YAKUTSK, July 7. /TASS/. A reshaping of current methods to forecast spring high water seasons on Yakutia's rivers may improve the system to prevent and respond to floods, Associate Professor of MGIMO's Regional Management and National Policy Department Raisa Shpakova told TASS.

"The urgent demand to improve spring flood forecasting quality requires the work to improve the methods. Simultaneously with the work on new methods, it is reasonable to reshape the existing methods. This work should focus on collecting all the methods developed so far to make, based on them, the so-called retro-forecasts for all the past years - that is "retroactive" forecasts," the expert said.

Obtained results over a long period should give an answer about the actual quality of the available methods, and possibly will lead to their improvement. "In recent years, specialists of the Larionov Institute of Physical and Technical Problems of the North of the Russian Academy of Sciences' Siberian Branch have been most active in development of methods to forecast spring floods in Yakutia, therefore it is reasonable to have these specialists coordinate these works in cooperation with the Yakut Hydrometeorological Center," she continued.

Students of the North-Eastern Federal University may be involved in performing routine calculations, she continued.

"The revision of the kind will highlight the current situation with methods to forecast spring floods, to analyze the modern scientific approaches and to structure effectively the work to improve the forecasting methods," she added.

Forecasting problems

A flood wave is a multifactorial process determined by a wide range of natural and climatic conditions, and every river basin has its unique conditions. The situation in Yakutia is complicated due to the huge sizes of basins and rivers, and a low density of hydrometeorological observation network.

"Most big rivers there are known for their northbound flow, which practically guarantees ice jams when ice melts, and, thus, makes complicated the water level changes," she said. "This requires more complex approaches to the development of forecasting techniques."

The biggest amount of materials on the methods has been accumulated at the Yakutsk Hydrometeorological Center. Simultaneously, research institutes also have been working on this topic. For example, the Far Eastern Regional Research Hydrometeorological Institute in the late 1980s - early 1990s developed methods for long-term forecasting of the time when ice begins melting away in the Lena River and long-term forecasting of the Lena River's second high water season. In the mid-2000s, the institute offered methods to predict the maximum spring flood water levels in Yakutia's rivers. The methods were based on a complex comparative geographical and statistical analysis, on satellite information on the snow cover, which has been partially adopted into the forecasting practice.

The development of methodological approaches continued in subsequent years. In 2015, the Larionov Institute of Physical and Technical Problems of the North initiated a statistical model to forecast maximum levels during spring floods and ice drift on the Lena River near the city of Yakutsk. In 2020, the institute attempted a long-term forecasting, where they used a popular modern analytical tool - artificial neural networks.

According to the expert, high-quality long-term forecasts of spring floods' maximum levels remain an unsolved problem. "The variety of hydrological processes makes it necessary to develop separate methodology for each river (and even for certain sections of rivers), and this work is far from being completed," she said. In some cases, what hinders is the dissociation of authors from different departments and practical forecasters, or that at times they are not using "technology" approaches, thus some methods remain unclaimed.

High water in Yakutia

Earlier, a group of scientists estimated Yakutia's accumulated damage from floods between 1998 and 2022 at 46.8 billion rubles ($512 million). Flood zones have been identified officially for Yakutia's 123 settlements, where 61% of the region's population lives.

A few major floods have occurred in Yakutia over recent two decades. The highest damage over the past decade was recorded in 2013, when the region introduced a federal emergency regime during the Lena River spring flood. Back then, 55 settlements were flooded, and 6,228 people were injured. Another major rain flood happened that very year in the Verkhoyansk area. The damage at 2013 prices amounted to 3.38 billion rubles ($ 37 million).

In 2022, Yakutia's some settlements suffered from spring floods and high water exacerbated by heavy rains. The federal and regional budgets for the current year plan about 200 million rubles ($2.2 million) for the safe flood in Yakutia. Another 200 million rubles are planned for the repair of regional and municipal roads washed away by the flood.

Yakutia is one of the flood-prone regions of Russia. Spring floods are specifically dangerous as rivers overflow banks when the ice cover begins melting. This is caused by high water levels, especially during the formation of ice jams.