Mapping of subsurface karst structure with gamma ray and electrical resistivity profiles: a case study from Pokhara valley, central Nepal

Gautam, Pitambar; Pant, Surendra Raj; Ando, Hisao

doi:10.1016/s0926-9851(00)00022-7

Cited by 52 publications

(28 citation statements)

References 12 publications

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“…It is filled by a large volume of layered clastic deposits of gravel, silt and clay of Quaternary age, deposited from the Annapurna mountain range probably by a series of catastrophic debris flows [12,13].…”

Section: Introductionmentioning

confidence: 99%

Growing City and Rapid Land Use Transition: Assessing Multiple Hazards and Risks in the Pokhara Valley, Nepal

Rimal¹,

Baral

Stork

et al. 2015

Land

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Pokhara is one of the most naturally beautiful cities in the world with a unique geological setting. This important tourist city is under intense pressure from rapid urbanization and population growth. Multiple hazards and risks are rapidly increasing in Pokhara due to unsustainable land use practices, particularly the increase in built-up areas. This study examines the relationship among urbanization, land use/land cover dynamics and multiple hazard and risk analysis of the Pokhara valley from 1990 to 2013. We investigate some of the active hazards, such as floods, landslides, fire, sinkholes, land subsidence and earthquakes, and prepare an integrated multiple hazard risk map indicating the highly vulnerable zones. Land use and land cover maps from 1990 and 2013 from Landsat images (30 m resolution) have been prepared and analyzed for the spatial dynamics of urbanization and the transition of land use and land cover. In the 23-year period, the built-up area more than doubled from 24.03 km² to 54.20 km². Although the landscape in the urban, peri-urban and rural areas appears to be fragmented, different drivers play pivotal roles in landscape change in these areas. The results provide OPEN ACCESSLand 2015, 4 958 substantial information for establishing innovative action plans for disaster risk management in the valley. Recommendations are made for the most suitable places for future urban expansion in the valley. This study is important for raising awareness among policy makers and other public officials to include multiple hazard risk mitigation in land use policies and plans. Establishing connections between urban expansions, escalating population growth and multiple hazards and risk assessment will also improve in modelling the latent impact of future catastrophes and emergency preparedness.

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Section: Introductionmentioning

confidence: 99%

Growing City and Rapid Land Use Transition: Assessing Multiple Hazards and Risks in the Pokhara Valley, Nepal

Rimal¹,

Baral

Stork

et al. 2015

Land

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“…Penelitian tentang karst menggunakan metode resistivity telah dilakukan oleh Gautam et. al (1999) untuk memetakan struktur bawah permukaan karst di Nepal Tengah [5] , Zhu et. al (2011) untuk menemukan saluran hidrologi karst di Kentucky AS [6] , Fadhly et.…”

Section: Pendahuluanunclassified

Identification Karst Underground River System in Gebangharjo Village, Pracimantoro using Tomography Resistivity Methode with Wenner-Schlumberger’s Configuration

Purwanto

Darsono

Koesuma

2017

Indonesian J Appl Phys

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This research is conducted using 4 lines data with 750 meters in length. Tomography resistivity with Wenner-Schlumberger configuration is used as this research methodology to take the data with a = 50 meters and n=1, 2, 3, 4, 5, 6. Resistivitymeter OYO 2119C McOHM-EL model is used as the instrument. Furthermore, the data is processed with two softwares; Res 2 Dinv ver. 3.56.22 to get 2D resistivity section and Rock Work 16 to make 3D model of the site. The underground river's chamber is made by hollow carbonate rocks with the resistivity of >412 Ωm and 117,6 Ωm -412 Ωm for limestone's resistivity as its capsrock. Researching to the depth of 173 meters, underground rivers are shown in the line 2 in the depth of 65 to 134 meters, 65 to 173 meters in the line 3, and in the cross section of line 3 and line 4. While in the line 1, another chamber is found within the depth of 12.5 to 40 meters. It is expected that the underground river is flowing to the south because of the chamber in line 3 and line 4 are lower than line 2.

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“…Such studies employ either total count scintillation or spectral detectors in aircraft or vehicles because the K, U or Th bearing rocks and minerals being sought emit high levels of gamma-rays. The application of gamma-ray detectors to surficial sediments has followed two courses of research: airborne, hazard detection or mineralisation studies (Tyler, 1999;El Nabi, 1995;Chiozzi et al, 1998) and surface, archaeological and geotechnical studies (Ruffell and Wilson, 1998;Gautam et al, 2000;Moussa, 2001;Ayres and Theilen, 2001;Jones et al, 2002). All of these applications have been made possible through the development of highly-sensitive, weatherproof, automated, spectral gammaray detectors.…”

Section: Gamma-ray Mapping In Subsurface Analysismentioning

confidence: 99%

Th∕K and Th∕U Ratios from Spectral Gamma-Ray Surveys Improve the Mapped Definition of Subsurface Structures

Ruffell

McKinley

Lloyd

et al. 2006

JEEG

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Spectral gamma-ray data can be obtained by non-destructive, automated, rapid and inexpensive survey methods. Previous studies utilise only total count, or total count as well as K, U and Th data. This work examines the use of [Formula: see text] and [Formula: see text] ratios to define the subsurface extent of partially-buried features at the centimeter to meter scale. On-site results are presented from two case studies as two-dimensional cross-sections. Changes in [Formula: see text] and [Formula: see text] ratios coincide with the known location of buried structures to within [Formula: see text] horizontal resolution. Gradual changes in total count, K, U and Th measurements give a lower horizontal accuracy of [Formula: see text]. Grids of data were manipulated in ArcGIS™ using a thin plate spline function to maximise information use and provide ‘easy to interpret’ maps of the survey areas. Unlike total count or individual element maps, [Formula: see text] and [Formula: see text] ratio maps can be compared to the known location of subsurface structures, vindicating the use of ratio cross-sections and maps in archaeological, geotechnical and forensic applications. It is concluded that the capacity to observe sub-surface features is enhanced through the use of [Formula: see text] and [Formula: see text] ratios.

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Mapping of subsurface karst structure with gamma ray and electrical resistivity profiles: a case study from Pokhara valley, central Nepal

Cited by 52 publications

References 12 publications

Growing City and Rapid Land Use Transition: Assessing Multiple Hazards and Risks in the Pokhara Valley, Nepal

Growing City and Rapid Land Use Transition: Assessing Multiple Hazards and Risks in the Pokhara Valley, Nepal

Identification Karst Underground River System in Gebangharjo Village, Pracimantoro using Tomography Resistivity Methode with Wenner-Schlumberger’s Configuration

Th∕K and Th∕U Ratios from Spectral Gamma-Ray Surveys Improve the Mapped Definition of Subsurface Structures

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