O siltation it is the accumulation of sediments (sand, earth, rocks), garbage and other materials carried to the bed of water courses by the action of rain, wind or human beings. It is a natural process that can be intensified by human action. In some cases, the watercourse may even cease to exist as a result of this phenomenon.
What are the causes of siltation?
THE withdrawal from riparian forest on the banks of rivers is one of the main causes of the intensification of the silting process. When the vegetation cover is removed, the ground and the rocks that are on the banks are carried easily to the bottom of the rivers. This phenomenon of unevenness of the banks is continuous and, in the event of rain, it intensifies;
The removal of riparian forest from river banks intensifies the silting process
THE deposition of trash, construction waste and sewage increases the load of debris in rivers, which accumulates at the bottom of these watercourses;
In places where the water flow is slower, such as in flatter regions and in places where the
construction ofdams (for the installation of hydroelectric plants, for example), the deposit of sediments in the riverbeds is intensified.
What are the consequences of silting?
Silting reduces the volume of water, makes it cloudy and makes it impossible for light to enter, making photosynthesis difficult and preventing the renewal of oxygen for algae and fish. For this reason, in many cases, extinguishes life in this watercourse;
At floods of the rivers are intensified by silting. As the river bed is occupied by debris, when heavy rains occur, the water overflows and can cause real tragedies, depending on where the watercourse is located;
In urban areas, it can occur scarcity or absence of water for supply in cities, because, in addition to the decrease in the river's water capacity, garbage and sewage deposited in these watercourses often make the water unfit for consumption;
Soil management in agricultural areas, when done wrongly, aggravates siltation
In the countryside, the siltation of rivers can limit water supply for agriculture and livestock activities;
Makes navigation difficult or impossible. When sediments accumulate in river beds, they become shallower, which makes it difficult for boats to circulate.
How to solve the silting problem?
avoid and control erosions on the ground, use proper agricultural practices, in addition to keep the riparian forests intact is the best recipe to avoid silting;
A solution for places where there is no longer riparian forest is the reforestation of areas near the banks of water courses, in addition to the use of techniques such as contour lines on the ground, construction planning and drainage systems.
Prevent the release of sewage and the disposal of garbage and debris in rivers, as well as limiting the damming of water courses.
By Amarolina Ribeiro
Graduated in Geography
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/geografia/o-que-e-assoreamento.htm
