JP3452777B2 - Rainfall prediction device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rainfall prediction device used in a rainfall information system having a plurality of observation points. 2. Description of the Related Art As a rainfall prediction device used in a rainfall information system having a plurality of observation points, a rainfall prediction device using a rain area tracking method is known at present. In the rainfall prediction apparatus using this rain area tracking method, each rainfall amount obtained for each observation point is binarized by a preset threshold value or the like, and a rainfall area is calculated. As shown in the flowchart of FIG. 3, the rain area t hours before the current rain area corresponds to Δx in the X-axis direction.
An evaluation function when sequentially shifted by Δy in the Y-axis direction is calculated (steps ST101 and ST102), and the evaluation function having the maximum value is selected from the evaluation functions (step S101).
T103), X used when calculating this evaluation function
A movement vector is calculated based on the shift amount Δx in the axial direction and the shift amount Δy in the Y-axis direction, the current rain area is moved by the movement vector, and a rain area after t hours is predicted (step ST104). . As rainfall prediction devices other than the rainfall prediction device using the rain area tracking method, for example, a rainfall prediction device using a cross-correlation function method and a rainfall prediction device using a gravity center method are known. ing. [0005] In this case, the rainfall prediction device using the cross-correlation function method calculates a cross-correlation coefficient of each rainfall at each observation point based on each rainfall at each observation time obtained at each observation point. Then, based on the change of the calculation result, the moving direction and the moving amount of the rainy area are calculated, and the rainfall of each observation point is predicted. In the rainfall prediction apparatus using the center of gravity method, the center of gravity of the rainfall area is calculated based on the amount of rainfall obtained for each observation point, and based on the temporal change of the center of gravity,
Calculate the moving direction, the moving amount, etc., and predict the rainfall at each observation point. [0007] However, the above-mentioned conventional rainfall prediction apparatus has the following problems. First, the rainfall prediction device using the rainfall area tracking method can predict rainfall areas with high accuracy for rainfall with a large change in rainfall intensity, so that stable rainfall prediction can be performed. In the case of rainfall where the shape change of the area is large, there is a problem that the accuracy of rainfall prediction is reduced. Conversely, a rainfall prediction device using the cross-correlation function method or a rainfall prediction device using the center of gravity method can perform stable rainfall prediction for rainfall in which the shape of the rainy area changes greatly. However, in the case of rainfall in which the change in rainfall intensity is large, there has been a problem that the accuracy of rainfall prediction is reduced. The present invention has been made in view of the above circumstances, and has as its object to provide a rainfall prediction device capable of performing accurate and stable rainfall prediction regardless of the shape of rainfall areas and the rainfall intensity. The purpose is. In order to achieve the above object, the present invention provides a rainfall prediction device used in a rainfall information system having a plurality of observation points.
A plurality of rainfall information with different observation times are input, and based on these rainfall information, the amount of movement of the rainy area, the amount of expansion / contraction of the rainy area,
Extraction means for extracting the three elements of the rainfall intensity change amount, and prediction means for predicting the rainfall amount of each observation point after a predetermined time based on the extracted three elements. The current rainfall intensity obtained for each point,
For each of these observation points, filtering of the rainfall intensity change is performed on the rainfall intensity for a predetermined time before to calculate a directional vector in which the influence of the rainfall intensity change is suppressed. Scaling filtering is performed to suppress the influence of the scaling of the rain area, a directional vector based on only the moving component is calculated, and each observation point after a predetermined time is calculated based on the calculated directional vector based on only the moving component. It is characterized by performing rainfall prediction. [0014] According to the above configuration, a stable and accurate rainfall prediction is performed regardless of the shape of the rainy area or the rainfall intensity. FIG. 1 is a block diagram showing an example of a rainfall information system to which an embodiment of a rainfall prediction device according to the present invention is applied. The rainfall information system 1 shown in FIG. 1 is provided for each observation point, and includes a plurality of ground rain gauges 2 for measuring the amount of rain falling on the ground, and each observation rain gauge measured by each ground rain gauge 2. A rainfall prediction device 3 for predicting the rainfall at each observation point after a predetermined time based on the rainfall at each point, and based on the rainfall at each time output from each ground rain gauge 2, The three elements of the amount of movement, expansion / reduction, and change in rainfall intensity in the rainy area are extracted, and the rainfall at each observation point after a predetermined time is predicted based on these three elements. In this case, the rainfall prediction device 3 executes the processing shown in the flowchart of FIG. 2 to predict the amount of rainfall at each observation point after a predetermined time. First, a rainfall area is calculated by binarizing each rainfall amount obtained for each observation point with a preset threshold value. Further, the current rainfall area obtained for each observation point is shifted by Δx in the X-axis direction and Δy in the Y-axis direction,
The rain area t hours ago is obtained (step ST1). Next, based on the present rainfall intensity obtained for each observation point in the rainfall area before Δt time and the rainfall intensity before t time, the following equation is calculated to calculate the rainfall intensity. determining whether a predetermined condition is satisfied, equation 1] _{C · R t- Δ t ≦ R} t ≦ R t- Δ t / C ... (1) the (1) is satisfied condition of formula The rainfall intensity is filtered by performing the calculation shown in the following equation to suppress the effect of the change in rainfall intensity (step ST
2). [0019] Equation 2] _{R t = R t- Δ t ...} (2) Then, based on the rainfall intensity performing a filtering process of rainfall intensity, for the current rainfall areas, X-axis rainfall areas before time t An evaluation function when sequentially shifting by Δx in the direction and by Δy in the Y-axis direction is calculated (step ST3). Hereinafter, the above-described processing is repeated while sequentially changing the shift amount Δx in the X-axis direction and the shift amount Δy in the Y-axis direction to obtain the shift amount Δx in the X-axis direction and the shift amount Δy in the Y-axis direction. A plurality of corresponding evaluation functions are obtained (steps ST1 to ST4). Thereafter, among the evaluation functions, the evaluation function having the maximum value is selected, and the shift amount .DELTA.x in the X-axis direction and the shift amount .DELTA.y in the Y-axis direction used in calculating the evaluation function. Is calculated on the basis of (step ST4). Next, based on the average movement vector obtained by averaging the movement vectors of the surrounding observation points around this observation point, the movement vector obtained for this observation point is filtered, and the Eliminate error components due to area enlargement / reduction (step ST
5). Based on the movement vector of each observation point obtained in this way, the current rain area is moved by each movement vector for each observation point, and the rain area after t time is predicted (step ST6). ). As described above, in the present embodiment, based on the rainfall amount at each time output from each ground rain gauge 2, the three elements of the movement amount in the rainy area, the enlargement / reduction amount, and the rainfall intensity change amount are calculated. Extraction, and based on these three factors, to predict the rainfall for each observation point after a predetermined time,
It is possible to accurately and stably predict rainfall even in the case of rainfall in which the shape of the rainfall area, the rainfall intensity, and the like change. As described above, according to the present invention, accurate and stable rainfall prediction is performed even if the shape of the rainfall area or the rainfall intensity changes. be able to.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an example of a rainfall information system using an embodiment of a rainfall prediction device according to the present invention. FIG. 2 is a flowchart showing an operation example of the rainfall prediction device shown in FIG. FIG. 3 is a flowchart showing an operation example of a conventionally known rainfall prediction device. [Description of Signs] 1 Rainfall information system 2 Ground rain gauge 3 Rainfall prediction device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-61546 (JP, A) JP-A-9-61545 (JP, A) JP-A-8-50181 (JP, A) 72965 (JP, A) JP-A-8-304561 (JP, A) JP-A-9-189773 (JP, A) JP-A-7-120551 (JP, A) JP-A-11-109048 (JP, A) Patent 3707773 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01W 1/00-1/18 JICST file (JOIS)

Claims (1)

(57) [Claims] [Claim 1] In a rainfall prediction device used in a rainfall information system having a plurality of observation points, a plurality of rainfall information having different observation times are input for each observation point in the previous period. Extracting means for respectively extracting three elements of a moving amount of a rain area, an expanding / contracting amount of a rain area, and a change amount of a rainfall intensity based on the rainfall information, and a predetermined time after a predetermined time based on the extracted three elements. Prediction means for predicting the amount of rainfall at each observation point, wherein the prediction means calculates the rainfall with respect to the current rainfall intensity obtained for each observation point and the rainfall intensity of each observation point before a predetermined time. Calculate direction vectors that suppress the effects of changes in rainfall intensity by performing filtering on intensity changes, and perform filtering on the calculated direction vectors to expand and reduce the rain area, and then apply the effects of expanding and reducing the rain area. Suppress Calculates a direction vector by only moving component, calculated movement component only rainfall prediction apparatus and performs rainfall prediction of each observation point after a predetermined time based on the direction vector by.