Distributed water movement multi-scenario simulation method
Technical Field
The invention relates to the technical field of irrigation and water conservancy, in particular to a multi-scenario simulation method under distributed different planting structures, soils, crop parameters, irrigation fertilization amount and time conditions in an irrigation area, and specifically relates to a distributed water movement multi-scenario simulation method.
Background
The scene simulation method is the most widely applied simulation technology under different crop planting conditions in the current areas and irrigation areas, and in order to design the planting structure distribution of crops, the water delivery and water rotation and irrigation system of the irrigation areas more reasonably and realize high-efficiency water saving, a large number of scenes need to be set to simulate the water circulation process under the conditions of various soil, crops, weather and irrigation and fertilization measures, namely the distributed water movement multi-scene simulation technology; the current distributed water movement multi-scenario simulation method comprises the following steps: dividing distributed basic computing units according to the elevation of the earth surface, the planting structure of crops, the soil type, the meteorological conditions, the distribution of irrigation canal systems and the like, computing the water movement process of each basic computing unit, obtaining water balance elements under the conditions of a plurality of computing units in an area, changing the soil, the meteorological conditions, the irrigation fertilization amount, the time and the crop parameters of the basic computing units, and carrying out scene simulation on the water movement process of each computing unit.
In the process of implementing the present invention, the inventor finds that the existing scene simulation technology has at least the following problems: (1) the setting of different scenes is single, and batch operation and setting under different parameter distribution types cannot be carried out; (2) the selected parameters are relatively fixed, and various subordinate parameters such as soil, weather, crops and the like cannot be combined one by one; (3) the proportion of the crop planting area is random, and the proportion attribution units of various crop areas and the spatial distribution of the units on the area cannot be accurately set. Therefore, a distributed water movement multi-scenario simulation method is provided.
Disclosure of Invention
The invention aims to provide a distributed water movement multi-scenario simulation method which runs in batches, sets and combines a plurality of groups of parameter distribution forms and accurately calculates the planting area and distribution of each crop, so as to solve the problems in the background technology.
In order to achieve the purpose, the invention provides the following technical scheme:
a distributed water movement multi-scenario simulation method comprises the following steps:
step 1: acquiring soil type, crop planting structure, surface elevation (gradient and relative altitude), meteorological parameters, irrigation and fertilization amount and time data of a target area;
step 2: dividing basic calculation units according to the data in the step 1, calculating the moisture movement process of each basic calculation unit under the current condition to obtain an output result, and calculating a set target value based on the output result;
and step 3: determining parameters for setting the scene based on the soil type, the crop planting structure, the surface elevation, the meteorological parameters, the irrigation and fertilization amount and the time data in the basic calculation unit in the step 2, and combining the distribution of various parameters by adopting various established parameter distribution types;
and 4, step 4: based on the basic computing unit determined in the step 2, determining a combination form under the conditions of different crop planting area occupation ratios according to the crop planting plan of the region and the development occupation ratio suitable for planting crops in the future;
and 5: and (4) under the combined conditions of the steps 3 and 4, carrying out multi-scenario simulation under different crop planting areas, soil types, crop planting structures, surface elevations, meteorological parameters, irrigation fertilization amounts and time data in batches to obtain output results, and calculating set target values under the multi-scenario conditions.
Preferably, the outputting result in step 2 includes: yield, evapotranspiration, irrigation water volume and leakage.
Preferably, the step of dividing the basic computing unit in step 2 includes:
the intersection function in arcgis is used for calculation:
a: inputting land utilization type, soil type and earth surface elevation data, selecting ALL (default) for connection attributes, and leaving XY tolerance unfilled (default);
b: output type INPUT (default);
and finally, calculating to obtain a basic calculation unit.
Preferably, the step of calculating the predetermined target value in step 2 includes:
according to the formula
Obtaining the given target value, wherein WUE is irrigation area scale moisture productivity (kg/m) 3 ) Q is the amount of irrigation water (m) 3 ),Y i,j Yield (kg/km) for jth field of ith crop 2 )。A i,j The area (m) of the jth field of the ith crop 2 ) The ith crop has j field pieces.
Preferably, the parameter distribution type in step 3 includes: normal distribution, uniform distribution and gamma distribution, wherein each distribution formula is as follows:
(1) normal distribution:
wherein μ is a mean value; σ is the standard deviation;
(2) uniform distribution:
wherein a and b are respectively a minimum value and a maximum value;
(3) gamma distribution:
wherein, α: a scale parameter; beta: a shape parameter.
Preferably, the parameter distribution type is uniform distribution.
Preferably, the step 4 of determining the combination form under the conditions of different crop planting area ratios comprises the following steps:
the greedy algorithm is used for carrying out combination under different crop planting area proportion conditions, and the specific calculation flow of the greedy algorithm is as follows:
determining HRU and Si with the largest area;
II, determining a maximum demand gap KdSj;
III, distributing Si:
si < KdSj, assigning Si to j,
si > KdSj, and Si is allocated to the largest Si/KSj;
wherein, si is the area of the ith HRU (basic computing unit), KSj is the jth keyword total area demand, and KdSj is the jth keyword area gap.
Compared with the prior art, the invention has the beneficial effects that: the invention provides a distributed water movement multi-scenario simulation method, which is characterized in that a basic calculation unit based on soil types, crop planting structures, surface elevations, meteorological parameters, irrigation fertilization amount and time data is established, parameters of the basic calculation unit participating in scenario setting are determined, distribution combination of various parameters is carried out according to various parameter distribution types, combination forms under different crop planting area ratio conditions are formulated, and water movement simulation is carried out under multi-scenario conditions in batches; compared with the conventional distributed water movement scene simulation method, the method has the advantages that the operation efficiency is higher, and the parameter distribution combination conditions are more targeted; meanwhile, compared with the existing arrangement of the occupied area of the crop planting area, the occupied area of the crop planting area is more accurate, and the spatial distribution form of the crop planting can be given.
Drawings
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is a plot of irrigation water production rate under various scenarios of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, the present invention provides a technical solution:
example 1
A distributed water movement multi-scenario simulation method comprises the following steps:
step 1: acquiring soil type, crop planting structure, surface elevation (gradient and relative altitude), meteorological parameters, irrigation and fertilization amount and time data of a target area;
step 2: dividing the basic calculation units according to the data in the step 1, calculating the moisture movement process of each basic calculation unit under the current condition to obtain an output result, and calculating a set target value based on the output result, wherein the output result comprises: yield, evapotranspiration, irrigation water volume and leakage;
the basic calculation unit for division adopts the intersection function in the arcgis to calculate:
a: inputting land utilization type, soil type and earth surface elevation data, selecting ALL (default) as a connection attribute, and not filling XY tolerance (default);
b: output type INPUT (default);
and finally, calculating to obtain a basic calculation unit.
And step 3: determining parameters for setting the scene based on the soil type, the crop planting structure, the surface elevation, the meteorological parameters, the irrigation and fertilization amount and the time data in the basic calculation unit in the step 2, and combining the distribution of various parameters by adopting various established parameter distribution types;
the parameter distribution type in the step 3 comprises the following steps: normal distribution, uniform distribution and gamma distribution, wherein each distribution formula is as follows:
(1) normal distribution:
wherein μ is a mean value; σ is the standard deviation;
(2) uniform distribution:
wherein a and b are respectively a minimum value and a maximum value;
(3) gamma distribution:
wherein, α: a scale parameter; beta: a shape parameter.
And 4, step 4: based on the basic computing unit determined in the step 2, determining a combination form under the conditions of different crop planting area occupation ratios according to the crop planting plan of the region and the development occupation ratio suitable for planting crops in the future;
the step 4 of determining the combination form under the conditions of different crop planting area ratios comprises the following steps:
the greedy algorithm is used for carrying out combination under different crop planting area proportion conditions, and the specific calculation flow of the greedy algorithm is as follows:
determining HRU and Si with the largest area;
II, determining a maximum demand gap KdSj;
III, distributing Si:
si < KdSj, assigning Si to j,
si > KdSj, and Si is distributed to the largest Si/KSj;
wherein, si is the area of the ith HRU (basic computing unit), KSj is the jth keyword total area demand, and KdSj is the jth keyword area gap.
And 5: and (4) under the combined conditions of the steps 3 and 4, carrying out multi-scenario simulation under different crop planting areas, soil types, crop planting structures, surface elevations, meteorological parameters, irrigation fertilization amounts and time data in batches to obtain output results, and calculating set target values under the multi-scenario conditions.
Wherein the given target value is calculated according to the formula
Obtaining a given target value, wherein WUE is irrigation scale moisture production rate (kg/m) 3 ) Q is the amount of irrigation water (m) 3 ),Y i,j Yield (kg/km) for jth field of ith crop 2 )。A i,j The area (m) of the jth field of the ith crop 2 ) The ith crop has j field pieces.
For example, the soil type is Huang Litu, and the further situation simulation is carried out on corn as planting, and specific parameter data are shown in table 1:
TABLE 1 data parameters of the basic calculation Unit
Wherein the maximum temperature is 24 ℃ and the minimum temperature is 14 ℃ in 26 days in 5 months, no rainfall exists, the obtained irrigation water amount of a basic calculation unit is 786mm, the evaporation amount is 571.33mm, and the yield is 9669.23Kg/hm 2 Irrigation water production rate is 1.23Kg/m 3 The parameters of the specific scenario setup are shown in table 2:
table 2 parameters embodying the scene settings
Based on the determined basic computing unit, according to the crop planting plan of the region and the development occupation ratio of crops suitable for planting in the future, the combination forms under the conditions of different crop planting area occupation ratios are determined, and the specific combination forms under the conditions of different crop planting area occupation ratios are shown in table 3:
TABLE 3 combination of different crop planting area ratios
And finally, carrying out multi-scenario simulation under different crop planting areas, soil types, crop planting structures, surface elevations, meteorological parameters, irrigation fertilization amounts and time data in batches to obtain output results, and calculating a set target value under multi-scenario conditions, wherein the irrigation water production rate under the specific multi-scenario conditions is shown in figure 2.
The invention provides a distributed water movement multi-scenario simulation method, which is characterized in that a basic calculation unit based on soil types, crop planting structures, surface elevations, meteorological parameters, irrigation fertilization amount and time data is established, parameters of the basic calculation unit participating in scenario setting are determined, distribution combination of various parameters is carried out according to various parameter distribution types, combination forms under different crop planting area ratio conditions are formulated, and water movement simulation is carried out under multi-scenario conditions in batches; compared with the conventional distributed water movement scene simulation method, the method has the advantages that the operation efficiency is higher, and the parameter distribution combination conditions are more targeted; meanwhile, compared with the existing arrangement of the occupied area of the crop planting area, the occupied area of the crop planting area is more accurate, and the spatial distribution form of the crop planting can be given.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.