Landslide development at the shores of a dam reservoir (Włocławek, Poland), based on 40 years of research

Abstract

This article presents results of our 40-year research on dynamics of a deep rotational landslide developed in clay deposits. The landslide is located in a lowland, within the shoreline of Włocławek Reservoir, with little water level variation, in Dobrzyń on the Vistula (northern Poland). It is an old landslide, which was active also before the construction of the reservoir. Our research was initiated in 1970, i.e. when the river Vistula was dammed there. Currently the landslide covers about 20,000 m 2 and has a volume of about 160,000 m 3 . During the 40 years, 3 periods of increased landslide activity were observed. The first, conspicuously, nearly 40 % increase in the rate of movements within the Central Landslide was initiated in the early 1970s and lasted till the early 1980s. It coincided with the initial filling of the reservoir and the first years of exploitation of Włocławek Reservoir. The increase in landslide dynamics was a direct effect of hydrological and morphological changes associated with the damming of the river. The next 2 periods of increased landslide activity occurred: in 2001/2002 and 2010/2011. The latter was the most spectacular displacement within the Central Landslide. It was recorded between December 2010 and February 2011, and reached 10.0-19.4 m, after unusually long-lasting, heavy rainfall in the summer and autumn of 2010, followed by snowmelt and unfavourable changes in air temperature. Since March 2011, no movements within the landslide have been recorded.

Assessment of Dukan Landslides, West of Sulaimani City, the Kurdistan Region, Northeast Iraq

“…(1) The intersection of the road cuts' trends with the trends of the bedding planes and two sets of joint planes (Table 1, and Figures 4-8 and 10), (2) the presence of active erosion areas surrounding the landslide areas (Figure 4), and (3) the oscillation of the water level in Dukan reservoir has formed unstable slopes along the lowermost parts of the already existing landslides ( Figure 12) and these in turn will effect on the toe area of the concerned slides. Such cases are well known and presented by many researchers, among them are Schuster (2006), Singh et al (2012), and Kaczmarek et al (2015). In Landslide No.…”

Mass-Movement Causes and Landslide Susceptibility in River Valleys of Lowland Areas: A Case Study in the Central Radunia Valley, Northern Poland

“…The main triggering factor responsible for the activation or reactivation of landslides is precipitation [2-5]. However, for landslides that develop in deeply entrenched river valleys, an additional trigger is the lateral erosion of the landslide toes (as shown in [6][7][8][9][10], to name but a few). Riverbank erosion, combined with the infiltration of rainwater into mobilised mass, makes near-river forms more susceptible to activation than slope landslides [11][12][13][14].…”

Multi-Sensor InSAR Assessment of Ground Deformations around Lake Mead and Its Relation to Water Level Changes

“…Ground deformation resulting from variations in the volume of surface water resources, such as impounded reservoirs, can also trigger landslides and sudden mass movements; if these feed into lakes. Associated large surges of water can lead to dam instability, threatening lives and properties along the shores [9][10][11][12].…”