A confidence region in a ternary diagram from point counts     

G. S. Watson  Ha Nguyen 《Mathematical Geology》1985,17(2):209-213

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RETRACTED ARTICLE: Search for time variation of the fine-structure constant using [\mathrm{O}_{\mathrm{III}}] emission lines     

Le Duc Thong  Tran Van Hung  Nguyen Thi Thu Huong  Ha Huy Bang 《Astrophysics and Space Science》2012,339(2):405-405

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Optimal spatial allocation of initial attack resources for firefighting in the republic of Korea using a scenario optimization model   总被引：1，自引：1，他引：0  

Yohan LEE  Byungdoo LEE  Kyung Ha KIM 《山地科学学报》2014,11(2):323-335

【Title】

This study explores the optimal spatial allocation of initial attack resources for firefighting in the Republic of Korea. To improve the effectiveness of Korean initial attack resources with a range of policy goals, we create a scenario optimization model that minimizes the expected number of fires not receiving a predefined response. In this study, the predefined response indicates the number of firefighting resources that must arrive at a fire before the fire escapes and becomes a large fire. We use spatially explicit GIS-based information on the ecology, fire behavior, and economic characterizations important in Korea. The data include historical fire events in the Republic of Korea from 1991 to 2007, suppression costs, and spatial information on forest fire extent. Interviews with forest managers inform the range of we address in the decision model. Based on the geographic data, we conduct a sensitivity analysis by varying the parameters systematically. Information on the relative importance of the components of the settings helps us to identify “rules of thumb” for initial attack resource allocations in particular ecological and policy settings.  相似文献   

Interdecadal change in the Northern Hemisphere seasonal climate prediction skill: part I. The leading forced mode of atmospheric circulation     

XiaoJing Jia  June-Yi Lee  Hai Lin  Andrea Alessandri  Kyung-Ja Ha 《Climate Dynamics》2014,43(5-6):1595-1609

Using observations and 1-month lead hindcast data from six coupled atmosphere–ocean climate models, this study investigates the interdecadal change in the leading maximum covariance analysis mode (MCA1) of atmospheric circulation in response to the changes in the El Niño and Southern Oscillation (ENSO) occurred around late 1970s. We focus on boreal winter climate variability and predictability over the North Pacific–North American (NPNA) region using December–January–February prediction initiated from November 1st in the period of 1960–1980 (P1) and 1981–2001 (P2). Observed analysis reveals that ENSO variability, the related tropical convective activity, and thus the MCA1 are considerably enhanced from P1 to P2. As a result, surface climate anomalies over the NPNA are more significantly correlated with the MCA1 in P2 than P1, particularly over North America. The six coupled models and their multi-model ensemble not only are capable of capturing the interdecadal change of the MCA1 and its relationship with surface air temperature and precipitation over the NPNA regions but also have significantly higher forecast skills for the MCA1 and the surface climate anomalies in P2 than P1. However, models have systematic biases in the spatial distribution of the MCA1. It is demonstrated that the interdecadal change in the MCA1 should contribute to the improved forecast skill of the NPNA climate during recent epoch.  相似文献   

Triggered earthquake study in Tranh River No. 2 (Vietnam) Hydropower Reservoir     

Cao Dinh Trieu  Cao Dinh Trong  Le Van Dung  Thai Anh Tuan  Dinh Quoc Van  Ha Vinh Long 《Journal of the Geological Society of India》2014,84(3):319-325

This article presents the results of investigating triggered earthquakes in the vicinity of Tranh River No.2 Hydropower Reservoir in recent years. It is found that earthquakes occurred in the vicinity of Tranh River Hydropower Reservoir, probably associated with the Trà My — Trà BÓng fault zone. It is estimated that this fault is capable of hosting an earthquake of M~6.1. The ‘b’ value for this earthquake sequence is 0.83, which is higher than the regional ‘b’ value of 0.60. We estimate that the return period of earthquakes of M=4.5, 5.0, 5.5 and 6.0 is 11, 29, 76 and 198 months respectively. On October 22, 2012 an earthquake M_S=4.6, I₀=6.0 (MSK-64) occurred at 13:41:28 hrs GMT. The epicenter of the earthquake was located at a distance of 5.5 km away from the center of the dam towards the west. The focal depth is about 4.5 km, and the rupture length is about 1.8 km.  相似文献   

Natural 222Rn as a tracer of mixing and volatilization in a shallow aquifer during a CO2 injection experiment     

Jaeyeon Kim  Seong-Sun Lee  Seung-Wook Ha  Won-Tak Joun  YeoJin Ju  Kang-Kun Lee 《水文研究》2020,34(26):5417-5428

This study aims to evaluate the application of ²²²Rn in groundwater as a tracer for monitoring CO₂ plume migration in a shallow groundwater system, which is important to detect potential CO₂ leakage in the carbon capture and storage (CCS) project. For this research, an artificial CO₂-infused water injection experiment was performed in a shallow aquifer by monitoring hydrogeochemical parameters, including ²²²Rn. Radon in groundwater can be a useful tracer because of its sensitivity to sudden changes in subsurface environment. To monitor the CO₂ plume migration, the data were analysed based on (a) the influence of mixing processes on the distribution of ²²²Rn induced by the artificial injection experiment and (b) the influence of a carrier gas role by CO₂ on the variation of ²²²Rn. The spatio-temporal distributions of radon concentrations were successfully explained in association with horizontal and vertical mixing processes by the CO₂-infused water injection. Additionally, the mixing ratios of each monitoring well were calculated, quantitatively confirming the influence of these mixing processes on the distribution of radon concentrations. Moreover, one monitoring well showed a high positive relationship between ²²²Rn and Total dissolved inorganic carbon (TIC) by the carrier gas effect of CO₂ through volatilization from the CO₂ plume. It indicated the applicability of ²²²Rn as a sensitive tracer to directly monitor CO₂ leakage. When with a little effect of carrier gas, natural ²²²Rn in groundwater can be used to compute mixing ratio of CO₂-infused water indicative of CO₂ migration pathways. CO₂ carrier gas effect can possibly increase ²²²Rn concentration in groundwater and, if fully verified with more field tests, will pose a great potential to be used as a natural tracer for CO₂.  相似文献   

Semi-empirical prediction method for monthly precipitation prediction based on environmental factors and comparison with stochastic and machine learning models     

Huihui Zhang  Hugo A. Loáiciga  Fu Ren  Da Ha 《水文科学杂志》2020,65(11):1928-1942

ABSTRACT

Precipitation prediction is central in hydrology and water resources planning and management. This paper introduces a semi-empirical predictive model to predict monthly precipitation and compares its predictive skill with those of machine learning (ML) methods. The stochastic method presented herein estimates monthly precipitation with one-step-ahead prediction properties. The ML predictive skill of the algorithms is evaluated by predicting monthly precipitation relying on the statistical association between precipitation and environmental and topographic factors. The semi-empirical predictive model features non-negative matrix factorization (NMF) for investigating the influence of multiple predictor variables on precipitation. The semi-empirical predictive model’s parameters are optimized with the hybrid genetic algorithm (GA) and Levenberg-Marquardt algorithm (LM), or GALMA, yielding a validated model with high predictive skill. The methodologies are illustrated with data from Hubei Province, China, which comprise 27 meteorological station datasets from 1988–2017. The empirical results provide valuable insights for developing semi-empirical rainfall prediction models.  相似文献   

太原西山岩溶发育特征及地下水天然资源的研究   总被引：3，自引：0，他引：3  

哈承祐  汤邦义  鲁荣安 《中国岩溶》1989,8(1):41-46

本文从岩石微观上、宏观上研究了太原西山中奥陶系碳酸盐岩的裂隙岩溶特征,并就地下水天然资源作了研究。   相似文献   

Centrifuge modeling of disconnected piled raft using vertical pushover tests     

Park  Heon-Joon  Ko  Kil-Wan  Song  Young-Hun  Song  Myung-Jun  Jin  Seokwoo  Ha  Jeong-Gon  Kim  Dong-Soo 《Acta Geotechnica》2020,15(9):2637-2648

Acta Geotechnica - A disconnected piled raft (DPR) foundation has been introduced as an effective pile design to reduce the vertical loading experienced by the pile. The characterization of DPRs...  相似文献