ИСТИНА

Extreme hydrological and hydrogeological events have appeared in different climate zones. In this study we presented extreme events in the frigid zone(Russia) and the subtropical zone (Taiwan). In the example of frigid zone, extreme hydrological events on the rivers of European part of Russia are closely related to the hydrological regime transformation answering recent climate changes. Rivers in this region used to be traditionally attributed to the Eastern-European type with well-pronounced seasonal flood wave and quite low flow period during summer and winter. During the last twenty years the role of the occasional floods became more and more important. Number of winter floods, connected with thaws rose dramatically, in the same manner as summer flash floods. Due to results increase in natural runoff regulation, does not reduce frequency of extreme events, in some regions it raises. In the example of subtropic zone, the large demand on water resources causes the groundwater overpumping in Taiwan to result in serious subsidence of plain area. Clarifying the causes and identifying the contribution of compaction from different pumping sources is a challenge for a multi-layer aquifer system. An integrated model was applied to Yuanchang, in the center of the Yunlin subsidence area, Taiwan. Data of groundwater level and compaction at aquifers 2 and 3 in dry-season periods were used to explore the pumping effects on compaction. The results show that single-layer groundwater users are responsible for the large-area compaction and that significant local compaction can be attributed to multi-layer users. Constraining multi-layer pumping activities and reducing the amount of groundwater exploitation are required to mitigate the subsidence in Taiwan. KEY WORDS: extreme hydrological and hydrogeological event, subsidence, climate change