Abstract

Data availability

References

Acknowledgements

Author information

Ethics declarations

Additional information

Rights and permissions

About this article

Abstract

Worldwide, nitrogen (N) deficiency is the main yield limiting factor owing to its losses via leaching and volatilization. Urease inhibitors slow down urea hydrolysis in soil by inhibiting urease enzyme activities whereas gibberellic acid is growth regulator. That is why, we evaluated the role of urease inhibitor [N-(n-butyl)thiophosphorictriamide (NBPT)] and gibberellic acid (GA3) in improving nitrogen uptake and yield of maize under different N levels (120 and 150 kg ha−1) along with control. Both N levels alone and in combination with GA3 and NBPT significantly increased yield and yield components of maize over control. In addition, 150 kg N ha−1 + NBPT + GA3 produced highest biological, grain, and stover yields, 1000 grain weight, plant height, and N uptake exhibiting 33.15%, 56.46%, 27.56%, 19.56%, 23.24%, and 78% increase over 150 kg N ha−1, respectively. The sole use of gibberellic acid or NBPT with each level of N also improved the yield and yield components of maize compared to sole N application and control. Furthermore, application of 120 kg N ha−1 along with NBPT and GA3 performed at par to 150 kg N ha−1 + NBPT + GA3 but it was superior than sole applied 150 kg N ha−1 for all the studied traits. These results imply that application of GA3 and/or NBPT can reduce dependence on urea and improve the yield and N uptake in maize by slowing urea hydrolysis in calcareous soils and shall be practiced.

Introduction

Maize (Zea mays L.) belongs to family Poaceae and is one of the most important cultivated crop in tropical and subtropical region of the world (Nabizadeh et al. 2012; Khan et al. 2014a, b). It is the 3rd largest grain crop in Pakistan following wheat and rice (Harris et al. 2007). Maize is an exhaustive crop needs an adequate amount of essential nutrients for its abundant production, in order to fulfill the demand of the rapid increasing population of the world. Nitrogen (N) is an essential nutrient, is a basic constituent of plant growth, and improves crop production and other nutrients uptake (Zaman et al. 2008a, b; Nasim et al. 2018). Nitrogen is a mobile nutrient, it moves and is lost easily from the soil (Junejo et al. 2011) and is usually deficient in calcarious soils (Adnan et al. 2018a; Snyder et al. 2007; Shah et al. 2012). Worldwide increase in crop yield is directly proportional to synthetic fertilizer application, though the higher N fertilizer has drastically declined nitrogen use efficiency (NUE) (Tilman et al. 2002; Liu et al. 2013; Erisman et al. 2007; Turan 2021a).

Abstract

Keyword

1. Introduction

2. Geotourism development and Geoheritage assessment in context of India

3. Description of the Geoheritage sites of Puruliya district, West Bengal (India)

4. Method of Assessment

5. Result and discussion

6. Conclusion

Funding agency

Acknowledgement

References

Abstract

Exploration of geoheritage sites is a new venture in tourism studies. The objective of the study is centred around the Geoheritage site conservation for geological and geomorphological interpretation and introduction of Geotourism involving the local people in Puruliya district. The main litho-unit of Puruliya district belongs to Chhotanagpur Granite Gneissic Complex of Archean era. Nine geological/geomorphological important sites are chosen for assessing their geoheritage values and analysing the Geotourism potential. A modified model of Kubalikova (2013) is adopted for the evaluation of the selected nine important sites, where five important criteria i.e. scientific (intrinsic) values, educational values, economical values, conservation values and added (cultural, ecological and aesthetic) values are considered. The result reveals that sites like Durgabera dam, Bhanratongri hill, Garpanchakot and Jaychandi hill can be assumed as top potential Geotourism site occupying highest geoheritage values, whereas Jabar hill, Poradih hill and Tamakhun old mine are quite low in the context of Geoheritage values. Based on the result, few strategies are suggested which can help to develop Geotourism in the study area and raise awareness about the geoheritage values among the students, general visitors and the local residents of the area.

1. Introduction

Geoheritage and geoconservation are two conceptions deal with the protection and conservation of earth science features. It concerns with rock monuments, fossil parks, geological marvels/features, geomorphological landforms. In a broader sense, geoheritage also includes cultural sites (such as mining sites)/archaeological sites (made of stones) that have an integrated value in response to a particular region. Preservation of natural heritage and associated cultural values to education, interpretation and entertainment is the main aim of Geotourism (Gordon, 2018). Therefore, a link can be established between the two notions Geotourism and Geoheritage. According to Hose and Vasiljević (2012) Geotourism can be defined as “the provision of interpretative and service facilities for geoheritage sites and geomorphosites and their encompassing topography, together with their associated in situ and ex situ artefacts, to constituency-build for their conservation by generating appreciation, learning and research by and for current and future generations” (Antić & Tomić, 2017; Hose, 2012; Kubalíková, 2013). Though it is a widely accepted definition of Geotourism concept, the scope of the concept in this definition has remained narrow in sense. Dowling (2013) truly remarked that “Geotourism is a form of sustainable tourism with a primary focus on experiencing the earth’s geological features in a way that fosters environmental and cultural understanding, appreciation and conservation, and is locally beneficial”. According to Panizza (2009), all the physical attributes over the earth surface, for example, a gorge, a mountain peak, a sea cliff have some kind of cultural values as it belongs to the certain cultural territory. Sometimes the natural heritage sites also become the sacred place for human being and is regarded an important element for geo-cultural understanding. Landscape often considers as a component of expressing architectural design, literature, poems, paintings and so on (Lindberg et al., 1997). So in this context, landscapes (including both geological and geomophological landforms/features) can be considered as a cultural component which not only posses scientific and aesthetic value but also bears an immense cultural value. All these aspects incorporate within the concept of ‘Geoheritage’ for sake of geoconservation of the territorial resources. Geotourism helps to identify the geoheritage resources and try to use for sustainable economic development with active participation of the local community.

Highlights

Abstract

Keywords

1. Introduction

2. Material and method

3. Result analysis

4. Discussion

5. Conclusion

CRediT authorship contribution statement

Declaration of Competing Interest

Acknowledgements

References

Abstract

Geological disasters not only hinder the ecological security guarantee in urban agglomerations, but also pose serious threat to the life and property of residents in the areas. The study establishes a “hazard-vulnerability-exposure” three-dimensional ecological risk assessment model, adopts an information value model to assess hazard, use landscape indices to analyze vulnerability and nighttime light data to indicate population exposure, and then quantitatively assesses the watershed-scale ecological risks of geological disasters and their patterns. The results show that ecological risks of geological disasters are mainly medium risks, presenting the trend of weakening from southeastern coastal areas to northwestern inland areas. The ecological risks exist in eight patterns in combination of the three dimensions of hazard, vulnerability and exposure. The elevation of 600–800 m, slope of 5 ~ 15°, aspect as southwest, NDVI of 0.4–0.6, lithology of metamorphic rocks, land use type as farmland, multi-year average precipitation of >1600 mm, distance to river of less than 200 m and distance to fault of less than 1000 m are the combination of greater likelihood of inducing geological disasters. The study finds that ecological risks of geological disasters show the trend of high in the southeast and low in the northwest and are the highest under combination of the high vulnerability and high exposure pattern out of the eight patterns that are predominated by high population exposure. In addition, the study discovers the combination of greater likelihood of inducing geological disasters, and puts forward the prevention and control measures against geological disasters in the future.

1. Introduction

The study on ecological risk assessment started in the 1970s (Calow, 1998). In 1992, the U.S. Environmental Protection Agency defined the ecological risk assessment and laid out the theoretical foundation and analysis framework for related study (Kang et al., 2016, U.S. Environmental Protection Agency, 1992, Zhang et al., 2014). Assessment of ecological risk mainly covers hazard assessment, exposure assessment, receptor analysis and risk characterization (Du et al., 2012, Du et al., 2016, Jin et al., 2019, Zhang et al., 2019). As the human society paid increasingly greater attention to the natural ecosystem, domestic and foreign scholars conducted extensive research on ecological risk assessment and related theories and methods were constantly developed and improved (Chen et al., 2013a, Chen et al., 2013b, Hope, 2006, Liu et al., 2014, Xu et al., 2016). Typical of mountain environment, the urban agglomeration in the Fujian Delta region suffers frequent geological disasters due to its particular topographic conditions and climatic features, causing tremendous casualties and economic losses every year. This has become a major obstacle to the sustainable development of the urban agglomeration (Lin et al., 2018, Lu et al., 2010). Therefore, ecological risk assessment over geological disasters in the urban agglomeration in the Fujian Delta region provides support for decision-making on local ecological protection and administration more effectively.

Highlights

Abstract

Keywords

1. Introduction

2. Selected study areas

3. Methods

4. Data

5. Geological mapping in the selected study areas

6. Discussion

7. Conclusions

Declaration of Competing Interest

Acknowledgements

References

Abstract

The subsurface in areas affected by the Pleistocene glaciations often reveal very complex architectures and because of this, the near-surface geology is generally difficult to map and model in high detail. A number of geophysical methods focus on the uppermost part of the subsurface and are capable of mapping details, but no single method has hitherto been able to provide the detail, the data density and the resolution required to map the near-surface Quaternary geology in 3D. Driven by the demands for high detail in the uppermost parts of the subsurface related to for instance surface water and groundwater vulnerability assessments and climate-change related projects, a new high-resolution electromagnetic survey method, tTEM, has been developed. We present examples and discuss the method and its applicability in four study areas where data from tTEM surveys has been combined with geological data and knowledge to map near-surface geological features that could not be resolved in 3D using other geophysical methods focusing on the deeper subsurface or methods with a wider data spacing.

1. Introduction

The subsurface deposits of many areas that were once covered or bordered by Pleistocene ice sheets reveal very complex architectures. During at least the three latest glaciations and the intervening interglacials, multiple episodes of erosion, deposition and deformation have left a marked impact on the upper parts of the subsurface: Glaciotectonic complexes with structural deformation to depths of up to 300–400 m are numerous (e.g. Aber and Ber, 2007; Gehrmann et al., 2019; Pedersen, 2005), and widespread subglacial erosion is evidenced by for instance the occurrence of a large number of buried tunnel valleys eroded to depths of up to 400 m (e.g. Van der Vegt et al., 2012; Jørgensen and Sandersen, 2006). In addition to this, other types of erosion, sedimentation and tectonics have resulted in extensive and complex near-surface sedimentary successions and highly varied terrain morphologies (e.g. Brandes et al., 2018; Houmark-Nielsen, 2007, Houmark-Nielsen, 2011; Lang et al., 2014; Sandersen and Jørgensen, 2015; Winsemann et al., 2018). Due to this complexity, the upper part of the subsurface geology is generally difficult to map and model in high detail.

Extensive groundwater mapping in Denmark since the mid 90’s (Thomsen et al., 2004) created a boost in the development of new geophysical methods that aimed at mapping the uppermost 100–200 m of the subsurface. Developed geophysical methods counted for instance Airborne ElectroMagnetic methods (AEM; e.g. SkyTEM; Danielsen et al., 2003; Sørensen and Auken, 2004), Electrical Resistivity Tomography (ERT; Loke et al., 2013), Induced Polarization (IP; Maurya et al., 2018), Pulled Array Continuous Electrical Sounding (PACES; Christensen and Sørensen, 2001), and ElectroMagnetic Induction (EMI; Christiansen et al., 2016; Doolittle and Brevik, 2014). The development of new methods also spurred new modelling workflows and new ways of combining data (e.g. Sørensen, 1996; Sørensen and Auken, 2004; Jørgensen et al., 2003, Jørgensen et al., 2013; Møller et al., 2009; Høyer et al., 2015a, Høyer et al., 2015b; Marker et al., 2015).

Abstract

Introduction

Figures (11)

Section snippets

References (40)

Recommended articles (6)

Abstract

Characterizing subsurface site conditions and understanding main geological features are critical components of any safety assessment for any construction, particularly defining subsurface flow paths and weakness (i.e. fracture and fault) zones. Poor definition of flow paths and weakness zones may lead to serious hazards during construction. This study, integrating geophysical and geological investigations, is undertaken to enhance the understanding of both surface and subsurface complexities of an engineering site characterization located in western Saudi Arabia near Red Sea. Two geophysical investigations, Electrical Resistivity Tomography (ERT) and Transient Electromagnetic (TEM), were carried out to characterize the subsurface of the study area. A total of three ERT profiles and sixteen TEM sounding measurements was conducted in the study area. Geological investigation was mainly focused to understanding geological features and bedrock conditions of the two opposite river’s abutments at the study site. Geophysical results show NNE-SSW and NNW-SSE fault zones which were confirmed by in-situ geological inspections and by satellite images. The results also reveal the presence of geothermal fluids validated by the observation of hot water flowing in the river along the measurements. This study demonstrates that the integrated geophysical and geological investigations provide means to infer geothermal fluids, locate fractures, and fault zones. This study enabled us to characterize and locate the geological structural framework as well as possible geothermal fluids existence in the study area.

Introduction

Site characterization is an important step in civil engineering study or design. In order to devise a design for an engineering project such as urban development, a range of conceptual factors need to be assessed. An important factor that should be taken into account is the geological situation at the site. Therefore, a geological assessment should be implemented prior to any constructions. A proposed site in the western part of Saudi Arabia, near the Red Sea (Fig. 1), was planned by the government to be developed. For that reason, the subsurface characterization of the local geological and tectonic conditions (Fig. 2) were needed and a geophysical survey was suggested. Thus, detailed geological and geophysical studies were carried out to conduct full assessment of the under-development site. Geophysical survey at the study area suggests that the site has been affected by almost E-W fault system that resulted in two depressions (Al-Homoud et al., 1995), which extended in the form of buried structural channels filled with porous alluvium and fractured greenstone rocks (Moustafa et al., 2013). These depressions are considered permeable zones and represent a favorable pathway for groundwater flow. Consequently, further geological and geophysical surveys are necessary to better characterize the site (Wang et al., 2019). Therefore, we carried out detailed geological and geophysical investigations to define the tectonic geological features, such as the existence of main faults, and to better understand the subsurface geological conditions. Detailed geological studies have been conducted at the exposed rocks of the two abutments of the site in order to identify rock types as well as the delineation of the tectonic features, especially those related to faulting at the proposed site. Geophysical survey has been conducted using electrical resistivity tomography (ERT) and transient electromagnetic (TEM) methods to characterize the subsurface geological elements such as geological structures and identify different subsurface fault zones.

1- Introduction

2- Method and model

3- Results

4- Discussion

5- Conclusions

References

Abstract

The XiLuoDu reservoir dam located on the Jinsha River is one of the largest dams in the world. Nearby faults are very active, and two M > 7 strong earthquakes have occurred around the dam. Simulating the rupture dynamics of potential earthquakes on the surrounding faults is very important to estimate the seismic hazard for the dam. In this research, we use the curved grid finite difference method (CG-FDM) to simulate spontaneous ruptures on the major faults around the dam. The main results are that the Leibo middle and south faults (LBMF and LBSF) are more likely to have large destructive earthquakes than the Mabian-Yanjin east fault (MB-YJEF). Asperities on faults that have an impact on strong ground motion are formed under the combined influence of the regional background stress field and fault geometry. Spontaneous ruptures on the LBMF and LBSF are mainly strike-slip with minor thrust components, while those on the MB-YJEF are strike-slip and thrust; these results are consistent with the focal mechanisms of recorded small and moderate earthquakes in this area.

Introduction

The Jinsha River , with a total length of 3364 km, is located in the upper reaches of the Yangtze River in China and is rich in water energy resources. There are four world -class reservoir dams on its lower reaches . The XiLuoDu reservoir is located in the Jinsha River gorge section between Leibo County in Sichuan Province and Yongshan County in Yunnan Province; it has a total reservoir capacity of 13.6 billion m3 and a maximum dam height of 278 m (https://www.ctg.com.cn/sxjt/zt98/cyjsj/xwtqh/313438/index.html). This reservoir is a large -scale project that is useful for power generation, flood control, sediment retention and improvement of downstream shipping conditions, but the reservoir is located within the Daliangshan sub -block at the junction of the Qinghai -Tibetan block and the South China block (Deng et al., 2003; Diao et al., 2014; Zhang et al., 2003 ). The seismicity and earthquake intensity are both very strong in this area. The seismic resistance of the reservoir dam is very important (https://www.ctg.com.cn/sxjt/zt98/cyjsj/xwtqh/313438/index.html), and a more accurate estimation of earthquake disasters in the dam site area is urgently needed. Some faults are active around the dam. The Lianfeng fault (LFF) and many small faults in the Mabian -Yanjin fault zone are mainly distributed within 20 -30 km of the XiLuoDu dam, forming a nearly triangular small block called the Leibo -Yongshan triangular block.

1- Introduction

2- The audiences of earthquake emergency maps

3- Earthquake emergency maps for different audiences

4- Mapping earthquake emergency maps

5- Case study and discussion

6- Conclusions

References

Abstract

Emergency response and rescue is an important way to mitigate the loss caused by earthquakes. Various maps containing information about earthquakes provide effective guidance and references for individuals undertaking such action. However, the production of earthquake emergency maps aimed at the “right” user in an effective manner is challenging. In this study, we focus on two questions: (1) Who are the users of earthquake emergency maps and what information do these individuals need? (2) How can the maps be produced quickly and efficiently according to the requirements of different users? To answer the first question, we classify the users into four categories under the guidance of audience theory: earthquake emergency decision-makers, auxiliary decision-making technicians, emergency rescue workers, and the public. The map contents are also described according to the requirements of different audiences. We depict the methods used for representation in such earthquake emergency maps for different audiences, which places a foundation for answering the second question. Following that, a template-matching mapping method is proposed for the rapid production of emergency maps, including two phases: before the earthquake templates of emergency maps for different audiences are prepared; after an earthquake, the template is updated with information from seismic models, so that the emergency maps are automatically plotted. Finally, a case study is provided to verify the mapping method. We conclude that the application of audience theory and the related template-matching method for map production not only answers the two questions but also will benefit the emergency mapping of other disasters.

Introduction

Earthquakes are natural disasters that usually lead to numerous deaths and injuries, and extensive economic loss [1]. China lies between the circum-Pacific seismic belt and the Eurasian seismic zone and has suffered from some of the most severe earthquake disasters in the world [2]. For example, the Wenchuan earthquake in 2008 caused 69,227 deaths, 374,643 injuries, 17,923 missing people, and more than 10,000 square kilometers of severe damage [3]. A method for the accurate short- and medium-period prediction of earthquakes has not yet been discovered. Earthquake emergency response and rescue is an important means by which mitigation of such disasters can take place after an earthquake, and the effectiveness of this system has often been verified [4]. After the occurrence of an earthquake, maps that include information pertaining to an earthquake and the associated possible disaster can provide a foundation for effective emergency search and rescue, and therefore play an important role in the emergency response and rescue process. These maps are therefore essential thematic maps that display the various types of information needed for earthquake emergency command and rescue. Earthquake emergency maps are important to the leaders of rescue operations and the staff members of governments. These individuals can intuitively understand the information regarding an earthquake disaster, and carry out rescue operations in a timely manner [5]. The three days following an earthquake are known as the “golden period of emergency rescue”; after this time the number of dead sharply increases [6,7]. In China, the government needs approximately 24 h to collect and send emergency rescue materials to a disaster area, which is usually located in the mountain regions of Southwest China. This means that the governmental lead needs to make rescue decisions within half a day following an earthquake. In such a situation, emergency maps that include useful information are crucial in aiding such decision-makers. However, the means by which useful maps in earthquake emergencies can be produced in an effective manner is challenging. Two questions concerning earthquake emergency mapping are discussed in this paper. Many people are involved in emergency response and rescue.

1- Introduction

2- Geological setting

3- Methods and data

4- Field observations

5- Discussion

6- Conclusions

References

Abstract

A speleoseismological study has been conducted at over a dozen cave sites along the Longmen Shan fault zone of the eastern Qinghai-Tibet Plateau. The aim was to assess the damage inflicted on speleothems by the Mw 7.9 Wenchuan earthquake. Results show that the earthquake led to either partial or complete collapse of the caves. ‘Soda straws’ are shown to be particularly vulnerable to earthquake damage, but statistical analyses indicate that the spindle and slender shapes are also very likely to break. Cave depth is also shown to play an important role in the fracture development during the earthquake. The measured orientations of fallen stalactites are preferentially aligned to the coseismic surface offset peaks and therefore to the direction of earthquake wave propagation. Several such damaged speleothems resulting from sudden co-seismic movements were observed. The direction of ceiling (hanging wall) movement caused by the Wenchuan earthquake is NW-NNW, consistent with block motion on the footwall of the Yingxiu-Beichuan fault. We inferred that the faults in the caves were not co-seismic structures of the Wenchuan earthquake; but instead they are likely normal faults as the result of gravity creeping induced by the earthquake.

Introduction

Speleothems are cave deposits forming from dripping of mineral -rich water. They are quite common in karst landforms and include stalagmites, stalactites and flowstones , etc . Speleothems are usually regarded as good proxies for high -resolution palaeoclimatic reconstructions, in that carbon and oxygen isotopes preserved in speleothems document climatic oscillations throughout the Quaternary (Wang, 2001; Tan et al., 2006; Fairchild et al., 2006; Calaforra et al., 2008; Sorin et al., 2010) . In tectonically active regions , deposition of speleothems is sometimes interrupted by earthquake s , forming damaged speleothems that are usually called as speleoseismites. Therefore, speleothems have also been used for palaeoseismi c research (Forti, 2001; Lacave et al., 2004; Kagan et al., 2005) and a concise overview of this topic has been given by Forti and Postpichl (1984) and Becker et al., (2006) . Earthquake -related speleoseismites include deformed (broken or offset) (stalactites and stalagmites) (Lemeille et al., 1999; Delaby, 2001; Šebela, 2008) , irregular stalagmite growth (Postpischl et al., 1991; Forti, 2001; Shao et al., 2014; Rajendran et al., 2016) , cave sediment deformation, rock falls in cave s , fault displacement in cave walls and ceilings (Becker et al., 2006; Forti, 2007; Camelbeeck et al., 2012; Camelbeeck et al., 2018) , and the termination and re -initiation of stalagmite growth (Panno et al., 2009; Shao et al., 2014; Panno et al., 2016) .

A combination of Geological mapping and two-dimensional electrical resistivity (2D-ER) surveys was applied to study the Unilorin Dam and its environment. The purpose of the study was to investigate the dam for structural anomalies that may compromise the purpose and safety of the dam. Field equipment for the study comprised a SuperSting R8/IP Multi-Electrodes Resistivity Meter, 84 metallic electrodes and the accessories, compass clinometer, and portable GPS equipment. Geological data were processed and plotted to obtain a Geological Map and Rosette Diagram that were used for structural interpretations. The structures interpreted include an asymmetric fold and a strike-slip fault. The 2D resistivity data were processed and tomographically inverted to obtain the resistivity models of the subsurface around the dam. Interpretations of 2D resistivity models showed that the dam reservoir floor is underlain by competent basement rocks, however, the basement rock is weathered in some places. Patches of low resistivities structures interpreted as seepages, fractures and water-saturated cavity were delineated in different sections of the dam. The surface structural elements from geological study support the subsurface structures interpreted in the 2D resistivity models. Weathered structures, fractures, and seepage in the reservoir floor constitute areas of excessive water loss in the dam. The cavity delineated in the dam foundation is a potential threat to the dam’s safety. The dam section with cavity has been referred to structural engineers for detailed study.

Introduction

Safety assessment test on civil engineering constructions such as dams, tunnels, and bridges is a necessary endeavor to forestall sudden failure and collapse of engineering infrastructure. The mechanical properties of old dams that have outlived their life span, or new dams affected by natural hazards might have suffered degradation that can cause some structural damages that may not be obvious on the surface. If such damages are not detected by routine safety checks and addressed in good time, it may deteriorates and consequently lead to the failure of the dam. A dam is a barrier constructed to slow down, direct, or obstruct the free flow of water. The purpose of dam construction includes irrigation, supply of water for human and industry uses, hydro-electric power generation, control of flood, fish rearing, recreation, and navigation (Biswas and Charttergee, 1971; Plata and Iragüen, 1992). In addition to water scarcity, dam failure can lead to flooding and monumental loss of lives and properties. The old method of dam testing for structural damages include drilling and sample testing. Usually, 250–300 mm hole(s) is drilled in some parts of the dam and the samples collected are structurally examined and tested in the laboratory. Despite the cost and time required, drilling provide limited information on the possible structural anomalies/damages in dams (Kepler et al., 2000).

This study aims to address how the 2008 Wenchuan Earthquake influenced knowledge generation and diffusion compared to the research stemming from the 1989 Loma Prieta Earthquake in the United States and the 1995 Hanshin Awaji Earthquake in Japan, for the three countries are exposed to high seismic risk. The findings show that (1) regarding research quantity, the influence of the Wenchuan Earthquake on disaster-related knowledge generation is just beginning compared with the gradual decreases in research on the other earthquakes; (2) regarding disciplinary development, the proportion of studies relating to the Wenchuan Earthquake in natural sciences and engineering technology is gradually decreasing, while the proportion of studies in medical science, social sciences and economics is increasing; (3) the quantity of earthquake-related studies is not solely related to the influence of a specific disaster but associated with the national financial support offered by the affected country. One reason why China experiences the high research output is that Chinese national finance strongly supports such research, similar to the United States and Japan. This phenomenon corresponds with the fact that the major research institutions in China are national institutions rather than universities. Finally, (4) interdisciplinary research on the Wenchuan Earthquake mainly involves interactions between natural sciences and engineering technology. Interactions between other disciplines need to be enhanced. Thus, this research argues that, although disaster knowledge generation and diffusion is imbalanced, the multidimensional nature of earthquakes has been recognized in the literature.

Introduction

The Sendai Framework for Disaster Risk Reduction 2015–2030 addresses knowledge-related issues and highlights the critical role knowledge plays in disaster risk reduction (UN, 2015). Knowledge of disaster risk in all its dimensions, such as vulnerability, capacity, hazard characteristics and the environment, can be leveraged for disaster risk assessment, prevention and mitigation, and for the development and implementation of effective response to disasters. Earthquakes, though rare and interruptive, trigger waves of learning, as they expose weaknesses and reveal previously unrealized potentials for change (Christianson et al. 2009). However, less knowledge has been generated from earthquakes than from other natural disasters (Housner, 1983). To address this gap, Liu et al. (2012) applied bibliometric methods to identify developments in disaster research. This study demonstrated that the quantity of disaster research has grown, including interdisciplinary research on the subject. Research in this area has focused on evolution, California, deformation, model, inversion, seismicity, tectonics, crustal structure, fault, zone, lithosphere, and attenuation. The Elsevier (2017) report on global disaster science demonstrated that research is increasingly focused more on prevention and preparedness and less on recovery. Countries’ scholarly output is also related to the disasters they face; for instance, Japan has more research focused on earthquakes and Tsunamis, the US on meteorological and biological disasters, Brazil and India on environmental disasters, and China on meteorological disasters.

Introduction

Structural control systems can be used in modern engineering practice to protect structures from destructive effects of earthquakes. Structural control systems are mainly categorized as passive, active, semi-active, and hybrid systems. The basic concept of passive control systems is to lower the effective earthquake forces by elongating the fundamental period of the structure, thereby, lowering both the floor accelerations and the inter-story drift ratios to keep them within desired limits. The main challenge that such systems face is the large displacement requirements of the isolation system in case of nearfault earthquakes [1], which may exceed practical and economical limits [2]. Such large base displacements may even exceed the seismic gap, thus, posing serious risks [3]. Providing high passive isolation damping may be of help but such a solution may cause increase in floor accelerations and inter-story drifts depending on the earthquake characteristics [4]. Various other studies [1,5–7] also revealed that additional damping that is necessary for controlling base displacement may not guarantee good performance in structural response under the near-fault earthquakes, which would be a problem for missioncritical buildings such as hospitals that house vibration-sensitive contents [2,8]. Thus, active or semi-active isolation systems that can adapt to earthquake excitations of different frequency contents are necessary. Although active control systems are effective, they require very high power to operate [9,10]. Moreover, adding mechanical energy actively to the building may cause stability problems to the structure [11–13]. These drawbacks increase the interest in semi-active control systems, which can provide the proper amount of damping without causing any stability problems. Also, they need much less power to operate than the active control systems [12,13]. Symans et al. [14] showed that both isolation displacement and superstructure response can be limited by such adaptive base isolation systems. Likewise, [15–17] confirmed that the safety performance of a seismic isolation system that is equipped with semi-active dampers are quite high and it is effective in simultaneously limiting both base displacement and superstructure responses. On the other hand, it is known that the mechanical properties of isolators can vary due to the variation in temperature, ageing, contamination, or scragging [18–20]. Likewise, the mechanical properties semi-active control devices can vary. Researchers [18,19,21] have evaluated the effect of variability in passive isolation system parameters on the response of superstructure. The results emphasized the significance of variability of these parameters on the response of isolated buildings. At this point, it can be said that probabilistic seismic risk analysis, which takes such uncertainties into account, is the best method for determining the realistic seismic performance of seismically isolated buildings equipped with semi-active control systems. Due to the difficulty of describing the probabilistic characteristic of the whole problem analytically, the Monte-Carlo Simulation technique can be used as a convenient alternative. It is an accurate method for conducting safety and reliability analysis [22] that is based on mathematical modeling and recursive computer analysis in which the uncertainty is taken into account by defining random variables to follow certain probabilistic distributions.