A New Approach for Identification of Potential Rockfall Source Areas Controlled by Rock Mass Strength at a Regional Scale

Abstract

The identification of rockfall source areas is a fundamental work for rockfall disaster prevention and mitigation. Based on the Culmann model, a pair of important indicators to estimate the state of slope stability is the relief and slope angles. Considering the limit of field survey and the increasing requirements for identification over a large area, a new approach using the relief–slope angle relationship to identify rockfall source areas controlled by rock mass strength at a regional scale is proposed in this paper. Using data from helicopter-based remote sensing imagery, a digital elevation model of 10 m resolution, and field work, historical rockfalls in the Wolong study area of Tibet where frequent rockfalls occur are identified. A clear inverse relationship between the relief and slope angles of historical rockfalls enables us to calculate the rock mass strength of the landscape scale by the Culmann model and the relief–slope angle relationship curve. Other parameters used in our proposed approach are calculated by ArcGIS and statistic tools. By applying our approach, the potential rockfall source areas in the study are identified and further zoned into three susceptibility classes that could be used as a reference for a regional rockfall susceptibility study. Using the space partition of historical rockfall inventory, our prediction result is validated. Most of the rockfall source areas (i.e., 71.92%) identified in the validation area are occupied by historical rockfalls, which proves the good prediction of our approach. The dominant uncertainty in this paper is derived from the process of calculating rock mass strength, defining the specific area for searching potential rockfall source areas, and the resolution of the digital elevation model.

Topographic Controls on the Distribution of Coseismic Landslides: A Case Study Using the Coefficient of Variation of the 2014 Ludian, Yunnan, China, Ms6.5 Earthquake

“…As shown in Wang's study, a pair of important indicators to estimate the state of slope stability is the relief and slope angles when the calculation is based on the Culmann model. They proposed a new approach to identify potential rockfall source areas at a regional scale by using the reliefslope angle relationship [20]. Our work, which applies the ES and S to predict the potential source for landslides, is another way to take advantage of the relief and slope angles.…”

“…Prediction of the potential locations of landslides is important for the assessment of landslide hazards at a regional scale. Numerous studies have addressed this issue by applying various methods, which in general can be divided into two categories, i.e., qualitative models and quantitative models [14][15][16][17][18][19][20][21][22][23][24]. Factors conducive to seismic triggering of landslides encompass geological topographic and seismic aspects.…”

“…In their study, excess topography is described as the column of rock material located between the terrain surface and an idealized topography with slopes less than or equal to a given threshold hillslope angle, so that it is an important material basis for landslide occurrences. Recent studies based on the Culmann two-dimensional slope stability model show that bedrock relief is controlled by the rock strength [20]. For a special area, the relief is subjected to its geological material strength.…”

Rockfall Hazard Assessment in the Taihang Grand Canyon Scenic Area Integrating Regional-Scale Identification of Potential Rockfall Sources

“…Identifying the potential rockfall source area is the first step to assessing the rockfall susceptibility and hazard and determining the prevention and control measures for rockfall events [11][12][13][14]. Due to the widespread distribution of potential rockfall points in the canyon area and most of them being located on the high, steep slopes, traditional manual survey methods are often limited in this situation.…”

“…Therefore, their applications are seriously limited by the rugged and complex terrain in alpine canyon regions. In addition, some scholars have used multi-temporal imagery data acquired by optical satellites and aircrafts to identify potential rockfall source areas at the regional scale [11,[19][20][21]. Considering the high and steep topographic conditions as the primary intrinsic factor for rockfall events [22], researchers have explored various empirical and statistical models for identifying potential rock sources based on a high-precision digital elevation model (DEM).…”