Vegetation ecological water reserve monitoring system based on remote sensing technology

Abstract

The invention relates to the technical field of remote sensing ecological detection, in particular to a vegetation ecological water reserve monitoring system based on a remote sensing technology, which comprises a monitoring starting unit, an environmental data acquisition unit, an influence analysis unit, a vegetation information acquisition unit and a vegetation ecological water reserve calculation unit, wherein the vegetation information acquisition unit comprises a canopy module, a trunk layer module and a soil layer module; the vegetation ecological water reserve calculation unit is divided into calculation of canopy ecological water reserves, calculation of trunk layer ecological water reserves and calculation of soil layer ecological water reserves. And the vegetation ecological water reserves are divided, monitored and calculated according to the moisture content and distribution characteristics of each layer of vegetation, so that the accuracy of ecological water reserve data monitoring is improved, and a more scientific basis is provided for water resource management and vegetation recovery.

Description

Technical Field

[0001] The present invention relates to the technical field of remote sensing ecological detection, and in particular to a vegetation ecological water storage monitoring system based on remote sensing technology. Background Art

[0002] Vegetation, as a vital component of Earth's ecosystems, plays a crucial role in regulating water resources. Monitoring vegetation ecological water reserves can help us understand the soil moisture retention capacity of different vegetation types, providing a scientific basis for the rational use of water resources and vegetation restoration. It also helps assess the health and stability of vegetation ecosystems.

[0003] However, existing technologies often ignore the important indicator of vegetation trunk runoff when monitoring vegetation ecological water reserves. Trunk runoff is the ecological water volume that flows along the surface of tree trunks and eventually penetrates into the soil after rainfall is intercepted by the vegetation canopy. It not only directly participates in the water cycle of vegetation, but also significantly affects the water supply to the roots of trees and the distribution of soil moisture. Because trunk runoff is an important way for vegetation to absorb and utilize water, the size and changes of its water volume directly affect the dynamic balance of soil moisture and the water use efficiency of vegetation. Ignoring the ecological water reserves of trunk runoff will lead to deviations in the assessment of vegetation ecological water reserves. If it is not included in the monitoring scope, the ecological water storage data obtained will be difficult to fully reflect the true water status of the vegetation ecosystem.

[0004] Therefore, it is necessary to propose a vegetation ecological water storage monitoring system based on remote sensing technology, increase the calculation and evaluation of vegetation trunk runoff, and improve the accuracy and comprehensiveness of ecological water storage data monitoring. Summary of the Invention

[0005] To solve the above problems, the present invention provides a vegetation ecological water reserve monitoring system based on remote sensing technology, which also includes the ecological water reserves of tree trunk runoff in the monitoring range, and divides, calculates and monitors the vegetation ecological water reserves according to the moisture content and distribution characteristics of each layer of vegetation, thereby improving the accuracy of ecological water reserve data monitoring and providing a more scientific basis for water resource management and vegetation restoration.

[0006] In order to achieve the above-mentioned object, the technical solution of the present invention is as follows: a vegetation ecological water reserve monitoring system based on remote sensing technology, comprising a monitoring start unit, an environmental data acquisition unit, an impact analysis unit, a vegetation information acquisition unit and a vegetation ecological water reserve calculation unit;

[0007] The monitoring start unit is used to collect and extract meteorological parameters, monitor and determine the monitoring reference node according to the meteorological parameters, use the detection reference node as the time node to trigger detection, and send a detection signal to the environmental data acquisition unit when the time node is detected;

[0008] Environmental data acquisition unit, used to receive detection signals, collect environmental factor data of the target monitoring area, and transmit the data to the impact analysis unit for analysis;

[0009] The impact analysis unit is used to receive data on various environmental factors, calculate the environmental impact attenuation coefficient based on the data, and transmit the attenuation factors to the vegetation ecological water storage calculation unit.

[0010] The vegetation information collection unit includes a canopy module, a trunk layer module, and a soil layer module;

[0011] The canopy module is used to collect the total leaf area WS, leaf fresh weight Yf and leaf dry weight Yd of the target monitoring site;

[0012] The trunk layer module is used to collect the trunk diameter D, trunk length L, trunk fresh weight Tf and trunk dry weight Td of the vegetation trunks in the target monitoring area, and calculate the average trunk diameter of the vegetation in the target monitoring area through the weighted average method and average trunk length

[0013] The soil layer module is used to collect and calculate the average root depth of vegetation in the target detection area by excavating soil profiles or using remote sensing technology and geophysical methods. Root fresh weight Rf and root dry weight Rd;

[0014] The vegetation ecological water storage calculation unit is used to calculate the ecological water storage Wtotal of the vegetation ecosystem by combining the parameters transmitted by the canopy module, trunk layer module and soil layer module.

[0015] The soil layer module is responsible for collecting the root depth, fresh root weight and dry root weight of the vegetation in the target monitoring area.

[0016] Furthermore, in the monitoring startup unit, meteorological parameters include precipitation, sunshine duration, and temperature change curves.

[0017] Furthermore, in the monitoring start-up unit, the detection benchmark nodes include the turning point of precipitation fluctuation, the critical point of sunshine duration change, and the inflection point of temperature change trend.

[0018] Furthermore, in the monitoring start-up unit, a minimum detection period of 8-10 days is set as the time interval for data collection and analysis.

[0019] Furthermore, in the environmental data collection unit, the environmental factor data include soil moisture, groundwater level and topography.

[0020] Furthermore, in the impact analysis unit:

[0021] The soil moisture attenuation factor ρt is calculated by comparing the real-time monitored soil moisture data with the standard humidity range and calculating the soil moisture attenuation factor ρt based on the difference in soil moisture from the standard value;

[0022] The groundwater level attenuation factor ρr is calculated by comparing the real-time groundwater level data with the appropriate groundwater level range of the target monitoring site and calculating the groundwater level attenuation factor ρr according to the degree of deviation of the groundwater level;

[0023] The terrain attenuation factor ρw is calculated based on the topographic and geomorphological characteristics of the target monitoring area, mainly taking the flatness of the terrain where the target monitoring area is located as the main parameter.

[0024] Furthermore, in the canopy module, the canopy module extracts the total area WS of vegetation leaves by combining remote sensing images with ground-based measured data, using image processing technology and machine learning algorithms. Then, several leaf samples are collected, and the fresh weight Yf of the leaves is obtained by weighing, and the dry weight Yd of the leaves is obtained after drying.

[0025] Furthermore, in the trunk layer module, the trunk layer module extracts the trunk diameter D and trunk length L of the trunks in the area by combining the images of vegetation trees in the remote sensing image with the ground measured data, and calculates the average trunk diameter of the vegetation in the target monitoring area by weighted average method. and average trunk length The same number of trunk samples as the leaf samples were collected, weighed and dried to obtain the trunk fresh weight Tf and trunk dry weight Td.

[0026] Furthermore, in the soil layer module, the soil layer module calculates the average depth of tree roots by digging soil profiles or using remote sensing technology and geophysical methods. The same number of root samples as the leaf samples were collected, weighed and dried to obtain the root fresh weight Rf and root dry weight Rd.

[0027] Furthermore, in the vegetation ecological water storage calculation unit, the ecological water storage Wtotal of the vegetation ecosystem needs to be calculated first by calculating the values of the canopy ecological water storage Wy, the trunk layer ecological water storage Wt, and the soil layer ecological water storage Wr. Then, the ecological water storage of each vegetation layer is added together to finally obtain the ecological water storage Wtotal. The specific values of the canopy ecological water storage Wy, the trunk layer ecological water storage Wt, and the soil layer ecological water storage Wr are:

[0028] The canopy ecological water storage Wy is calculated by using the leaf fresh weight Yf and leaf dry weight Yd to calculate the canopy water content MY, and then combining the total leaf area WS and the terrain attenuation factor ρw to calculate the canopy ecological water storage Wy;

[0029] The calculation of the ecological water storage Wt of the trunk layer is to calculate the trunk water content MT using the trunk fresh weight Tf and trunk dry weight Td, and then combine the average trunk diameter Average trunk length and calculate the ecological water storage Wt of the trunk layer;

[0030] The calculation of the ecological water storage Wr of the soil layer is to use the fresh weight Rf and dry weight Rd of the roots to calculate the moisture content MR of the soil layer, and then combine the average depth of the roots The ecological water storage Wr of the soil layer is calculated based on the known monitored vegetation area A, soil moisture attenuation factor ρt and groundwater level attenuation factor ρr.

[0031] The above scheme has the following beneficial effects:

[0032] 1. This proposal incorporates the calculation of tree trunk runoff, or the ecological water reserves at the trunk layer, into the monitoring and calculation of vegetation ecological water reserves. Compared to traditional methods that only consider canopy ecological water reserves, the canopy, while the primary site of water storage and transpiration, is often profoundly influenced by water transport from the trunk layer. Therefore, incorporating trunk ecological water reserves into the monitoring scope provides a more comprehensive and accurate reflection of the dynamic water balance in vegetation ecosystems, providing more precise data support for ecological water resource management and protection.

[0033] 2. This plan breaks down the calculation of vegetation ecological water reserves into the calculation of canopy ecological water reserves, trunk ecological water reserves, and soil ecological water reserves, that is, into leaf and branch layer, trunk layer, and root layer. This helps to gain a deeper understanding of the water storage and distribution characteristics of each layer of vegetation, and can also reveal the relationship between water transmission and transformation between different layers. It is of great significance for revealing the mechanism of water cycle in vegetation ecosystems, evaluating the status of ecological water resources, and formulating scientific ecological water resources management strategies.

[0034] 3. This solution implements meteorological monitoring, using characteristic turning points in precipitation fluctuations, critical points in sunshine duration changes, and inflection points in temperature trends as monitoring time points. Compared to conventional monitoring methods that conduct regular monitoring by month or season, this approach is more timely and targeted. Meteorological factors such as precipitation, sunshine duration, and temperature are key factors affecting vegetation ecological water reserves. By monitoring changes in these meteorological factors in real time, we can promptly understand the changing trends in the dynamic balance of water in vegetation ecosystems, providing early warning and decision-making support for ecological water resource management and protection.

[0035] 4. This plan incorporates a minimum monitoring cycle of 8-10 days. Through regular monitoring and data analysis, it can promptly identify trends and potential issues in the dynamic water balance of vegetation ecosystems, providing timely and effective information support for ecological water resource management and protection. This plan takes into account the cyclical nature of the dynamic water balance of vegetation ecosystems and the continuity and reliability requirements of monitoring data. This plan also helps avoid probabilistic errors in monitoring and improves the accuracy and reliability of monitoring data.

[0036] 5. This plan takes into account a variety of environmental influencing factors, including soil moisture, groundwater, and topography. Soil moisture is a key factor affecting water absorption and transpiration by vegetation roots; groundwater is an important component of the water cycle of vegetation ecosystems; topography indirectly affects vegetation ecological water reserves by affecting factors such as precipitation distribution, surface runoff, and groundwater levels. Using these environmental factor data as attenuation factors and calculating the ecological water reserves for the vegetation layer with the greatest impact can more accurately reflect the actual situation of the dynamic balance of water in vegetation ecosystems, providing more scientific and comprehensive data support for ecological water resource management and protection.

[0037] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the operation of an embodiment of the vegetation ecological water storage monitoring system based on remote sensing technology of the present invention. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0042] The following is further described in detail through specific implementation methods:

[0043] Example 1:

[0044] As attached Figure 1 Shown: A vegetation ecological water reserve monitoring system based on remote sensing technology, including a monitoring start-up unit, an environmental data acquisition unit, an impact analysis unit, a vegetation information acquisition unit and a vegetation ecological water reserve calculation unit.

[0045] The monitoring start-up unit collects data from meteorological observation stations and extracts meteorological parameters, including precipitation, sunshine duration, and temperature change curves. In order to ensure the timeliness and accuracy of the monitoring activities, the monitoring start-up unit monitors and determines the detection reference node as the time node to trigger monitoring, wherein the detection reference node includes the turning point of precipitation fluctuations, the critical point of sunshine duration change, and the inflection point of the temperature change trend; when the monitoring reference node is monitored, the monitoring start-up unit sends a detection signal to the environmental data acquisition unit. In order to reduce the probability of excessive redundancy and clutter in the detection data, the monitoring start-up unit sets a minimum detection period of 8-10 days as the time interval for data collection and analysis. The specific minimum detection period is determined according to the specific environmental conditions of the target monitoring site. Through this setting, the monitoring start-up unit can efficiently respond to changes in meteorological conditions and provide strong support for subsequent monitoring work.

[0046] After receiving the detection signal, the environmental data acquisition unit collects the environmental factor data of the target monitoring site, including soil moisture, groundwater level and topography, and promptly transmits this data to the impact analysis unit for further processing and analysis.

[0047] Impact Analysis Unit The impact analysis unit is responsible for receiving the impact factor data from the environmental data acquisition unit and calculating the environmental impact attenuation coefficient based on this data. The environmental impact attenuation coefficients include the soil moisture attenuation factor ρt, the groundwater level attenuation factor ρr, and the topography attenuation factor ρw. The soil moisture attenuation factor ρt is calculated by comparing real-time monitored soil moisture data with the standard moisture range (determined by consulting relevant data from local soil moisture monitoring stations) based on the difference in soil moisture deviation from the standard value. This factor reflects the impact of soil moisture on ecological water reserves. The groundwater level attenuation factor ρr is calculated by comparing real-time groundwater level data with the suitable groundwater level range of the target monitoring site (the specific suitable groundwater level range of the target monitoring site is determined by the actual vegetation type at the target monitoring site) based on the degree of groundwater level deviation. The topography attenuation factor ρw is calculated based on the topography and geomorphology characteristics of the target monitoring site and reflects the impact of topography and geomorphology on ecological water reserves. These coefficients are used to quantify the contribution of various environmental factors to changes in ecological water reserves and are of great significance for in-depth understanding of the dynamic change mechanism of ecological water reserves and the formulation of effective protection measures.

[0048] The vegetation information collection unit includes a canopy module, a trunk layer module, and a soil layer module;

[0049] The canopy module combines remote sensing images with ground-based data, using image processing technology and machine learning algorithms to extract the total leaf area (WS). The leaf area directly reflects the photosynthetic area of the vegetation, which in turn affects the ecological water storage of the vegetation. Several leaf samples are then collected and weighed to obtain the fresh weight (Yf). After drying, the leaf dry weight (Yd) is obtained. These two parameters can reflect the water content and organic matter content of the vegetation leaves.

[0050] The trunk layer module extracts the trunk diameter D and trunk length L of the tree trunks in the area by combining the images of vegetation and trees in the remote sensing image with the ground measured data, and calculates the average trunk diameter of the vegetation in the target monitoring area by weighted average method. and average trunk length This information helps to understand the growth status and water transport capacity of vegetation. It is also necessary to collect a certain number of trunk samples, weigh them and dry them to obtain the trunk fresh weight Tf and trunk dry weight Td; these two parameters can reflect the moisture content and lignification degree of the trunk;

[0051] The soil layer module is responsible for collecting and calculating the average root depth of vegetation in the target monitoring area. Fresh root weight Rf and dry root weight Rd. Estimate the average root depth by excavating the soil profile or using remote sensing technology and geophysical methods. Root depth directly affects vegetation's ability to utilize deep soil moisture. Furthermore, a certain number of root samples were collected, weighed, and dried to determine their fresh root weight (Rf) and dry root weight (Rd); these two parameters reflect the root's moisture content and organic matter content.

[0052] The vegetation ecological water storage calculation unit combines the parameters transmitted by the canopy module, trunk layer module and soil layer module to first calculate the values of the canopy ecological water storage Wy, the trunk layer ecological water storage Wt and the soil layer ecological water storage Wr. Then, the ecological water storage of each vegetation layer is added together to finally obtain the ecological water storage Wtotal. The specific values of the canopy ecological water storage Wy, the trunk layer ecological water storage Wt and the soil layer ecological water storage Wr are:

[0053] The calculation of canopy ecological water storage Wy is done by using leaf fresh weight Yf and leaf dry weight Yd to calculate canopy water content MY, and then combining the total leaf area WS and terrain attenuation factor ρw to calculate canopy ecological water storage Wy. Due to the different terrains, especially hillside terrains, the area of the canopy exposed to sunlight is much smaller than that of plain terrain. Therefore, the influence of terrain attenuation factor ρw on canopy ecological water storage Wy is considered.

[0054] Since the ecological water storage Wt in the trunk layer is mainly the ecological water that flows along the trunk surface and eventually penetrates into the soil, the calculation of the ecological water storage Wt in the trunk layer is to calculate the trunk water content MT using the trunk fresh weight Tf and the trunk dry weight Td, and then combine it with the average trunk diameter Average trunk length and calculate the ecological water storage Wt of the trunk layer;

[0055] The calculation of the ecological water storage Wr of the soil layer is to use the fresh weight of the roots Rf and the dry weight of the roots Rd to calculate the moisture content MR of the soil layer, and then combine the average depth of the roots The ecological water storage Wr of the soil layer is calculated based on the known monitored vegetation area A, soil moisture attenuation factor ρt, and groundwater level attenuation factor ρr. The groundwater level and soil moisture mainly affect the ability of tree roots to absorb groundwater, which in turn affects the calculation of the ecological water storage of the soil layer.

[0056] Finally, the ecological water storage Wtotal of the entire vegetation ecosystem can be obtained by adding the ecological water storage Wy of the canopy layer, the ecological water storage Wt of the trunk layer, and the ecological water storage Wr of the soil layer.

[0057] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A vegetation ecological water storage monitoring system based on remote sensing technology, characterized in that: It includes monitoring start-up unit, environmental data collection unit, impact analysis unit, vegetation information collection unit and vegetation ecological water storage calculation unit; The monitoring start unit is used to collect and extract meteorological parameters, monitor and determine the monitoring reference node according to the meteorological parameters, use the detection reference node as the time node to trigger detection, and send a detection signal to the environmental data acquisition unit when the time node is detected; Environmental data acquisition unit, used to receive detection signals, collect environmental factor data of the target monitoring area, and transmit the data to the impact analysis unit for analysis; The impact analysis unit is used to receive data on various environmental factors, calculate the environmental impact attenuation coefficient based on the data, and transmit the attenuation factors to the vegetation ecological water storage calculation unit. The vegetation information collection unit includes a canopy module, a trunk layer module, and a soil layer module; The canopy module is used to collect the total leaf area WS, leaf fresh weight Yf and leaf dry weight Yd of the target monitoring site; The trunk layer module is used to collect the trunk diameter D, trunk length L, trunk fresh weight Tf and trunk dry weight Td of the vegetation trunks in the target monitoring area, and calculate the average trunk diameter of the vegetation in the target monitoring area through the weighted average method and average trunk length The soil layer module is used to collect and calculate the average root depth of vegetation in the target detection area by excavating soil profiles or using remote sensing technology and geophysical methods. Root fresh weight Rf and root dry weight Rd; The vegetation ecological water storage calculation unit is used to calculate the ecological water storage Wtotal of the vegetation ecosystem by combining the parameters transmitted by the canopy module, trunk layer module and soil layer module.

2. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 1 is characterized in that: In the monitoring startup unit, meteorological parameters include precipitation, sunshine duration, and temperature change curves.

3. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 2 is characterized in that: In the monitoring start-up unit, the detection benchmark nodes include the turning point of precipitation fluctuations, the critical point of changes in sunshine duration, and the inflection point of temperature change trends.

4. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 3 is characterized in that: In the monitoring startup unit, a minimum detection period of 8-10 days is set as the time interval for data collection and analysis.

5. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 4 is characterized in that: In the environmental data collection unit, environmental factor data include soil moisture, groundwater level and topography.

6. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 5 is characterized in that: In the impact analysis unit: The soil moisture attenuation factor ρt is calculated by comparing the real-time monitored soil moisture data with the standard humidity range and calculating the soil moisture attenuation factor ρt based on the difference in soil moisture from the standard value; The groundwater level attenuation factor ρr is calculated by comparing the real-time groundwater level data with the appropriate groundwater level range of the target monitoring site and calculating the groundwater level attenuation factor ρr according to the degree of deviation of the groundwater level; The terrain attenuation factor ρw is calculated based on the topographic and geomorphological characteristics of the target monitoring area, mainly taking the flatness of the terrain where the target monitoring area is located as the main parameter.

7. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 6 is characterized in that: In the canopy module, the canopy module combines remote sensing images with ground-based measured data, uses image processing technology and machine learning algorithms to extract the total area of vegetation leaves WS, then collects several leaf samples, obtains the fresh weight Yf of the leaves by weighing, and obtains the dry weight Yd of the leaves after drying.

8. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 7 is characterized in that: In the trunk layer module, the trunk layer module extracts the trunk diameter D and trunk length L of the trunks in the area by combining the images of vegetation trees in the remote sensing image with the ground measured data, and calculates the average trunk diameter of the vegetation in the target monitoring area by weighted average method. and average trunk length , and collect the same number of trunk samples as the leaf samples, weigh and dry them to obtain the trunk fresh weight Tf and trunk dry weight Td.

9. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 8 is characterized in that: In the soil layer module, the soil layer module calculates the average depth of tree roots by excavating soil profiles or using remote sensing technology and geophysical methods The same number of root samples as the leaf samples were collected, weighed and dried to obtain the root fresh weight Rf and root dry weight Rd.

10. The vegetation ecological water storage monitoring system based on remote sensing technology according to claim 9 is characterized in that: In the vegetation ecological water storage calculation unit, the ecological water storage Wtotal of the vegetation ecosystem needs to be calculated first. The values of the canopy ecological water storage Wy, the trunk layer ecological water storage Wt, and the soil layer ecological water storage Wr are then added together to obtain the ecological water storage Wtotal. The specific values of the canopy ecological water storage Wy, the trunk layer ecological water storage Wt, and the soil layer ecological water storage Wr are: The canopy ecological water storage Wy is calculated by using the leaf fresh weight Yf and leaf dry weight Yd to calculate the canopy water content MY, and then combining the total leaf area WS and the terrain attenuation factor ρw to calculate the canopy ecological water storage Wy; The calculation of the ecological water storage Wt of the trunk layer is to calculate the trunk water content MT using the trunk fresh weight Tf and trunk dry weight Td, and then combine the average trunk diameter Average trunk length and calculate the ecological water storage Wt of the trunk layer; The calculation of the ecological water storage Wr of the soil layer is to use the fresh weight Rf and dry weight Rd of the roots to calculate the moisture content MR of the soil layer, and then combine the average depth of the roots The ecological water storage Wr of the soil layer is calculated based on the known monitored vegetation area A, soil moisture attenuation factor ρt and groundwater level attenuation factor ρr.

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