bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring Regional Drainage with Ecosystem Service in Taiwan
Authors: Fu Yu-Min , Hsu Yu-Chen , Huang Hung-Pin
Published: March 2020

In Taiwan, the regional drainage is the system of two or more of urban, agricultural and enterprise drainages. Communities locate in or around the urban river, farmland or estuary are significantly involved in four services of ecosystem services. From 2016, central government forced each public construction project has to implement ecologic check work. However, these check work did not yet follow the idea of ecosystem services so that the operation of public construction projects in these two years could not reach the target completely. This study introduces the idea of ecosystem services into the ecologic check work of regional drainage projects to explore the feasibility of selected parameters in ecosystem services.          

This study refers to ecosystem service strategies such as the Millennium Ecosystem Assessment (MEA, 2005), the Economics of Ecosystems and Biodiversity (TEEB, 2010) and the Common International Classification of Ecosystem Services (CICES, 2017), considering the extensiveness, feasibility, and regional characteristics of regional drainage for ecosystem services. In addition, this study designs two checklist forms for master plan and project, respectively. After implementing ecologic check work for three cases in Taiwan, the result explores the feasibility of ecosystem services in regional drainage system.   
Rhizosphere effect of woody plants: A meta-analysis
Authors: Gan Dayong , Feng Jiguang , Zhu Biao
Published: March 2020

Interactions among plants, soil and microbiota play an important role in maintaining the function of terrestrial ecosystems, which often occur in rhizosphere. The rhizosphere effect is defined as the difference in soil properties and biogeochemical processes between rhizosphere and root-free bulk soil. Despite its importance in controlling soil biogeochemical cycling, quantitative assessments of the rhizosphere effects of woody plants are still rare. In this study, we synthesized the rhizosphere effects of woody plants on soil physicochemical properties, microbial biomass and community structure, enzyme activities, and carbon (C) and nitrogen (N) mineralization rates. We also explored the controls of rhizosphere effects by functional traits (eg. leaf life form, mycorrhizal type), environmental and experimental variables (eg. soil sampling method).

Our results showed that the rhizosphere effects on most soil physicochemical variables were positive (except pH). For example, the rhizosphere stimulated C mineralization rate by 56.7%, gross N mineralization rate by 57.9%, and net N mineralization by 60.9% on average compared to the root-free bulk soil. Moreover, for enzyme activities and C mineralization rate, the rhizosphere effects were generally higher in shrubs than in trees. For C mineralization rate, the rhizosphere effects of evergreen species were stronger than those of deciduous species. However, the rhizosphere effects did not vary significantly between species associated two mycorrhizal types (arbuscular mycorrhizal, AM vs. ectomycorrhizal ECM), with few exceptions for NO3-, NH4+, bacteria and fungi biomass. Overall, this meta-analysis comprehensively assessed the rhizosphere effects of woody plants (187 species and 29 variables) on global scale and strengthened our understanding of the effect of living roots on soil C and nutrient cycling in the rhizosphere.
Log-log linearity of the asymptotic distribution - a valid indicator of multi-fractality?
Authors: Bossew Peter
Published: March 2020

The asymptotic shape of the marginal frequency distribution of geochemical variables has been proposed as indicator of multi-fractality. Transition into a certain statistical regime as inferred from the distribution function may be considered as criterion to delineate geochemical anomalies, including mineral resources or pollutants such as radioactive fallout or geogenic radon.

The argument is that asymptotic linearity in log-log scale, log(F(z)) = a - b log(z) as z→∞, b>0 a constant, indicates multi-fractality.

We discuss this with respect to two issues:

(1) What are the consequences of estimating the slope b for non-ergodic, in particular non-representative and preferential sampling schemes, as often the case in geochemical or pollution surveys?

(2) Frequently in geochemistry, multiplicative cascades are considered valid generators of multifractal fields, corroborated by observed f(α) functions and variograms (Matèrn or power, for low lags). This generator leads to marginally asymptotically (high cascade orders) log-normal distributions, which in log-log scale are asymptotically (high z) parabolic, not linear.

Theoretical aspects are addressed as well as examples given.
Climate Change, Traditional Life Styles and Livelihood Questions: Socio-cultural and Physical Constraints of Remotely Located Societies of Western Himalaya.
Authors: Negi Virender Singh
Published: March 2020

Himalaya presents a great range of lifestyle and livelihood base to its native communities. The extreme climatic condition imposes a restriction on the living conditions, local ownership, alternative sources of income, women's empowerment, and long-term sustainable livelihoods are main elements of community work. But improvements in communication and transportation system have improved the lifestyle of the people living in those regions. The breadth of natural biodiversity in the Himalayas is complemented by a rich mosaic of cultures, traditions and people. But the ethnic groups living in remote valleys of the Himalayan region have generally conserved their traditional cultural identities. Ancient traditions and livelihoods of many communities remain woven into the balanced use of natural resources. They depend on these resources for their livelihoods, and value ecosystem services such as freshwater, erosion control, and agricultural and subsistence harvests.

Forests are strained as demand continues to grow for timber and food crops. Himalaya’s communities have suffered a disastrous slump in production due to erratic weather in recent years, but the government is helping out with various insurance and relief scheme. For such remotely located communities of this part of Himalaya agriculture, nomadic herding, hunting and gathering are the main activities of the people who are unable to fulfil their basic requirements. The present paper investigates factors that have brought about physical and socio-economic changes in various parts of Indian region of Himalayas, interlinked with the fragile Himalayan environment by mapping, monitoring and change analysis with the help of remote sensing and GIS techniques.
Western Pacific marginal basin plate tectonics: overview, questions, and insights from mantle structure
Authors: Wu Jonny , Suppe John
Published: March 2020

The western Pacific marginal basins are a collage of plates and marginal seas that primarily formed in the Cenozoic and occupy the complex tectonic area between the converging major Eurasian, Indo-Australian and Pacific plates.  Strongly contrasting plate tectonic reconstructions continue to be proposed for this region.  Here we review current plate models, key questions, and highlight recent insights from mantle structure studies. 

The Philippine Sea plate (PSP) is one of the largest marginal seas in the region.  The plate is currently moving WNW, in a similar orientation to the Pacific and Caroline plates.  Multiple studies show that PSP plate tectonics are key to unravelling the history of the region, for several reasons: (1) the PSP is far-travelled; paleomagnetism indicates relatively rapid (5.5 cm/yr) PSP northward motions since the Eocene from a near-equatorial latitude; (2) PSP tectonic histories imply interactions with many surrounding plates and regions, including the South China Sea (SCS), Taiwan, Japan, the western Pacific, and other smaller plates or fragments (i.e. Luzon or Celebes Sea); (3) the pre-subduction size of the PSP is not well-established because most of the plate is surrounded by subduction zones.  We review recent studies that attempt to ‘unsubduct’ the PSP from tomography and discuss their regional implications.

Another key but highly controversial topic is South China Sea (PSCS) formation and associated proto-South China Sea (PSCS) disappearance, if such a plate had existed.  The most popular proto-South China Sea plate model invokes southward subduction of the proto-South China Sea beneath NW Borneo during the Cenozoic.  Although southward PSCS subduction is most consistent with our current geological understanding, the regional mantle structure does not easily fit with this model; other scenarios may be possible.  In particular, it has not been straightforward for the southward PSCS model to explain the origin of sub-horizontal slabs under the present SCS at relatively shallow (500 to 800 km) depths.  We show an alternative ‘double-sided’ PSCS subduction model that produces testable hypotheses for future NW Borneo studies. 

Finally, the Caroline Sea plate has an enigmatic history but is important for understanding the southern Marianas, Yap and Palau trenches.  We first review previous evidence for a ‘Caroline hotspot track’ and overlapping LIPs that traverse the northern Caroline plate.  We link these features to an imaged lower mantle plume and show their implications for Caroline-Pacific plate motions since the latest Eocene. 
A New Approach to Monitoring the Interplanetary Shock Induced Pulse: TEC Measurements by the GNSS Receiver Network
Authors: Chen Xingran , Li Quanhan , Zong Qiugang , Hao Yongqiang
Published: March 2020

We revisit the typical interplanetary shock event on November 7, 2004, with high resolution total electron content (TEC) measurements obtained by the distributed Global Navigation Satellite System (GNSS) receivers. TEC impulses were observed after the IP shock impinged on the dayside agnetosphere at ~18:27 UT. In view of the similarity of the wave form and the time-delay characteristics, the TEC impulses were regarded as responses to the IP shock, despite the small amplitude (in the order of 0.4 TECU). Particularly, the peak of the TEC impulse was first observed by the receivers located around 120°W geographic longitude (corresponding to noon magnetic local time), while receivers at both sides recorded the impulse sequentially afterwards. From the timedelay of the TEC impulse, we derive the propagation velocity of the shock induced pulse. The angular velocity of the pulse is estimated to be ~2 degree per second, which is in the same order as the propagation speed of a typical shock pulse in the magnetosphere. Our results present global observational features of the shock pulse and provide new aspects to understand the ionospheric-magnetospheric dynamics in response to IP shocks.
Documentary evidence of historical floods in lowland Romania during the last millennium
Authors: Badaluta Gheorghe , Badaluta Carmen - Andreea , Ionita Monica , Mindrescu Marcel
Published: March 2020

Floods are among the most destructive natural hazards which affect socio-economical systems. Flood occurrence is considered to be a sensitive indicator of climate variability and is related in particular with changes in atmospheric circulation modes. One of the best archive of the floods evidence are historical documents. In this study we present 1000 years of floods reconstruction, which are some of the most frequent and well documented hazards in lowland areas of Romania. Our investigation spans over three distinct periods: the Medieval Warm Period (MWP), the Little Ice Age (LIA) and the Modern Period (MD), respectively, and it’s the longest one, on record, over this area. In total, we extracted 191 flood events which occurred in 167 years. Of 191 flood events, 16 occurred in winter, 34 in spring, 76 in summer, 18 in autumn, whereas for 47 flood events the season was not specified. The results show three periods of increasing floods activity during the Late Medieval Warm Period, middle part of LIA (between AD 1550-1750) and the entire Modern Period. A small increase in the number of flood events was observed during the MWP with an occurrence rate slightly higher than 0.15/year. The highest flood occurrence rates have been documented during LIA (i.e. 16th and 17th centuries) with an increasing trend of up to ~ 0.4/year. The majority of these events were recorded in summer and were typically generated by heavy thunderstorms. Moreover, the rising temperatures of MD were reflected in the increasing flood occurrence rates of up to 0.39/year. In conclusion, our 1000-year long reconstruction of past flood events could bring a major contribution to the knowledge of hydro-meteorological events of Central Eastern Europe and may be used as an indicator for assessment of floods hazards and for predicting the influence in future, in the context of ongoing climatic changes.
Seismic evidence for residual mantle underplating the lithosphere beneath the Ontong Java Plateau
Authors: Isse Takehi , Suetsugu Daisuke , Ishikawa Akira , Shiobara Hajime , Sugioka Hiroko , Ito Aki , Kawano Yuki , Yoshizawa Kazunori , Ishihara Yasushi , Tanaka Satoru , Obayashi Masayuki , Tonegawa Takashi , Yoshimitsu Junko
Published: March 2020

The Ontong Java Plateau (OJP), one of the largest oceanic plateaus located in the western Pacific Ocean, was first formed by a massive volcanism at 122 Ma, which had a major effect on the Earth's environments, including global climate change, oceanic anoxic events, and mass extinction of marine life. However, the cause of the volcanism remainscontroversial since the underground structure beneath the OJP has been poorly understood due to limited geophysical and geochemical data. To improve such situation, we conducted about 1.6-year long-term seafloor observation on the OJP and its vicinity. Using seismograms obtained by this observation as well as those from existing seismic stations, we obtained three dimensional radially anisotropic shear wave velocity structure beneath the OJP at depths down to 300 km.

Obtained structure shows the following new features:

(1) Beneath the Caroline Islands, in the north of the OJP, 1 % slow anomalies exist, which may be associated with the Caroline hotspot activity;

(2) In the center of the OJP at depths between 70–130 km, about 2% fast anomalies, whose shear wave speed is about 4.45-4.55 km/s, exists.

(3) The seismic structure clearly shows that the lithosphere–asthenosphere boundary (LAB) beneath the center of the OJP is located about 40 km deeper than that beneath the surrounding normal oceanic seafloor.

Judging from our results and petrological/rheological constraints given by previous studies, we interpret that the LAB is deepened by dehydrated residual material from hot mantle plume underplating a pre-existing lithosphere during a formation of OJP.
Early and late Holocene paleoenvironmental reconstruction of the Pearl River estuary, South China Sea
Authors: Chen Huixian , Wang Jianhua , Khan Nicole S. , Wu Jiaxue , Horton Benjamin P.
Published: March 2020

Proxy reconstructions of estuarine evolution provide perspectives on regional to global environmental changes, including relative sea-level changes, climatic changes, and agricultural developments. Although there are studies of the Holocene sedimentary processes in the Pearl River estuary, the understanding of early Holocene sedimentation in unknown due to limited preservation.

Here, we present a new record of lithological, benthic foraminiferal, and geochemical (δ13C and C/N) change from a sediment core in the west shoal of the modern Lingding Bay along a paleo-valley. The lithologic and foraminiferal record reveal the transgressive evolution from fluvial, inner estuary to middle estuary in the early Holocene between 11300 and 8100 cal a BP in response to rapid sea-level rise. δ13C and C/N data indicate high freshwater discharge from 10500 to 8100 cal a BP driven by a strong Asian monsoon. The middle Holocene (8100 - 3300 cal a BP) sediment is absent in this core and others in the northward of the Lingding Bay. Seismic profiles reveal a tidal ravinement surface across Lingding Bay, which contributed to subaqueous erosion on the mid-Holocene sedimentation hiatus, might be resulted from unique geomorphology of the Pearl River Delta. In the late Holocene (3300 cal a BP to the present), the lithology and foraminiferal assemblages suggest further regressive evolution from outer estuary, middle estuary channel, to middle estuary shoal due to deltaic progradation under stable relative sea levels. In the last 2000 years, δ13C and C/N values reveal the intensive development of agriculture coupled with the reduction of freshwater input derived from a weakening Asian monsoon. Our study illustrates the interaction of Asian monsoon and sea-level changes within the Pearl River estuary landform and their impact on Holocene sedimentary processes.
A reconstruction of the East Asian summer monsoon index over the half past millennium
Authors: Shi Feng , Goosse Hugues , Li Jianping , Ljungqvist Fredrik Charpentier , Zhao Sen , Liu Ting , Yin Qiuzhen , Guo Zhengtang
Published: March 2020

The EASM largely determines variations in summer precipitation in the East Asian monsoon region where approximately one-quarter of the world’s population live. A reliable East Asian summer monsoon (EASM) index covering several centuries is important in order to understand EASM dynamics. The wind-field is frequently used to calculate the EASM index during the instrumental period. However, available climate proxy data rather respond to direct precipitation changes. A gridded extended summer (May–September, MJJAS) precipitation reconstruction for China covering AD 1470–2000 is used to indirectly reconstruct two types of EASM indices (defined by the strength of the 850hPa southwesterly winds and a north-south gradient of the zonal winds), using the negative correlation between the EASM index and summer (June–August, JJA) rainfall in the middle and lower reaches of the Yangtze River of China. The two EASM indices are validated by independent historical documentary data for eastern China. The physical processes ruling the EASM variability are explored, highlighting a baroclinic structure over the middle and lower reaches of the Yangtze River. It includes an anticyclonic circulation accompanied by high pressure anomalies in the lower troposphere and a cyclonic circulation with low pressure anomaly in the upper troposphere. This is associated with a decrease in atmospheric water vapor content (due to divergence), which will decrease summer rainfall in the region, and contribute to the strengthen of the EASM variability. The dominated and inter-annual component of the EASM variation is possibly linked to the ‘ENSO-like’ sea surface temperature according to a data assimilation experiment performed with the Community Earth System Model-Last Millennium Ensemble (CESM-LME) simulation.
Predictability of estuarine model using Information Theory: ROMS Ocean State Ocean Model
Authors: Sane Aakash , Fox-Kemper Baylor , Ullman David , Kincaid Christopher , Rothstein Lewis
Published: March 2020

With a focus on modelling physical aspects of estuaries covering Rhode Island, USA, the Ocean State Ocean Model (OSOM) has been implemented using the Regional Ocean Modeling System. The estuary includes Narragansett Bay, Mt. Hope Bay, and nearby regions including the shelf circulation from Long Island to Nantucket. Our goal is to find predictability and estuarine time scales in order to build a forecasting system 

 

Perturbed ensemble simulations with altered initial condition parameters (temperature, salinity) are combined with concepts from Information Theory to quantify the predictability of the OSOM forecast system. Predictability provides a theoretical estimate of the potential forecasting capabilities of the model in the form of prediction time scales and enhances readily estimable timescales such as the freshwater/ saline water flushing timescale. The predictability of the OSOM model is around 10-40 days, varying by perturbation parameters and season. Internal variability is low when compared to forced variability for the current resolution of OSOM suggesting modest chaos at this resolution.

 

Freshwater flushing time scale and total exchange flow was calculated for the OSOM model. The freshwater flushing time scale was found to be ~20 days and varies with the choice of the estuary boundary. The predictability time scales and flushing time scales reveal important dynamics of the tracers involved and elucidate their role in driving the estuary.  
Surface topography effects on seismic ground motion and correlation with earthquake-induced landslide: An example of the JiuJiu peaks in 1999 Chi-Chi Taiwan earthquake
Authors: Chen Chun-Te , Lee Shiann-Jong , Chan Yu-Chang
Published: March 2020

The topography effect has been thriving investigated based on numerical modeling. It impacts the seismic ground shaking, usually amplifying the amplitude of shaking at top hills or ridges and de-amplifying at valleys. However, the correlation between the earthquake-induced landslide and the topographic amplification is relatively unexplored. To investigate the amplification of seismic response on the surface topography and the role in the Chi-Chi earthquake-induced landslide in the JiuJiu peaks area, we perform a 3D ground motion simulation in the JiuJiu peaks area of Taiwan based on the spectral element method. The Lidar-derived 20m resolution Digital Elevation Model (DEM) data was applied to build a mesh model with realistic terrain relief. To this end, in a steep topography area like the JiuJiu peaks, the designed thin buffer layers are applied to dampen the mesh distortion. The three doubling mesh layers near the surface accommodate a more excellent mesh model. Our results show the higher amplification of PGA on the tops and ridges of JiuJiu peaks than surrounding mountains, while the de-amplification mostly occurs near the valley and hillside. The relief topography could have a ±50% variation in PGA amplification for compression wave, and have much more variety in PGA amplification for shear wave, which could be in the range between -50% and +100%. We also demonstrate that the high percentages of the landslide distribution right after the large earthquake are located in the topographic amplified zone. The source frequency content interacts with the topographic feature, in general, small-scale topography amplifies the higher-frequency seismic waves. It is worthy of further investigating the interaction between the realistic topography and the velocity structure on how to impact the seismic response in the different frequency bands. We suggest that the topographic seismic amplification should be taking into account in seismic hazard assessment and landslide evaluation.
The characteristics of the mid-depth striations in the North Indian Ocean
Authors: Du Yan , Xia Yifan , Qiu Bo , Cheng Xuhua , Wang Tianyu , Xie Qiang
Published: March 2020

Argo trajectory data is used to estimate the velocities of mid-depth (1000db) currents in the North Indian Ocean (NIO). Based on these estimated velocities rather than an assumed level of “no motion”, the structure of upper ocean absolute geostrophic currents can be derived more accurately from the Argo temperature and salinity profiles. The derived flow field reveals that eastward zonal velocities have a striation-like structure in the Arabian Sea, while barely observed in the Bay of Bengal. The striation-like structure is most prominent in the layer from 500db, with a meridional scale of about 300km. Both the meridional scale and the distribution of these mid-depth striations are unique as compared to the other ocean basins. The nonlinear 1 1/2 -layer reduced gravity model and the baroclinic Rossby wave triad interaction theory capture the essential factors controlling the characteristics of the quasi-zonal striation structure. Compared to the Pacific Ocean, the narrower meridional scale in the NIO is because of the smaller basin scale in the equatorial zone rather than semiannual wind stress forcing period or slope of the eastern boundary. Coastal trapped Kelvin waves contribute significantly to the generation of the zonal striation in the Arabian Sea.
Permeability contrasts of fault zones - from conceptual model to numerical simulation
Authors: Kelka Ulrich , Poulet Thomas , Peeters Luk
Published: March 2020

Fault and fracture networks can govern fluid flow patterns in the subsurface and predicting fluid flow on a regional scale is of interest in a variety of fields like groundwater management, mining engineering, energy, and mineral resources. Especially the pore fluid pressure can have a strong impact on the strength of fault zones and might be one of the drivers for fault reactivation. Reliable simulations of the transient changes in fluid pressure need to account for the generic architecture of fault zones that comprises strong permeability contrast between the fault core and damage zone.

Particularly, the distribution and connectivity of large-scale fault zones can have a strong impact on the flow field. Yet, modelling numerically such features in their full complexity remains challenging. Often faults zones are conceptualized as forming exclusively either barriers or conduits to fluid flow. However, a generic architecture of fault zones often comprises a discrete fault core surrounded by a diffuse damage zone and conceptualizing large scale discontinuities simply as a barrier or conduit is unlikely to capture the regional scale fluid flow dynamics. It is known that if the fault zone is hosted in low-permeability strata, such as clays or crystalline rocks, a transversal flow barrier can form along the fault core whereas the fracture-rich fault damage zone represents a longitudinal conduit. In more permeable host-rocks (i.e. sandstones or carbonates) the reverse situation can occur, and the permeability distributions in the damage zones can be governed by the abundance of low-permeability deformation features. A reliable numerical model needs to account for the difference and strong contrasts in fluid flow properties of the core and the damage zone, both transversally and longitudinally, in order to make prediction about the regional fluid flow pattern.

Here, we present a numerical method that accounts for the generic fault zone architecture as lower dimensional interfaces in conforming meshes during fluid flow simulations in fault networks. With this method we aim to decipher the impact of fault zone architecture on subsurface flow pattern and fluid pressure evolution in fractures and faulted porous media. The method is implemented in a finite element framework for Multiphysics simulations. We demonstrate the impact of considering the more generic geological structure of individual faults on the flow field by conceptualizing discontinuities either as barriers, conduits or as a conduit-barrier system and show were these conceptualizations are applicable in natural systems. We further show that a reliable regional scale fluid flow simulation in faulted porous media needs to account for the generic fault zone architecture. The approach is finally used to evaluate the fluid flow response of statistically parameterised faulted media, in order to investigate the impact and sensitivity of each variable parameter.
Flow simulation in karst regions from the scale of single aquifers to entire continents
Authors: Liu Yan , Wagener Thorsten , Hartmann Andreas
Published: March 2020

Large-scale hydrological models have been widely used for water resources management, such as studying human impacts (e.g., pumping and irrigation) on groundwater. Currently, most of these models do not explicitly include karst features for the recharge and groundwater simulations. However, the geological properties in karst regions substantially differ from non-karst areas, which makes recharge and groundwater flow behaviors distinctly different between the two types of systems. Due to challenges of combining karstic and non-karstic processes, of simulating inter-catchment groundwater flow, and of parameterizing karstification over large areas in karst regions, global karst groundwater flow models currently do not exist. In this study, we propose a general approach to integrate karstic and non-karstic processes and a hierarchical approach to confine the karstic groundwater flow parameters over large domains. First, we selected six karstic catchments (with different catchment sizes and climates) with adequate observations to test the combination of karstic and non-karstic simulations at the aquifer and catchment scale. We show that using system signatures helps to identify the necessary model structures and to integrate karstic and non-karstic processes. Second, we defined an Inter-catchment Groundwater Flow index (IGF) to quantitatively address groundwater flow crossing topographic boundaries. Third, we classify the level of karstification based on spring and catchment properties and evaluate different strategies for parameterization of karstic groundwater flow processes at varying degrees of karstification. Overall, our study provides a solid basis for a continental-scale karstic groundwater flow model, complementary to current global scale hydrologic modeling efforts where this process is still missing.
Study on Conversion Permission Standard based on Topographical and Ecological Indices in South Korea
Authors: Ha Siyeon , Kwak Dooahn , Choi Jungsun
Published: March 2020

Since 1970s, South Korea has been developed rapidly in the aspects of economy and industry over 40 years due to the Economic Development Plans led by the Korean government. Consequently, urbanization has been accelerated and the population then began to be flowed into major cities. In result, many parts of forestland in South Korea have been changed into urban areas by urban expansion and population migration under forestland conversion permission by South Korean Forestland Management Law. However, such permission standards cannot help being friendly to the development due to the line of national policy, and so several environmental problems, i.e., topographical and ecological changes, have been caused over couple of decades. In this study, therefore, we suggested new enhanced permission standards in terms of topographical and ecological protection in converted forestland. In Mountainous Districts Management Act of Korea Forest Service, slope and elevation criteria have been operated to regulate the indiscriminate use of risky land parcels when forestland is converted to other land use types. However, it is impossible to consider topographical variation with only such two indices in the land parcel because the indices values are averaged in each target parcel. Therefore, for supplementing insufficient criteria, the slope gradient by Catena was suggested by converted land use types. Furthermore, the ecological indices and criteria such as stand age, Diameter at Breast Height (DBH) and soil depth were considered in this study according to the forestland-watershed and –use types on converted target parcel. Firstly, we suggested flexible degree criteria by 14 land development types as topographical standards for forestland conversion. Secondly, the ratio of ‘risky slope’ below 40% in a target forestland parcel was defined to decrease the risk of disasters such as landslides. Thirdly, standard of ecological condition were proposed as ecological score by integrating stand age, DBH and soil depth classes in the target forestland parcels by 5 forestland-watershed and 14 land use types. As a result, we could prepare acceptable standards in South Korean that can reduce topographical and ecological damages by converting other land use type.
Lander Radioscience (LaRa) in ExoMars 2020 to obtain the rotation and orientation of Mars.
Authors: Dehant Véronique , Baland Rose-Marie , Le Maistre Sébastien , Karatekin Ozgur , Péters Marie-Julie , Rivoldini Attilio , Umit Ertan , Van Hoolst Tim , Yseboodt Marie , Folkner William M. , Kosov Alexander , team LaRa
Published: March 2020

The Lander Radioscience (LaRa) experiment on the ESA-Roscosmos ExoMars 2020 mission is designed to obtain coherent two-way Doppler measurements from the radio link between a lander on Mars and the Earth over at least one Martian year. The Doppler measurements will be used to determine the orientation and rotation of Mars in space (precession, nutations, and length-of-day variations). LaRa, on another location on the Martian surface with respect to the InSight mission could allow to observe the polar motion of Mars, in addition to further increase the accuracy on precession, nutation, and length-of-day measurements. The ultimate objective of LaRa is to obtain information on the Martian interior and about the sublimation/condensation cycle of atmospheric CO2. Concerning the nutations, a knowledge of the rigid body nutation can be computed and shall be used to constrain the interior properties of Mars.
An Archaeometric Characterization of Ancient Pottery from Huagangshan Site, Eastern Taiwan
Authors: Liou Ying San
Published: March 2020

Micro-Raman spectroscopy and petrographic analysis was carried out on ancient potsherds and sediments excavated from the Huagangshan site and river sediments collected from the northern part of eastern Taiwan. The ceramic fragments analyzed, dating back to 1600-2100 B.P., are recognized to be Early Metal Age of Taiwan. The aims of this study are mainly to identify the mineralogical compositions of ceramics, to explore technical processes such as firing temperature and redox state, and to decipher the nature of clays and its raw materials source.

The results of micro-Raman analysis for ancient potsherds show the presence of 12 minerals. Quartz, anatase, amorphous carbon, hematite, and pyroxenes are the main components of tempers. In addition, amorphous carbon and hematite are the main constitutes for black- and red- hues pottery, respectively. From the point of view of manufacturing techniques, a large amount of amorphous amorphous carbon indicates that the gray-black pottery is fired under a reducing condition. On the contrary, hematite reveals an oxidizing atmosphere for red-hues pottery. The presence of quartz and anatase implies that the firing temperature is estimated to be 750-950°C. A total of 66 samples, containing 23 ceramic fragments (local and imported products) and 6 sediment from cultural strata of archaeological site and 33 river sediments around the site, is implemented by petrographic analysis of thin sections. Petrographic analytic results of 23 potshards show that the proportion of clay is consistent (60.5~69.1%). The inclusions principally include quartz (polycrystalline and monocrystalline quartz), feldspar, muscovite, and volcanic, sedimentary and metamorphic lithic fragments, and quartz is the main component. In addition, the triangle map with ingredients (volcanic lithics+quartz－sedimentary lithics－metamorphic lithics) shows that the raw materials source of local and main stream pottery recognized by archaeologist is not local, but comes from a distance area (the Coastal Range). On the other hand, imported pottery indicates the raw materials source is indeed from the central and southern Central Range (some distance south of the site). The result further illustrates the vigorous exchange and/or trade activities between the populations of eastern Taiwan during the Early Metal Age (1600-2100 B.P.).
The impact of Ghislain de Marsily in Nuclear Waste Management
Authors: Bruno Jordi
Published: March 2020

In August 1977, Ghislain de Marsily published in Science an article with the provocative title: “Nuclear Waste Disposal: Can the Geologist Guarantee Isolation?", together with E. Ledoux, A Barbreau and J. Margat. It was a joint publication between Ecole de Mines de Paris, IPSN, CEA and BRGM and it could be pointed out as the foundation of the French Scientific programme regarding High Level Nuclear Waste (HLNW) Management . The paper explored the various alternatives regarding HLNW management and concluded that deep geological disposal was the most feasible alternative. The authors discussed also the key processes controlling radionuclide migration from a geological repository and concluded that retardation by rock sorption (ion-exchange) was the critical parameter, provided the rest of the waste and groundwater parameters were kept under reasonable values.

Since then and particularly in the 80’ and 90’s, Ghislain de Marsily has played a fundamental role in devising a strategy towards safe geological nuclear waste disposal in France, Europe and the rest of world. This, he has done by a combination of key scientific contributions as well as his participation in many scientific committees concerning HLNW management.

In my presentation I will discuss how the scientific, but also the personal contributions of Ghislain de Marsily helped to pave the way for the development of HLNW concepts and programmes all around the world.
Exploring elevation zone similarity in large case studies for the semi-distributed regionalisation of the HBV model parameters
Authors: Neri Mattia , Toth Elena , Parajka Juraj
Published: March 2020

The study aims to propose and test the performance of a group of techniques for transposing rainfall-runoff model parameters to ungauged catchments, especially adapted to the semi-distributed structure (the catchment is split into different altitude zones) of the HBV-based TUWien model.

The methods are tested for two large, but deeply different, datasets: the first is a very densely gauged set of more than 200 catchments across Austria, while the second refers to more than 500 US watersheds (part of the CAMELS dataset) covering most of the country, including wider variety of hydrological conditions and catchment characteristics.

The potential of the semi-distributed structure is fully exploited: first in the model calibration, where, differently from the typical application of the model, the parameters controlling the runoff generation are allowed to vary over the different elevation zones.

Secondly, in the regionalisation procedure, the parameters of each specific altitude zone in any ungauged catchment are estimated based on the parameters obtained for the same altitude zones of the donors. The rationale is to implement a procedure that operates at sub-basin level, in order to have a better simulation of the different hydrological processes taking place at different altitudes.

The set of regionalisation approaches includes both i) “parameters averaging”, where each parameter is obtained as a weighted (according to donors’ similarity) average of the parameters of the donor catchments (independently from each other) and ii) “output averaging”, where the model is run over the ungauged basin using the entire set of parameters of each donor basin and the simulated outputs are then averaged to estimate the target simulated streamflow.

The measure of similarity needed for implementing the regionalisation procedure is of course applied at sub-basin scale, testing geo-morphological and climatic catchment descriptors characterising the elevation bands. One of the main focus is the study of such similarity in order to asses which attributes are more influential at different altitudes.

The performance of the proposed approaches and similarity measures is assessed by jack-knife cross-validation against the observed daily runoff for all the study catchments.

Finally, the resulted regionalisation efficiencies are compared to those obtained by applying the same methods with the typical lumped calibration-regionalisation procedure, thus assessing the potential of the semi-distributed regionalised parameterisation.
Precise dating of centennial-millennial scale climate variations in sediment archives from the Antarctic continental margin off Dronning Maud Land by 14C plateau tuning
Authors: Tiedemann Ralf , Müller Juliane , Lembke-Jene Lester , Mollenhauer Gesine
Published: March 2020

Rapid changes in ocean circulation and polar temperature variability have been observed in glacial and deglacial paleoclimate records from marine and ice core archives. However, an obstacle to progress in understanding the ice-ocean-bedrock-climate interactions on centennial-millennial timescales is due to the paucity of sediment records with precise chronologies. The sediment archive along the continental margin of Dronning Maud Land provides an excellent opportunity for high resolution 14C dating as it contains sufficient amounts of planktonic foraminifers. We dated a 7 m long sediment sequence from core PS111/13 by means of 14C plateau tuning (Sarnthein et al., 2015) to produce a solid chronological framework for multi-proxy reconstructions of climate and environmental change from 7000 to 30,000 years that can be linked to ice core chronologies.

Sarnthein et al., Radiocarbon, 2015, 57 (1), 129–151.
Forecasting vegetation condition to mitigate the impacts of drought in Kenya.
Authors: Rowhani Pedram , Barrett Adam , Oliver Seb , Muthoka James , Salakpi Edward , Duivenvoorden Steven
Published: March 2020

Droughts are a major threat globally as they can cause substantial damage to society, especially in regions that depend on rain-fed agriculture. Acting early based on alerts provided by early warning systems (EWS) can potentially provide substantial mitigation, reducing the financial and human cost. However, existing EWS tend only to monitor current, rather than forecast future, environmental and socioeconomic indicators of drought, and hence are not always sufficiently timely to be effective in practice. In Kenya, the National Drought Management Authority (NDMA) provides monthly bulletins assessing food security in the 23 arid and semiarid regions using current biophysical (e.g., rainfall, vegetation condition) and socio-economic (production, access, and utilisation) factors. One key biophysical indicator used by the NDMA drought phase classification is based on the Vegetation Condition Index (VCI).

In this study we explore machine-learning techniques to forecast (up to six weeks ahead) the 3-month VCI, commonly used in the pastoral areas of Kenya to monitor droughts. we specifically focus on Gaussian Process modelling and linear autoregressive modelling to forecast this indicator, which are derived from both Landsat (every 16 days at 30m resolution) and the MODerate resolution Imaging Spectroradiometer (MODIS - daily data at 500m resolution).

Our methods provide highly skillful forecasting several weeks ahead. As a benchmark we predicted the drought alert marker used by NDMA (VCI3M< 35). Both of our models were able to predict this alert marker four weeks ahead with a hit rate of around 89% and a false alarm rate of around 4%, or 81% and 6% respectively six weeks ahead.

The forecasts developed here could, for example, help establish a new drought phase classification (`Early Alert') which, along with adequate preparedness actions developed by the disaster risk managers, would minimise the risk of a worsening drought condition.
Experimental study on longitudinal mixing in open channel flow with various vegetation patterns
Authors: Park Hyoungchul , Hwang Jinhwan
Published: March 2020

In natural streams, vegetation considerably has an influence on the flow characteristics in a variety of ways. For example, vegetation distorts flow structure in both lateral and vertical directions and changes the magnitude of turbulence and shear flow. Due to these effects, diluted contaminants in river transport and disperse differently. Accordingly, many previous researchers have investigated the impact of vegetation on the mixing process. Most of them have estimated the dispersion coefficient since this is the crucial parameter to quantify the degree of dispersion of contaminants numerically. They mainly studied in diverse characteristics of vegetation, such as density or submergence, etc., and identified the change in hydraulic parameters involving the dispersion coefficient.

In this work, considering the vegetation distributed in various forms in the natural river, we studied the effect of vegetation patterns on the longitudinal mixing coefficient. Six types of spatial patterns considered in this study are represented numerically by introducing the standardized Morisita index. Laboratory experiments with artificial emergent vegetation were performed in multiple vegetation patterns, and the longitudinal dispersion coefficient was estimated from the measured concentration curves by applying the routing technique. And we analyzed the cause of change in dispersion coefficient by calculating not only the dispersion coefficient but also the magnitude of mean velocity, shear flow, turbulence, etc.

According to the experimental results, the mean velocity in the vegetated channel is almost the same regardless of the type of pattern but is always lower than that in the non-vegetated channel. The longitudinal dispersion coefficient gets larger as the arrangement changes from uniform to 2D clumped pattern. The cause of change in coefficient is closely related to the spatial velocity gradients in both lateral and vertical directions since the spatial heterogeneity of velocity increases the magnitude of shear flow.
The ESA Sentinel Next-Generation Land & Ocean Optical Imaging Architectural Study, an Overview
Authors: Löscher Armin , Martimort Philippe , Jutz Simon , Gascon Ferran , Donlon Craig , Manolis Ilias , Del Bello Umberto
Published: March 2020

ESA initiated in 2018 an architectural design study to prepare the development of the next generation of the optical component of Sentinel 2 and Sentinel 3. This encompasses the next generation of the Multi Spectral Imager (MSI), Ocean and Land Color Imager (OLCI) and Sea and Land Surface Temperature Radiometer (SLSTR) observations. The aim of this activity was to analyse and trade-off different architectural options for the Next-Generation of the Copernicus Space Component optical imaging missions in the 2032 time horizon, considering user needs, addressing mainly the Copernicus Marine and Land services, starting from user requirements for Copernicus Next Generation derived from EC studies and related workshops. It also did draw from the experience and lessons learned regarding the current generation of Sentinel 2 and Sentinel 3, to ensure continuity of services and further enhancement as identified, necessary to meet new and emerging user needs. The study investigated also trends both in terms of other spaceborne optical missions by national agencies in Europe and worldwide, as well as commercial missions e.g. with the advent of “New Space” constellations of small satellites. Observation gaps and potential synergies were identified to avoid duplication when establishing the architecture of the next generation of the Copernicus Space Component optical imaging family for land and ocean applications. A wide range of scenarios have been analysed for possible combination of several observation capabilities within the same instrument, on the same platform or on satellites flying in formation, assessing pros and cons with respect to scenarios with free-flyer satellites for each observation capability. Based on the above analysis of user needs, gap/synergy analysis and architectural concept trade-offs, high level mission assumptions and technical requirements are being established for the continuity of the MSI, OLCI and SLSTR observations, including any additional elements, as identified, to meet user requirements in the respective Copernicus services and application areas.