scholarly journals Aquifer Analysis With Seismic Methods in Parambahan Region

2021 ◽  
Vol 4 (2) ◽  
pp. 35-40
Author(s):  
Yaumal Arbi ◽  
Ari Syaiful Rahman Arifin ◽  
Muvi Yandra
Keyword(s):  
Data Collection ◽  
Wave Velocity ◽  
Seismic Data ◽  
Rainy Season ◽  
Agricultural Land ◽  
Soft Soil ◽  
Agricultural Activities ◽  
Soil Layers ◽  
Irrigation Channels ◽  
First Pass

The problem faced by farmers in Parambahan Region during the dry season is agricultural land does not get adequate water supply from existing irrigation channels, as a result, farmers can only carry out agricultural activities during the rainy season in Parambahan Region Lima Kaum Subdistrict, district of Tanah Datar. This study aims to determine the location and depth of soil layers containing groundwater by using the seismic method, measurements are carried out at two points, with the length of the track at the first point is 80 meters, and at the second point of 70 meters, each measurement on seismic data collection using 4 geophones as signal capture sensors, with a distance between geophones of 5 meters. The results of this study that the wave velocity at the first data point collection was 169.49 m / s and the lowest were 87.1 m / s, and the wave velocity at the second point was 129.68 m / s and the lowest was 48.07 m / s. from the wave velocity, it can be seen the type and depth of the groundwater layer at the point of data collection on the first pass, which is a depth of up to 27.5 meters of the possibility of soft soil and a depth of about 30 to 40 meters of watery soft soil at that depth may have groundwater, and at that point, the second passage at a depth of up to 25 meters is likely to be soft soil and at a depth of around 25 to 35 meters of watery soft soil at that depth, there is groundwater.

scholarly journals Impacts of Agricultural Land Acquisition for Urbanization on Agricultural Activities of Affected Households: A Case Study in Huong Thuy Town, Thua Thien Hue Province, Vietnam

2021 ◽  
Vol 13 (15) ◽  
pp. 8559
Author(s):  
Nhung Pham Thi ◽  
Martin Kappas ◽  
Heiko Faust
Keyword(s):  
Agricultural Development ◽  
Agricultural Land ◽  
Rice Cultivation ◽  
Mixed Data ◽  
Land Acquisition ◽  
Agricultural Activity ◽  
Agricultural Activities ◽  
Farmland Abandonment ◽  
Before And After ◽  
The Government

Agricultural land acquisition for urbanization (ALAFU) has strongly impacted agriculture in Vietnam during the last decades. Given the mixed data obtained from a survey with 50 households who lost 50% of their farmland area (in-depth interviews, a group-focused discussion and observation) this study shows the different impacts of ALAFU on each agricultural activity of affected household by comparing before and after ALAFU. Rice cultivation and animal breeding have sharply declined, but potted flower plantation (PFP) has quickly grown and is the main income of 34% of surveyed households. Rice cultivation has declined not only as a result of agricultural land acquisition, which has resulted in the loss of rice land, but also as a result of urbanization, which has resulted in rice land abandonment. Conversely, PFP is growing due to advantages associated with urbanization, such as a good consumer market and upgraded infrastructure. However, whether they are declining or increasing, all agricultural activities have to face challenges related to the shortcomings in agricultural land allocation and agricultural development plans. This study suggests that if ALAFU projects are continued, the government should evaluate agricultural development and forecast farmland abandonment after ALAFU. Simultaneously, they should put more effort into maintaining agriculture in the form of peri-urban or urban agriculture, which is significant for sustainable development in affected communities.

A reality check on full-wave inversion applied to land seismic data for near-surface modeling

2022 ◽  
Vol 41 (1) ◽  
pp. 40-46
Author(s):  
Öz Yilmaz ◽  
Kai Gao ◽  
Milos Delic ◽  
Jianghai Xia ◽  
Lianjie Huang ◽  
...  
Keyword(s):  
Wave Velocity ◽  
Seismic Data ◽  
Surface Modeling ◽  
P Wave ◽  
Borehole Data ◽  
Near Surface ◽  
Traveltime Tomography ◽  
Wave Inversion ◽  
Full Wave ◽  
Elastic Inversion

We evaluate the performance of traveltime tomography and full-wave inversion (FWI) for near-surface modeling using the data from a shallow seismic field experiment. Eight boreholes up to 20-m depth have been drilled along the seismic line traverse to verify the accuracy of the P-wave velocity-depth model estimated by seismic inversion. The velocity-depth model of the soil column estimated by traveltime tomography is in good agreement with the borehole data. We used the traveltime tomography model as an initial model and performed FWI. Full-wave acoustic and elastic inversions, however, have failed to converge to a velocity-depth model that desirably should be a high-resolution version of the model estimated by traveltime tomography. Moreover, there are significant discrepancies between the estimated models and the borehole data. It is understandable why full-wave acoustic inversion would fail — land seismic data inherently are elastic wavefields. The question is: Why does full-wave elastic inversion also fail? The strategy to prevent full-wave elastic inversion of vertical-component geophone data trapped in a local minimum that results in a physically implausible near-surface model may be cascaded inversion. Specifically, we perform traveltime tomography to estimate a P-wave velocity-depth model for the near-surface and Rayleigh-wave inversion to estimate an S-wave velocity-depth model for the near-surface, then use the resulting pairs of models as the initial models for the subsequent full-wave elastic inversion. Nonetheless, as demonstrated by the field data example here, the elastic-wave inversion yields a near-surface solution that still is not in agreement with the borehole data. Here, we investigate the limitations of FWI applied to land seismic data for near-surface modeling.

Using Seismic Data to Predict Shale Pore Pressure and Overpressure Sweet Spots: A Case Study from the Lower Silurian Longmaxi Formation in Sichuan Basin, China

2021 ◽  
Author(s):  
Sheng Chen ◽  
Qingcai Zeng ◽  
Xiujiao Wang ◽  
Qing Yang ◽  
Chunmeng Dai ◽  
...  
Keyword(s):  
Prediction Model ◽  
Wave Velocity ◽  
Shale Gas ◽  
Seismic Data ◽  
P Wave ◽  
Formation Pressure ◽  
S Wave ◽  
P Wave Velocity ◽  
New Formation ◽  
Sweet Spots

Abstract Practices of marine shale gas exploration and development in south China have proved that formation overpressure is the main controlling factor of shale gas enrichment and an indicator of good preservation condition. Accurate prediction of formation pressure before drilling is necessary for drilling safety and important for sweet spots predicting and horizontal wells deploying. However, the existing prediction methods of formation pore pressures all have defects, the prediction accuracy unsatisfactory for shale gas development. By means of rock mechanics analysis and related formulas, we derived a formula for calculating formation pore pressures. Through regional rock physical analysis, we determined and optimized the relevant parameters in the formula, and established a new formation pressure prediction model considering P-wave velocity, S-wave velocity and density. Based on regional exploration wells and 3D seismic data, we carried out pre-stack seismic inversion to obtain high-precision P-wave velocity, S-wave velocity and density data volumes. We utilized the new formation pressure prediction model to predict the pressure and the spatial distribution of overpressure sweet spots. Then, we applied the measured pressure data of three new wells to verify the predicted formation pressure by seismic data. The result shows that the new method has a higher accuracy. This method is qualified for safe drilling and prediction of overpressure sweet spots for shale gas development, so it is worthy of promotion.

scholarly journals PERSEPSI GENERASI MUDA TERHADAP KEGIATAN PERTANIAN DI KELURAHAN BUHA KECAMATAN MAPANGET KOTA MANADO

2018 ◽  
Vol 14 (3) ◽  
pp. 123 ◽  
Author(s):  
Carolina Sofya Werembinan ◽  
Caroline B. D. Pakasi ◽  
Lyndon R. J. Pangemanan
Keyword(s):  
Agricultural Sector ◽  
Agricultural Land ◽  
Descriptive Analysis ◽  
Secondary Data ◽  
Primary Data ◽  
Young Generation ◽  
Agricultural Activities ◽  
Gender And Age ◽  
Younger Generation ◽  
Parental Work

This study aims to determine the perceptions of the younger generation of agricultural activities in the Buha Sub-District of Mapanget District. This research was carried out from August 2017 to May 2018. Primary data was collected through interviews of 15 generations of young people with the help of filling out questionnaires. Secondary data was obtained from the Buha Village Office, Mapanget District. This analysis uses descriptive analysis. The results of this study indicate that the perception of the younger generation of agricultural activities in the Buha Sub-District is overall negative for agricultural activities. Viewed from internal factors include education, employment, gender and age. The higher the level of education, the wider the insight of the younger generation so that the lack of interest in the younger generation in agricultural activities is getting bigger. The younger generation who already have permanent jobs in the non-agricultural sector look down on agricultural activities because they assume that agricultural activities have a low social level. Women have a low interest in agricultural activities because they assume that agricultural activities are not suitable for women because it will damage their appearance. Respondents aged 21-30 years have a low interest in agricultural activities, in addition to reduced agricultural land. External factors include socialization, parental work status and land ownership status. The younger generation with a low level of socialization results in a lack of interest in the younger generation in agricultural activities. Parents of respondents who work in agriculture or non-agriculture do not want their children to make agricultural activities the main job. The young generation whose parents still own agricultural land is still doing agricultural activities to help their parents work on their farms.

scholarly journals ANALISIS PENGGUNAAN PREFABRICATED VERTICAL DRAINS (PVD) PADA TANAH LEMPUNG LUNAK YANG TERDAPAT LAPISAN LENSA

2020 ◽  
Vol 3 (1) ◽  
pp. 119
Author(s):  
Andreyan Prasetio ◽  
Aniek Prihatiningsih
Keyword(s):  
Soft Soil ◽  
Soil Improvement ◽  
Cohesive Soils ◽  
Consolidation Process ◽  
Prefabricated Vertical Drains ◽  
Soil Layers ◽  
Vertical Drains ◽  
Vertical Drain ◽  
Installation Depth ◽  
Consolidation Time

Problem that often occurs in soft cohesive soils is settlement caused by consolidation process. If  construction activities doing when the soils has not been consolidated, settlement can occur. To accelerate  the consolidation process, soil improvement are usually do, one method of soil improvement to accelarate the consolidation process is vertical drain using prefabricated vertical drains (PVD). The soft soil layers in the field are not always continuous, sometimes found soft soil layers that have a lens layer. In this study, will discuss about the settlement and consolidation time of soft  soil layers that have a lens layer which has been improved by PVD with 1 meter distance. Infrastructure that stand on a location that is installed by PVD is taxiway and loading by Airbus A380 aircraft of 18,22ton/m2. Analysis using the 1 dimensional consolidation theory of Terzaghi. For PVD installation to a depth of 50 meters, preloading settlement of 234,80 cm with a consolidation time of  2260 days for the square pattern PVD and 1918 days for triangle pattern PVD. Post loading settlement for PVD installation depth of 50 meters by 2,50 cm. AbstrakMasalah yang sering terjadi pada tanah kohesif dan lunak adalah penurunan yang disebabkan proses konsolidasi. Penurunan dapat menyebabkan keretakan pada struktur konstruksi yang berada di atasnya. Jika suatu kegiatan konstruksi dilakukan saat tanah belum terkonsolidasi, maka konstruksi tersebut dapat mengalami penurunan.. Untuk mempercepat proses konsolidasi biasanya dilakukan perbaikan tanah, salah satu metode perbaikan tanah untuk mempercepat proses konsolidasi yaitu vertical drain dengan menggunakan prefabricated vertical drains (PVD). Lapisan tanah lunak yang terdapat di lapangan tidak selalu kontinu, terkadang ditemukan lapisan tanah lunak yang terdapat lapisan lensa. Pada penelitian ini, penulis akan membahas mengenai waktu konsolidasi yang dibutuhkan oleh lapisan tanah kohesif dan lunak yang terdapat lapisan lensa yang telah diperbaiki dengan menggunakan PVD berjarak 1 meter. Infrastruktur yang berdiri di atas lokasi yang dipasang PVD berupa taxiway dengan beban berupa pesawat Airbus A380 sebesar 18,22 ton/m2. Analisis dilakukan menggunakan teori konsolidasi 1 dimensi Terzaghi. Untuk pemasangan PVD hingga kedalaman 50 meter diperoleh penurunan pra pembebanan sebesar 234,80 cm dengan waktu konsolidasi selama 2260 hari untuk pemasangan PVD pola persegi dan selama 1918 hari untuk pola segitiga . Penurunan pasca pembebanan untuk pemasangan PVD hingga kedalaman 50 meter sebesar 2,5 cm.

Seismic data collection, reduction, and digitization

1961 ◽  
Vol 51 (4) ◽  
pp. 515-525
Author(s):  
B. P. Bogert
Keyword(s):  
New Jersey ◽  
Data Collection ◽  
Seismic Data ◽  
Visual Data ◽  
Recording Equipment ◽  
Field Laboratory ◽  
Set Up ◽  
Seismic Instrumentation

Abstract The facilities set up at the Bell Telephone Laboratories for seismic data collection and reduction are described. The digitization of the data so collected was carried out with existing equipment used for processing speech and visual data. We consider the seismic instrumentation and telemetry set up at the Chester Field Laboratory, Chester, New Jersey, the observation and recording equipment installed at the Murray Hill Laboratory, and finally and digitization and associated computer reduction to punched card form.

Importance of Plant Production in Development of Rural Areas

2020 ◽  
pp. 241-252
Author(s):  
Marijana Jovanović Todorović ◽  
Anton Puškarić
Keyword(s):  
Future Development ◽  
Rural Areas ◽  
Agricultural Land ◽  
Current Situation ◽  
Plant Production ◽  
Agricultural Activities

This chapter analyzes plant production from the perspective of development rural areas and it is based on the case study for rural areas on territory of Smederevo. The main goal of this chapter points to the current situation in plant production as one of the most important agricultural activities and that creates the basis for future development. It will be presented data collected from Census of agriculture, yearbooks, and local reports, but also data collected in the field. The authors apply theoretical and practical frame of research based on the case of study, which is oriented on used agricultural land, realized production and yield in period 2013-2017.

scholarly journals The potential of seismic cross-hole tomography for geotechnical site investigation

2019 ◽  
Vol 92 ◽  
pp. 18006
Author(s):  
Yannick Choy Hing Ng ◽  
William Danovan ◽  
Taeseo Ku
Keyword(s):  
Wave Velocity ◽  
Site Investigation ◽  
Velocity Model ◽  
P Wave ◽  
Reconstruction Technique ◽  
Sufficient Information ◽  
Eastern Region ◽  
S Wave ◽  
Near Surface ◽  
Soil Layers

Seismic cross-hole tomography has been commonly used in oil and gas exploration and the mining industry for the detection of precious resources. For near-surface geotechnical site investigation, this geophysical method is relatively new and can be used to supplement traditional methods such as the standard penetration test, coring and sampling, thus improving the effectiveness of site characterization. This paper presents a case study which was carried out on a reclaimed land in the Eastern region of Singapore. A seismic cross-hole test was performed by generating both compressional waves and shear waves into the ground. The signals were interpreted by using first-arrival travel time wave tomography and the arrival times were subsequently inverted using Simultaneous Iterative Reconstruction Technique (SIRT). A comparison with the borehole logging data indicated that P-wave velocity model cannot provide sufficient information about the soil layers, especially when the ground water table is near the surface. The S-wave velocity model seemed to agree quite well with the variation in the SPT-N value and could identify to a certain extent the interface between the different soil layers. Finally, P-wave and S-wave velocities are used to compute the Poisson's ratio distribution which gave a good indication of the degree of saturation of the soil.

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