Organic geochemistry of the Lower Permian Tak Fa Formation in Phetchabun Province,Thailand: implications for its paleoenvironment and hydrocarbon generation potential     

Chenrai  Piyaphong  Fuengfu  Supawich 《中国地球化学学报》2020,39(3):291-306

Acta Geochimica - The outcrop samples of the Tak Fa Formation (Lower Permian) in Phetchabun Province have been studied to determine their organic geochemical characteristic, depositional...  相似文献   

Spatial and temporal variation of groundwater recharge in shallow aquifer in the Thepkasattri of Phuket,Thailand          下载免费PDF全文

Yacob T Tesfaldet  Avirut Puttiwongrak  Tanwa Arpornthip 《地下水科学与工程》2020,8(1):10-19

Whether groundwater resources can be sustainably utilized is largely determined and characterized by hydrogeological parameters.Estimating the groundwater recharge is one of the essential parameters for managing water resources and protecting water resources from contamination.This study researched the spatial and temporal variation of groundwater recharge in the Thepkasattri sub-district through integrating chloride mass balance(CMB)and water table fluctuation(WTF)methods.The chloride content of representative rainfall and groundwater samples was analyzed.Besides,WTF method was adopted from groundwater level data from 2012 to 2015.According to the CMB method,the mean recharge was estimated to be 1172 mm per year,accounting for 47%of the annual rainfall.Moreover,the estimated recharge from the WTF method took 26%of annual rainfall in 2015.The recharge was underestimated according to the WTF method,because of the uncertainty in specific yield estimates and the number of representative wells in the study area.Moreover,the correlation between rainfall and water table fluctuation data indicated the positive linear relationship between two parameters.The spatial recharge prediction indicated that recharge was higher(1200-1400 mm/yr)in the eastern and western catchment,while that in the central floodplains was between 800 mm/yr and 1100 mm/yr.In addition,low recharge value between 450 mm/yr and 800 mm/yr was observed in the south-west part of Thepkasattri.The spatial variation of recharge partly reflects the influences of land use and land cover of the study area.  相似文献   

Co-productive agility and four collaborative pathways to sustainability transformations     

《Global Environmental Change》2022

Co-production, the collaborative weaving of research and practice by diverse societal actors, is argued to play an important role in sustainability transformations. Yet, there is still poor understanding of how to navigate the tensions that emerge in these processes. Through analyzing 32 initiatives worldwide that co-produced knowledge and action to foster sustainable social-ecological relations, we conceptualize ‘co-productive agility’ as an emergent feature vital for turning tensions into transformations. Co-productive agility refers to the willingness and ability of diverse actors to iteratively engage in reflexive dialogues to grow shared ideas and actions that would not have been possible from the outset. It relies on embedding knowledge production within processes of change to constantly recognize, reposition, and navigate tensions and opportunities. Co-productive agility opens up multiple pathways to transformation through: (1) elevating marginalized agendas in ways that maintain their integrity and broaden struggles for justice; (2) questioning dominant agendas by engaging with power in ways that challenge assumptions, (3) navigating conflicting agendas to actively transform interlinked paradigms, practices, and structures; (4) exploring diverse agendas to foster learning and mutual respect for a plurality of perspectives. We explore six process considerations that vary by these four pathways and provide a framework to enable agility in sustainability transformations. We argue that research and practice spend too much time closing down debate over different agendas for change – thereby avoiding, suppressing, or polarizing tensions, and call for more efforts to facilitate better interactions among different agendas.  相似文献   

Design equations of uplift capacity of circular piles in sands     

《Applied Ocean Research》2019

Uplift capacity of circular piles in sands is one important design parameter for many pile foundations supporting important structures subjected to tensile forces. Even though a number of formulas based on the limit equilibrium or semi-empirical methods are proposed to predict the uplift capacity of piles in sands, there is a major limitation of the methods in obtaining the accurate predictions. In this paper, the computational limit analysis is employed to investigate the uplift capacity of circular piles in sands. The effects of the important variables including pile length and diameter, soil friction angle and unit weight, and roughness factor at soil-pile interface are examined extensively using the dimensionless parameters while the predicted failure mechanisms associated with the parameters are discussed and compared. Approximate statistical design equations of the uplift capacity of circular piles in sands are developed based on the numerically derived solutions and the existing experimental data. It is found that the proposed design equations provide the most accurate prediction of the uplift capacity of circular piles in sands as compared to the existing formulas.  相似文献   

Performance of geosynthetic cementitious composite mat and vetiver on soil erosion control   总被引：1，自引：0，他引：1  

《山地科学学报》2020,17(6):1410-1422

An understanding of how different land covers affect soil erosion caused by rainfall is necessary in mountainous areas. The land cover usually plays an important role in controlling landslide hazards associated with these terrains. This paper presents the results of a field experiment where several types of land covers were placed on a full-scale embankment as erosion control. An 8 m wide, 21 m long, and 3 m high embankment with a 45° side-slope was built with lateric soil. The soil was compacted under a relative compaction of 70% to simulate a natural soil slope. Two sides of the embankment were divided into six land cover areas, with three different areas of bare soil, and one each of a geosynthetic cementitious composite mat(GCCM), vetiver grass,and a combination of GCCM and vegetation. Soil erosion and moisture levels were monitored for each land cover area during six natural rainfall events encountered over the experimental period. Field results were compared with a numerical simulation and empirical soil loss equation. The results revealed that the GCCM gave the best erosion control immediately after installation, but vetiver grass also exhibited good erosion control six months postconstruction.  相似文献   

泰国难府-程逸缝合带中灰岩块的 虫筳 类生物地层学     

Thasinee CHAROENTITIRAT  Sarawute CHANTRAPRASERT 《地球学报》2012,33(S1):74-74

The study area, Nan Province, northern Thailand is geotectonically situated within the Nan-Uttaradit Suture, the once back-arc basin between the Sukhothai Zone and Indochina Block. Permian Fusulinacean fauna from limestone blocks within the suture has been investigated and the Nan area has been mapped in detail. These may provide the useful information for understanding the faunal assemblage and overall ge-ometry of stratigraphic successions in the basin. The strata were intensely folded and thrust. Scattered Per-mian limestones found in Nan area are blocks within shale interbedded with tuffaceous rock. The contact between this unit and the adjacent units, the strongly foliated shale and tuffaceous sedimentary strata that are mildly metamorphosed and giving phyllitic tex-tures, has been interpreted as a west-dipping normal fault, namely the Pha Sing Fault. This fault runs par-allel to the Highway no.1080 (Nan-Tha Wang Pha). Middle and early Late Permian fusulinacean fauna found in the Nan area contains Neoschwagerina, Pseudodoliolina, Colania, Lepidolina, and Colaniella. Additionally, late Early Permian fusulinacean and Middle Triassic radiolarian fauna have been reported in this area (e.g., Fontaine, 2002; Saesaengseerung et al. 2008). These paleontological data show the existence of Nan Back-arc Basin during late Early Permian (Artin-skian) to Middle Triassic. Moreover, the similarity of fusulinacean assemblage yielding Permian limestone blocks of the Nan Back-arc Basin and the ones of the Indochina Block has been interpreted that the Permian limestone blocks in the Nan Back-arc Basin were part of the continental shelf within the Indochina Block.  相似文献   

Post-installation pore-pressure changes around spudcan and long-term spudcan behaviour in soft clay     

《Computers and Geotechnics》2014

This paper presents a dual-stage Eulerian–Lagrangian analysis for modelling the entire process of spudcan installation in soft clay, followed by consolidation and working load operation. The analysis consists of three components, namely undrained effective stress Eulerian analysis of spudcan installation, mesh-to-mesh variable mapping and coupled-flow Lagrangian analysis for the post-installation spudcan working behaviour. The results show good agreement with centrifuge model data but also highlight the importance of replicating the hysteretic behaviour of the soil. The findings also show that while a wished-in-place approach was able to model the long-term bearing response of the spudcan, rotational stiffness was over-estimated. This is due to the fact that, while the wished-in-place analysis was able to model the hardening of the soil ahead of the spudcan, it was unable to model the softening of back-flowed soil behind spudcan. The latter influences the spudcan fixity significantly, but not bearing response. Although the analyses were conducted using ABAQUS, they can, in principle, be conducted using other codes.  相似文献   

Modelling the economic vulnerability of households in the Phang-Nga Province (Thailand) to natural disasters     

P. Willroth  J. Revilla Diez  N. Arunotai 《Natural Hazards》2011,58(2):753-769

The 2004 tsunami devastated large areas in the southern part of Thailand. This paper takes a particular look at the circumstances of vulnerability and the process of recovery in the area of Khao Lak and its surrounding villages, which constitute a booming tourist hotspot at the centre of a region that is still dominated by agriculture. A quantitative vulnerability model was developed, integrating a quantitative household survey and remote sensing data. This model describes and specifies the circumstances of vulnerability and the factors leading to a recovery of the area. Indirect effects on the livelihood of households in particular, such as the disruption of infrastructure or the loss of income, show a negative effect on the recovery time. External help received by the households even shows an extending influence on the duration of their recovery period.  相似文献   

Isotope Geology of Upper Paleozoic Carbonates, Loei Area, NE Thailand: Implication for Paleoenvironments and Tectonic Setting     

P. Charusiri  S. Assavapatchara  X. Xu  V. Daorerk 《Gondwana Research》2001,4(4):590

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Nanoscale porosity in SAFOD core samples (San Andreas Fault)     

Christoph Janssen  Richard Wirth  Andreas Reinicke  Erik Rybacki  Rudolf Naumann  Hans-Rudolf Wenk  Georg Dresen 《Earth and Planetary Science Letters》2011,301(1-2):179-189

With transmission electron microscopy (TEM) we observed nanometer-sized pores in four ultracataclastic and fractured core samples recovered from different depths of the main bore hole of the San Andreas Fault Observatory at Depth (SAFOD). Cutting of foils with a focused ion beam technique (FIB) allowed identifying porosity down to the nm scale. Between 40 and 50% of all pores could be identified as in-situ pores without any damage related to sample preparation. The total porosity estimated from TEM micrographs (1–5%) is comparable to the connected fault rock porosity (2.8–6.7%) estimated by pressure-induced injection of mercury. Permeability estimates for cataclastic fault rocks are 10^? 21–10^? 19 m² and 10^? 17 m² for the fractured fault rock. Porosity and permeability are independent of sample depth. TEM images reveal that the porosity is intimately linked to fault rock composition and associated with deformation. The TEM-estimated porosity of the samples increases with increasing clay content. The highest porosity was estimated in the vicinity of an active fault trace. The largest pores with an equivalent radius > 200 nm occur around large quartz and feldspar grains or grain-fragments while the smallest pores (equivalent radius < 50 nm) are typically observed in the extremely fine-grained matrix (grain size < 1 μm). Based on pore morphology we distinguish different pore types varying with fault rock fabric and alteration. The pores were probably filled with formation water and/or hydrothermal fluids at elevated pore fluid pressure, preventing pore collapse. The pore geometry derived from TEM observations and BET (Brunauer, Emmett and Teller) gas adsorption/desorption hysteresis curves indicates pore blocking effects in the fine-grained matrix. Observations of isolated pores in TEM micrographs and high pore body to pore throat ratios inferred from mercury injection suggest elevated pore fluid pressure in the low permeability cataclasites, reducing shear strength of the fault.  相似文献