site.btaExperts on Forests' Role in Tackling Natural Disasters

Climate experts Georgi Stefanov and Dr Valentin Simeonov spoke with BTA about the factors that cause drought and the risks of floods after a prolonged drought. The two drew attention to the need for Bulgarian institutions to work together to ensure prevention against extreme events.

A few days ago, the Ministry of Environment and Water reported an alarming trend of decreasing river runoff of inland rivers, which is due to the reduced water resources and low water volumes in the country's reservoirs. The prolonged drought, high temperatures, lack of rainfall, mild winter with no spring high water are all factors that inevitably lead to a reduction in water quantities in rivers.

Drought in the mountains

Stefanov, an expert on energy and climate policies, said that in August he toured the Western Rhodopes and Rila. This area provides much of the water for the entire Balkan Peninsula, for power generation as well as for irrigation in the Upper Thracian Plain. He specified that this part of Bulgaria is a climate regulator and contributes to climate stabilization. There is a partial drying of the forests on the southern mountain slopes. Due to decreasing surface runoff, a water regime has been introduced in the cities of Pleven and Lovech.

What is very worrying is that drought is already having an impact on the high parts of the mountains in Bulgaria, which until recently were isolated from such phenomena, the expert stressed. This problem is not only due to the hot and dry summer of 2024, but also to the fact that we already have a permanent decrease in the amount of precipitation in our country. Surface water runoff is also permanently declining. According to the National Institute of Meteorology and Hydrology, the surface water runoff formed on the territory of Bulgaria in 2023 is about 13,000 million cu m, which is similar to the amount of 2022, however, it is lower by about 29%, 20%, 16% and 23% compared to the 1961–1990, 1971–2000, 1981–2010 and 1991–2020 periods respectively.

There is already ample evidence that rainfall in Bulgaria has decreased by almost a third. The people who suffer most are those in the regions who get their water for all their needs from surface water sources, while the most affected sector is agriculture.

Because of the extreme temperatures and the series of heat waves since the end of May, there have been huge evaporations from water basins into the atmosphere, which invariably follows the meteorological and climatic logic of heavy local rainfall, similar to that in the Tsarevo region in September 2023, the expert said.

Bulgaria and the region's climate is entering a spiral of irreversible changes, a so-called tipping point, abrupt changes in the environment in a very short period of time, Stefanov said. He said this proves two things: Bulgaria has almost no readiness to adapt to the already changed climate and Bulgarians are paying unaffordable costs, which are increasing every year. There is dire need to adapt quickly and learn that conservation is the only sure and cheap way to reduce the negative impact of what is happening.

Forests - key against drought and floods

Simeonov of the Federal Polytechnic Institute in Lausanne (Ecole Polytechnique Federale de Lausanne or EPFL) said that floods often occur after prolonged droughts. He stressed the need for more serious and permanent care of forests as a prevention against climate change. The water retained in the soil is one of the main natural reservoirs, which is important for providing water during the summer and in the absence of rainfall. Forests help in flood prevention and maintaining water supplies in case of drought. During heavy rainfall, rainwater is distributed evenly from the tree canopy and falls with a lag to the ground, which prevents rapid runoff and flood hazards.

Forests absorb and reflect portions of the sunlight thus reducing the warming of the earth's surface, Simeonov said. They also evaporate large amounts of water, causing local and overall cooling of the atmosphere.

The main threats to forests are industrial logging, increased temperatures and droughts due to climate change, Simeonov said. Many trees are not adapted to these changes, which is killing them. Under such conditions, trees are more susceptible to diseases and pests. The expert also pointed to fires as a cause of forest destruction. He stressed the need to prevent the occurrence of fires or extinguish them at an early stage. Simeonov believes that Bulgaria does not have the necessary equipment to extinguish fire from the air in the early hours of its occurrence.

More frequent and intense extreme phenomena such as heat waves, droughts, fires, floods, storms, hailstorms, etc. inevitably draw the attention to the root cause of these disasters, namely man-made changes in the Earth's climate, the expert added.

Stefanov and Simeonov believe that authorities should be more active in the fight against climate change. In Bulgaria, water management and the collection and analysis of water sector data suffers from a lack of central planning and management, Stefanov said.

Simeonov said that not only Bulgaria but other countries as well struggle to solve problems concerning natural disasters. The application of administrative measures such as the French rule of the three 30s, which prohibits access to forests at temperatures above 30C, wind speeds above 30 km/h and humidity below 30%, also have a positive effect, Simeonov said.