Ice Cover, Subglacial Landscape, and Estimation of Bottom Melting of Mac. Robertson, Princess Elizabeth, Wilhelm II, and Western Queen Mary Lands, East Antarctica

This study demonstrates the results of Russian airborne radio-echo sounding (RES) investigations and also seismic reflection soundings carried out in 1971–2020 over a vast area of coastal part of East Antarctica. It is the first comprehensive summary mapping of these data. Field research, equipment, errors of initial RES data, and methods of gridding are discussed. Ice thickness, ice base elevation, and bedrock topography are presented. The ice thickness across the research area varies from a few meters to 3620 m, and is greatest in the local subglacial depressions. The average thickness is about 1220 m. The total volume of the ice is about 710,500 km3. The bedrock heights vary from 2860 m below sea level in the ocean bathyal zone to 2040 m above sea level in the Grove Mountains area (4900 m relief). The main directions of the bedrock orographic forms are concentrated mostly in three intervals: 345∘–30∘, 45∘–70∘, and 70∘–100∘. The bottom melting rate was estimated on the basis of the simple Zotikov model. Total annual melting under the study area is about 0.633 cubic meters. The total annual melting in the study area is approximately 1.5 mm/yr.

Analysis of Floating Net Cages on The Carrying Capacity of The Darma Reservoir

Darma Reservoir functions as a reservoir for irrigation, fisheries, and recreational and sports facilities. Currently, it only functions for irrigation and fish farming by floating net ponds. The development of floating net frameworks was so rapid that it conflicted with reservoir management. This study aims to determine the density of the floating net framework of the sedimentation conditions of the Darma Reservoir and to determine the development of the sedimentation rate of the Darma Reservoir in relation to the service life of the reservoir characterized by reduced dead storage. The first step was carried out by surveying the presence of the number of floating net cages, the distribution of the feed, the percentage of feed demand, the carrying capacity of the reservoir, then a topographic survey of the depth of the Darma reservoir to determine the capacity, rate and volume of sediment deposits. This study used quantitative approach, it began with distributing questionnaire forms and measuring the depth of the reservoir. The current condition of floating net cages is 4916 occupying 5.819% of the inundation area of 312.15 ha with an elevation of 712.50 m, while floating net cages are allowed according to the carrying capacity of Darma Reservoir waters amounting to 1,021. tons / harvest while the spawning pond is 3.483 tons/harvest. The volume of normal active storage for elevation 712.50 in 2020 is 28.086 million m3, while the volume of sediment deposits is 9.262 million m3 32.98%, the average sediment rate in the reservoir from 1988 to 2020 is 0.2894 million m3/year, while the sediment rate in catchment area Dam Dharma with an area of 23.5 km2 of 71.873 mm/year. Sedimentation in the Darma Reservoir has exceeded the limit of the base elevation of the reservoir, the elevation of the dead reservoir and the lowest elevation, but the reservoir is still functional. The planning life of the darma reservoir is up to 50 years, the suitability of the initial planning of operations in 1970 with operations until 2020.

Analisis Pemanfaatan Barisan Tiang Bor Sebagai Konstruksi Penahan Tanah Pada Lokasi yang Sempit dan Padat

[ID] Peningkatan sektor wisata di Bukittinggi memberi dampak terhadap peningkatan kebutuhan akan penginapan sebagai tempat tinggal sementara para wisatawan. Pada kondisi lain, wilayah Kota Bukittinggi cenderung memiliki lahan yang terbatas dan sudah dipadati dengan bangunan. Bagian lain pembangunan hotel di Kota Bukittinggi memerlukan fasilitas parkir, karena keterbatasan wilayah parkir di Kota yang sempit ini maka pembangunan gedung dengan memanfaatkan basement kedalam tanah menjadi alternatif pilihan. Sementara stabilitas bangunan yang telah memadati lokasi rencana pembangunan gedung baru menjadi kendala yang harus dihadapi. Kerusakan struktur tanah dapat terjadi baik secara langsung seperti penurunan daya dukung tanah dan keruntuhan dinding penahan tanah, sedangkan secara tidak langsung dapat terjadi seperti adanya kerusakan bangunan akibat getaran yang disalurkan dari tanah ke struktur bangunan. Berdasarkan latar belakang tersebut maka perlu dilakukan penelitian tentang pemanfaat tiang bor sebagai konstruksi penahan tanah pada lokasi yang sempit dan padat Tujuan penelitian ini adalah untuk mengetahui angka aman pada stabiltas tanah dengan pemanfaatan barisan tiang bor. Metoda peneltian dengan menggunakan barisan pondasi bor sebagai penahan tanah. Berdasarkan analisis dengan parameter geoteknik tanah di lokasi, maka diperlukan dua lapis barisan tiang bor dengan diameter 50 cm untuk kedalaman yang berbeda. Lapisan pertama dari elevasi muka tanah asli hingga elevasi kedalaman 15m dan lapisan kedua dari elevasi dasar basement kedua hingga kedalaman 18m. Berdasarkan analisis maka diperoleh faktor keamanan 1,2 untuk galian hingga kedalamam 4 m. Untuk kedalaman galian yang lebih dari nilai faktor keamanan berkurang hingga mendekati nilai 1,0 sehingga diperlukan penanganan modifikasi dalam pemanfaatan barisan tiang bor ini. [EN] The increase of the tourism in Bukittinggi has an impact on the increasing need for lodging as temporary residence for tourists. In other condition, restrictions on artificial tall buildings area are limited of regulations. Meanwhile, restrictions on the construction of tall buildings in an area are limited regulations. In Bukitinggi, West Sumatra, the construction of high buildings is a less than the "Clock Tower". Meantime, the construction of hotels in the city of Bukittinggi requires parking facilities. Building construction is using basement into the ground becomes an alternative choice. However, the stability has been packed with the location of building construction plans is an obstacle that must be faced. Damage to the soil structure can directly, bearing capacity of the soil and the retaining wall is collapse. Damage of buildings by vibrations transmitted from the ground to the building structure. Soil retaining construction is a civil building that has a function of ground motion barrier that caused by pressure forces on the ground and water. Methods using sheet pile are also considered, but due to environmental disturbance these methods are not used. As a suitable choice, a row of drill foundation is used as a buffer. Based on the analysis of the soil geotechnical parameters at the site, two layers of bored pillars with a diameter of 50 cm are needed for different depths. The first layer from the original ground level elevation to 15m depth elevation and the second layer from the second basement base elevation to 18m depth.

Elevation gaps in fluvial sandbar deposition and their implications for paleodepth estimation

Accurate estimation of paleo–streamflow depth from outcrop is important for estimation of channel slopes, water discharges, sediment fluxes, and basin sizes of ancient river systems. Bar-scale inclined strata deposited from slipface avalanching on fluvial bar margins are assumed to be indicators of paleodepth insofar as their thickness approaches but does not exceed formative flow depths. We employed a unique, large data set from a prolonged bank-filling flood in the sandy, braided Missouri River (USA) to examine scaling between slipface height and measures of river depth during the flood. The analyses demonstrated that the most frequent slipface height observations underestimate study-reach mean flow depth at peak stage by a factor of 3, but maximum values are approximately equal to mean flow depth. At least 70% of the error is accounted for by the difference between slipface base elevation and mean bed elevation, while the difference between crest elevation and water surface accounts for ∼30%. Our analysis provides a scaling for bar-scale inclined strata formed by avalanching and suggests risk of systematic bias in paleodepth estimation if mean thickness measurements of these deposits are equated to mean bankfull depth.

THE CHARACTERISTICS OF SEDIMENTATION PATTERN AND MORPHOLOGICAL CHANGE OF SIGELENG RIVER ESTUARY IN RANDUSANGA KULON VILLAGE BREBES DISTRICT

Sigeleng River Estuary is located in Brebes Regency. The mouth of Sigeleng River Estuary suffering morphological change that caused by the sand spit that close the mouth of river estuary and creating deflection. The results of characteristics test of the sediment from the estuary of Sigeleng River shows that the average density is 2.228 kg/l and the average particle diameter (D60) is 0.466 mm. On the other hand the largest result of total suspended solid test of the sediment samples is 1.58 mg/l. According to USDA, the soil texture in B location is Silt Loam and in A and C location are Sandy Loam. SED2D modeling that performed for 720 hours that assumed as 1 year shows a base elevation change that is 11,79%-30,20% in the river estuary mouth at the existing condition Sediment cumulation that occurred around the mouth of the Sigeleng River Estuary within 5 years is 0.007 m - 2,560 m, while the depth of the Sigeleng River Estuary is only -3.00 m. Therefore, a treatment by dredging the sediment aroud the mouth of Sigeleng River Estuary is needed so that the river estuary is not closed.

A microtopographic signature of life: Ecohydrologic feedbacks structure wetland microtopography

Microtopography in wetlands can be a visually striking landscape feature, and also critically influences biogeochemical processes at both the scale of its observation (10−2–102m2) and at aggregate scales (102–104m2). However, relatively little is known about how microtopography develops in wetlands or the factors that influence its structure and pattern. For example, wetland vegetation appears to have a strong affinity to elevated microsites, but the degree to which wetland vegetation simply preferentially occupies elevated microsites (“hummocks”) versus the degree to which wetland vegetation reinforces and maintains these elevated microsites is not clear. Growing research across different ecosystems suggests that such reinforcing processes may be common between plants and their environment, resulting in self-organized patch features, like hummocks. Here, we made use of landscape ecology techniques and diagnostics to evaluate the plausibility of plant-environment feedback mechanisms in the maintenance of wetland microtopography. Using a novel terrestrial laser scanning dataset, we were able to quantify the sizing and spatial distribution of hummocks in 10 black ash (Fraxinus nigra Marshall) wetlands in northern Minnesota, U.S.A. We observed clear elevation bimodality in our wettest sites, indicating microsite divergence into two states: elevated hummocks and base elevation hollows. We coupled the TLS dataset to a three-year water table record and soil-depth measurements, and showed that hummock height is largely predicted by mean water table depth, with little influence of subsurface microtopography on surface microtopography. We further show that hummocks in wetter sites exhibit regular spatial patterning in contrast to hummocks in drier sites, which exhibit more random spatial arrangements. We show that hummock size distributions (perimeters, areas, and volumes) are lognormal, and that hummocks exhibit a characteristic patch area of approximately 1 m2 across sites. Finally, we show that hummocks may be responsible for increased reactive surface area in black ash wetlands by up to 32 %, and may also influence surface water dynamics through modulation of specific yield by up to 30 %. We suggest that vegetation develops and maintains hummocks in response to anaerobic stresses from saturated soils, leading to a microtopographic signature of life.

Selection of Suitable Dam Axis Location Considering Permeability and Grout Curtain Optimization

ABSTRACT This study investigated the effects of active tectonism on the construction of hydraulic structures. Apart from the effect of dynamic loads, active tectonism can cause permeability problems. The focus of this study was on overcoming the permeability problems considering the economic yield in terms of grout curtain design and optimum dam axis location. The ground permeability of dam locations is one of the decisive factors affecting the feasibility and economic yield of dam construction. Techniques (such as grouting) for ensuring ground permeability reduction are generally expensive and time-consuming; the experience at the first location of the Turgutlu Dam is a case in point. Construction of the first location of Turgutlu Dam was planned on a fault terrace that is part of the North Anatolian Fault Zone, which is the most important active tectonic feature in Turkey. A grout curtain was planned to provide permeability reduction and ground treatment for the terrace material. However, the base elevation of the adjacent valley is deeper, and thus potential leakage to this valley was expected. In spite of its big reservoir area, the Turgutlu Dam Project became infeasible in terms of economic yield due to the ground remediation (construction of grout curtain) costs for this location. To solve this problem, the dam was relocated downstream to avoid the fault terrace, choosing an optimum grout curtain to minimize cost and improve water retention of the reservoir, and increase economic yield of the dam.

PERENCANAAN TUBUH BENDUNGANAIR LUAS KABUPATEN KAUR PROVINSI BENGKULU

The purpose of this study was to plan the dimensions of the dam body that is technically feasible to build, as well as secure the stability. Flood discharge plan used amounted to 1,152 meters cubic/ sec with a return period of 1000 years. Based on the analysis that has been done, get a plan of flood water level is + 303,22 meters, surveillance obtained high of 3,0 meters, the body of the dam crest elevation gained + 306,22 meters high dam that is obtained by subtracting the height elevation of the peak body dam with a base elevation of the dam is 56,16 meters, width of the dam crest beacon of 11.0 meters, rockfill the upstream slope of 1:3 and for rockfill downstream slope is 1: 2,.25. Using the scheme of depression line formation with drainage leg with a graphic way, do not occur out of the body dam seepage and flow filtration capacity value of the calculation, Q = 9,553 x 10-5 meters cubic / sec, smallest than 2% Qinflow mean = 5,785 mmeters cubic / sec, dam secure against flow filtration. The stability of the main dam of landslide with the value of safety factor in a variety of conditions, namely dams both empty and fully charged in a normal state or an earthquake, for rockfill dam by calculating the weight of the dam, sliding moment, pore water pressure and earthquake loads. Using the method of slices Fellenius glide plane, the value obtained above safe rate (1,2), the planneddam safety to landslides

Numerical modelling of tsunami bore impact on low-rise residential buildings using SPH

The resilience of buildings subject to tsunami bore impact can be improved by reducing tsunami-induced lateral hydrodynamic pressure by allowing part of the tsunami bore to pass through the buildings via openings and break-away walls. This research investigated the reduction of lateral pressure caused by tsunami bore impact on a low-rise residential building with openings proposed as the prototype of tsunami-resistant house. Numerical method using smoothed particle hydrodynamic (SPH)- based software called DualSPHysics was used to create simulation in numerical boundary in the form of a water tank. The tsunami-like bore simulations were generated based on dam-break analogy and were validated against experimental results. Four simulation cases were conducted in this study: Case 1 and Case 2 were dealing with the parameter sensitivity of reservoir height and distance between reservoir and building, while Case 3 and Case 4 were related to the effectiveness of openings and the base elevation of building in reducing wave impact pressures. The numerical modelling results show that the presence of openings and building’s base elevation significantly reduced the lateral hydrodynamic pressures on buildings up to 50% and this could become an effective strategy for improving the resilience of low-rise residential buildings under tsunami bore impact.

Quantitative and Qualitative Approaches of Delineation in Detailed Mapping of Vineyard Landscape. Case Study: Vicinity of Pezinok (Slovakia)

The main goal of this paper is the application of qualitative and quantitative free available data for geographical delineation based on reconnaissance research in vineyard landscape. The results of delineation are useful in agricultural management or environmental planning. Our delineation may serve as the basic information on site conditions of vineyards near Pezinok (Slovakia), with historical use from the beginning of 13th century. We have studied the actual land cover and classified physiotopes of the study area into a set of relatively homogenous and coherent landscape units. The landscape units defined in this work consist of homogenous physiotopes in terms of their structural and functional characteristics, which have been shaped by natural factors (land-forms, soil type and subtype, geological base, elevation, slope, aspect, solar radiation and normal different vegetation index (NDVI)). The characteristics were used to define 23 landscape units in qualitative delineation (based on both qualitative and quantitative data). Only quantitative characteristics – elevation, aspect, slope, solar radiation and NDVI, were used in a K-means cluster analysis to define the 17 landscape units. The number of landscape units was computed by WB-index, and standardisation of data was computed by factor analysis. The whole classification process was statistically significant. The strength of the grouping procedure was tested by using Discriminant Analysis, which found that 92.70% of objects in qualitative and 98.50% of objects in quantitative delineation were correctly classified.