A Simple GIS-Based Tool for the Detection of Landslide-Prone Zones on a Coastal Slope in Scotland

Effective landslide detection is crucial to mitigate the negative impacts derived from the occurrence of these natural hazards. Research on landslide detection methods has been extensively undertaken. However, simplified methods for landslide detection requiring a minimum amount of data inputs are still lacking. Simple approaches for landslide detection should be particularly interesting for geographical areas with limited information or resources availability. The aim of this paper is to present a refined, simple, GIS-based tool for the detection of landslide-prone and slope restoration zones. The tool only requires a digital elevation model (DEM) dataset as input, it is interoperable at multiple spatial scales, and it can be implemented on any GIS platform. The tool was applied on a coastal slope prone to instability, located in Scotland, in order to verify the functionality of the tool. The results indicated that the proposed tool is able to detect both shallow and deeper landslides satisfactorily, suggesting that the spatial combination of steep and potentially wet soil zones is effective for detecting areas prone to slope failure.

Influence of Storm Conditions on Changes in the Granulometric Composition of Bottom Sediments in the Coastal Zone of the Western Crimea

The aim of this work is to study the dynamics of bottom sediments granulometric fractions in the Kalamitsky Gulf coastal zone near the Lake Sakskoe bay-bar under influence of storm surge based on the XBeach numerical morphodynamic model. A series of numerical experiments has been carried out, in which the parameters of waves at the seaward boundary of the computational domain changed in time, simulating the passage of a cyclonic atmospheric anomaly over the investigated region. The initial distribution of the sediment volume concentrations in different parts of the underwater coastal slope profile was set based on the results of field observations. The duration of model calculations was 24 h. The quantitative characteristics of the spatial distribution of various bottom sediments fractions, sediments median diameter and values of bottom deformations were obtained. It has been established that the main morphodynamic changes occurs in the area 0–120 m from the shoreline and are limited by the 3.5 m isobath. It was noted that the maximum changes in the relief of the coastal zone and the upper section of the underwater coastal slope occur during the development and attenuation phases of a storm. In the same time intervals an intensive redistribution of sandy material is observed. It has been established that, with a change in the parameters of wind waves in time at the seaward boundary, the scales of sand material redistribution and deformations of the coastal zone are higher than in the experiment when the direction of the waves does not change with time at the seaward boundary of the computational domain.

Snow Patches and Their Influence on Coastal Erosion at Baydaratskaya Bay Coast, Kara Sea, Russian Arctic

The Arctic coastal environment is a very dynamic system and sensitive to any changes. In our research we demonstrate that nivation (snow patch activity) impacts the Arctic landscape especially in the coastal dynamic at the western part of Russian Arctic. During fieldwork, snowbanks were described and studied and their qualitative role in the development of coastal systems was revealed for Baydaratskaya Bay coast, the Kara Sea. On one side, the large snow cover protects the coastal slope from thermodenudation and thermoabrasion; on the other side, a thick layer of snow affects the ground temperature regime. During snow melting, snow patches contribute to the removal of material from the coastal slope. The quantitative effect of snow on the ground temperature regime was assessed according to numerical simulations. The critical snow thickness was determined based on a calculation. Critical snow thicknesses based on simulation and field data correlated well. The numerical simulation showed the talik formation under the snow patch. Talik size essentially depends on the freezing temperature of sediment (influenced by salinity). The changes of ground temperature regime might further generate thawing settlement of sediment under snow and contribute to beach topography, which might be a trigger for thermoabrasion.

Integrated Field Surveying and Land Surface Quantitative Analysis to Assess Landslide Proneness in the Conero Promontory Rocky Coast (Italy)

Rock slopes involved in extensive landslide processes are often characterized by complex morphodynamics acting at different scales of space and time, responsible for different evolutionary scenarios. Mass Rock Creep (MRC) is a critical process for long-term geomorphological evolution of slopes and can likewise characterize actively retreating coastal cliffs where, in addition, landslides of different typologies and size superimpose in space and time to marine processes. The rocky coast at the Conero promontory (central Adriatic Sea, Italy) offers a rare opportunity for better understanding the predisposing role of the morphostructural setting on coastal slope instability on a long-time scale. In fact, the area presents several landslides of different typologies and size and state of activity, together with a wide set of landforms and structural features effective for better comprehending the evolution mechanisms of slope instability processes. Different investigation methods were implemented; in particular, traditional geomorphological and structural field surveys were combined with land surface quantitative analysis based on a Digital Elevation Model (DEM) with ground-resolution of 2 m. The results obtained demonstrate that MRC involves the entire coastal slope, which can be zoned in two distinct sectors as a function of a different morphostructural setting responsible for highly differentiated landslide processes. Therefore, at the long-time scale, two different morphodynamic styles can be depicted along the coastal slopes that correspond to specific evolutionary scenarios. The first scenario is characterized by MRC-driven, time-dependent slope processes involving the entire slope, whereas the second one includes force-driven slope processes acting at smaller space–time scales. The Conero promontory case study highlights that the relationships between slope shape and structural setting of the deforming areas are crucial for reaching critical volumes to induce generalized slope collapse as the final stage of the MRC process. The results from this study stress the importance of understanding the role of morphostructures as predisposing conditions for generalized slope failures along rocky coasts involved in MRC. The findings discussed here suggest the importance of the assessment of the slope instability at the long time scale for a better comprehension of the present-day slope dynamics and its major implications for landslide monitoring strategies and the hazard mitigation strategies.

Runup of long waves on composite coastal slopes: numerical simulations and experiment

<p>The goal of this study is to investigate the effect of the bottom shape on wave runup. The obtained results have been confronted with available analytical predictions and a dedicated numerical simulation campaign has been carried out by the team. We study long wave runup on composite coastal profiles. Two types of beach profiles are considered. The Coastal Slope 1 consists of two merged plane beaches with lengths 1.2 m and 5 m and beach slopes tan α = 1:10 and tan β = 1:15 respectively. The Coastal Slope 2 also consists of two sections: plane beach with length 1.2 m and a beach slope α, which is merged with a convex (non-reflecting) beach. The latter is constructed in the way, that its total height and length remain the same as for the Coastal Slope 1.</p><p>The study is conducted with numerical (in silico) and experimental approaches.</p><p>Experiments have been conducted in the hydrodynamic flume of the Nizhny Novgorod State Technical University n.a. R.E. Alekseev. Both composite beach profiles were constructed in 2019. The Coastal Slope 1 consists of three parts made of aluminum. The plain beach part of the Coastal Slope 2 is also made of aluminum, and the convex profile consists of two parts made of curved PLEXIGLAS organic glass. The water surface oscillations are measured using capacitive and resistive wave gauges with recording frequencies of up to 80 Hz and 100 Hz respectively. Wave runup is measured by a capacitive string sensor installed along the slope.</p><p>A series of experiments on the generation and runup of regular wave trains with a period of 1s, 2s, 3s and 4s were carried out. The water level was kept constant for all experiments and was equal to 0.3 meters. Up to now, 21 experiments have been carried out (10 and 11 experiments for each Coastal Slope respectively).</p><p>A comparative numerical study is carried out in the framework of the nonlinear shallow water theory and the dispersive theory in the Boussinesq approximation.</p><p>As a result, we compare the long wave dynamics on these two bottom profiles and discuss the influence of nonlinearity and dispersion on the characteristics of wave runup. It is shown numerically that, in the framework of the nonlinear shallow water theory, the runup height on the Coastal Slope 2 tends to exceed the corresponding runup height on the Coastal Slope 1, that also agrees with our previous results (Didenkulova et al. 2009; Didenkulova et al. 2018). Taking dispersion into account leads to an increase in the spread in values of the wave runup height. As a consequence, individual cases when the runup height on the Coastal Slope 1 is higher than on the Coastal Slope 2 have been observed. In experimental data, such cases occur more often, so that the advantage of one slope over another is no longer obvious. Note also that the most nonlinear breaking waves with a period of 1s have a greater runup height on Coastal Slope 2 for both models and most experimental data.</p>

PERIODS OF ACTIVITY DERMACENTOR RETICULATUS IN THE TAIGA ZONE

The range of D. reticulatus ticks mainly covers forest-steppe and steppe, where they occupy open spaces. The discovery of high-abundance populations of this tick in the taiga zone is a rare phenomenon. On the outskirts of the city of Tomsk, on the coastal slope of the Tom River of the south-southwestern exposure, such a population was found in 2015. In 2018, this species was also found on the slope of the southern exposure, on the outskirts of the city, which has a very rare young stand. In contrast to the coastal slope, people practically did not appear here, which made it possible to trace the natural dynamics of the population and, using marks, determine the duration of their life. Here, mites appeared on the surface immediately after the snow melted. The spring period of activity lasted until the end of June, then during July there was a summer diapause, and in the beginning of August the autumn period of activity began. The number in spring was higher than in autumn. The life span, as shown by the tagging, in this area, is no more than 1 year.

Kecocokan Habitat Bertelur Penyu Sisik Eretmochelys imbricate, Linnaeus, 1766 (Reptilia : Cheloniidae) di Balai Taman Nasional Laut Kepulauan Seribu, Jakarta

Penyu Sisik (Eretmochelys imbricata) adalah penyu yang memiliki ciri khas moncong berbentuk paruh, rahang atasnya melengkung ke bawah dan relatif tajam seperti burung kakak tua sehingga sering disebut “Hawksbill turtle”. Penyu jenis ini adalah pemakan terumbu karang yang tidak sehat sehingga terumbu karang menjadi sehat kembali.Tujuan dari penelitian ini adalah Mengetahui lokasi atau hotspot area peneluran penyu di Pulau Peteloran Timur Balai Taman Nasional Laut Kepulauan Seribu dan Mengetahui karakteristik habitat penyu dalam memilih lokasi bersarang dan bertelur. Metode yang digunakan dalam penelitian ini adalah metode Survey Deskriptif. Pengumpulan data dilakukan dengan cara observasi langsung di lapangan meliputi pengukuran panjang, lebar, dan kemiringan pantai, pengukuran suhu, identifikasi vegetasi pantai, predator dan kelembaban sarang serta pengukuran jenis substrat sarang di laboratorium geologi Universitas Diponegoro. Penentuan stasiun pengamatan menggunakan metode Purposive Random Sampling. Hasil penelitian menunjukkan ditemukannya 2 sarang Penyu Sisik (Eretmochelys imbricata) di bagian sebelah timur pulau dengan total jumlah 390 butir telur. Panjang pantai Pulau Peteloran Timur setiap stasiunnya berkisar 4,80–13,20 m, lebar pantainya 12–19,60 m. Kemiringan pantai Pulau Peteloran Timur mencapai 0,07–0,23°. Hasil pengukuran suhu berkisar 31–34 °C. Kadar air sedimen berkisar antara 0,002–0,004 %. Ukuran butir pasir Pulau Peteloran Timur didominasi pasir kasar dengan mencapai 48,55%. Vegetasi yang mendominasi adalah Pandan (Pandanus tectorius) selebihnya vegetasi campuran. Predator yang dijumpai di lapangan adalah Biawak (Varanus salvator). Hawksbill turtle (Eretmochelysimbricata) is a turtle that has the characteristics of a half-shaped muzzle, its upper jaw is curved downward sharply and often called the "Hawksbill Turtle". This type of turtle is an unhealthy coral reef eater so that the coral reefs are able to maintain its healthy condition.The purpose of this research is to know the location or hotspot area of turtle nesting in the east peteloran, Seribu Archipelago national park and to know the habitat characteristics of turtle in choosing nesting and laying eggs location. The method used in this research was descriptive survey method. The data collection were done by direct observation in a long-distance field by assessing the width, and coastal slope, temperature measurement, predator and humidity of nest and measurement of nest type in the geological laboratory of Diponegoro University. Determination of the location was determined by purposive random sampling method. The results showed 2 Hawksbill nests (Eretmochelysimbricata) in the eastern part of the island had a total of 390 eggs. The length of the East Peteloran Island beach each station ranged from 4.80 to 13.20 m, the beach width of 12-19.60 m. The eastern coastal slope of East Peteloran Island reached 0.07-0.23°. The temperature measurements ranged from 31-34° C. Sediment air content ranged from 0.002-0.004%. The size of the sand grains of East Peteloran Island was dominated by a sand average of 48.55%. Vegetation that dominates were Pandan (Pandanustectorius) and the others were mixed vegetation. Predator found in the field was monitor Lizards (Varanussalvator).