Current climate changes in Russia are attended by the increase in frequency of dangerous weather events. This chapter researches long-term variations of the dangerous weather's events on Western Siberia and to reveal general regularity, which can be associated with forest fires. The researches have been carried out for the territories of southeast of Western Siberia. The duration of the fire season increases due to climate change. This is due both to the earlier snowfall and the onset of the phenological spring, and to the increase in the duration of the thunderstorm period. Thunderstorms in Siberia are a much more frequent cause of forest fires (28%) than in other territories. Wildfire frequency is correlated with air temperature and drought anomalies.
TopBackground
The global climate is warming and this may have a profound and immediate impact on wildland fire activity (Flannigan at al., 2013). Some suggest that wildland fire activity has already increased due to climate change. Hansen and colleagues (Hansen, Ruedy, Sato, & Lo, 2010) showed in their work that warming for the territory of Siberia has more rapid growth, than for Northern Hemisphere, in general. The positive trend of annual averaged surface air temperature is 0.36°C per every 10 years with higher values in some months. It was found that the rise in temperature occurs in February, March, October and May basically (Intergovernmental Panel on Climate Change [IPCC], 2013, 2014). Note that in May in Siberia most often the fire-dangerous season begins. Increases in average annual temperatures create conditions that dramatically elevate the risk and severity of forest fires.
The authors Ponomarev and Kharuk (2016) noted an increase of fire frequency and burned area in Altai-Sayan region of southern Siberia. The important issue of climate impact on the wildfires and burns dynamics in Siberia was discussed only in a few papers. The authors of Flannigan at al. (2013); Gorbatenko, Gromnitskaya, Konstantinova, Ershova, & Nechepurenko (2015); Ponomarev, Kharuk, & Ranson, (2016); Polyakov, Barashkova, & Kuzhevskaya (2014) discuss it in their research. It was also shown that the occurrence of extreme fire events in Central Siberia and the Trans-Baikal region were related to soil moisture and precipitation anomalies (Ponomarev et al., 2016). Lightning frequency, air temperature and moisture, wind speed have an impact on the fire regime too. Under scenarios of climate change many predictions show an intensification of the fire regime, i.e. more frequent and/or more intense fires (IPCC, 2014). It is known, that the increase in mid-annual values of temperature of air even on 1 degree provides increase in storm activity at least on 10 per cent (Gorbatenko et al., 2015). Therefore, will increase not only quantity of thunderstorms, but also quantity of downpours, squalls and other phenomena that accompany them. Weather conditions conducive to forest fires in Western Siberia:
- •
The increase in the duration of the fire season: when early warm weather sets in, it leads to premature snow melt and runoff. In recent decades, snow cover in Siberia is melting one to three weeks earlier than 30 years ago and the duration of the fire hazard season is increasing (Konstantinova, Gorbatenko, & Polyakov, 2017).
- •
Dry conditions: if in some areas the amount of precipitation has decreased, the probability and duration of forest fires naturally increases. At higher temperatures, the soil dries faster and the relative humidity is less (Ponomarev et al., 2016).
- •
Lightning: One major impact of climate change is increasingly severe storms. Severe storms carry a lot of lightning, and are often caused by forest fires (Konstantinova, Gorbatenko, & Ershova, 2010).