An irrigation oasis water-saving and salt-control collaborative irrigation water supply amount determination method

Abstract

The present application relates to a kind of irrigation oasis water-saving salt control collaborative irrigation water supply quantity determination method, comprising: the acquisition of regional salinization distribution and salinization degree;Regional fine water-salt cycle model construction and simulation;The acquisition of the degree of soil salinization of simulation unit and the acquisition of water cycle element under corresponding water cycle structure, and calculate the drainage ratio of each unit;Comprehensive judgment of land salinization state;According to transpiration, analyze water consumption;Estimate regional irrigation water supply quantity.The present application is based on irrigation oasis water cycle, comprehensively the effectiveness of the support of water in different links of water cycle to vegetation / crop water consumption and the driving action to the dynamic change of soil salinity, proposes the basic irrigation water supply quantity determination method under the double target of collaborative "water-saving salt control", and includes irrigation water supply quantity for salt removal, which is of great significance for effective water resources management and realization of soil salinity collaborative prevention and control.

Description

Technical Field

[0001] This invention relates to a method for determining irrigation water supply volume that combines water conservation and salt control in irrigated oases. It is an environmental protection and governance method, and a method for the rational utilization of regional water resources and the coordinated prevention and control of saline-alkali land. Background Technology

[0002] Soil salinization, especially secondary soil salinization, is a result of the interaction between water and soil. It not only affects regional soil quality but also the rational development of regional water resources, jointly threatening regional food production and ecological security. It has become one of the long-standing ecological issues of global concern. Existing methods for controlling soil salinization have different focuses. On the one hand, some methods target only the existing salt content in the soil, lacking a synergistic consideration of the water-soil relationship and failing to achieve fundamental control. On the other hand, improvement methods that to some extent embody the idea of ​​synergistic water-salt management or regulation, such as water conservancy improvements, face challenges due to water scarcity, including issues like excessive irrigation or insufficient water supply for leaching salts, thus questioning the effectiveness of water resource utilization. Considering the driving forces of water-salt transport, such as "salt comes with water, salt water goes with water, and salt remains after water leaves," and given the situation of water scarcity and severe soil salinization, improving irrigation and drainage methods and more effective water resource management are still key measures to alleviate soil salinization in order to promote the coordinated development of "water-soil-food-ecology" in irrigated oases. Among these measures, determining the appropriate irrigation and drainage water volume is the primary step in effectively managing water resources and controlling soil salinization. How to rationally determine the appropriate irrigation water volume in irrigated oasis areas where water scarcity and salinity coexist, and how to synergistically achieve "water conservation and salt control" to promote regional sustainable development, is a problem that needs to be solved. Summary of the Invention

[0003] To overcome the problems of existing technologies and promote the coordinated development of "water-soil-food-ecology" in oases, this invention proposes a method for determining irrigation water supply in irrigated oases that coordinates water conservation and salt control. The method aims to address the problems of regional effective water resource shortage and soil salinization. Taking the water cycle of the irrigated oasis as a starting point, it comprehensively considers the supporting role of water in different stages of the water cycle on the water consumption of vegetation / crops and the effectiveness of its driving role in the dynamic changes of soil salinity, proposing a method for determining irrigation water supply under the dual objectives of "water conservation and salt control."

[0004] The objective of this invention is achieved as follows: a method for determining irrigation water supply volume that combines water conservation and salt control in irrigation oases, the steps of which are as follows:

[0005] Step 1, Obtaining the regional salinization distribution and degree: Based on remote sensing images and ground measurement data, the distribution of soil salinization in the irrigated oasis area is obtained through inversion analysis, and the degree of regional soil salinization is determined.

[0006] Step 2, Construction and Simulation of a Regional Refined Water-Saline Cycle Model: Step 2 includes the following sub-steps:

[0007] Sub-step 21: Collect relevant basic data on water cycle and salinity changes in the irrigated oasis area; construct a refined water cycle simulation model or numerical model based on the principles of water balance and salinity balance; and simulate the regional water cycle process by combining a series of annual water supply and water use data and meteorological conditions.

[0008] The regional soil water balance relationship is as follows:

[0009]

[0010] In the formula: The change in soil moisture content in the irrigated oasis over a certain period of time is represented by the change in groundwater level, as the unsaturated soil storage capacity tends to zero under the multi-year average water cycle conditions. t is the time scale of the verified water supply and demand, usually taken on an annual scale, but in the model calculation, t is taken on a daily scale according to the refinement of the model. This represents the amount of precipitation infiltrating during the time period. These represent the infiltration of surface water and groundwater into the unsaturated soil zone during the time period; T and E represent the vegetation transpiration and soil evaporation in the unsaturated soil zone during the time period, respectively. This represents the amount of seepage from the unsaturated zone to the saturated zone of the soil during the specified time period. Interflow within a given time period refers to the amount of water that flows out of the oasis soil layer as interflow within a certain time period. These represent the inflow, outflow, and extraction volume of groundwater in the saturated zone of the oasis area during the specified time period.

[0011] Regional soil salinity balance equation:

[0012]

[0013] In the formula: This represents the change in salinity in the saturated zone of irrigated oasis soil over a given period of time. The concentration of salt carried by precipitation; and These are the salinity concentrations of irrigation surface water and groundwater, respectively. The concentration of salts is carried by water vapor transpired from vegetation; This refers to the salt concentration carried by water vapor evaporating from the soil; typically... , It basically approaches 0; The salt concentration is carried by the inflow of groundwater into the saturated zone of the oasis area; This refers to the concentration of salt in the interflow soil. The salt concentration carried by groundwater outflow; These represent the salt concentration carried by the amount of groundwater extracted;

[0014] Sub-step 22, based on the simulation in sub-step 21, obtains quantitative results for various water cycle elements in the refined simulation unit, such as infiltration, discharge, and evaporation / transpiration consumption; where infiltration includes precipitation infiltration recharge. and surface water irrigation infiltration recharge and groundwater irrigation infiltration recharge Discharge volume Dr includes runoff discharged outside the unit, such as soil flow. and groundwater drainage and mining volume Evapotranspiration includes vegetation transpiration (T) and soil evaporation (E).

[0015] Step 3: Obtain the degree of soil salinization in the simulation unit and the water cycle elements under the corresponding water cycle structure, and calculate the infiltration ratio of each unit. Step 3 specifically includes the following sub-steps:

[0016] Sub-step 31: Based on the basic calculation units in the fine water cycle simulation, resample the soil salinization of the area obtained in step 1 to obtain the degree of salinization of different units.

[0017] Sub-step 32: By comparing the water cycle elements under different unit water cycle structures, calculate the infiltration amount of the water cycle corresponding to the salinization degree of each unit. Excretion volume Given the evaporation and transpiration rate E+T, calculate and determine the infiltration ratio of each unit using the following formula:

[0018] ;

[0019]

[0020] In the formula: Total irrigation infiltration into the soil layer: The soil water cycle infiltration ratio;

[0021] Step 4, comprehensively assess the soil salinization status: Step 4 specifically includes the following sub-steps:

[0022] Sub-step 41: Based on the principle of regional soil salinity balance relationship, and using the results of step 3, or through a water-salt cycle model or a water-salt equilibrium model, determine the accumulation state of soil salinity; if it is in a desalination state, further determine the groundwater depth and proceed to sub-step 42; if it is in a salt accumulation state, it indicates that the groundwater depth does not meet the requirements, and directly proceed to the adjustment of step 2.

[0023] Sub-step 42: Using the storage variable in the water cycle structure, combined with the regional groundwater depth, determine whether the unit's groundwater depth is within a reasonable and appropriate range.

[0024] When groundwater storage changes Furthermore, the maximum burial depth for preventing vegetation degradation is less than the groundwater burial depth, which is less than the maximum saline burial depth. This indicates that the region is generally in a state of desalination. Moreover, from the perspective of salt discharge and vegetation growth, the groundwater level is suitable and the water cycle is generally in a relatively good state.

[0025] When groundwater storage changes Furthermore, the groundwater depth is less than the limit depth for preventing vegetation degradation, indicating that the region is generally in a state of desalination. From the perspective of salinity, the water cycle structure is reasonable, but it is not suitable for vegetation growth, which will lead to vegetation degradation.

[0026] Otherwise, there is a risk of salt accumulation or vegetation degradation in other situations; it needs to be determined in conjunction with reasonable water level adjustments.

[0027] Sub-step 43: Based on the above, select the unit groundwater storage variable. Furthermore, the water cycle structure and corresponding infiltration ratio corresponding to the unit of the limit burial depth for preventing vegetation degradation < groundwater burial depth < limit saline burial depth are summarized to obtain the infiltration ratio α threshold corresponding to the benign water cycle of the regional soil layer.

[0028] Step 5, analyze water consumption based on evaporation and transpiration: Step 5 specifically includes the following sub-steps:

[0029] Sub-step 51: Obtain typical crops in the irrigated oasis area and calculate the basic water consumption requirements of various typical crops under the current conditions where water-saving measures are widely adopted in the area. ;

[0030] Sub-step 52: Compare the total evapotranspiration in the current simulation results, and through adjustment and comparison, finally determine the basic evapotranspiration water demand required to ensure the growth of vegetation or crops in the region. :

[0031] when , ;

[0032] when , ;

[0033] Step 6, Estimate Regional Irrigation Water Supply: Sub-step 6 specifically includes the following sub-steps:

[0034] Sub-step 61, combining the regional infiltration ratio threshold from step 4 and the suitable regional evaporation and transpiration consumption from step 5, and based on the basic requirements of maintaining stable groundwater depth and preventing soil salinization, determines the basic soil infiltration water requirement for irrigated oases. and irrigation infiltration water demand Specific calculation formula:

[0035]

[0036] and

[0037] In the formula: The required amount of infiltration water for irrigating oasis soil; ;

[0038] Sub-step 62 involves considering the influence of regional precipitation, soil type, and hydrogeological characteristics on the water-salt cycle, and then considering the soil infiltration coefficient. The basic irrigation water volume required to ensure the dual objectives of "water conservation and salt control" in irrigated oasis areas is determined using a formula:

[0039]

[0040] The irrigation water supply used for desalination is as follows:

[0041]

[0042]

[0043] In the formula: The basic irrigation water volume is required to achieve the dual goals of water conservation and salt control in the irrigated oasis area. Irrigation water supply for salt removal; The actual rainfall in the irrigated oasis area; The infiltration coefficients for precipitation and irrigation water;

[0044] Based on the above, we can conclude the basic water supply volume and total water supply structure for achieving the dual goals of "water conservation and salt control" under the current water conservation level and climate conditions.

[0045] The advantages and beneficial effects of this invention are as follows: Based on the water cycle of irrigated oases, this invention integrates the supporting role of water in different links of the water cycle on the water consumption of vegetation / crops and the effectiveness of driving the dynamic changes in soil salinity and alkali. It proposes a method for determining the basic irrigation water supply under the dual objectives of "water conservation and salt control", and includes the irrigation water supply for salt removal. This is of great significance for effectively carrying out water resource management, realizing the coordinated prevention and control of soil salinity and alkali, and promoting the coordinated development of "water-soil-food-ecology" in irrigated oases. Attached Figure Description

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0047] Figure 1 This is a flowchart of the method described in an embodiment of the present invention. Detailed Implementation

[0048] Example:

[0049] This embodiment is a method for determining the irrigation water supply volume for synergistic water conservation and salt control in irrigated oases. The method for determining the irrigation water supply volume for synergistic water conservation and salt control in irrigated oasis areas includes the following steps:

[0050] Step 1, Obtaining the regional salinization distribution and degree: Based on remote sensing images and ground measurement data, the distribution of soil salinization in the irrigated oasis area is obtained through inversion analysis, and the degree of regional soil salinization is determined.

[0051] By combining remote sensing imagery and ground monitoring data, the regional distribution of soil salinization was determined through regional soil salinization inversion. The degree of regional soil salinization was determined by comparing it with local / national salinization classification standards, and specifically classified into mild, moderate and severe levels of soil salinization.

[0052] Step 2, Construction and Simulation of Regional Refined Water and Salt Cycle Model: Collect basic data related to water and salt cycles in the irrigated oasis area (including hydrogeological data, soil, land use, meteorology, river network and water use information, and salt content at different stages, etc.), construct a regional refined water cycle simulation model / numerical model or water and salt cycle simulation model / numerical model; conduct regional refined water cycle process or water and salt cycle process simulation to obtain the regional refined water cycle structure and corresponding water cycle elements;

[0053] Step 2 specifically includes the following sub-steps:

[0054] Sub-step 21: Collect relevant basic data on water cycle and salinity changes in the irrigated oasis area; construct a refined water (salt) cycle simulation model or numerical model based on the principles of water balance and salinity balance; and simulate the regional water cycle process by combining a series of annual water supply and water use data and meteorological conditions.

[0055] Among them, the regional soil water balance relationship is (1):

[0056] (1)

[0057] In the formula: The change in soil moisture content in the irrigated oasis over a certain period of time is represented by the change in groundwater level, as the unsaturated soil storage capacity tends to zero under the multi-year average water cycle conditions. t is the time scale of the verified water supply and demand, usually taken as an annual scale. However, in the model calculation, t is taken as a daily scale based on the refinement of the model. The unit is d (day). This represents the amount of precipitation infiltrating during the time period. These represent the infiltration of surface water and groundwater into the unsaturated soil zone during the time period; T and E represent the vegetation transpiration and soil evaporation in the unsaturated soil zone during the time period, respectively. This represents the amount of seepage from the unsaturated zone to the saturated zone of the soil during the specified time period. Interflow within a given time period refers to the amount of water that flows out of the oasis soil layer as interflow within a certain time period. These represent the inflow, outflow, and extraction of groundwater in the saturated zone of the oasis area during the specified time period.

[0058] The water volume is uniformly converted into the water volume of the target area within the time period, with the unit being m³. 3 When the original monitoring data is water depth in mm, the water volume is calculated as water depth × target area; when the original monitoring data is in m... 3 When / ha, it is converted to m based on the target area area. 3 .

[0059] Regional soil salinity balance equation (2):

[0060] (2)

[0061] In the formula: This represents the change in salinity within the unsaturated zone of irrigated oasis soil over a given period. This represents the change in salinity in the saturated zone of irrigated oasis soil over a given period of time. The concentration of salt carried by precipitation; and These are the salinity concentrations of irrigation surface water and groundwater, respectively. The concentration of salts is carried by water vapor transpired from vegetation; This refers to the salt concentration carried by water vapor evaporating from the soil; typically... , It basically approaches 0; The salt concentration is carried by the inflow of groundwater into the saturated zone of the oasis area; This refers to the concentration of salt in the interflow soil. The salt concentration carried by groundwater outflow; These represent the salinity concentration carried over from groundwater extraction. All salinity concentrations are converted to mass concentration, with units of kg / m³. 3 When the original monitoring data is in g / L, it is calculated as 1 g / L = 1 kg / m³. 3 Conversion.

[0062] Sub-step 22, based on the simulation in sub-step 21, obtains quantitative results for various water cycle elements in the refined simulation unit, such as infiltration, discharge, and evaporation / transpiration. Infiltration includes precipitation infiltration recharge. and surface water irrigation infiltration recharge and groundwater irrigation infiltration recharge Excretion volume This includes runoff discharged outside the unit, such as soil flow. and groundwater drainage and mining volume Evaporation and transpiration consumption include vegetation transpiration T and soil evaporation E, as detailed in formula (1).

[0063] Step 3: Obtain the degree of soil salinization in the simulation unit and the water cycle elements under the corresponding water cycle structure, and calculate the infiltration ratio of each unit: For the soil salinization distribution obtained in Step 1, resample according to the basic units divided by the model simulation in Step 2 to obtain the degree of salinization at the simulation unit scale; Combine the simulation results in Step 2 to obtain the water cycle elements corresponding to each unit, mainly including the infiltration, discharge and consumption of various soil layers, and calculate the infiltration ratio of each unit through the total discharge and soil infiltration of the unit;

[0064] Step 3 specifically includes:

[0065] Sub-step 31: Based on the basic calculation units in the fine water cycle simulation, resample the soil salinization of the area obtained in step 1 to obtain the degree of salinization of different units.

[0066] Sub-step 32: By comparing the water cycle elements under different unit water cycle structures, calculate the infiltration amount of the water cycle corresponding to the salinization degree of each unit. Excretion volume The infiltration ratio of each unit is calculated based on the evaporation and transpiration rate E+T, as shown in formula (3).

[0067] ;

[0068] (3)

[0069] In the formula: Total irrigation infiltration into the soil layer: This represents the soil water cycle infiltration ratio; the meanings of other symbols are the same as those mentioned above.

[0070] Step 4, comprehensively judge the soil salinization status: based on the regional soil salt balance relationship in the comprehensive unit water cycle structure {i.e., formula (2)}, judge whether the soil salinization status of each unit is desalination; at the same time, further judge whether the groundwater depth under the corresponding water cycle structure is within the reasonable groundwater depth range to prevent soil salinization and vegetation degradation; combine with Step 2 to perform scheme adjustment, obtain the drainage ratio of each unit corresponding to different salinity and salt accumulation status, and summarize and determine the drainage ratio under the control of suitable groundwater depth in the region. Threshold.

[0071] Step 4 specifically includes the following sub-steps:

[0072] Sub-step 41, based on the principle of the regional soil salinity balance relationship {formula (2)}, and on the basis of the results of step 3, or through the water-salt cycle model or water-salt equilibrium model, determine the accumulation state of soil salinity; when it is in the desalination state, further determine the groundwater depth and proceed to sub-step 42; when it is in the salt accumulation state, it indicates that the groundwater depth does not meet the requirements, and directly proceed to the adjustment of step 2.

[0073] Sub-step 42: Using the storage variable in the water cycle structure, combined with the regional groundwater depth, determine whether the unit's groundwater depth is within a reasonable and appropriate range.

[0074] When groundwater storage changes Furthermore, the maximum burial depth for preventing vegetation degradation is less than the groundwater burial depth, which is less than the maximum saline burial depth. This indicates that the region is generally in a state of desalination. Moreover, from the perspectives of salt discharge and vegetation growth, the groundwater level is suitable and the overall water cycle is in a relatively good state.

[0075] When groundwater storage changes Furthermore, the groundwater depth is less than the limit depth for preventing vegetation degradation, indicating that the region is generally in a state of desalination. From the perspective of salinity, the water cycle structure is reasonable, but it is not suitable for vegetation growth, which will lead to vegetation degradation.

[0076] Otherwise, there is a risk of salt accumulation or vegetation degradation in other situations; it needs to be determined in conjunction with reasonable water level adjustments.

[0077] Sub-step 43: Based on the above, select the unit groundwater storage variable. Furthermore, the water cycle structure and corresponding infiltration ratio corresponding to the unit of the limit burial depth for preventing vegetation degradation < groundwater burial depth < limit saline burial depth are summarized to obtain the infiltration ratio α threshold corresponding to the benign water cycle of the regional soil layer.

[0078] Step 5: Analyze water consumption based on evapotranspiration: Based on the evapotranspiration T, soil evaporation E, and total evapotranspiration consumption E+T of each unit obtained in Step 2, and combined with the basic water consumption requirements of crops and terrestrial vegetation under current water-saving conditions, determine the effectiveness of evapotranspiration consumption; based on the judgment results, and in accordance with the principles of effectiveness and controllability, through adjustments, finally determine the basic evapotranspiration water consumption requirements for ensuring the growth of vegetation / crops in the region. Unit: m 3 .

[0079] Step 5 specifically includes the following sub-steps:

[0080] Sub-step 51: Obtain typical crops in the irrigated oasis area and calculate the basic water consumption requirements of various typical crops under the current conditions where water-saving measures are widely adopted in the area. (Water demand under real water-saving conditions).

[0081] Sub-step 52: Compare the total evapotranspiration in the current simulation results, and through adjustment and comparison, finally determine the basic evapotranspiration water demand required to ensure the growth of vegetation or crops (or both) in the region. :

[0082] when , ;

[0083] when , .

[0084] Step 6, estimate regional irrigation water supply: Based on the results of Step 4 and Step 5, taking into account precipitation conditions, soil characteristics and other factors, and in accordance with regional water balance, calculate the regional irrigation water supply with appropriate groundwater depth constraints to ensure the dual objectives of "water conservation and salt control", as well as the irrigation water supply used for salt removal.

[0085] Sub-step 6 specifically includes the following sub-steps:

[0086] Sub-step 61, combining the regional infiltration ratio threshold from step 4 and the suitable regional evaporation and transpiration consumption from step 5, determines the basic soil infiltration water demand based on the fundamental requirements of maintaining stable groundwater depth and preventing soil salinization. and irrigation infiltration water demand Specific calculation formulas (4) and (5):

[0087] (4)

[0088] and (5)

[0089] In the formula: The required amount of soil infiltration water for irrigating oases, in m³. 3 ; Unit: m 3 ;

[0090] Sub-step 62 involves considering the influence of regional precipitation, soil type, and hydrogeological characteristics on the water-salt cycle, and then considering the soil infiltration coefficient. The basic irrigation water volume for ensuring the dual objectives of "water conservation and salt control" in the irrigated oasis area is determined by formulas (6) and (7). And the amount of irrigation water used for salt removal :

[0091] (6)

[0092] The irrigation water supply used for desalination is as follows:

[0093] (7)

[0094]

[0095] In the formula: The basic irrigation water volume for achieving the dual goals of water conservation and salt control in oasis irrigation areas is expressed in m³. 3 ; Irrigation water supply for salt removal, unit: m³ 3 ; Actual rainfall in the irrigated oasis area, unit: m 3 ; This represents the infiltration coefficient for precipitation and irrigation water.

[0096] Based on the above, we can deduce the basic water supply volume and total water supply structure for achieving the dual goals of "water conservation and salt control" under the current water conservation level and climate conditions.

[0097] Finally, it should be noted that the above is only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred arrangement, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of the present invention (such as the irrigated oasis environment studied, the application of various formulas, the order of steps, etc.) without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for determining irrigation water supply volume for synergistic water-saving and salt-controlling irrigation of oases, characterized in that, The steps of the method are as follows: Step 1, Obtaining the regional salinization distribution and degree: Based on remote sensing images and ground measurement data, the distribution of soil salinization in the irrigated oasis area is obtained through inversion analysis, and the degree of regional soil salinization is determined. Step 2, Construction and Simulation of a Regional Refined Water-Saline Cycle Model: Step 2 includes the following sub-steps: Sub-step 21: Collect relevant basic data on water cycle and salinity changes in the irrigated oasis area; construct a refined water cycle simulation model or numerical model based on the principles of water balance and salinity balance; and simulate the regional water cycle process by combining a series of annual water supply and water use data and meteorological conditions. The regional soil water balance relationship is as follows: In the formula: The change in soil moisture content in the irrigated oasis over a certain period of time is represented by the change in groundwater level, as the unsaturated soil storage capacity tends to zero under the multi-year average water cycle conditions. t is the time scale of the verified water supply and demand, usually taken on an annual scale, but in the model calculation, t is taken on a daily scale according to the refinement of the model. This represents the amount of precipitation infiltrating during the time period. These represent the infiltration of surface water and groundwater into the unsaturated soil zone during the time period; T and E represent the vegetation transpiration and soil evaporation in the unsaturated soil zone during the time period, respectively. This represents the amount of seepage from the unsaturated zone to the saturated zone of the soil during the specified time period. Interflow within a given time period refers to the amount of water that flows out of the oasis soil layer as interflow within a certain time period. These represent the inflow, outflow, and extraction volume of groundwater in the saturated zone of the oasis area during the specified time period. Regional soil salinity balance equation: In the formula: This represents the change in salinity in the saturated zone of irrigated oasis soil over a given period of time. The concentration of salt carried by precipitation; and These are the salinity concentrations of irrigation surface water and groundwater, respectively. The concentration of salts is carried by water vapor transpired from vegetation; This refers to the salt concentration carried by water vapor evaporating from the soil; typically... , It basically approaches 0; The salt concentration is carried by the inflow of groundwater into the saturated zone of the oasis area; This refers to the concentration of salt in the interflow soil. The salt concentration carried by groundwater outflow; These represent the salt concentration carried by the amount of groundwater extracted; Sub-step 22, based on the simulation in sub-step 21, obtains quantitative results for various water cycle elements in the refined simulation unit, such as infiltration, discharge, and evaporation / transpiration consumption; where infiltration includes precipitation infiltration recharge. and surface water irrigation infiltration recharge and groundwater irrigation infiltration recharge Excretion volume This includes runoff discharged outside the unit, such as soil flow. and groundwater drainage and mining volume Evapotranspiration includes vegetation transpiration (T) and soil evaporation (E). Step 3: Obtain the degree of soil salinization in the simulation unit and the water cycle elements under the corresponding water cycle structure, and calculate the infiltration ratio of each unit. Step 3 specifically includes the following sub-steps: Sub-step 31: Based on the basic calculation units in the fine water cycle simulation, resample the soil salinization of the area obtained in step 1 to obtain the degree of salinization of different units. Sub-step 32: By comparing the water cycle elements under different unit water cycle structures, calculate the infiltration amount of the water cycle corresponding to the salinization degree of each unit. Excretion volume Given the evaporation and transpiration rate E+T, calculate and determine the infiltration ratio of each unit using the following formula: ； In the formula: Total irrigation infiltration into the soil layer: The soil water cycle infiltration ratio; Step 4, comprehensively assess the soil salinization status: Step 4 specifically includes the following sub-steps: Sub-step 41: Based on the principle of regional soil salinity balance relationship, and using the results of step 3, or through a water-salt cycle model or a water-salt equilibrium model, determine the accumulation state of soil salinity; if it is in a desalination state, further determine the groundwater depth and proceed to sub-step 42; if it is in a salt accumulation state, it indicates that the groundwater depth does not meet the requirements, and directly proceed to the adjustment of step 2. Sub-step 42: Using the storage variable in the water cycle structure, combined with the regional groundwater depth, determine whether the unit's groundwater depth is within a reasonable and appropriate range. When groundwater storage changes Furthermore, the maximum burial depth for preventing vegetation degradation is less than the groundwater burial depth, which is less than the maximum saline burial depth. This indicates that the region is generally in a state of desalination. Moreover, from the perspective of salt discharge and vegetation growth, the groundwater level is suitable and the water cycle is generally in a relatively good state. When groundwater storage changes Furthermore, the groundwater depth is less than the limit depth for preventing vegetation degradation, indicating that the region is generally in a state of desalination. From the perspective of salinity, the water cycle structure is reasonable, but it is not suitable for vegetation growth, which will lead to vegetation degradation. Otherwise, there is a risk of salt accumulation or vegetation degradation in other situations; it needs to be determined in conjunction with reasonable water level adjustments. Sub-step 43: Based on the above, select the unit groundwater storage variable. Furthermore, the water cycle structure and corresponding infiltration ratio corresponding to the unit of the limit burial depth for preventing vegetation degradation < groundwater burial depth < limit saline burial depth are summarized to obtain the infiltration ratio α threshold corresponding to the benign water cycle of the regional soil layer. Step 5, analyze water consumption based on evaporation and transpiration: Step 5 specifically includes the following sub-steps: Sub-step 51: Obtain typical crops in the irrigated oasis area and calculate the basic water consumption requirements of various typical crops under the current conditions where water-saving measures are widely adopted in the area. ; Sub-step 52: Compare the total evapotranspiration in the current simulation results, and through adjustment and comparison, finally determine the basic evapotranspiration water demand required to ensure the growth of vegetation or crops in the region. : when , ; when , ; Step 6, Estimate Regional Irrigation Water Supply: Sub-step 6 specifically includes the following sub-steps: Sub-step 61, combining the regional infiltration ratio threshold from step 4 and the suitable regional evaporation and transpiration consumption from step 5, and based on the basic requirements of maintaining stable groundwater depth and preventing soil salinization, determines the basic soil infiltration water requirement for irrigated oases. and irrigation infiltration water demand Specific calculation formula: and In the formula: The required amount of infiltration water for irrigating oasis soil; ; Sub-step 62 involves considering the influence of regional precipitation, soil type, and hydrogeological characteristics on the water-salt cycle, and then considering the soil infiltration coefficient. The basic irrigation water volume required to ensure the dual objectives of "water conservation and salt control" in irrigated oasis areas is determined using a formula: The irrigation water supply used for desalination is as follows: In the formula: The basic irrigation water volume is required to achieve the dual goals of water conservation and salt control in the irrigated oasis area. Irrigation water supply for salt removal; The actual rainfall in the irrigated oasis area; The infiltration coefficients for precipitation and irrigation water; Based on the above, we can conclude the basic water supply volume and total water supply structure for achieving the dual goals of "water conservation and salt control" under the current water conservation level and climate conditions.

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