Response of Siberian River Discharge to Disturbances of Forests Caused by Wildfires

• Published in: ECWS-3
• Main Authors: Evgenii I. Ponomarev, Tatiana V. Ponomareva
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2018
• Subjects: Siberia; permafrost zone; river basins; discharge; wildfire; relative burned area; Aldan; Nizhnyaya Tunguska; Podkamennaya; Tunguska; permafrost
• Online Access: https://doi.org/10.3390/ECWS-3-05801

The objective of this work was to perform a quantitative analysis of the correlation between the forest burning index and abnormal decrease in river discharge under conditions of the cryolithozone of Siberia. We analyzed the long-term and seasonal variation of river discharge in Central Siberia (Nizhnyaya Tunguska and Podkamennaya Tunguska rivers) and in Eastern Siberia (Aldan, Viluy rivers) together with the forest burning dynamics within the river basins. The data on river discharge were obtained from the archive of The Global Runoff Data Centre for 1939–2015. The relative burned area (RBA) index was calculated from wildfire databases collected using satellite technique for 1996–2017. RBA was evaluated as the ratio of the annual burned area within the river basin to the total area of the river basin. RBA values of 2.5–6.1% per year were considered as extremely high. The analysis of available chronologies of extreme fire events in Central and Eastern Siberia showed high correlation (r > −0.55) with long-term data on the runoff minima. Abnormally low levels of discharge were 68–78% of the averaged annual rate. The most significant response of river discharge to the wildfire effect was shown for the summer–autumn period of the season after extreme burning in mid-summer.