55 results about "Crop evapotranspiration" patented technology

The invention relates to a crop evapotranspiration model-based intelligent drop irrigation control system and a method thereof. The drop irrigation system is arranged in a greenhouse and is characterized by comprising a data acquisition module, multiple A/D conversion modules connected with the data acquisition module, a controller (3), a D/A conversion module, a driving circuit and an execution mechanism, wherein the data acquisition module is used for acquiring a corresponding input signal, the signal output terminal of the data acquisition module is connected with the signal input terminal of a corresponding A/D conversion module, the signal output terminal of the A/D conversion module is connected with the signal input terminal of the controller (3), the controller (3) controls an output driving circuit connected with the controller, and the execution mechanism is operated by virtue of the driving circuit to realize irrigation. In the invention, the evapotranspiration is calculated and is indirectly taken as irrigation volume to carry out irrigation on a crop, and moisture required by the crop is supplemented more accurately; and the structure is simple, and the cost is low, thus the system and the method provided by the invention have high promotional value.

An atmometer device comprises a porous evaporator member, a suction tube communicating water from a reservoir to the porous evaporator member, a sensor measuring a moisture characteristic of soil associated with a crop, a mechanism arranged for controllably varying a rate of evaporation of the water through the porous evaporator member responsive to the moisture characteristic measured by the sensor, and an indicator arranged to indicate water loss in the reservoir. By controlling rate of evaporation of the water through the porous evaporator member responsive to the measured moisture characteristic of the soil, the amount of water loss in the reservoir during the given time period more accurately reflects crop evapotranspiration.

The invention discloses a farmland reference crop evapotranspiration prediction method based on an improved BP neural network. The method comprises the steps of obtaining the meteorological data of afarmland reference crop growth environment according to weather forecast information, and calculating the farmland reference crop evapotranspiration through a PM method; constructing a training set and a test set, and performing preprocessing; adopting an LM algorithm to construct a BP neural network model considering rainfall factors, and carrying out training optimization; and utilizing the optimized BP neural network model to predict the evapotranspiration of the farmland reference crops according to the meteorological data of the test set. According to the invention, the LM algorithm is used to construct the BP neural network model considering rainfall factors; the farmland reference crop evapotranspiration is used as the measured value to train and optimize the model, the convergencedegree and calculation speed of the model are improved, the nonlinear relation between the farmland reference crop evapotranspiration and the driving factors of the farmland reference crop evapotranspiration is effectively constructed, and therefore the prediction precision and prediction effect of the farmland reference crop evapotranspiration are remarkably improved.

The invention discloses a method for determining the evapotranspiration of a reference crop, which belongs to the field of agricultural scientific research. The method comprises the following steps: calculating the evapotranspirations pET0 and hET0 of 72 pentads each year of m meteorological sites in n years; calculating the ratio of pET0 to hET0; and then calculating the average value Ks of the ratio based on the pentads and the average value Ksj of the ratio based on years in each pentad; obtaining the Ks and the Ksj at any position in a target area through a spatial interpolation method; calculating the hET0 aiming at a target location in the target area; and calculating the evapotranspiration of the reference crop at the target location based on that ET0 is equal to K * hET0, wherein K is equal to Ks or Ksj. The method needs fewer basic meteorological data, and only needs the average maximum and minimum temperatures in a period of time to be measured; besides, the method is simple and convenient for calculation, is easy to master, and does not lose accuracy at the same time, is suitable to calculate the reference crop evapotranspiration at any place and in any time period in the range of the main land.

The invention discloses an irrigation decision-making method and an irrigation decision-making device based on weather forecast. The method includes determining a field water holding point and an irrigation compensation point according to a soil moisture content accumulation curve, wherein the soil moisture content accumulation curve is a curve showing time-dependent changes of the soil volumetricwater content corresponding to a specific soil depth; determining a predicted value of reference crop evapotranspiration ET0 according to weather forecast data; predicting a predicted value of actualcrop evapotranspiration ETc in the future according to the predicted value of the ET0 and a crop coefficient Kc; and predicting the number of irrigation days according to the predicted value of the ETc in the future, the field water holding point and the irrigation compensation point. By the method and the device, the problem of complexity of related irrigation forecasting ways is solved.

There is provided a method of planning irrigation, comprising: performing for a certain interval of time: computing a value of a crop evapotranspiration parameter indicative of an amount of water consumed by a reference crop, computing a value of a potential evapotranspiration parameter indicative of weather conditions associated with the field of the reference crop, computing a value of a dynamic crop coefficient for the reference crop based on the crop evapotranspiration parameter and the potential evapotranspiration parameter, and providing the dynamic crop coefficient computed for the certain time interval of time of the reference crop that corresponds to a target time interval of a target growing season of the target crop, wherein the target crop is growing in a target field which is geographically distinct from the reference field, and outputting instructions for irrigation of the target crop according to an irrigation plan based on the dynamic crop coefficient.

The invention discloses a portable reference crop evapotranspiration amount measurement distribution system, comprising a sensor group for collecting the reference crop evapotranspiration amount measuring parameters; a collection main machine for processing the reference crop evapotranspiration amount measuring parameters. The accurate measurement of the reference crop evapotranspiration amount measuring parameters can be performed by the less sensors and the device cost is reduced. The system is provided with the remote access and distribution function by an Ethernet and the application of GSM/GPRS, with no geographical restriction and unified management and the data is provides for constituting the area crop irrigation procedure and area irrigation water use, the water resources utilization plan, the irrigation project planning design and management.

The invention provides a reference crop evapotranspiration calculation method based on remote sensing data and belongs to the field of quantitative irrigation design and agricultural water resource management. The method comprises the steps that firstly, training weather data of a researching area is acquired, an output data set with corresponding training reference crop evapotranspiration ET0 asa training set is calculated, training remote sensing data of the researching area is acquired as an input data set of the training set, and a reference crop evapotranspiration calculation model of the researching area is established; then EY0 and remote sensing data are verified, and the precision of the model is verified; during use, the remote sensing data in a required time period is acquiredand input into the verified model, and the model outputs the reference crop evapotranspiration in the selected time period of the researching area. According to the reference crop evapotranspiration calculation method, by combining less weather station data with easily acquired remote sensing data, the method can be actually applied to area reference crop evapotranspiration calculation of an areawithout weather station data and an area with sparse weather stations and effectively assist in local irrigation planning and agricultural water management.

The invention discloses a farmland evapotranspiration short-term prediction method, which relates to the technical field of crop monitoring and comprises the steps of determining a prediction reference date and a short-term prediction date; obtaining a reference crop evapotranspiration ET0 of the prediction reference day by using a PM method; obtaining the actual crop evapotranspiration ETc of thetarget farmland prediction reference date by using a vorticity related system; calculating a crop coefficient Kc of the target farmland for short-term prediction; predicting a reference crop water demand ET '0 of each short-term prediction day by adopting a Hargeavies-Samani model; obtaining evapotranspiration ET'c of each short-term prediction day; calculating a historical experience correctionparameter alpha; and calculating the predicted evapotranspiration ET ''c of each short-term prediction day of the target farmland to complete the short-term prediction of the evapotranspiration of thefarmland. The method is higher in application value, high in prediction precision and good in stability for farmland evapotranspiration short-term prediction, and a scientific basis is provided for farmland moisture management in a plain region in the future.

The invention discloses a farmland evapotranspiration short-term prediction method considering crop coefficient dynamic change and rainfall. The method comprises the steps of obtaining meteorologicaldata of a farmland crop growth environment; calculating a crop coefficient of the prediction reference date according to the reference crop evapotranspiration of the prediction reference date and theactually measured evapotranspiration of the farmland; respectively constructing a training set and a test set, and carrying out preprocessing; establishing a feedforward neural network model considering crop coefficient dynamic change and rainfall influence, and performing training optimization; and utilizing the optimized feedforward neural network model to predict the evapotranspiration of the farmland crops in a short term according to the test set data. The influence of crop coefficient change and rainfall on the farmland crop evapotranspiration is considered, the nonlinear relation between the farmland reference crop evapotranspiration and driving factors of the farmland reference crop evapotranspiration is effectively constructed, accordingly, the crop evapotranspiration better meeting the actual growth condition of crops can be obtained, and a scientific basis is provided for future moisture management of the farmland underlying surface.

The invention discloses a crop coefficient estimation method based on crop stress index. According to the estimation method, a crop water stress index (CWSI) and a crop coefficient (Kc) calculation formula are combined to obtain a theoretical model that utilizes a practical crop evapotranspiration (Eta) and CWSI to estimate Kc. The method has the advantages that the Eta data is easy to obtain; the sufficient water supply condition, which is required in conventional crop coefficient calculation, is not needed; and the whole calculation of crop coefficient is simplified.

The invention discloses construction and application of a control module for precision irrigation of farmland, and aims to solve the technical problems that irrigation control is not accurate enough,reliability is poor, and use and maintenance are inconvenient in the prior art. The invention provides a construction method for the control module for precision irrigation of the farmland and a precision irrigation method for the farmland, and the irrigation water amount is calculated according to the effective soil water capacity of the constructed model, real-time monitored soil moisture content and field evaporation rate. Based on the soil texture, the invention derives a transfer function of farmland soil effective water content (maximum allowable irrigation capacity), real-time monitoredsoil moisture and crop evapotranspiration (water consumption) data to perform real-time quantitative precision control irrigation; intelligent irrigation of the farmland can be realized; the irrigation water amount is accurate; the water-saving effect is obvious; water productivity is increased by 90% or more in comparison with conventional irrigation; and the crop yield is effectively increased,and can be increased by 20% or more per mu.

The invention discloses a combined prediction method of reference crop evapotranspiration; an Hargreaves model subjected to regional correction, a Fourier series model based on time series, a multiple regression model based on multi-year average correction method and an ET<0> estimating model based on symbolic regression (SR) algorithm are utilized, calculating is performed by using standard method Penman formula based on historical data, calculation results of each model and a residual sum of squares between standard methods under different weather conditions are acquired based on the calibration and evaluation of the four models, weight of each model in combined prediction is determined based on the respective residual sum of squares, and ET<0> combined prediction value based on the four models is acquired by using weather forecast data as an input. Therefore, uncertainty of single-method prediction is decreased, and reliability of ET<0> prediction is improved.

The invention provides a facility crop irrigation quota calculation method and system, and belongs to the field of water-saving irrigation, and the method comprises the steps: collecting a crop planting scheme and data in a facility greenhouse through on-site investigation and analysis; according to the collected data, the planting time period is divided into a facility uncovering ventilation time period, a covering setting heat preservation time period and a facility shading time period; determining the duration of each time period and a related parameter change coefficient under the monthly scale; determining crop evapotranspiration ET0, mi under the influence of the greenhouse according to the meteorological data; calculating the monthly water demand ETc of the facility crops; and calculating the quota of irrigation water for the facility crops. According to the method, the blank in the quota calculation aspect of facility planting irrigation water is filled.

The invention relates to an irrigation control method for Tie Guanyin tea trees. According to the method, the water deficit state of the Tie Guanyin tea trees is maintained through controlling the irrigation period and the amount for each time of irrigation of the Tie Guanyin tea trees, therefore deficit training to a certain extent is experienced by the Guanyin tea trees, and the tea quality can be improved. Water supplementary irrigation is performed when the water potential of the Tie Guanyin tea tree blades is reduced to -2.10+/-0.20MPa or the soil water potential is reduced to 0.80+/-0. 05MPa (the tea trees are under a water deficit state). Crop evapotranspiration 1/2ETc is taken as a reference value for each irrigation amount, and the 1/2ETc of the Tie Guanyin tea trees is 55+/-8m<3>/mu.

The invention discloses an automatic measurable accumulated light radiation irrigation device and method. The device comprises an accumulated light radiation intensity sensor, a central controller, awater pump, a pipeline electromagnetic valve, a conveying system and a remote control terminal, wherein the accumulated light radiation intensity sensor, the remote control terminal, the water pump and the pipeline electromagnetic valve are respectively connected by taking the central controller as a center; the accumulated light radiation intensity sensor, the water pump and the pipeline electromagnetic valve are in wired transmission with the central controller; and the central controller is in wireless transmission with the remote control terminal through GPRS (general packet radio service)communication. By adopting the device and method, interconnection of irrigation and accumulated light radiation sensors, real-time monitoring, feedback and intelligent judgment on an accumulated light radiation intensity are achieved in the irrigation and fertilization process, schemes can be modified, and precise control on irrigation and fertilization can be executed. The accumulated light radiation intensity is directly associated with evapotranspiration of a crop, irrigation starting time is recommended, and an irrigation amount can be accurate and in-time.

The embodiment of the invention provides a determining method and device for the irrigation opportunity and the irrigation volume. The method comprises the steps that crop evapotranspiration of an area to be irrigated is calculated according to meteorological data of the area to be irrigated within a past preset time period and meteorological data within a future preset time period; the actual soil water content of the area to be irrigated is measured continuously, and water consumption of the area to be irrigated is calculated according to the variable quantity of the actual soil water content; the irrigation opportunity and the irrigation volume of the area to be irrigated are determined according to the crop evapotranspiration and the water consumption of the area to be irrigated. According to the method, an evapotranspiration method used for large-range decision making and a soil water method used for small-range decision making are effectively combined together and can be used for making irrigation decisions for large-range open type farmlands, grasslands and forests, and accuracy of irrigation decision making can be improved.

A farmland reference crop evapotranspiration prediction method based on uncertainty of meteorological factors, includes: S1. acquiring a set number of groups of weather forecast data of a prediction region within a preset time period; S2. inputting each group of weather forecast data into a Bayesian probability forecast system to obtain corrected weather forecast data; and S3. inputting each group of the corrected weather forecast data into a trained RBF neural network, and predicting to obtain a farmland reference crop evapotranspiration. In the present invention, the Bayesian probability forecast system is configured to correct the weather forecast data and eliminate uncertainty of weather forecast data to obtain the accurate reference crop evapotranspiration forecasted by the RBF neural network using these data.

The invention discloses a method for predicting evaporation transpiration of a reference crop. The method comprises the following steps: (1) determining a research area; (2) acquiring meteorological data; (3) calculating an evaporation transpiration standard value of the reference crop; (4) analyzing the correlation between common meteorological factors and a standard value; (5) establishing a reference crop evapotranspiration prediction model of the BP neural network based on genetic algorithm optimization; and (6) verifying the model precision in the step (5). According to the invention, theprediction precision of the reference crop evaporation transpiration is higher, the actual requirements are met, and an effective method is provided for predicting the reference crop evaporation transpiration.

The invention discloses a method for calculating water resource consumption of grassland irrigation land, which comprises the following steps of: performing ET long-sequence expansion on an equivalent decomposition area by utilizing a stable gradual change characteristic of a grassland area reference crop coefficient on a time scale, and coupling area reference crop evapotranspiration by utilizing an improved reference crop coefficient method to calculate the water resource consumption of grassland irrigation land. The grassland region evapotranspiration long sequence extension under remote sensing image missing, especially non-sunny interference, is realized, the problem that remote sensing region evapotranspiration ET calculation is difficult is solved, and the precision of grassland region evapotranspiration ET long sequence calculation is improved. Aiming at the grassland irrigation land water resource consumption calculation problem, the method quantitatively determines the water resource consumption GW value of the grassland area irrigation land crop growth season through the irrigation land water resource consumption calculation model, defines the key area of grassland area underground water resource real-time monitoring and management, and improves the grassland irrigation land water resource utilization rate. Typical case analysis reference is provided for grassland area underground water resource development and utilization management and grassland ecosystem research in irrigated land vegetation construction.

The invention discloses a calculation method and system for non-uniform underlying surface evapotranspiration based on hot advection and application, and relates to the field of crop cultivation, and the calculation method for non-uniform underlying surface evapotranspiration based on hot advection comprises the following steps: 1, building a surface energy balance calculation model; 2, establishing a hot advection calculation model; 3, acquiring the surface temperature by using the thermal infrared image of the unmanned aerial vehicle, and establishing a crop evapotranspiration calculation model; and 4, substituting the data in the step 1 and the step 2 into the step 3 to obtain the evapotranspiration of the crops, and analyzing the contribution rate of the climatic elements to the evapotranspiration of the crops. According to the technical scheme, the farmland surface temperature is inversed based on unmanned aerial vehicle (UAV) thermal infrared remote sensing, a farmland hot advection energy value is calculated by adopting an earth surface energy balance equation and a hot advection calculation model, and a hot advection item-based crop evapotranspiration model calculation method is deduced by combining a thermal infrared-based crop evapotranspiration model with the thermal advection calculation model.