A soil salinization control method based on water cycle process

Abstract

The present invention discloses a soil salinization control method driven by a water cycle process, including: based on the principle of water balance, obtaining water cycle elements in different water cycle processes in a salinized area; based on the principle of salt balance, obtaining the salt concentration of water cycle elements, and judging the state of salt accumulation in the unsaturated zone of soil in the salinized area according to the salt concentration of water cycle elements; analyzing the main sources of salt accumulation in the unsaturated zone of soil; selecting corresponding salt control measures according to the state of salt accumulation in the unsaturated zone of soil and the main sources of salt accumulation in the unsaturated zone of soil. The present invention is based on water cycle-driven salinization control, integrating water resource allocation, water cycle process control and other measures to achieve different types of soil salinization prevention and control; at the same time, it can also coordinate irrigation and drainage, reduce ineffective consumption of water resources, improve water resource utilization efficiency, implement rigid constraints on water resources, and coordinate to achieve water-saving and salt control, and enhance the role of ecological security.

Description

Technical Field

[0001] The invention belongs to the technical field of regulating the utilization of water and soil resources in saline-alkali land, and specifically relates to a soil salinization regulation method driven by a water cycle process. Background Art

[0002] Soil salinization is one of the main causes of soil degradation. In recent years, with the impact of climate change and human activities, global soil salinization has shown a trend of local easing and global aggravation, which not only causes waste of land resources, but also increasingly affects world food security. my country is a country with a large number of saline-alkali lands. There are more than 500 million mu of various types of saline-alkali land resources that can be utilized, and they are distributed in vast areas from tropical to cold temperate zones, coastal to inland, humid areas to extremely arid areas. Under the situation of scarce arable land resources and misplaced distribution of water and soil resources, saline-alkali land, as a non-traditional arable land resource that can be transformed and utilized, is a "potential granary" for increasing grain production; making good use of saline-alkali land is of great significance to food security and improving ecological fragility.

[0003] However, the current methods for the management and control of saline-alkali soil mainly include: physical control, chemical conditioning, biological improvement, large-scale water washing and other single measures or the use of multiple measures combined with the above methods. Although the relevant management and improvement methods can effectively curb the expansion of saline-alkali land and play an important role in increasing production capacity, their target is the accumulation of soil salt. There is a lack of systematic consideration of the dynamic process of "salt comes with water and salt goes with water", which makes it difficult to control it fundamentally. In the face of global climate change, the conservation and intensive use of water resources, and the formation of national and regional water network patterns, the matching relationship between water and soil resources will change, and the control of salinization driven by water is also facing new challenges. Summary of the invention

[0004] The purpose of the present invention is to provide a soil salinization regulation method based on water cycle process driven by the above-mentioned deficiencies in the prior art, so as to solve the problem that the prior art regulation of soil salinity lacks the control of system dynamic processes and is difficult to control fundamentally.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A soil salinization control method based on water cycle process driving comprises the following steps:

[0007] S1. Based on the principle of water balance, obtain the water cycle elements in different water cycle processes in salinization areas;

[0008] S2. Based on the principle of salt balance, obtain the salt concentration of water cycle elements, and judge the salt accumulation state of the unsaturated zone of the soil in the salinized area according to the salt concentration of the water cycle elements;

[0009] S3. Analyze the main sources of salt accumulation in the unsaturated zone of the soil;

[0010] S4. Select corresponding salt control measures based on the salt accumulation status in the unsaturated zone of soil and the main source of salt accumulation in the unsaturated zone of soil.

[0011] Furthermore, the water cycle process in step S1 includes: surface process, underground process and soil process of the water cycle with water and salt migration in the unsaturated zone of soil as the core.

[0012] Furthermore, the surface processes include natural precipitation, irrigation water diversion and surface runoff, which all carry salt into the soil through infiltration;

[0013] Soil processes: Accompanying the infiltration movement of water in the surface process, driving the redistribution of water in the soil layer;

[0014] Underground processes: accept the discharge of deep infiltration and groundwater evaporation from soil processes and surface processes, accompanied by the storage and change of groundwater, affecting the vertical migration of soil moisture and carrying salt in and out of the soil.

[0015] Furthermore, the water cycle structure of the soil process is:

[0016]

[0017] in, is the change of soil moisture content during the period; P e I is the amount of precipitation infiltration during the period; 入渗 is the irrigation infiltration volume during the period; E 潜水 is the evaporation of underground saturated zone in the period; ET is the evaporation of soil water in the period, including soil evaporation E and vegetation evaporation T; R 深层渗漏 is the deep leakage in the period; Rs 出流 It is the soil flow within the period.

[0018] Furthermore, the water cycle structure of the underground process is:

[0019]

[0020] in, Rg is the change of groundwater in a period of time; 入 Lateral inflow into the saturated aquifer during the period; Rg 出流 is the regional groundwater outflow during the period; G g0 is the groundwater extraction volume during the period.

[0021] Furthermore, water cycle elements include: precipitation infiltration, irrigation water infiltration, groundwater evaporation, soil evaporation, vegetation transpiration, deep infiltration, soil and groundwater outflow.

[0022] Furthermore, judging the salt accumulation state of the unsaturated zone of the soil in the salinized area in step S2 includes:

[0023]

[0024] in, is the change of soil salt content over time; C pe is the salt concentration of precipitation; C s and C g are the salinity concentrations of irrigation surface water and groundwater, respectively; C et is the salt concentration carried by vegetation transpiration; C0 is the salt concentration carried by soil evaporation; C Rg is the salt concentration carried by deep seepage water; Cs is the salt concentration in soil outflow; I s ,I g are the surface water irrigation and groundwater irrigation entering the unsaturated zone of the soil, respectively; T and E are the vegetation transpiration and soil evaporation in the unsaturated zone of the soil, respectively;

[0025] When the salt content of the regional water cycle input item is greater than the salt content of the output item, that is, When the soil is salty,

[0026] When the salt content of the input item of the regional water cycle is less than the salt content of the output item, that is, When , it is judged as soil desalination.

[0027] Furthermore, the main sources of salt accumulation in the unsaturated zone of the soil in step S3 include: the salt stock in the soil and the salt increment in the soil accompanying water circulation;

[0028] Based on the salt stock in the soil at the beginning of the period and the salt increment in the soil during the water cycle during the period, the change of soil salt content in the unsaturated zone of the soil is obtained:

[0029] Sws(t+1)-Sws(t)=(P e C pe +I s C s +I g C g )+E 潜水 C g -TC et -EC0-R 深层渗漏 C Rg -Rs 出流 C s

[0030] Among them, Sws(t+1) is the soil salt content at the end of the time period at time t+1; Sws(t) is the soil salt content at the beginning of the time period at time t.

[0031] Further, step S4 includes:

[0032] S4.1. Control the incremental amount of salt in the soil according to the depth of the groundwater level;

[0033] Among them, the desalination process is maintained as follows:

[0034] (P e C pe +I s C s +I g C g )+E 潜水 C g +R g入 C Rg入 ≤Rs 出流 C s +Rg 出流 C Rg出 +G g0 C g0 +TC et +EC0

[0035] Among them, C Rg入 is the salt concentration of the inflowing groundwater; C Rg出 is the salt concentration of the outflowing groundwater; C g0 is the concentration of groundwater extraction; usually the salt concentration C0 carried by soil evaporation is extremely small and can be ignored; the salt concentration carried by vegetation transpiration is C et The salt tolerance of vegetation varies, and most of them are non-salt-tolerant. et ≈0;

[0036] S4.2. Manage the salt content in the soil in the unsaturated zone;

[0037] S4.3, combined with S4.1 and S4.2, by tracking the recharge and discharge ratio of the water cycle in the salinized area, selecting reasonable drainage engineering measures, and combining with the management of salt stocks in the unsaturated zone, comprehensive regulation of salinization can be achieved to achieve the goal of water conservation and salt control.

[0038] Furthermore, step S4.1 specifically includes:

[0039] S4.1.1. If the groundwater level is within the constraint range and the soil unsaturated zone is in a state of salt accumulation, priority shall be given to salt control measures for salt increment; the specific salt control measures for salt increment are: according to the dynamic process of water cycle, based on the geological structure, terrain conditions, regional climate conditions and irrigation conditions, determine the controllable items of water cycle that affect soil salt accumulation, and determine the recharge and discharge ratio; that is, control input I s ,I g and output Rg 出流, G g0 proportion;

[0040] S4.1.2. If the groundwater depth is not within the constraint range and the soil unsaturated zone is in a state of salt accumulation, first determine the groundwater depth, and then control the soil salt increment according to the salt control measures for salt increment in S4.1.1;

[0041] S4.1.3. If the groundwater level is within the constraint range and the soil unsaturated zone salinity is in a desalinated state, the salt control measures in S4.1.1 are used to regulate the soil salinity increment;

[0042] S4.1.4. If the groundwater level is not within the constraint range and the soil unsaturated zone is in a desalinated state, determine the groundwater level, control groundwater evaporation, increase horizontal discharge, implement the recharge and discharge relationship of the water cycle according to the measures in S4.1.2, determine the recharge and discharge ratio, and then implement salt control measures for soil salt increment.

[0043] The soil salinization control method based on water cycle process driving provided by the present invention has the following beneficial effects:

[0044] The present invention focuses on the core link that soil salt migration and redistribution are controlled by the circulation of water, and achieves the purpose of fundamentally controlling soil salinization through reasonable regulation of the water circulation process.

[0045] The present invention is based on water cycle-driven salinization regulation and control, integrating water resource allocation, water cycle process control and other measures to achieve salinization prevention and control of different types of soils; at the same time, it can also coordinate irrigation and drainage, reduce ineffective consumption of water resources, improve water resource utilization efficiency, implement rigid constraints on water resources, and coordinately achieve water conservation and salt control to enhance ecological security. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of the soil salinization control method driven by the water cycle process in Example 1 of the present invention. DETAILED DESCRIPTION

[0047] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0048] Example 1

[0049] This embodiment provides a soil salinization control method driven by the water cycle process. This embodiment can achieve comprehensive control of salinization by selecting reasonable drainage engineering measures and coordinating the management of salt reserves in the unsaturated zone to achieve the goal of water saving and salt control. Figure 1 , which specifically includes the following steps:

[0050] Step S1, based on the water balance principle, analyzing the water cycle structure and obtaining water cycle elements in different water cycle processes in the salinization area;

[0051] The water cycle process of this embodiment includes: the surface process, underground process and soil process of the water cycle with the water and salt migration in the unsaturated zone of the soil as the core.

[0052] Specifically, the surface processes are: mainly including natural precipitation, irrigation water and surface runoff. Natural precipitation, irrigation water and surface runoff all carry salt into the soil through infiltration and affect the redistribution of water and salt in the unsaturated zone of the soil; the main source of salt carrying is concentrated in the soil process.

[0053] Soil process: The infiltration movement of water in the surface process drives the redistribution of water in the soil layer and affects the accumulation of salt in the soil, which can be expressed as:

[0054]

[0055] in, is the change of soil moisture content during the period; P e I is the amount of precipitation infiltration during the period; 入渗 is the irrigation infiltration volume during the period; E 潜水 is the evaporation of underground saturated zone during the period; ET is the soil evaporation and transpiration during the period; R 深层渗漏 is the deep leakage in the period; Rs 出流 It is the soil flow within the period.

[0056] Among them, I 入渗 =I s +I g ;

[0057] I s ,I g They represent the amount of surface water irrigation and groundwater irrigation entering the unsaturated zone of the soil respectively.

[0058] ET=T+E, where T and E represent vegetation transpiration and soil evaporation out of the unsaturated zone of the soil, respectively.

[0059] Underground process: accepting the deep seepage and evaporation of groundwater from soil and surface processes, along with the storage and change of groundwater, it affects the vertical movement of soil moisture and carries salt in and out of the soil. The water cycle structure of the underground process is:

[0060]

[0061] in, Rg is the change of groundwater over time; 入 Lateral inflow into the saturated aquifer during the period; Rg 出流 is the regional groundwater outflow during the period; G g0 is the groundwater extraction volume during the period.

[0062] This embodiment is accompanied by the water cycle process, and the direct water cycle elements of water in the soil include: precipitation infiltration, irrigation water infiltration, groundwater evaporation, vegetation transpiration, soil evaporation, deep seepage, soil and groundwater outflow. The deep seepage supply of groundwater in the water cycle structure based on the underground process is reflected in the change of groundwater burial depth through the impact on the groundwater storage volume, and then acts on groundwater evaporation; accompanied by the movement of water, the distribution of salt in different areas is realized.

[0063] Step S2: Based on the principle of salt balance, the salt concentration of the water cycle elements is obtained, and the salt accumulation state of the unsaturated zone of the soil in the salinized area is judged according to the salt concentration of the water cycle elements, which specifically includes the following contents:

[0064] Determine the salt accumulation status of the unsaturated zone of the soil in the salinized area, including:

[0065]

[0066] in, is the change of soil salt content over time; C pe is the salt concentration of precipitation; C s and C g are the salinity concentrations of irrigation surface water and groundwater, respectively; C et is the salt concentration carried by vegetation transpiration; C0 is the salt concentration carried by soil evaporation; C Rg is the salt concentration carried by deep seepage water; Cs is the salt concentration in soil outflow; I s ,I g are the surface water irrigation volume and groundwater irrigation volume entering the unsaturated zone of the soil, respectively; T and E are the vegetation transpiration and soil evaporation in the unsaturated zone of the soil, respectively.

[0067] When the salt content of the regional water cycle input item is greater than the salt content of the output item, that is, When the soil is salty,

[0068] When the salt content of the input item of the regional water cycle is less than the salt content of the output item, that is, When , it is judged as soil desalination.

[0069] Step S3, analyzing the main sources of salt accumulation in the unsaturated zone of the soil, which specifically includes the following contents:

[0070] The main sources of salt accumulation in the unsaturated zone of soil include: the salt stock in the soil and the salt increment in the soil accompanying water cycle;

[0071] Based on the salt stock in the soil at the beginning of the period and the salt increment in the soil during the water cycle during the period, the change of soil salt content in the unsaturated zone of the soil is obtained:

[0072] Sws(t+1)-Sws(t)=(P e C pe +I s C s +I g C g )+E 潜水 C g -TC et -EC o -R 深层渗漏 C Rg -Rs 出流 C s

[0073] Among them, Sws(t+1) is the soil salt content at the end of the time period at time t+1; Sws(t) is the soil salt content at the beginning of the time period at time t.

[0074] Combined with step S2, judging the salt accumulation state of the unsaturated zone of the soil in the salinized area, it can be seen that with the changes in the water cycle process and soil storage capacity, the reasonable regulation of regional salt changes includes two directions:

[0075] First, reduce input to reduce salt carryover;

[0076] The second is to increase output and increase salt discharge;

[0077] Considering that evaporation carries less salt, a large amount of water evaporates and the salt is left in the soil. Therefore, the key to controlling the process of soil salinization is to reasonably regulate the relationship between the supply and discharge in the form of runoff, in combination with the salt concentration. At the same time, considering that groundwater evaporation is also a complete input item of salt, controlling the groundwater level and reducing groundwater evaporation is a prerequisite constraint for controlling the salt process.

[0078] Step S4: Select corresponding salt control measures according to the state of salt accumulation in the unsaturated zone of the soil and the main source of salt accumulation in the unsaturated zone of the soil, which specifically include the following contents:

[0079] According to the salt accumulation situation and main sources, the "increment" of the salt accumulation process and the "stock" accumulated in the soil are comprehensively considered. That is, based on the salt stock in the soil and the salt increment in the soil during water circulation, under the premise of reasonable groundwater level constraints, appropriate regulation methods are selected to comprehensively achieve the purpose of water saving and salt control.

[0080] The desalination process is maintained according to the following formula:

[0081] (P e C pe +I s C s +I g C g )+E 潜水 C g +R g入 C Rg入 ≤Rs 出流 Cs+Rg 出流 C Rg出 +G g0 C g0

[0082] Among them, C Rg入 is the salt concentration of the inflowing groundwater; C Rg出 The salt concentration of the outflowing groundwater; C g0 is the groundwater extraction concentration;

[0083] R 出流 and G g0 It is determined by combining the discharge volume of regional drainage ditches, the discharge volume of drainage wells, and the amount of groundwater extraction.

[0084] This embodiment controls the salt stock in the soil and the salt increment in the soil during water circulation based on the judgment of a reasonable groundwater level, which specifically includes the following steps:

[0085] Step S4.1: According to the reasonable groundwater level, the salt increment is regulated, which specifically includes the following contents:

[0086] Step S4.1.1: If the groundwater level is within the constraint range and the soil unsaturated zone is in a state of salt accumulation, priority is given to salt control measures for salt increment; the specific salt control measures for salt increment are: according to the dynamic process of water cycle, based on geological structure, terrain conditions, regional climate conditions and irrigation conditions, determine the controllable items of water cycle that affect soil salt accumulation, and determine the recharge and discharge ratio; usually R g入 , Rs, Pe are affected by regional topography, landform, soil structure and climate, and are difficult to control artificially. Therefore, the salt content is balanced; that is, the input I is controlled s ,I g and output Rg 出流 , Cg0 ratio; under reasonable recharge and discharge ratio, the process is regulated by monitoring the groundwater level.

[0087] Step S4.1.2: If the groundwater depth is not within the constraint range and the soil unsaturated zone salinity is in a salt accumulation state, first determine the groundwater depth, and then control the soil salinity increment according to the salt control measures of the salt increment in step S4.1.1;

[0088] Step S4.1.3: If the groundwater level is within the constraint range and the soil unsaturated zone salinity is in a desalination state, the salt control measures in step S4.1.1 are used to control the soil salinity increment to achieve soil salinity “incremental” control;

[0089] Step S4.1.4: If the groundwater level is not within the constraint range and the soil unsaturated zone salt is in a desalinated state, then the groundwater level is determined to strictly control groundwater evaporation, and horizontal discharge must be increased. The recharge and discharge relationship of the water cycle is realized according to the measures of step S4.1.2, the recharge and discharge ratio is determined, and then salt control measures for soil salt increment are implemented.

[0090] Step S4.2: Control the salt content in the soil in the unsaturated zone.

[0091] Instead of following S4.3, and combining S4.1 and S4.2, by tracking the recharge and discharge ratio of the water cycle in the salinized area, selecting reasonable drainage engineering measures, and managing the salt stock in the unsaturated zone, comprehensive regulation of salinization can be achieved to achieve the goal of water conservation and salt control.

[0092] Example 2

[0093] This embodiment is based on the control method of Example 1. Specifically, taking the Yinchuan Plain as an example, according to the water conditions over the years from 1960 to 2020, the average underground burial depth in the entire region is controlled within a reasonable range of 1.8m. The salt content of the Yellow River water is 0.45g / L, the average salt content of drainage is 1.3 / L, and the salt absorption of salt-tolerant vegetation and crops is set to 0.03g / L, to regulate the salt content of the regional soil.

[0094] Step S1: Analyze the water cycle structure based on the water balance principle to obtain the main water cycle elements that affect salinity in the study area.

[0095] Step S2 and step S3, use the surface groundwater joint simulation model to quantitatively calculate the various elements of the water cycle. Through investigation and experimental sampling, the salt concentration of the soil water cycle is obtained. See Table 1 for details. As can be seen from Table 1, the entire plain is in a state of slight salt accumulation, and the water diversion and river discharge account for a large proportion of the salt contribution. Based on the water-salt balance, the identification area is in a slight salt accumulation process, and irrigation diversion and river drainage have a greater impact on the change of salt accumulation.

[0096] Table 1 Water cycle structure integrated salt content

[0097]

[0098] Step S4: According to the principle of water-salt balance and the control ideas of S4.1, the salt concentration carried by the current water diversion and river drainage is converted into K 水 =0.41;

[0099] According to the controllable constraints, the ratio of infiltration to discharge can be maintained at about 0.41 to control the balance of salt increment. Under the control of the above quantitative ratio, water resource allocation and drainage measures can be selected according to local conditions;

[0100] While tracking the groundwater level, reduce the existing salt or carry out soil-suitable planting through the use of soil conditioners or the planting of salt-tolerant vegetation.

[0101] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A soil salinization control method based on water cycle process, characterized in that: The following steps are involved: S1. Based on the principle of water balance, obtain the water cycle elements in different water cycle processes in salinization areas; S2. Based on the principle of salt balance, obtain the salt concentration of water cycle elements, and judge the salt accumulation state of the unsaturated zone of the soil in the salinized area according to the salt concentration of the water cycle elements; S3. Analyze the main sources of salt accumulation in the unsaturated zone of the soil, which include: salt stock in the soil and salt increment in the soil accompanying water circulation; S4. Select corresponding salt control measures according to the salt accumulation state and main sources of salt accumulation in the unsaturated zone of soil; The water cycle process in step S1 includes: surface process, underground process and soil process of the water cycle with water and salt migration in the unsaturated zone of soil as the core; The surface process includes natural precipitation, irrigation water and surface runoff, which all carry salt into the soil through infiltration; Soil processes: Accompanying the infiltration movement of water in the surface process, driving the redistribution of water in the soil layer; Underground process: receiving the discharge of deep seepage and phreatic evaporation from soil and surface processes, accompanied by the storage and change of groundwater, affecting the vertical movement of soil moisture and carrying salt in and out of the soil; The water cycle structure of the soil process is: in, is the change of soil moisture content during the period; P e I is the amount of precipitation infiltration during the period; 入渗 is the irrigation infiltration volume during the period; E 潜水 is the evaporation of underground saturated zone in the period; ET is the evaporation of soil water in the period, including soil evaporation E and vegetation evaporation T; R 深层渗漏 is the deep leakage in the period; Rs 出流 It is the soil flow in the time period; The water cycle structure of the underground process is: in, Rg is the change of groundwater in a period of time; 入 Rg is the lateral inflow of groundwater during the period; 出流 is the lateral outflow of groundwater during the period; G g0 is the groundwater extraction volume during the period; The water cycle elements include: precipitation infiltration, irrigation water infiltration, groundwater evaporation, soil evaporation, vegetation transpiration, deep seepage, and soil and groundwater outflow.

2. The soil salinization control method based on water cycle process drive according to claim 1 is characterized in that: The step S2 of determining the salt accumulation state of the unsaturated zone of the soil in the salinized area includes: in, is the change in soil salt content during the period; C pe is the salt concentration of precipitation; C s and C g are the salinity concentrations of irrigation surface water and groundwater, respectively; C et is the salt concentration carried by vegetation transpiration; C0 is the salt concentration carried by soil evaporation; C Rg is the salt concentration carried by deep seepage water; Cs is the salt concentration in soil outflow; I s ,I g are the surface water irrigation and groundwater irrigation entering the unsaturated zone of the soil, respectively; T and E are the vegetation transpiration and soil evaporation in the unsaturated zone of the soil, respectively; When the salt content of the regional water cycle input item is greater than the salt content of the output item, that is, When the soil is salty, When the salt content of the input item of the regional water cycle is less than the salt content of the output item, that is, When , it is judged as soil desalination.

3. The soil salinization control method based on water cycle process drive according to claim 2 is characterized in that: In step S3, based on the salt inventory in the soil at the beginning of the time period and the salt increment in the soil during the water circulation during the time period, the change in the salt content of the soil in the unsaturated zone of the soil is obtained: Sws(t+1)-Sws(t)=(P e C pe +I s C s +I g C g )+E 潜水 C g -TC et -EC0-R 深层渗漏 C Rg -Rs 出流 C s Among them, Sws(t+1) is the soil salt content at the end of the time period at time t+1; Sws(t) is the soil salt content at the beginning of the time period at time t.

4. The soil salinization control method based on water cycle process drive according to claim 3 is characterized in that: The step S4 comprises: S4.

1. Control the incremental amount of salt in the soil according to the depth of the groundwater level; Among them, the desalination process is maintained as follows: (P e C pe +I s C s +I g C g )+E 潜水 C g +R g入 C Rg入 ≤Rs 出流 Cs+Rg 出流 C Rg出 +G g0 C g0 +TC et +EC0 Among them, C Rg入 is the salt concentration of the inflowing groundwater; C Rg出 is the salt concentration of the outflowing groundwater; C g0 is the concentration of groundwater extraction; the salt concentration C0 carried by soil evaporation is extremely small and can be ignored; the salt concentration C carried by vegetation transpiration is et The salt tolerance of vegetation varies. Most of the non-salt-tolerant vegetation has C et ≈0; S4.

2. Manage the salt content in the soil in the unsaturated zone; S4.3, combined with S4.1 and S4.2, by tracking the recharge and discharge ratio of the water cycle in the salinized area, selecting reasonable drainage engineering measures, and combining with the management of salt stocks in the unsaturated zone, comprehensive regulation of salinization can be achieved to achieve the goal of water conservation and salt control.

5. The soil salinization control method based on water cycle process drive according to claim 4 is characterized in that: The step S4.1 specifically includes: S4.1.

1. If the groundwater level is within the constraint range and the soil unsaturated zone is in a state of salt accumulation, priority shall be given to salt control measures for salt increment; the specific salt control measures for salt increment are: according to the dynamic process of water cycle, based on the geological structure, terrain conditions, regional climate conditions and irrigation conditions, determine the controllable items of water cycle that affect soil salt accumulation, and determine the recharge and discharge ratio; that is, control input I s ,I g and output Rg 出流 , G g0 proportion; S4.1.

2. If the groundwater depth is not within the constraint range and the soil unsaturated zone is in a state of salt accumulation, first determine the groundwater depth, and then control the soil salt increment according to the salt control measures for salt increment in S4.1.1; S4.1.

3. If the groundwater level is within the constraint range and the soil unsaturated zone salinity is in a desalinated state, the salt control measures in S4.1.1 are used to regulate the soil salinity increment; S4.1.

4. If the groundwater level is not within the constraint range and the soil unsaturated zone is in a desalinated state, determine the groundwater level, control groundwater evaporation, increase horizontal discharge, implement the recharge and discharge relationship of the water cycle according to the measures in S4.1.2, determine the recharge and discharge ratio, and then implement salt control measures for soil salt increment.

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