CN104462721A

CN104462721A - Sub-compartment forest fire spreading simulation method base on multiple plane directions

Info

Publication number: CN104462721A
Application number: CN201410822070.5A
Authority: CN
Inventors: 冯仲科; 冯泽邦; 杨柳; 郭江
Original assignee: Beijing Forestry University
Current assignee: Beijing Forestry University
Priority date: 2014-12-26
Filing date: 2014-12-26
Publication date: 2015-03-25

Abstract

The invention discloses a sub-compartment forest fire spreading simulation method base on multiple plane directions. According to the method, the fire spreading speeds in multiple directions around the inflammation point are calculated, sub-compartment forest fire catching area simulation is achieved based on raster image data, and sub-compartment forest fire spreading is simulated accurately.

Description

A kind of forest bottom class forest fire simulation method based on plane multiple directions

One, technical field

The present invention relates to a kind of forest fire simulation method being used to guide the forest bottom class yardstick of forest-fire model, particularly a kind of forest bottom class forest fire simulation method based on plane multiple directions.

Two, technical background

Apply maximum Fire spreading model in China and comprise Rothermel model and the just non-Fire spreading model of king.The just non-Fire spreading model of king is only applicable to the landform of the gradient below 60 °, upward slope and wind are along the situation to upward slope, afterwards, the people such as Mao Xianmin consider the combination of wind direction and landform, be derived the system of equations in 5 directions in upward slope, descending, left flat slope, right flat slope and wind direction, the Speed of forest fire spreading in these five directions can be drawn as calculated.

So Wang Zhengfei and after the people such as Mao Xianmin expansion forest fire Spread Model practical application in, owing to only considered the parameter of wind speed on above-mentioned five directions, practical application is restricted.The present invention, from the yardstick of forest bottom class, calculates Speed of forest fire spreading in multiple directions, for the simulation to forest fire appealing, can obtain more high-precision analog result.

Three, summary of the invention

In order to improve the precision of forest bottom class forest fire simulation, the object of this invention is to provide a kind of forest bottom class forest fire simulation method based on plane multiple directions.

The object of the present invention is achieved like this: the included angle of any direction wind on domatic ' and, meet tan φ '=tan φ * cos Δ, wherein, φ is the angle of gradient, and Δ is slope aspect and wind direction drift angle, and Δ=θ-A, θ is wind angle, and A is slope aspect angle.Forest bottom class any direction Speed of forest fire spreading R, wherein, R is rate of propagation, R ₀the initial velocity spread, K _sbe combustible coefficient, φ is terrain slope angle, and V is wind speed, for the angle of any direction wind on domatic, for along clockwise direction with directly over to angle.The angle of particular orientation is as follows: upward slope φ '=φ, descending φ '=180 °-φ, left flat slope φ '=0, right flat slope φ '=0.

This invention compared with prior art has the following advantages:

From multiple directions, forest fires are simulated, avoid the imperfection of previously only by five direction speed, forest fires being simulated, its dynamic is strong, dependence parameter is few, it is convenient to obtain, improve precision and the efficiency of simulation, thus accurately can locate the position of all directions after forest fire appealing, and model has simple feature; Can the process of direct modeling bottom class forest fire appealing according to proposed plane multiple directions digital-to-analogue.

Four, accompanying drawing explanation

Fig. 1 is the multiple directions schematic diagram of incendiary source forest fire appealing.

Fig. 2 is forest bottom class forest fire appealing plane multiple directions schematic diagram.

Five, embodiment:

Based on plane multiple directions forest bottom class forest fire simulation method unlike the prior art, done significant improvement, specifically:

First, first, as shown in Figure 1, by forest bottom class forest fire appealing direction centered by kindling point towards periphery multiple directions be forest bottom class forest fire appealing direction.

Secondly, by forest bottom class forest fire appealing direction centered by kindling point to multiple directions be forest bottom class forest fire appealing direction.The included angle of any direction wind on domatic ', φ '=arctan (tan φ * cos Δ), wherein, φ is the angle of gradient, and Δ is slope aspect and wind direction drift angle, and Δ=θ-A, θ is wind angle, and A is slope aspect angle.

Finally, forest bottom class any direction Speed of forest fire spreading R, wherein, R is rate of propagation, R ₀the initial velocity spread, K _sbe combustible coefficient, φ is terrain slope angle, and V is wind speed, for the angle of any direction wind on domatic, for along clockwise direction with directly over to angle.The angle of particular orientation is as follows: upward slope φ '=φ, descending φ '=180 °-φ, left flat slope φ '=0, right flat slope φ '=0.

Claims

1. the forest bottom class forest fire simulation method based on plane multiple directions, it is characterized in that: in forest bottom class, consider on the basis of forest fire appealing initial velocity, combustible coefficient, terrain slope, wind speed, forest fire appealing deflection, the method for forest fire simulation on any wind direction.

2. the method for forest bottom class according to claim 1 any direction forest fire simulation, it is characterized in that the included angle of any direction wind on domatic ', meet tan φ '=tan φ × cos Δ wherein, φ is the angle of gradient, Δ is slope aspect and wind direction drift angle, Δ=θ-A, θ is wind angle, and A is slope aspect angle.

3. forest bottom class any direction Speed of forest fire spreading R according to claim 1,

wherein, R is rate of propagation, R ₀the initial velocity spread, K _sbe combustible coefficient, φ is terrain slope angle, and V is wind speed, for the angle of any direction wind on domatic, for along clockwise direction with directly over to angle.The angle of particular orientation is as follows: upward slope φ '=φ, descending φ '=180 °-φ, left flat slope φ '=0, right flat slope φ '=0.