Geoscience Reference
In-Depth Information
the different inhabited areas, different roads, different types of vegetation cover that
are present, or the different locations of the nearest fire stations, etc.
8.2. The influence that different climate and weather factors have on forest
fires. The indexes
8.2.1.
The water content of vegetation determines how long it takes for the
vegetation to catch fire and burn
8.2.1.1.
Measuring the water content of plants
The influence of weather factors on forest fires is important because they play a
role in the combustion process by acting both on the fuel and as an oxidant to a fire,
at different speed. In order to understand how a fire develops, or to forecast its
development, we need able to evaluate these factors, and to measure them. This is
important because these same weather factors will eventually be used in the
framework of meteorological risk indexes.
In order to examine and measure the hydration levels of plants that are prone to
burning, several different methods have been developed. These methods are based
on either taking a direct measurement from the plants or by providing an estimation
of the measurements.
The best method used to measure the water content of plants involves weighing
the plant before and after the plant is sent to an incubator to make sure that all of the
water present in plants cells has been completely evaporated. The water content of
the plant is then calculated by using the following equation: water (humid weight -
dry weight) / humid weight. This equation is used to create a dehydration rate, from
which we can work out whether a plant will burn easily or not. If we want to obtain
information in real time, it is not possible to use such a method because it requires
too much time and too much effort.
In order to measure the water content of trees, a different process is used. The
process is based on the micrometric expansion that occurs in the trunks, branches,
and twigs. This micrometric expansion is caused due to the flow of water that takes
place in these individual parts of the trees. Close monitoring of the flow of water
makes it possible to work out the hydration rate of the trees, and as a result, it makes
it possible to work out whether it is necessary to carry out a process of irrigation in
the area. However, we are not aware of this process being used to protect forests
from fires.
Two different methods have been developed to work out the dehydration rates of
plants: one of these methods is recent and relies on the use of remote sensing,
whereas the older method involves estimating the water reserves of the soil by
calculating the soils' water budget.
