Environmental association ZERO has called for some urgent action by the public authorities to prevent erosion, soil degradation and water pollution in those areas damaged by recent forest fires before the arrival of the first heavy rainfall of the autumn.
The next few days will see that start of the seasonal rains across most of mainland Portugal and ZERO says the authorities need to act in concert especially in areas where water is used to feed into the public supply.
ZERO wants the forestry authority, the National Civil Protection Authority, the Portuguese Environment Agency and those municipalities affected, to:
• carry out a diagnosis of the situation on the ground for the preliminary assessment of the impacts and identify the most vulnerable areas, with particular focus on protected areas such as Natura 2000, Ramsar Sites and Biosphere Reserves, and the upstream areas from which water is supplied to the population.
• carry out an assessment for emergency actions in the risk areas where natural engineering can be used to install barriers against erosion using the burnt wood, the use of wood waste to cover the soil and the planting of native plants that grow rapidly. These actions also should prevent landslides and mudslides which could cause damage to people and property. Forestry teams and the specialised natural engineering technicians should carry out the work.
One of the main causes for the loss of vegetation in forest fires is the reduced water holding capacity of the soil, leading to water erosion when the first rains sweep soil-laden water into the reservoirs.
The consequences for water quality are many and public authorities should monitor quality as nitrates, suspended solids, iron and manganese can feed into the public supply requiring increased treatment and added costs whcih will eb passed on to consumers.
For reservoir storage systems, these impacts are compounded because the sediment accumulates in the reservoirs and the excess of nutrients can cause an increase in algae blooms and a consequent reduction of oxygen in the water.
The loss of soil and vegetation also inevitably leads to increased rainfall runoff, which leads to higher flow rates and possible flooding downstream of the burned areas.
Portugal is one of Europe's countries with the highest risk of desertification, thus post-fire responses are important despite the public authorities not undertaking such activity in recent years
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ZERO was constituted in 2015 by around 100 experts in sustainable development in Portugal.
Its members and supporters believe that through with balance between the environment, society and economy it is possible to build a more cohesive world, socially and economically, with respect for the natural limits of the planet.
