm and the outer diameter of 4mm is bundled on a pressure type water level gauge in 22 underground water wells to be used as an underground water sampling point. And arranging a negative pressure system on the side walls of two sides of the drainage basin to pump soil water and underground water into the sampling bottle.

From experimental data measured by hydrographic mountain devices, the following conclusions have been reached:

(1) rainfall was generally uniform in the hydrological mountain runoff area, which can be reflected by the distribution of rainfall of different magnitudes measured by 11 rain gauges, with a mean square error within 0.6mm (table 1), which had little effect on analyzing the rainfall-runoff relationship for rainfall above 20 mm. Therefore, the measurement requirement can be met by using 2 rain gauges (with the resolution of 0.1mm and 1mm) to measure the heavy rainfall process and then using 2 rain gauges to measure the rainfall from 8 points to 8 points. The reason for setting 2 rain gauges is to prevent the appearance of artificial gross errors.

TABLE 1 RECORDING TABLE FOR MEASURING FIELD AND SUSPENSION LEVEL OF RAIN MEASURER

(2) The triangular-logarithmic weir provided in the observation chamber can accurately measure the rainfall and stratified runoff processes (see fig. 4 and 5), and the change process of water chemical ions in runoff (see fig. 6). Under the condition that the rainfall is more than 25mm, the runoff proportions of the four layered runoff surface runoff of the hydrographic mountain, 0-30cm, 30-60cm and 60-100cm are respectively 35.3%, 17.7%, 13.6% and 33.4%. The ground runoff is the sum of the latter, and accounts for about 65%, which indicates that the ground runoff of the hydrological basin is dominant during heavy rain. The layered runoff results cannot be obtained by adopting the traditional total runoff measurement mode, and the hydrological process can be deeply known.

Claims (9)

1. An artificial watershed suitable for studying the relationship between rainfall and stratified runoff is characterized in that: the input, output and internal variables of the watershed are comprehensively obtained, and the rainfall-stratified runoff relationship of the watershed is used to study, including three parts: artificial The main part, the input part and the output part of the watershed, the input part includes the artificial rainfall system and the network of measuring stations, the output part refers to the observation room (7) of the artificial watershed, and the main part includes the watershed boundary (1) , the experimental soil (2), the longitudinal collecting ditch (3) and the lateral collecting ditch (4); the watershed boundary (1) is composed of a surrounding boundary and a bottom boundary, and the surrounding boundary and the bottom boundary are both constructed with concrete Waterproof boundary, the shape of the surrounding boundary is leaf-like or fan-shaped natural watershed boundary, not using rectangular regular boundary, the watershed area is 100-10000m ² ; Center line; the longitudinal inclination angle of the bottom boundary from upstream to downstream of the watershed is 5-20 degrees; within the watershed boundary (1), 1-5 m thick soil is backfilled in layers as the experimental soil body (2); in the experimental soil body (2) ) with a longitudinal collecting ditch (3) with a width of 30-100 cm in the center of the excavation, and no ditch is opened in the area above the longitudinal collecting ditch (3), as an independent flow-producing area, that is, a ditch-free area; at the outlet boundary of the watershed Lay horizontal collecting ditch (4), in the lateral collecting ditch (4), erect multi-layer collecting troughs every 30-60cm, including a layer of collecting troughs (25) for directly collecting rainfall, and a layer for collecting surface runoff. A collecting trough (26) and several layers of collecting troughs (27) for collecting subsurface runoff; the layered panels (21) with 10-20 cm on both sides of the collecting trough are directly cut into the experimental soil (2) for To separate the runoff generated by different layers of soil, in the observation room (7) of the artificial watershed, according to the number of collecting grooves, set up layered flow measuring weirs (9), vertical collecting ditch (3), and horizontal collecting ditch (4) It is connected with the stratified weir (9) by a bent diversion groove (8); after each stratified runoff passes through the stratified weir (9), it is collected into the buffer pool (10), and the runoff in the buffer pool ( A total runoff flow measuring weir (11) is arranged at the outlet of 10). 2. The artificial watershed suitable for studying rainfall-stratified runoff relationship according to claim 1, is characterized in that: described experimental soil body (2) is arranged with soil moisture profile speed measuring instrument (16) to monitor soil moisture content. change; laying groundwater wells (15), installing pressure-type water level meters in the wells to monitor groundwater levels, and preset suction pipes for taking groundwater samples; arranging large- or small-aperture scintillator transmitters at two points outside the watershed (19 ) and a receiver (20) to monitor the evapotranspiration in the watershed; clay heads (17) are pre-buried at different depths of the experimental soil body in the watershed for taking soil water samples. 3. The artificial watershed suitable for studying the relationship between rainfall and stratified runoff according to claim 1 is characterized in that: the water-proof floor of the watershed boundary (1) is constructed on the hard bedrock surface, and the Soil and regolith removal above the bedrock face. 4. The artificial watershed suitable for studying the relationship between rainfall and stratified runoff according to claim 1, is characterized in that: the collecting trough (25) for directly collecting rainfall, the collecting trough (26) for collecting surface runoff, The collecting tank (27) for collecting the runoff under the ground and the layered panels (21) on both sides are made of 304 stainless steel plate with a thickness of 2-5mm. 5. The artificial watershed suitable for studying the relationship between rainfall and stratified runoff according to claim 1 is characterized in that: the vertical collecting ditch (3) and the lateral collecting ditch (4) and the experimental soil body (2) are arranged between The reverse filter quartz sand layer (24) can make the flow in the soil smoothly enter the collecting ditch and prevent soil loss at the same time; the interface between the reverse filter quartz sand layer (24) and the experimental soil (2) is made of nylon The mesh (23) is separated, and the quartz sand layer (24) for reverse filtering is separated from the vertical collecting ditch (3) and the horizontal collecting ditch (4) by a stainless steel mesh (22); the width of the reverse filtering quartz sand layer (24) The diameter is 10-20 cm, and the half near the nylon mesh (23) is fine sand with a diameter of 0.5-1 mm, and the half near the stainless steel mesh (22) is coarse sand with a diameter of 1-2 mm. 6. the artificial watershed suitable for researching rainfall-stratified runoff relationship according to claim 1, is characterized in that: laying artificial rainfall system and measuring station network, artificial rainfall system comprises several movable driving sprinkler groups (5) , the number of layouts is determined according to the ability to ensure that the entire artificial watershed can be covered. The rain intensity that can be controlled by the artificial rainfall system is within the range of 6-240mm/h. Move to the artificial watershed; when not in the artificial rainfall experiment, move the artificial rainfall system outside the artificial watershed to avoid affecting the measurement of natural rainfall. Real-time monitoring of artificial and natural rainfall. 7. The artificial watershed suitable for studying the relationship between rainfall and stratified runoff according to claim 1, is characterized in that: stratified weir (9) and total runoff measuring weir (11) can adopt triangular weir according to the size of flow , rectangular weirs or logarithmic weirs and their combinations. 8. The artificial watershed suitable for studying the relationship between rainfall and stratified runoff according to claim 1 is characterized in that: not only can the uppermost layer of the collecting trough (25) for directly collecting rainfall be used to directly collect rainfall, but also On the observation room (7), a rainfall sampler composed of a rain catcher (12), a water storage bottle (13) and a connecting pipe (14) between them is used to collect rainfall. 9. The artificial watershed suitable for studying the relationship between rainfall and stratified runoff according to claim 1, characterized in that: a stratified runoff sampling point ( 28), used to collect stratified runoff water samples.

Images