Land consolidation planning method for farmland with cold inundation or secondary salinity in northern China

Abstract

The invention discloses a land consolidation planning method for the consolidation of cold-soaked or secondary saline-alkali farmland in the north, which specifically comprises the following steps: collecting relevant data of the secondary salinization consolidation area; analyzing and determining the main crop types in the consolidation area; analyzing and determining the suitable groundwater burial depth and excavation and filling depth of different crop types; dividing and calculating parameters of different planting areas with the goal of balancing the excavation and filling of the entire consolidation area and planting the same type of crops in concentrated and continuous areas; and arranging and calculating parameters of different planting areas with the goal of balancing the excavation and filling in situ within the consolidation area and reducing the transportation distance. The first planning method uses the land consolidation with the excavation and filling balance of the entire consolidation area to avoid abandoning or borrowing soil, reduce the engineering volume of land consolidation and facilitate the concentrated and continuous management of the same type of crops. The second planning method uses the excavation and filling balance in situ within the consolidation area to carry out land consolidation, which not only balances the excavation and filling of the entire consolidation area, but also greatly reduces the earthwork transportation distance, minimizes the engineering volume of land consolidation and is most economical.

Description

Technical Field

[0001] The invention belongs to the technical field of land development and utilization, and relates to a land improvement planning method for managing farmland with cold infiltration or secondary salinization in the north. Background Art

[0002] In the farmland along the river and valley in the north, the groundwater level is high, the water level gradient is small, and the drainage is poor, which leads to serious soil cold soaking, low soil temperature, and may also cause secondary soil salinization, which directly affects the emergence rate and normal growth of dry crops, resulting in obvious reduction or even no yield of dry crops, and the planting industry is seriously affected. For plain areas, the soil salinization problem caused by the long-term high groundwater level will also lead to low emergence rate, low yield of dry crops or even no yield. At present, there is no farmland management method for stabilizing and increasing the yield of dry crops in cold soaked fields in the north. In order to stabilize and increase the yield of crops, a planning method for improving and managing cold soaked farmland is proposed. After the application of this method, the groundwater level can be reduced in time, the soil temperature can be increased, the water, heat, and air conditions and soil structure characteristics of the crop root zone can be improved, the reductive toxic substances in the cold soaked field can be reduced, the effectiveness of soil nutrients can be improved, and planting can be achieved according to the local conditions and water, and finally the purpose of increasing the crop yield of the group can be achieved. Moreover, this method is also applicable to the management planning of secondary saline-alkali land with high groundwater level. It can greatly reduce the salt accumulation in the soil tillage layer, improve the germination rate and achieve increased production. Summary of the invention

[0003] The purpose of the present invention is to provide a land improvement planning method for managing farmland in the north that is cold-soaked or accompanied by secondary salinization, which can effectively plan and manage farmland in the north that is cold-soaked or accompanied by secondary salinization.

[0004] The technical solution adopted by the present invention is a land consolidation planning method for the management of farmland with cold infiltration or secondary salinization in the north, which is specifically implemented in the following steps:

[0005] Step 1: Collect relevant data on the secondary salinization control area caused by cold infiltration / high groundwater level;

[0006] Step 2: Analyze and determine the main crop planting zones and their suitable groundwater depths in the governance area;

[0007] Step 3: Select and determine the land consolidation planning method, and preliminarily formulate the scope and area of ​​different crop planting areas according to the selected planning method; one of the planning methods is: the division and parameter calculation of different planting areas with the goal of obtaining concentrated and continuous planting of the same type in the entire consolidation area and balanced excavation and filling of land consolidation earthwork;

[0008] Step 4, analyzing and determining the earthwork excavation and filling depth under the conditions of suitable groundwater burial depth for different types of crops;

[0009] Step 5, through trial calculation, obtain the division of different planting areas with the goal of cut-and-fill balance and the parameter calculation of land reclamation area and square cut-and-fill engineering volume.

[0010] The trial calculation process of the planning method is specifically as follows:

[0011] Assume that the land area of ​​the planned governance area is A 0 Based on the preliminary scope of each planting area on the plan layout of the planned management area, the area of ​​the planned dryland crop planting area is calculated as A. 1 The planned rice planting area is A 2 The planned underwater planting area is A 3 ;

[0012] A 0 =A 1 +A 2 +A 3 (1)

[0013] Planned dryland crop planting area ratio α 1 =A 1 / A 0 (2)

[0014] Planned rice planting area ratio α 2 =A 2 / A 0 (3)

[0015] Planned underwater planting area ratio α 3 =A 3 / A 0 (4)

[0016] α 1 +α 2 +α 3 =1(5)

[0017] According to the scope of various planting areas initially planned in the plan layout of the management area, the average excavation and filling depth of each planting area is preliminarily determined, and the average filling height PH of the planned dry crop planting area is set. 11 , the average depth of excavation and filling in the planned rice planting area is PH 22 , the average excavation depth of the planned underwater planting area is PH 33 , then the excavation and filling balance formula in the treatment area is as follows:

[0018] A 1 ×PH 11 =A 2 ×PH 22 +A 3 ×PH 33 (6)

[0019] According to equations (1) to (6), equation (7) can be transformed into the following equation:

[0020] α 1 ×PH 11 =α 2 ×PH 22 +α 3 ×PH 33 (7)

[0021] Substitute the initially planned planting area and the corresponding average excavation and filling depth into formula (7). If the equilibrium relationship is not satisfied, it is necessary to re-adjust the scope of each planting area on the management area plan, calculate its area and average excavation and filling depth, and then substitute them into the above formula for calculation until the equilibrium relationship is satisfied.

[0022] The present invention is also characterized in that:

[0023] Step 2 is as follows: taking the suitability of crops to soil water as the core control factor, a plane layout with differentiated elevation treatment is carried out, and the crop planting area is divided into three types: dry crop planting area, rice planting area and underwater planting area. According to the data collected in step 1, the main types of dry crops, the suitability of rice and the crops suitable for underwater planting in the treatment area are analyzed and determined; and the corresponding suitable groundwater burial depth is determined according to the soil texture, groundwater mineralization and crop types;

[0024] Another planning method for step 3 is:

[0025] The layout and parameter calculation of different planting areas aiming at balancing the cut and fill in the treatment area and reducing the transportation distance;

[0026] According to the selected planning method, the scope and area of ​​different crop planting areas are drawn up on the plan layout of the management area;

[0027] Step 4 analyzes and determines the earth filling height of dry crops in the treatment area as follows:

[0028] The planned dry crop planting area should be filled with earth to increase the groundwater depth H 1 , the filling height H of the dry crop planting area 11 To plan the groundwater depth H 1 Subtract the current groundwater depth H in the planned dry crop planting area 0 , as shown in formula (8):

[0029] H 11 =H 1 -H 0 (8)

[0030] In the dry crop planting area, due to the different current field elevations at each point, the filling height H at each point is 11 Obtain the average filling height PH of the dry crop area 11 , as follows:

[0031] (9)

[0032] Where m is the number of locations for calculating the filling height in the dry crop planting area. i =1,2,3…… m ;

[0033] Step 4 calculates and determines the excavation and filling depth of the rice planting area in the treatment area as follows:

[0034] Fill height H at the planned rice planting area 22 is the current groundwater depth H at the location 0 Subtract the planned groundwater depth H 2 , as follows:

[0035] H 22 =H 0 -H 2 (10)

[0036] If H 22 ﹥0, then the current groundwater depth at the location is H 0 Greater than the planned groundwater depth H 2 , then the location is excavation; if H 22 ﹤0, then the current groundwater depth H 0 Less than the planned groundwater depth H 2 , then the location is fill;

[0037] In the rice planting area, due to the different elevations of the existing field surface at each point, the filling height H of each point is 22 Calculate the average excavation depth PH of the rice planting area 22 .

[0038] (11)

[0039] Where n is the number of locations for calculating the depth of excavation and filling in the rice planting area. j =1,2,3…… n ;

[0040] The specific depth of digging in the underwater planting area for different crop types in step 4 is:

[0041] The excavation depth H of the underwater planting area 33 is the groundwater depth H at the location 0 The thickness of the water layer on the field surface H 3 The sum is as follows:

[0042] H 33 =H 0 +H 3 (12)

[0043] In the underwater planting area, due to the different elevations of the existing field surface at each point, the digging depth H of each point is 33 Calculate the average digging depth PH of the underwater planting area 33 :

[0044] (13)

[0045] In the formula, l The number of locations for calculating the depth of the underwater planting area. k =1,2,3…… l ;

[0046] The specific calculation process of another planning method in step 5 is as follows:

[0047] In order to reduce the amount of treatment works and minimize the transportation distance of excavation and filling, the excavation and filling of various planting areas in the local unit combination should be balanced; each planting area is arranged adjacent to the strip field, and a preliminary plan layout of the local unit combination of dry crop planting areas, rice planting areas and underwater planting areas in the treatment area is drawn, and the strip field length and width of each planting area in each local unit combination are obtained from the plan layout;

[0048] For a certain local unit combination, the strip lengths of the dry crop planting area, rice planting area and underwater planting area obtained from the preliminary plan layout are set as L 1 , L 2 , L 3 and width are B 1 , B 2 , B 3 Calculate the average depth of digging and filling within each planting area PH 11 , PH 22 , PH 33 , then the excavation and filling of various planting areas in the local unit combination should be balanced, and the excavation and filling balance relationship of the local unit combination is obtained:

[0049] B 1 ×L 1 ×PH 11 =B 2 ×L 2 ×PH 22 +B 3 ×L 3 ×PH 33 (14)

[0050] The width of each field is calculated by trial and error, and the length of each field and the average depth of excavation and filling are corrected from the plane map. Finally, the B that makes equation (14) valid is determined. 1 , B 2 , B 3and L 1 , L 2 , L 3 .

[0051] The calculation of land consolidation area in the planning layout is as follows:

[0052] Land improvement area of ​​local unit combination:

[0053] Land improvement area A of local unit combination d is equal to the sum of the areas of all types of crop planting areas in the combination, that is,

[0054] A d =B 1 ×L 1 +B 2 ×L 2 +B 3 ×L 3 (15)

[0055] Total area of ​​the governance zone:

[0056] The total area of ​​the governance area is A 0 It is equal to the sum of the areas of all local unit combinations, and also equal to the sum of the areas of all types of crop planting areas, as shown in formula (1); i =1,2,3…… M， Therefore:

[0057] (16)

[0058] Total area of ​​dryland crop planting area in the governance area A 1 is the sum of the dryland crop planting areas of each local unit combination; that is,

[0059] (17)

[0060] The total rice planting area in the governance area is A 2 is the sum of rice planting areas of each local unit combination;

[0061] (18)

[0062] Total area of ​​underwater planting area in the treatment area A 3 is the sum of the underwater planting areas of each local unit combination; that is,

[0063] (19)

[0064] In formulas (16), (17), (18), and (19), M is the number of local unit combinations in the treatment area, and B is 1i is the strip width of each dry crop planting area in each local unit combination, B 2iis the width of the rice field in each rice planting area in each local unit combination, B 3i is the strip width of each underwater planting area in each local unit combination, L 1i is the length of the strip field in each dry crop planting area in each local unit combination, L 2i is the length of each rice planting area in each local unit combination, L 3i is the length of the strips of each underwater planting area in each local unit combination, i =1,2,3…… m ;

[0065] The calculation of earthwork excavation and filling engineering quantity in the planning layout is as follows:

[0066] Calculation of earthwork excavation and filling quantity of local unit combination:

[0067] When PH 22 When ﹥0, the excavation volume of the local unit combination is: B 2 ×L 2 ×PH 22 +B 3 ×L 3 ×PH 33 ; The filling volume of the local unit combination is: B 1 ×L 1 ×PH 11 ;

[0068] When PH 22 When ﹤0, the excavation volume of the local unit combination is: B 3 ×L 3 ×PH 33 ; The filling volume of the local unit combination is: B 1 ×L 1 ×PH 11 +B 2 ×L 2 ×PH 22 ;

[0069] Calculation of total earthwork excavation and filling quantity in the treatment area: The scope of the treatment area is composed of a combination of local units;

[0070] The total excavation volume of the treatment area is the sum of the excavation volumes of each local unit combination;

[0071] The total filling volume of the treatment area is the sum of the filling volumes of each local unit combination.

[0072] The beneficial effects of the present invention are:

[0073] The land reclamation planning method for the treatment of cold-soaked or secondary saline-alkali farmland in the north of the present invention includes two planning methods, which improve the utilization rate of land planting; the land reclamation with balanced excavation and filling of earthwork in the entire treatment area achieves the goal of not abandoning or borrowing earthwork, and reduces the engineering workload of land reclamation; the first planning method can not only balance the excavation and filling of earthwork in the entire treatment area, but also enable the same type of crops to be planted in concentrated and continuous areas for easy management; the second planning method can not only balance the excavation and filling of earthwork in the entire treatment area, but also achieve the balance of excavation and filling of earthwork within the combination range through the combination of local units in different planting areas, greatly reducing the transportation distance of earthwork construction, minimizing the engineering workload of land reclamation in the entire treatment area and making it most economical. At the same time, the reduction of groundwater level is conducive to improving the water, fertilizer, air and heat conditions of the soil in the dry crop planting area, and increasing crop yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a schematic diagram of the planned filling height of the dryland area in the land improvement planning method for the treatment of the northern cold-soaked or secondary saline-alkali farmland of the present invention;

[0075] Figure 2 It is a schematic diagram of the planned excavation and filling depth of the rice planting area in the land improvement planning method for the treatment of cold-soaked or secondary saline-alkali farmland in the north of the present invention;

[0076] Figure 3 It is a schematic diagram of the elevation relationship and the digging depth of the planned underwater planting area in the land improvement planning method for the treatment of cold-soaked farmland in the north or with secondary saline-alkali in the present invention;

[0077] Figure 4 It is a cross-sectional view of the combination of local units in different planting areas in the land management planning method for the management of farmland with cold infiltration or secondary salinization in the north of the present invention;

[0078] Figure 5 It is a schematic diagram of the plan layout of local unit combinations of different planting areas in the land improvement planning method for the management of northern cold-soaked or secondary saline-alkali farmland of the present invention. DETAILED DESCRIPTION

[0079] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0080] The present invention provides a land management planning method for managing farmland with cold inundation or secondary salinization in the north, as shown in the following embodiments:

[0081] Governance planning scenarios and goals:

[0082] There are two main scenarios for governance planning: soil cold infiltration caused by high groundwater levels, or secondary soil salinization; the groundwater level is high, soil cold infiltration is not serious, but there is a problem of secondary soil salinization;

[0083] Groundwater quality in the planned management area: in line with national standards for farmland irrigation water quality.

[0084] The objectives of the governance plan are: ① For the first scenario, solve the problem of soil cold soaking in dry crop planting areas and increase ground temperature; ② For the second scenario, greatly reduce the accumulation of salt in the dry crop farming layer; ③ Coordinate the adjustment of soil water, heat, salt and air conditions in dry crop planting areas to increase dry crop yields; ④ Make full use of the suitability of soil water, heat, salt and air conditions, plan suitable planting areas, and improve the land planting utilization rate in the governance planning area: For areas suitable for growing dry crops, plan to grow dry crops; for areas not suitable for growing dry crops, plant rice or carry out underwater planting to maximize the land planting utilization rate.

[0085] The key factors to solve the soil subsurface cold infiltration and secondary salinization:

[0086] For dryland crop planting areas, the wet and cold soaking of the soil is mostly caused by the low-lying terrain in the area, the accumulation of groundwater, which makes the groundwater level too high, and the groundwater depth is small. The secondary salinization of the soil is mainly due to the high groundwater level and the small groundwater depth. Under the action of atmospheric evaporation, the water is evaporated into the atmosphere, and the salt in the water remains on the surface, forming the secondary salinization of the soil. It can be seen that whether it is wet and cold soaking of the soil or secondary salinization of the soil, the core factor causing the problem is the height of the groundwater level.

[0087] Therefore, the key issue in solving soil infiltration or secondary soil salinization is to control the groundwater level in the area.

[0088] Collect relevant information on the secondary salinization control area caused by cold infiltration / high groundwater level:

[0089] The data that need to be collected mainly include the geographical environment, topographic conditions, hydrometeorological conditions, hydrogeological and groundwater conditions, soil conditions, planting conditions, farmers' planting intentions, management costs and planting economic analysis of the management area.

[0090] The division of crop planting areas and determination of suitable groundwater depth are carried out based on the water suitability of crops to soil as the core control factor:

[0091] Based on the relevant data collected in the governance area, the plane layout with the crop's suitability for soil water as the core control factor is carried out with differentiated elevation treatment. The crop planting area can be divided into three types: dry crops, rice and underwater planting (lotus root), and the appropriate groundwater depth can be determined;

[0092] The soil moisture in the dryland crop planting area is mainly in an unsaturated state. The groundwater level is required to be buried at a reasonable depth. The capillary rise of groundwater will not cause the soil moisture in the plough layer to become saturated and cause cold soaking. The main dryland crop types in the treatment area are selected and determined, and the corresponding groundwater depth is determined according to the determined dryland crop types, soil properties and groundwater mineralization.

[0093] In rice-growing areas, there is usually a water layer on the surface of the field (except during the field baking period), and the groundwater level must also be controlled at a certain depth (usually 0.4-0.6 meters);

[0094] The underwater planting area (lotus root) has a certain water layer thickness on the field surface according to the field operation requirements (for shallow water lotus root, the suitable water depth is 5-50cm; for deep water lotus root, the suitable water depth is 50-100cm).

[0095] Determination of earthwork excavation and filling depths in different planting areas that meet the suitability of the species within the treatment area:

[0096] In the wet and cold land or secondary saline-alkali land with high groundwater level, the planned dry crop planting area should be filled with earth to increase the groundwater depth. 1 ,like Figure 1 As shown, considering the soil properties, the reasonable groundwater depth of the planned dry crops is achieved, and the filling height H of the dry crop planting area is 11 To plan the groundwater depth H 1 Subtract the current groundwater depth H in the dry crop planting area 0 , as shown in formula (8):

[0097] H 11 =H 1 -H 0 (8)

[0098] Formula (1) is the filling height of a certain point. In the dry crop planting area, since the current field elevation of each point is different, the filling height H at its location is 11 Therefore, the filling height H of each point is 11 Obtain the average filling height PH of the dry crop area 11 , as follows:

[0099] (9)

[0100] Where m is the number of locations for calculating the filling height in the dry crop planting area, i=1,2,3...m;

[0101] For the planned rice planting area, it is necessary to determine the depth of land management in the rice planting area, whether it is excavation or filling, based on the current depth and planned depth of the groundwater level. Figure 2 As shown; the filling height H of the planned rice planting area22 is the current groundwater depth H at the location 0 Subtract the planned groundwater depth H 2 , as follows:

[0102] H 22 =H 0 -H 2 (10)

[0103] If H 22 ﹥0, then the current groundwater depth at the location is H 0 Greater than the planned groundwater depth H 2 , then the location is excavation; if H 22 ﹤0, then the current groundwater depth H 0 Less than the planned groundwater depth H 2 , then the location is fill;

[0104] In the rice planting area, due to the different elevations of the current field surface at each point, the excavation depth H at its location is 22 are also different, then the filling height H of each point 22 Calculate the average filling height PH of the rice planting area 22 :

[0105] (11)

[0106] Where n is the number of locations for calculating the depth of excavation and filling in the rice planting area. j =1,2,3…… n ;

[0107] The water level of the planned underwater planting area (lotus root) should be consistent with the groundwater level. The relationship between the elevation and the depth of earthwork excavation is as follows: Figure 3 As shown, the digging depth H of the underwater planting area 33 is the groundwater depth H at the location 0 The thickness of the water layer on the field surface H 3 The sum of; as follows:

[0108] H 33 =H 0 +H 3 (12)

[0109] In the underwater planting area, due to the different elevations of the existing field surface at each point, the digging depth H of each point is 33 Calculate the average digging depth PH of the underwater planting area 33 :

[0110] (13)

[0111] In the formula, lThe number of locations for calculating the depth of the underwater planting area. k =1,2,3…… l .

[0112] Balance of excavation and filling of earthwork in the treatment area:

[0113] For the wet and cold infiltration or secondary saline-alkali areas under the treated soil, when determining the proportion of crop planting areas (dry crops, rice and underwater planting (lotus root)), the principle of balanced excavation and filling in the treated area should be adhered to, that is, 1) when the average excavation depth of the planned rice planting area is greater than 0, the amount of filling earth required for land treatment in the planned dry crop planting area should be consistent with the amount of excavation for land treatment in the planned rice planting area and the planned underwater planting area; 2) when the average excavation depth of the planned rice planting area is less than 0, the amount of filling earth required for land treatment in the planned dry crop planting area and the planned rice planting area should be consistent with the amount of excavation for land treatment in the planned underwater planting area, and no earthwork should be abandoned or borrowed in the earthwork excavation and filling project.

[0114] Example 1, the first planning method:

[0115] Assume that the land area of ​​the planned governance area is A 0 , preliminarily define the scope of each planting area on the plan layout of the management area, and calculate the area of ​​the planned dry crop planting area as A 1 The planned rice planting area is A 2 The planned underwater planting area is A 3 ;

[0116] A 0 =A 1 +A 2 +A 3 (1)

[0117] Planned dryland crop planting area ratio α 1 =A 1 / A 0 (2)

[0118] Planned rice planting area ratio α 2 =A 2 / A 0 (3)

[0119] Planned underwater planting area ratio α 3 =A 3 / A 0 (4)

[0120] α 1 +α 2 +α 3 =1(5)

[0121] According to the scope of various planting areas initially planned in the plan layout of the management area, the average excavation and filling depth of each planting area is preliminarily determined, and the average filling height PH of the planned dry crop planting area is set. 11 , the average depth of excavation and filling in the planned rice planting area is PH 22 , the average depth of the planned underwater planting area is PH 33 , then the excavation and filling balance formula in the treatment area is as follows:

[0122] A 1 ×PH 11 =A 2 ×PH 22 +A 3 ×PH 33 (6)

[0123] According to equations (1) to (6), equation (7) can be transformed into

[0124] α 1 ×PH 11 =α 2 ×PH 22 +α 3 ×PH 33 (7)

[0125] As long as the various planned planting areas (dry crops, rice, underwater planting) meet the conditions of formula (7), the excavation and filling balance of the management area can be achieved; in the planning process, it is necessary to adjust the area ratio of each planting area and its average excavation / filling depth through trial calculation to make the equation (7) hold.

[0126] Finally, the field dimensions (length, width) of each planting area can be obtained from the management area planning plan to calculate the earthwork excavation and filling volume.

[0127] Example 2, the second planning method:

[0128] Principles of local unit combination planning in different planting areas:

[0129] In order to minimize the cost of the treatment project in the treatment area, in addition to satisfying the above-mentioned condition of formula (13) and achieving the balance of excavation and filling in the treatment area, the transportation distance of excavation and filling in the treatment area should be reduced as much as possible to achieve the balance of excavation and filling in the local or close distance. Therefore, it is necessary to carry out the plane combination layout of different planting areas according to the excavation and filling depth and engineering volume of each planned planting area to achieve the balance of excavation and filling in the local area; Figure 4 As shown in the figure, the dry crop planting area, rice planting area and underwater planting area are all planned as strip fields, and the width of the strip fields is B 1 , B 2 , B 3; The strips of fields in each planting area can be arranged adjacent to each other on the plane, such as dry farming area-rice area-underwater planting area for local unit combination (different order combinations are also possible), and similar multi-unit layout can be carried out on the plane, such as Figure 5 As shown;

[0130] In order to reduce the amount of management work and minimize the transportation distance of excavation and filling, the excavation and filling of various planting areas within the local unit combination should be balanced; each planting area is arranged in adjacent strips, and the strip width of the dry crop planting area, rice planting area and underwater planting area of ​​each local combination unit in the management area can be preliminarily drawn up, and the local unit combination plan layout of the dry crop planting area, rice planting area and underwater planting area in the management area can be drawn on the topographic map. From the plan layout, the strip length of each planting area in each local unit combination can be obtained;

[0131] For a certain local unit combination, the excavation and filling of various planting areas within the local unit combination should be balanced. Figure 4 The excavation and filling balance relationship of the local unit combination is obtained:

[0132] B 1 ×L 1 ×PH 11 =B 2 ×L 2 ×PH 22 +B 3 ×L 3 ×PH 33 (14)

[0133] In the formula, B 1 , B 2 , B 3 L is the width of the strips of various planting areas within the local unit combination; 1 , L 2 , L 3 is the length of the strips of various planting areas in the local unit combination, PH 11 , PH 22 , PH 33 is the average depth of excavation and filling of each field in the local unit combination, which is calculated by equations (8), (10), and (12); the width of each field is calculated by trial and error. In this process, the length of each field and the average depth of excavation and filling in the field should be corrected accordingly, and finally the B that makes equation (14) valid is determined. 1 , B 2 , B 3 , L 1 , L 2 , L 3 At this point, the specifications and dimensions (length, width) of the various planting area strips in this local unit combination and the amount of earthwork excavation and filling can be determined.

[0134] Combination planning method of local units in different planting areas:

[0135] Land consolidation layout of local unit combination: the consolidation area can be composed of several local unit combinations; according to the topographic map and groundwater depth map of the consolidation area, analyze the topographic trend and groundwater flow direction; according to the topographic trend and groundwater flow direction, analyze and determine the direction of the local unit combination (the length direction of the strip field) and the type combination of planting areas; the direction of the local unit combination should be roughly parallel to the topographic contour line and the groundwater level contour line, and be as straight as possible with few bends to form a strip field for easy cultivation;

[0136] Draw the plan layout of different local unit combinations in the treatment area: First, make a preliminary layout of the first local unit combination on the plan layout map (topographic map); the first local unit combination should be arranged at the boundary of the treatment area according to the determined direction; according to the groundwater depth, select the land improvement layout (planting crop type and combination form) of the first local unit combination; according to the above-mentioned planning principles of local unit combinations in different planting areas, determine the length, width and average excavation and filling depth of various strips of fields in the first local unit combination. At this point, the plane position, specifications and dimensions, and earthwork excavation and filling engineering volume of each strip of field in the first local unit combination have been determined; according to the direction of the local unit combination in the treatment area and the first The arrangement of the local unit combination on the plane layout diagram can be preliminarily drawn with the local unit combination adjacent to the first local unit combination, and according to the above-mentioned planning principle of the local unit combination in different planting areas, the position and planning parameters of the strip fields of each planting area of ​​the local unit combination can be determined; according to this method, the local unit combination in the treatment area can be started from one side of the boundary, take the preliminarily planned position - calculate and determine the position and planning parameters - preliminarily plan the position of the adjacent local unit combination - calculate and determine the position and planning parameters of the adjacent local unit combination again..., and preliminarily arrange the last local unit combination - determine it to the other side of the boundary of the treatment area; at this point, all the unit combinations in the treatment area are arranged, and this figure is the planning result figure;

[0137] The calculation of land improvement area (including the area occupied by field ridges and ditches) is as follows:

[0138] (1) Land improvement area of ​​local unit combination:

[0139] Land improvement area A of local unit combination d is equal to the sum of the areas of all types of crop planting areas in the combination, that is,

[0140] A d =B 1 ×L 1 +B 2 ×L 2 +B 3 ×L 3 (15)

[0141] (2) Total area of ​​the governance area:

[0142] The total area of ​​the governance area is A 0 It is equal to the sum of the areas of all local unit combinations, and also equal to the sum of the areas of all types of crop planting areas, as shown in formula (1); i =1,2,3…… M， Therefore:

[0143] (16)

[0144] Total area of ​​dryland crop planting area in the governance area A 1 is the sum of the dryland crop planting areas of each local unit combination; that is,

[0145] (17)

[0146] The total rice planting area in the governance area is A 2 is the sum of rice planting areas of each local unit combination;

[0147] (18)

[0148] Total area of ​​underwater planting area in the treatment area A 3 is the sum of the underwater planting areas of each local unit combination; that is,

[0149] (19)

[0150] In formulas (16), (17), (18), and (19), M is the number of local unit combinations in the treatment area, and B is 1i is the strip width of each dry crop planting area in each local unit combination, B 2i is the width of the rice field in each rice planting area in each local unit combination, B 3i is the strip width of each underwater planting area in each local unit combination, L 1i is the length of the strip field in each dry crop planting area in each local unit combination, L 2i is the length of each rice planting area in each local unit combination, L 3i is the length of the strips of each underwater planting area in each local unit combination, i =1,2,3…… m ;

[0151] The calculation of earthwork excavation and filling volume is as follows:

[0152] (1) Calculation of earthwork excavation and filling quantities for local unit combinations:

[0153] When PH 22When ﹥0, the excavation volume of the local unit combination is: B 2 ×L 2 ×PH 22 +B 3 ×L 3 ×PH 33 ; The filling volume of the local unit combination is: B 1 ×L 1 ×PH 11 ;

[0154] When PH 22 When ﹤0, the excavation volume of the local unit combination is: B 3 ×L 3 ×PH 33 ; The filling volume of the local unit combination is: B 1 ×L 1 ×PH 11 +B 2 ×L 2 ×PH 22 ;

[0155] (2) Calculation of total earthwork excavation and filling volume in the treatment area: The scope of the treatment area is composed of a combination of local units;

[0156] The total excavation volume of the treatment area is the sum of the excavation volumes of each local unit combination;

[0157] The total filling volume of the treatment area is the sum of the filling volumes of each local unit combination.

[0158] exist Figure 4 The middle field ridge has a side slope with a steep slope. According to formula (14), a small amount of filling earthwork will be added; the cross-section of the field ditch is small, which will also increase a small amount of excavation. In the calculation of formula (14), these factors are not considered, but this will not cause a large error in the governance effect. The small amount of filling and the small amount of excavation not included in the over-calculation can be used as the ridges in the dry crop planting area and the rice planting area, and are conducive to the layout of field irrigation and drainage projects.

[0159] Example 3, different planting area combinations at different groundwater depths:

[0160] The land consolidation mode with a combination of dryland planting area, rice planting area and underwater planting area (the combination order can be changed) can achieve the balance of earthwork excavation and filling; depending on the different groundwater depth conditions, the planting area can be either Class 3 or Class 2;

[0161] When the groundwater depth is small (less than about 0.5 meters), a combination of rice planting areas and underwater planting areas can be used;

[0162] When the groundwater depth is between 0.5 and 1.5 meters, three planting area combinations can be adopted, namely, dry crop planting area, rice planting area and underwater planting area, according to the soil texture and the height of capillary water rise;

[0163] When the groundwater depth is between 1.0 and 2.2 meters, a combination of two planting areas, namely, dry crop planting areas and rice planting areas, can be adopted based on the soil texture and the height of capillary water rise.

Claims

1. A land consolidation planning method for farmland consolidation with cold inundation or secondary salinization in the north, characterized in that: Please follow the steps below to implement: Step 1: Collect relevant data on the secondary salinization control area caused by cold infiltration / high groundwater level; Step 2: Analyze and determine the main crop planting zones and their suitable groundwater depths in the governance area; Step 3: Select and determine the land consolidation planning method, and preliminarily formulate the scope and area of ​​different crop planting areas according to the selected planning method; one of the planning methods is: the division and parameter calculation of different planting areas with the goal of obtaining concentrated and continuous planting of the same type in the entire consolidation area and balanced excavation and filling of land consolidation earthwork; Step 4, analyzing and determining the earthwork excavation and filling depth under the conditions of suitable groundwater burial depth for different types of crops; Step 5, through trial calculation, obtain the division of different planting areas with the goal of cut-and-fill balance and the parameter calculation of land improvement area and square cut-and-fill engineering quantity; The trial calculation process of the planning method is specifically as follows: Assuming the land area of ​​the planned management area is A0, based on the preliminary scope of each planting area on the plan layout of the planned management area, the planned dry crop planting area is A1, the planned rice planting area is A2, and the planned underwater planting area is A3; A0=A1+A2+A3(1) Planned dryland crop planting area ratio α1 = A1 / A0 (2) Planned rice planting area ratio α2 = A2 / A0 (3) Planned underwater planting area ratio α3 = A3 / A0 (4) α1＋α2＋α3＝1（5） According to the scope of various planting areas initially planned in the plan layout of the management area, the average excavation and filling depth of each planting area is preliminarily determined, and the average filling height PH of the planned dry crop planting area is set. 11 , the average depth of excavation and filling in the planned rice planting area is PH 22 , the average depth of the planned underwater planting area is PH 33 , then the excavation and filling balance formula in the treatment area is as follows: A1×PH 11 =A2×PH 22 +A3×PH 33 (6) According to equations (1) to (6), equation (7) can be transformed into the following equation: α1×PH 11 =α2×PH 22 +α3×PH 33 (7) Substitute the initially planned planting area and the corresponding average excavation and filling depth into formula (7). If the equilibrium relationship is not satisfied, it is necessary to re-adjust the scope of each planting area on the management area plan, calculate its area and average excavation and filling depth, and then substitute them into the above formula for calculation until the equilibrium relationship is satisfied.

2. The land management planning method for farmland management with cold inundation or secondary salinization in the north according to claim 1 is characterized in that: The step 2 is specifically as follows: taking the suitability of crops to soil for water as the core control factor, a plane layout with differentiated treatment in elevation is carried out, and the crop planting area is divided into three types: dry crop planting area, rice planting area and underwater planting area. According to the data collected in step 1, the main types of dry crops in the management area, the suitability of rice and the crops suitable for underwater planting are analyzed and determined; and the corresponding suitable groundwater burial depth is determined according to the soil texture, groundwater mineralization and crop types.

3. The land management planning method for farmland management in northern China with cold inundation or secondary salinization according to claim 1, characterized in that: Another planning method of step 3 is: different planting area layout and parameter calculation with the goal of balancing the on-site excavation and filling within the treatment area and reducing the transportation distance; Based on the selected planning method, the scope and area of ​​different crop planting areas shall be preliminarily determined on the management area plan.

4. The land management planning method for farmland management in northern China with cold inundation or secondary salinization according to claim 2 or 3, characterized in that: The step 4 analyzes and determines the earth filling height of the dry crops in the treatment area as follows: The planned dry crop planting area needs to be filled with earth to increase the groundwater depth H1. The filling height of the dry crop planting area is H 11 The planned groundwater depth H1 minus the current groundwater depth H0 in the planned dry crop planting area is as follows (8): H 11 =H1-H0 (8) In the dry crop planting area, due to the different current field elevations at each point, the filling height H at each point is 11 Obtain the average filling height PH of the dry crop area 11 , as follows: （9） Where m is the number of locations for calculating the filling height in the dry crop planting area. i =1,2,3…… m .

5. The land management planning method for farmland management in northern China with cold inundation or secondary salinization according to claim 2 or 3, characterized in that: The step 4 calculates and determines the excavation and filling depth of the rice planting area in the treatment area as follows: Fill height H at the planned rice planting area 22 It is the current groundwater depth H0 at the location minus the planned groundwater depth H2, as shown in the following formula: H 22 =H0-H2(10) If H 22 ﹥0, the current groundwater depth H0 at the location is greater than the planned groundwater depth H2, and the location is excavation; if H 22 ﹤0, then the current groundwater depth H0 is less than the planned groundwater depth H2, and the location is fill; In the rice planting area, due to the different elevations of the existing field surface at each point, the filling height H of each point is 22 Calculate the average excavation depth PH of the rice planting area 22 : （11） Where n is the number of locations for calculating the depth of excavation and filling in the rice planting area. j =1,2,3…… n .

6. The land management planning method for farmland management in northern China with cold inundation or secondary salinization according to claim 2 or 3, characterized in that: The specific depth of digging in the underwater planting area for different crop types in step 4 is: The excavation depth H of the underwater planting area 33 It is the sum of the groundwater depth H0 at the location and the water layer thickness H3 on the field surface, as shown in the following formula: <h2 style=";text-align:left;direction:ltr">H<h2 style=";text-align:left;direction:ltr"> 33 <h2 style=";text-align:left;direction:ltr"> (H0) + (H3) + (12) In the underwater planting area, due to the different elevations of the existing field surface at each point, the digging depth H of each point is 33 Calculate the average digging depth PH of the underwater planting area 33 : （13） In the formula, l The number of locations for calculating the depth of the underwater planting area. k =1,2,3…… l .

7. The land management planning method for farmland management with cold inundation or secondary salinization in the north according to claim 3, characterized in that: The trial calculation process of another planning method in step 5 is specifically as follows: Each planting area is arranged adjacent to the strips, and a preliminary plan layout diagram of the local unit combination of the dry crop planting area, the rice planting area and the underwater planting area in the management area is drawn, and the strip length and width of each planting area in each local unit combination are obtained from the plan layout diagram; For a certain local unit combination, the strip lengths of the dry crop planting area, rice planting area and underwater planting area obtained from the preliminary plan layout are set as L1, L2, L3 and the widths are B1, B2, B3 respectively. The average excavation and filling depth PH within the strip range of each planting area is calculated. 11 , PH 22 , PH 33 , then the excavation and filling of various planting areas in the local unit combination should be balanced, and the excavation and filling balance relationship of the local unit combination is obtained: B1×L1×PH 11 =B2×L2×PH 22 +B3×L3×PH 33 (14) The width of each field is calculated by trial and error, and the length of each field and the average depth of excavation and filling are corrected from the plan. Finally, B1, B2, B3 and L1, L2, L3 are determined to make equation (14) valid.

8. The land management planning method for farmland management in northern China with cold inundation or secondary salinization according to claim 2 or 3, characterized in that: The calculation of land consolidation area in the above plan is as follows: Land improvement area of ​​local unit combination: Land improvement area A of local unit combination d is equal to the sum of the areas of all types of crop planting areas in the combination, that is, A d =B1×L1+B2×L2+B3×L3(15) Total area of ​​the governance zone: The total area of ​​the governance area A0 is equal to the sum of the areas of each local unit combination, which is also equal to the sum of the areas of various crop planting areas, as shown in formula (1); i =1,2,3…… M， Therefore: （16） The total area of ​​dryland crop planting area A1 in the governance area is the sum of the dryland crop planting areas of each local unit combination; that is, （17） The total rice planting area A2 in the governance area is the sum of the rice planting areas of each local unit combination; that is, （18） The total area of ​​underwater planting in the treatment area A3 is the sum of the underwater planting areas of each local unit combination; that is, （19） In formulas (16), (17), (18), and (19), M is the number of local unit combinations in the treatment area, and B is 1i is the strip width of each dry crop planting area in each local unit combination, B 2i is the width of the rice field in each rice planting area in each local unit combination, B 3i is the strip width of each underwater planting area in each local unit combination, L 1i is the length of the strip field in each dry crop planting area in each local unit combination, L 2i is the length of each rice planting area in each local unit combination, L 3i is the length of the strips of each underwater planting area in each local unit combination, i =1,2,3…… m。 9. The land management planning method for farmland management in northern China with cold inundation or secondary salinization according to claim 2 or 3, characterized in that: The calculation of earthwork excavation and filling engineering quantity in the above plan is as follows: Calculation of earthwork excavation and filling quantity of local unit combination: When PH 22 When ﹥0, the excavation volume of the local unit combination is: B2×L2×PH 22 +B3×L3×PH 33 ; The filling volume of the local unit combination is: B1×L1×PH 11 ; When PH 22 When ﹤0, the excavation volume of the local unit combination is: B3×L3×PH 33 ; The filling volume of the local unit combination is: B1×L1×PH 11 +B2×L2×PH 22 ; Calculation of total earthwork excavation and filling quantity in the treatment area: The scope of the treatment area is composed of a combination of local units; The total excavation volume of the treatment area is the sum of the excavation volumes of each local unit combination; The total filling volume of the treatment area is the sum of the filling volumes of each local unit combination.

Images