Raindrop Size and Flow Depth Control Sediment Sorting in Shallow Flows on Steep Slopes

2018 ◽  
Vol 54 (12) ◽  
pp. 9978-9995 ◽  
Author(s):  
L. Wang ◽  
N. F. Fang ◽  
Z. J. Yue ◽  
Z. H. Shi ◽  
L. Hua
Keyword(s):  
Flow Depth ◽  
Control Sediment ◽  
Shallow Flows ◽  
Depth Control ◽  
Sediment Sorting ◽  
Raindrop Size ◽  
Steep Slopes

Field Survey of the 2018 Anak Krakatau Tsunami on the Islands in the Sunda Strait

2020 ◽  
Author(s):  
Hermann M. Fritz ◽  
Tubagus Solihuddin ◽  
Costas E. Synolakis ◽  
Gegar S. Prasetya ◽  
Jose C. Borrero ◽  
...  
Keyword(s):  
Tsunami Source ◽  
Flow Depth ◽  
Community Based Education ◽  
Tsunami Hazards ◽  
Survey Team ◽  
Tsunami Runup ◽  
Awareness Programs ◽  
Education And Awareness ◽  
Krakatau Volcano ◽  
Steep Slopes

<p>On December 22, 2018, an eruption and partial collapse of the Anak Krakatau volcano generated a tsunami in the Sunda Strait. The tsunami caused catastrophic damage and more than 400 deaths in coastal regions of the Sunda Strait in Lampung (Sumatra) and Banten (Java). An international tsunami survey team (ITST) was deployed 6 weeks after the event to document flow depths, runup heights, inundation distances, sediment deposition, impact on the natural environment and infrastructure. The 4 to 9 February 2019 ITST focused on islands in the Sunda Strait: Rakata, Panjang, Sertung, Sebesi and Panaitan. The survey team logged more than 500 km by small boat. The collected survey data includes almost 100 tsunami runup and flow depth measurements. The tsunami impact peaked along steep slopes facing Anak Krakatau with an 85 m runup on Rakata and an 83 m runup on Sertung. The extreme runup heights were within less than 5 km of Anak Krakatau. Flow depth reached more than 11 m above ground on Sertung where a boat landing was possible and trees remained standing. On Sebesi Island located 15 km northeast of the source tsunami runup heights remained below 10 m. In contrast, tsunami heights exceeding 10 m were observed in the Ujung Kulon National Park located 50 km southwest of Anak Krakatau. The runup distributions on the islands encircling Anak Krakatau highlight the directivity of the tsunami source with the Anak Krakatau collapse towards the southwest. Inundation and damage were mostly limited to within 400 m of the shoreline given the relatively short wavelengths of volcanic tsunamis. Significant variation in tsunami impact was observed along shorelines of the Sunda Strait with tsunami heights rapidly decreasing with distance from the point source. Field observations, drone videos, and satellite imagery are presented. The team interviewed numerous eyewitnesses based on established protocol and educated residents about tsunami hazards. The tsunami caught the locals off guard despite the history and a six-month long eruptive activity in the lead up. Community-based education and awareness programs are essential to save lives in locales at risk from locally generated tsunamis. The 500 m initial height difference between the 1883 Krakatau and 2018 Anak Krakatau collapses provides a perspective on these two tsunamis. Remaining and future tsunami hazards will be affected by volcanic edifice regrowth.</p>

Soil erosion processes and sediment sorting associated with transport mechanisms on steep slopes

2012 ◽  
Vol 454-455 ◽  
pp. 123-130 ◽  
Author(s):  
Z.H. Shi ◽  
N.F. Fang ◽  
F.Z. Wu ◽  
L. Wang ◽  
B.J. Yue ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Transport Mechanisms ◽  
Erosion Processes ◽  
Sediment Sorting ◽  
Steep Slopes

Adaptive depth control algorithm for sound tracing

2018 ◽  
Vol 24 (5) ◽  
pp. 21-30
Author(s):  
Eun Jae Kim ◽  
Woonam Chung ◽  
Woochan Park ◽  
Yun Juwon ◽  
Youngsik Kim
Keyword(s):  
Control Algorithm ◽  
Depth Control

DEVELOPING AND SELECTING SLOPE STABILIZATION TECHNIQUES IN MANAGING SLOPE FAILURES

2016 ◽  
Vol 12 (4) ◽  
Author(s):  
Ari Sandyavitri
Keyword(s):  
Retaining Wall ◽  
Value Engineering ◽  
Rating Systems ◽  
Slope Stabilization ◽  
Rockfall Hazard ◽  
Proactive Approach ◽  
West Sumatra ◽  
Hazard Rating ◽  
Hazard Rating Systems ◽  
Steep Slopes

This paper objectives are to; (i) identification of risky slopes (within 4 Provinces in Sumatra including Provinces of Riau, West Sumatra, Jambi and South Sumatra encompassing 840 kms of the “Jalan Lintas Sumatra” highway) based on Rockfall Hazard Rating Systems (RHRS) method; (ii) developing alternatives to stabilize slope hazards, and (iii) selecting appropriate slopes stabilization techniques based on both proactive approach and value engineering one. Based on the Rockfall Hazard Rating Systems (RHRS) method, it was identified 109 steep slopes prone to failure within this highway section. Approximately, 15 slopes were identified as potential high-risk slopes (RHRS scores were calculated >200 points). Based on the proactive approach, seven riskiest slopes ware identified. The preferred stabilization alternatives to remedy most of these slopes are suggested as follow; either (i) a combination of retaining wall and drainage, or (ii) gabion structure and drainage. However, different approaches may yield different results, there are at least 2 main consideration in prioritizing slope stabilization; (i) based on the riskiest slopes, and(ii) the least expensive stabilization alternatives.

ECONOMIC AND SILVICULTURAL EFFICIENCY OF CREATION OF PROTECTIVE FOREST PLANTATIONS ON STEEP SLOPES

2018 ◽  
Vol 10 (4) ◽  
pp. 35-41
Author(s):  
P.N. Proyezdov ◽  
◽  
D.A. Mashtakov ◽  
A.N. Avtonomov ◽  
◽  
...  
Keyword(s):  
Forest Plantations ◽  
Protective Forest ◽  
Steep Slopes

ANALISIS KONDISI BAWAH PERMUKAAN DAN RISIKO BENCANA TANAH LONGSOR UNTUK ARAHAN PENATAAN KAWASAN DI DESA TENGKLIK KECAMATAN TAWANGMANGU KABUPATEN KARANGANYAR JAWA TENGAH

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Heru Sri Naryanto
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
Regional Planning ◽  
Rainy Season ◽  
Great Influence ◽  
Landslide Risk ◽  
Potential Hazard ◽  
Volcanic Deposits ◽  
Steep Topography ◽  
Steep Slopes

Karanganyar District is a hilly area with steep slopes, rock constituent of young volcanic deposits of Lawu Volcano products, thick soil and relatively high rainfall, so it is potential for large landslides in this region. The landuse in the Karanganyar District including the Tengklik Village is generally dominated by rice fields, seasonal gardens and settlements. Plantation made up in areas with steep topography has great influence on erosion and landslides. Similarly, many settlements are built on a slope so that the area is very vulnerable to the threat of landslides. In the rainy season landslides are common. The potential hazard of landslidesoccurred in 14 sub districts in Karanganyar District. Large landslides have occurred in Karanganyar on December 26, 2007 which claimed the lives of 62 people, with the greatest victims were in the Ledoksari Village, Tawangmangu. The Tengklik Village has already experienced creep type landslides, which have destroyed settlements, roads, seasonalgardens and all existing infrastructure in the area. In order to do the proper handling and anticipation of a catastrophic landslide, a variety of technological applications landslides using geographic information system (GIS) was then carried out, to detect the configuration of 2D geoelectrical subsurface prone areas for landslide risk study and regional planning.

Kajian Debit Sungai di DAS Wae Ruhu, Kota Ambon

2018 ◽  
Vol 1 (1) ◽  
pp. 18-23
Author(s):  
Matheus Souisa ◽  
Paulus R. Atihuta ◽  
Josephus R. Kelibulin
Keyword(s):  
River Discharge ◽  
River Flow ◽  
Secondary Data ◽  
Data Retrieval ◽  
Sediment Discharge ◽  
Flood Prevention ◽  
Retrieval Processes ◽  
Water Catchment ◽  
Steep Slopes ◽  
Station Point

Ambon City is a region consisting of hilly areas and steep slopes with diverse river characteristics. Research has been carried out in the Wae Ruhu watershed in Ambon City which starts from upstream (water catchment) to downstream. This study aims to determine the magnitude of river discharge and sediment discharge in the Wae Ruhu watershed. This research was conducted in several stages including, secondary data collection, research location survey, preparation of research tools and materials as well as field data retrieval processes which included tracking coordinates at each station point and entire watershed, calculation of river flow velocity, river geometry measurements, and sampling sediment. The results showed that the average river discharge in the Wae watershed in the year 2018 was 1.24 m3 / s, and the average sediment discharge was 6.27 kg / s. From the results of this study and the field observations proposed for flood prevention and the rate of sediment movement are the construction of cliffs with sheet pile and gabions.

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