Land Management Versus Natural Factors in Land Instability: Some Examples in Northern Spain

Abstract

The objective of this work is to test a hypothesis formulated on the basis of former results which considers that there might be a ‘‘global geomorphic change,’’ due to activities related to land management and not determined by climate change, which could be causing an acceleration of geomorphic processes. Possible relationships between some geomorphic processes related to land instability (landslides or sediment generation) and potential triggering factors are analyzed in study areas in northern Spain. The analysis is based on landslide inventories covering different periods, as well as the determination of sedimentation rates. Temporal landslide and sedimentation rate trends are compared with different indicators of human activities (land-use change, logging, forest fires) and with potential natural triggers (rainfall, seismicity). The possible influence of the road network in the distribution of landslides is also analyzed. Results obtained show that there is a general increase of both landslide and sedimentation rates with time that cannot be explained satisfactorily by observed rainfall trends and even less by seismicity. Land use change appears to be by far the main factor leading to land instability, with some changes producing up to a 12-fold increase of landslide rate. A relationship between road network and the spatial distribution of landslides has also been observed. These results do confirm the existence of an acceleration of geomorphic processes in the region, and also suggest that climate-related factors play a limited role in the changes observed.

Anthropogenic geomorphic change as a potential generator of renewable geologic resources in the humid Pampa of Argentina

“…They were used to estimate sediment generation within the lakes' basins and their consequent sediment supply. As expected from previous results (Bonachea et al, 2010;Bruschi et al, 2013), the latter data yielded significantly higher potential sedimentation rates than the former.…”

“…In general, human-induced geomorphic changes have led to increasing surface geologic processes, particularly after the middle of the 20th century, coinciding with the sharp increase in human activities and their effects known as the 'Great Acceleration' (Steffen et al, 2004(Steffen et al, , 2011(Steffen et al, , 2015. The Great Acceleration represents a 'great geomorphic acceleration' (Bruschi et al, 2013;Bruschi et al, 2012a,b;Hurtado et al, 2012), which can be problematic but beneficial as well.…”

Major Natural Disasters in China, 1985–2014: Occurrence and Damages

“…On the other hand, in densely-populated regions, the impacts of humans on the environment contribute significantly to the initiation and reactivation of landslides [40,42,43,44,45,46]. Thus, landslide episodes usually are serious in developing countries where the environment protection and management are hardly sustainable [43,45,47]. We have found that landslide episodes might significantly concentrate in Southwest China, which is in line with previous studies [48,49].…”

Finding key vulnerable areas by a climate change vulnerability assessment

“…The Delphi method, one of the important methods used in this study, is an effective tool for reaching a consensus value; however, it cannot provide objective weights. Additionally, only the climate conditions are changed in the future vulnerability assessment even though damage can have a significantly stronger dependence on other conditions such as land surface modification (Bonachea et al 2010;Bruschi et al 2013). This limitation is attributed to the lack of future environmental and socioeconomic data.…”