to new and unseen examples. Another significant
advantage is their potential to find solutions to
difficult problems, which are rich in data but poor in
models.
The basic input data used in most predictors are
the measured temperature, relative humidity, wind
speed, precipitation (rain), [6], [16], [17], [18],
vegetation, [19], [20], as well as satellite images,
[21]. They are extended in some predictors with
indices computed from the measured variables,
time, topographic, and spatial variables, [18], [20].
The predicted variables are the burned forest fire
area, [6], [16], [17], [18], the fire danger index
defined by the daily number of forest fires, [19]; fire
spatial and temporal probability expressed as dates
and locations of fire events, etc., [19], [20], [21].
The ANN-based predictors are most often multi-
layer networks trained by BP. All developed
predictors are duly validated.
Fuzzy logic predictors of the total burned area
are suggested in [6]. They are based on Fuzzy
Inductive Reasoning and ANFIS tuned by gradient
descent and least-square algorithms. The data cover
17 years. A meteorological station records 12 input
variables - the first five of the basic and also spatial
location, month, day, and 4 indexes characterizing
the fuel moisture according to the Canadian Fire
Weather Index System. Due to the limitations of the
fuzzy model, the most significant five variables are
selected - the first four of the basic and Fine Fuel
Moisture codes.
All 12 variables are used in the development of
an ANN predictor of the total burned area [16]. The
ANN has one hidden layer of heuristically
determined 36 neurons.
Two ANN predictors for the risk of forest fire
occurrences, defined by a fire danger index on a
scale of 1–4 (1 for the lowest and 4 for fire the
highest danger) depending on the daily number of
forest fires, are suggested in [19]. The input data are
from fixed weather stations across the country
covering 8 years and consist of two variables -
relative humidity and cumulative precipitation,
selected from six weather variables – the minimal
and the maximal temperatures, the average humidity
of the day, the solar radiation, the average wind
speed, and the cumulative precipitation. The ANN
has three layers with 4 neurons in each hidden layer
and 1 neuron in the output layer. All neuron
activation functions are hyperbolic tangent sigmoid.
The first ANN predictor is trained by Levenberg–
Marquardt BP while the second ANN predictor - by
SVM with a Gaussian kernel function.
In [20] an ANN for identifying areas of forest
fires (ignition) by predicting their spatial
probability, i.e. the dates and locations of fire events
is developed. The input data cover 10 years and
contain 12 variables including topographic,
anthropogenic, hydrologic, vegetation, and land
(identified features include elevation, aspect, slope,
tree cover density, forest type, settlement proximity,
settlement density, water proximity, power line
proximity, normalized vegetation density index,
modified normalized water density index, and land
use and cover. The activation function in the two
ANN hidden layers is rectified linear (ReLU) and in
the output layer - logarithmic sigmoidal (logsig).
In [17], a two-layer ANN is trained to predict the
forest fire spread by evaluating the historical forest
fire disturbance data– time and location from 18
years. The 16 input variables characterize climatic,
topographic, combustible factors, and land cover
(the 4 basic, wind direction, slope and slope
direction, elevation, vegetation, surface water
content, roads, railways, settlements, lakes, ditches,
wells). The activation function of the neurons in the
hidden layer is hyperbolic tangent and in the output
layer – “logsig”.
A deep learning ANN for early warning of forest
fire occurrence based on Long- and Short-Term
Memory network (LSTM) was developed in [18].
The data used are from 536 historical records for a
set of 12-dimensional meteorological measured
influencing variables – special coordinates, month
of the year, day of the week, temperature, relative
humidity, wind speed, rain, 4 fuel moisture indexes
derived from the Canadian Fire Weather Index
System - Fine Fuel Moisture Code, Duff Moisture
Code, Drought Code (DC) and the Initial Spread
Index as well as the burned area. The designed ANN
consists of a 6-layered deep architecture (one input
layer, one LSTM layer, two fully connected layers,
one dropout layer, and one regression layer). The
number of neurons in the LSTM layer is set to 100.
The dropout probability is set to 0.5. The sigmoid
function is used to scale the signals in the interval
[0, 1]. Similarly, the hyperbolic tangent function
scales the output of a particular memory cell. Four
other machine learning methods are applied for the
prediction of forest fire to the same dataset -
Decision Trees with fine tree architecture, Linear
Regression, SVM with a linear kernel function, and
Narrow Neural Network with ReLU activation
function. The result shows that LSTM outperforms
the rest of the methods.
In [21], a Region-Based Convolutional Neural
Network (R-CNN) is trained to predict forest fire
occurrence based on satellite images. R-CNN object
detection model has full image convolutional
features. The raw images and the training dataset
WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT
DOI: 10.37394/232015.2023.19.128
Hristina Nikova, Snejana Yordanova,
Radoslav Deliyski