Topographic Levels Research Articles

The role of bedrock and climate for the Late Quaternary erosive-depositional behavior of an intraplate tropical river: The Tietê River case, southeastern Brazil

The evolution of fluvial systems has been related to tectonics and climate controls across various spatiotemporal scales. Despite the growing efforts to investigate the effects of those controls in the fluvial dynamics, there is a lack of studies in intraplate tropical regions. Here, we applied geomorphological, sedimentological, and optically stimulated luminescence dating (OSL) techniques to investigate the effects of climate and tectonic factors on the evolution of the Upper and Middle Tietê River during the late Quaternary, especially concerning alluvial aggradation and terraces formation. The Tietê River is one of the most important rivers of southeast Brazil, flowing from crystalline steep to sedimentary low-relief intraplate terrains, in an area with evidence of Cenozoic tectonics and under tropical monsoon climate. We recognized one fluvial terrace level in the Upper Tietê valley and a sequence of seven terraces, from 2 to 105 m above the channel level, in the Middle Tietê. These terraces are formed by thin deposits (<10 m), composed of sandy and gravelly sediments. The terraces of the Upper Tietê and the high and intermediate terrace levels of the Middle Tietê River are strath, while the low terraces of the middle reach are cut-and-fill. Lithological shifts and structural features of the watershed terrain play a strong control in the occurrence and distribution of these terrace levels. The Serra de Paranapiacaba, a regional knickzone, hinders the lowering of the base level and the river incision to upstream, limiting the formation and preservation of terraces in high topographic levels in the Upper Tietê. The formation of seven terrace levels in the Middle Tietê River was controlled by the combination of low erosion resistance of the lithological substrate and high stream power and coarse bedload that increased the erosion efficiency of the channels. Thus, the influence of intraplate tectonics on the fluvial landscape is restricted to passive controls by exhumated basement structures from older tectonic events. OSL dating of sedimentary deposits in different terrace levels indicate five periods of aggradation in the Middle Tietê valley since 18 ka: 17.7 ± 1.7 ka; 9.8 ± 1.0 to 8.6 ± 0.8 ka; 7.1 ± 0.7 to 5.8 ± 0.5 ka; 4.2 ± 0.4 to 3.1 ± 0.3 ka; and 0.6 ± 0.06 ka. The results indicate that changes in the activity of the South American Monsoon System induced changes in vegetation cover and water discharge in the river valleys of southeastern Brazil over the past 18 ka. The aggradation periods are correlated with drier environmental conditions and sparser vegetation. In contrast, valley incision occurred under transitions to wetter environmental conditions and was potencialized by vegetation recovery. Therefore, climate-induced changes in the water discharge were the main allogenic control on the late Quaternary landscape evolution.

Soil conditions in the “donga” soils in subhumid zone in West Africa

Water erosion threatens large areas around the world. “Donga” is one of the witnesses of gully erosion in northern Benin, which induces serious threats to the natural habitats. This study was conducted to evaluate soil moisture content in different donga types (“microdongas”, “mesodongas”, and “megadongas”) and its variation at different topographic levels. The thermogravimetric soil moisture measurement technique was used for moisture estimation on saturated and unsaturated soil. Data were analyzed through analysis of variance test and t test with SAS software. The results showed that soil moisture content varied according to donga types. On unsaturated soil, higher difference (2.75%, p = 0.0328) was obtained in mesodongas at the middle followed by megadongas at the middle (2.6%, p = 0.034). On saturated soil, higher difference was obtained in mesodongas at the upstream (6.51%, p &lt; 0.0001) at downslope (4.55%, p = 0.0032) and in the middle (4.32%, p = 0.0328) followed by microdongas at the upstream (2.25%, p &lt; 0.0001). The findings in this paper should be useful to researchers looking for soil moisture information in subarid and subhumid zone at different topographic levels to develop afforestation strategies based on species that can make the best use of soil water.

Development and collapse of karstic cavities in folded marbles: Geomorphological and geophysical evidences in Nerja Cave (southern Spain)

Karstic evolution leads to the growth and collapse of cavities by the interaction between geological structures and the hydrogeological framework. Nerja Cave developed within marbles belonging to the Alpujarride complex of the Internal Zones in the Betic Cordillera of Spain. The residual gravity anomaly map of the karstified areas –surrounding the known Nerja Cave– may indicate a likely elongated parallel cave system, N-S oriented, unknown up to present, and formed by both small shallow and large deep caves below a nearby hill located north-westwards to the known cave. At the east hillside, a moderate gravity anomaly minimum and geomorphological evidence (vertical walls and sunken terrains) suggest the presence of an old collapsed cave. At the west hillside, a marked gravity minimum is associated with a strongly folded marble layer without evidence of collapse. An electrical resistivity tomography (ERT) profile across the hill –in the E-W direction– supports an interpretation of several voids, two of the bigger ones located on either side of the hill. The combination of geomorphological, ERT and gravity forward modelling indicate the location of unknown caves, one of them partially collapsed. These caves, located at a higher topographic level than the known Nerja Cave, may represent an early stage of cave development, and suggest the preferred dissolution of some layers in the folded marbles. This field example provides new insights on the interaction of structure in the karstic evolution that determines the cavity stability.

The matrix in cancer.

The extracellular matrix is a fundamental, core component of all tissues and organs, and is essential for the existence of multicellular organisms. From the earliest stages of organism development until death, it regulates and fine-tunes every cellular process in the body. In cancer, the extracellular matrix is altered at the biochemical, biomechanical, architectural and topographical levels, and recent years have seen an exponential increase in the study and recognition of the importance of the matrix in solid tumours. Coupled with the advancement of new technologies to study various elements of the matrix and cell-matrix interactions, we are also beginning to see the deployment of matrix-centric, stromal targeting cancer therapies. This Review touches on many of the facets of matrix biology in solid cancers, including breast, pancreatic and lung cancer, with the aim of highlighting some of the emerging interactions of the matrix and influences that the matrix has on tumour onset, progression and metastatic dissemination, before summarizing the ongoing work in the field aimed at developing therapies to co-target the matrix in cancer and cancer metastasis.

西北干旱区生态脆弱性时空演变分析

西部大开发政策实施以来，随着社会经济的发展和环境政策的调整，西北干旱区生态环境发生深刻变化。基于西北干旱区生态本底特征，选取土壤、地形、气候并结合夜间灯光数据构建西北干旱区生态脆弱性评价体系，运用空间主成分分析法（SPCA）、地理探测器对西北干旱区2000、2007、2012、2018年生态脆弱性时空演变及驱动力进行分析。结果表明：（1）从西北干旱区生态脆弱性时空演变特征来看，研究区生态脆弱性以重度脆弱性为主；从不同土地利用脆弱性来看，微度脆弱区以草地、林地为主，轻度脆弱区以草地为主，中度脆弱区和重度脆弱区以未利用地为主，18年来研究区生态脆弱性整体保持不变；（2）影响西北干旱区生态脆弱性分异的主导因素包括土壤有机质含量、地形位指数、气温、降水、夜间灯光指数，各因素对生态脆弱性的平均决定力分别为0.63、0.36、0.27、0.26和0.22。（3）基于生态脆弱性监测结果和驱动因素分析，将西北干旱区划分为5个生态功能区：生态核心保护区、生态综合监测区、生态优化关注区、生态恢复治理区、生态潜在治理区，并提出相应管理方案。研究可以为干旱区生态环境保护提供借鉴。;With the development of social economy and the adjustment of environmental policies, the ecological environment in the arid areas of Northwest China has undergone profound changes since the western regions development policies. This paper selects soil, topography, climate and night lighting data to construct ecological vulnerability assessment indicators based on the ecological background characteristics of the arid areas of Northwest China, which was analyzed the spatio-temporal evolution and motivation of ecological vulnerability by Spatial Principal Component Analysis (SPCA) and geographic detector in 2000, 2007, 2012, and 2018. The results showed that (1) from the spatio-temporal evolution of ecological vulnerability, the research area was mainly dominated by heavy vulnerability. Over the past 18 years, the ecological vulnerability of the study area has remained unchanged. From the perspective of different vulnerability of land use types, grassland and woodland are the slight vulnerability, grassland is the light vulnerability, and unused land is the moderate vulnerability and heavy vulnerability. (2) The dominant factors affecting ecological vulnerability differentiation include soil organic matter content, topographic level index, temperature, precipitation and night light index. Their average power determinant values to ecological vulnerability differentiation are 0.63, 0.36, 0.27, 0.26 and 0.22. (3) Based on the monitoring results of ecological vulnerability and analysis of driving factors, we divide the arid areas of Northwest China into five ecologically functional zones:coreareas of ecological protection, ecological comprehensive concern areas, ecological optimal-concern areas, ecological restoration management areas, and ecological potential management areas. The corresponding management plans are proposed. This study can provide reference for ecological environmental protection in arid areas.

Using Direct and Indirect Methods to Assess the Influence of High-Energy Waves over Beach Sedimentary Balance (Brazilian Northeastern Region)

Eduardo, L.M.; Carvalho, A.M.; Lima, S.B.; Claudino-Sales, V.; Costa Gastão, F.G.; Castelo Branco, J.L., and Souza Pinheiro, L., 2021. Using direct and indirect methods to assess the influence of high-energy waves over beach sedimentary balance (Brazilian Northeastern region). Journal of Coastal Research, 37(6), 1235–1246. Coconut Creek (Florida), ISSN 0749-0208. Because of the high dynamicity of atmospheric and oceanographic variables in coastal processes, local sedimentary balance is a matter of great interest for Integrated Coastal Zone Management. The diversity of environmental factors associated with the history of anthropic interventions, in addition to detailed topographic changes related to storm surge events, is assessed in this research for a stretch of the northeastern Brazilian coast. For this purpose, an association of conventional and improved digital methods was applied for data acquisition and processing. Remote sensing techniques with unmanned aerial vehicles (UAVs), three-dimensional modeling, and sedimentary analysis were performed, as well as detailed monitoring of meteorological and oceanographic variables with in situ sources and environmental modeling. The results of 1-year monitoring revealed a sedimentary balance with different variations in response to high-energy events associated with extratropical cyclones in the North Atlantic. The sedimentary balance showed an erosional rate of 25.5%, reflected in a 17.4% diminution in average topographic level of the area. Beach erosion was correlated to long period waves and great variability of wave types. Positive volumetric changes were correlated to mild weather environmental conditions. Swell waves presented a significant role in both beach erosion and following consequential topographic recovery. There was an asymmetric susceptibility to volume losses in different beach sectors.

Paisagem natural e patrimônio cultural na região da Araucanía, Chile

O Chile é um país que apresenta uma diversidade paisagística representada pelos variados níveis topográficos, os diferentes tipos climáticos, a rica biodiversidade e a irregular ocupação humana. Nesse cenário, o presente trabalho enfoca a região de Araucanía, onde são evidenciadas as diferentes paisagens naturais, o patrimônio cultural, bem como os segmentos e roteiros turísticos implantados na região, com destaque para o turismo etnicocultural mapuche. A pesquisa priorizou estudar os mecanismo de gestão das áreas protegidas, observando as ocorrências da gestão compartilhada e a oportunidade de serviços oferecidos à população local. O processo investigativo adotou o procedimento metodológico integrado reunindo diferentes campos das ciências, como a Geografia Física, Geologia, Biologia, Ecologia, Paisagismo e o Turismo.

A Trial for Mitigation of Waterlogging Problem in New Reclaimed Areas in The Desert Fringes of Beni Suef and El-Minya Governorates, Egypt.(Dept.C)

Expanding the reclamation of new lands within the unlimited desert area of Egypt has started to face the continuous growth of population and the urgent need for food security. The reclamation of the Nile valley's desert fringes affects its traditional cultivated areas as a result of the difference in the topographic level, inadequate drainage system and the existence of shallow depth clay lenses beneath these sites which creates a perched condition that helps greatly in fasting the rising rate of water table. The present paper threw light on a trial to mitigate the waterlogging problem due to the reclamation activities in the high-land desert fringes of Beni Suef and El-Minya governorates. The reclamation area was increased by 250% through the interval 1984-2001 as detected from the processed satellite images. The topographic feature of the reclaimed area reached 6 cm/km as detected from Digital Elevation Model (DEM). Two proposed scenarios for mitigation of waterlogging problem were checked by using groundwater flow model in two spatial dimensions (ASM). Draining the water excess using suitable dewatering design is proposed as a first scenario to mitigate the problem. The proposed design has been tested and calibrated using mathematical modeling techniques under the present pumping conditions (583 m3 /h in summer and 375 m3/h in winter) with increase in magnitude 0.08 m/sec through ten proposed dewatering-wells well distributed in the low-land logged area. The results showed that the losses from the logged area reached 0.048 m3/sec after 100 days which approaches 36% of the average annual supplemented groundwater. So, the third of the supplemented groundwater abstractions can be saved when reusing the dewatering quantity in irrigation. The second scenario proposed the construction of four experimental biological-drainage farms in the most deteriorated areas with evapotranspiration consumption process of 0.118 m3/sec. The second short-term proposed scenario is considered more adequate since the drainage of the pumped water during dewatering process is still a problem, Improvement of drainage techniques, minimizing irrigation rate and replacing the present flooding irrigation method used in the surrounding cultivated lands by another suitable dripping techniques are recommended for mitigation of waterlogging problem. The reuse of drainage water will decrease the groundwater demand. The decrease of irrigation openings diameter and the increase of lifting stations' efficiency will contribute in mitigation process.

Displacement Monitoring in Airport Runways by Persistent Scatterers SAR Interferometry

Deformations monitoring in airport runways and the surrounding areas is crucial, especially in cases of low-bearing capacity subgrades, such as the clayey subgrade soils. An effective monitoring of the infrastructure asset allows to secure the highest necessary standards in terms of the operational and safety requirements. Amongst the emerging remote sensing techniques for transport infrastructures monitoring, the Persistent Scatterers Interferometry (PSI) technique has proven effective for the evaluation of the ground deformations. However, its use for certain demanding applications, such as the assessment of millimetric differential deformations in airport runways, is still considered as an open issue for future developments. In this study, a time-series analysis of COSMO–SkyMed satellite images acquired from January 2015 to April 2019 is carried out by employing the PSI technique. The aim is to retrieve the mean deformation velocity and time series of the surface deformations occurring in airport runways. The technique is applied to Runway 3 at the “Leonardo da Vinci” International Airport in Rome, Italy. The proposed PSI technique is then validated by way of comparison with the deformation outcomes obtained on the runway by traditional topographic levelling over the same time span. The results of this study clearly demonstrate the efficiency and the accuracy of the applied PSI technique for the assessment of deformations in airport runways.

Influence of Three Dental Implant Surfaces on Cell Viability and Bone Behavior. An In Vitro and a Histometric Study in a Rabbit Model

The chemical composition and the surface characteristics of dental implants are factors that have a decisive effect on the osseointegration process. The surface characterization at the compositional and topographic level of three dental implants available in the market was performed with different surface treatments: (1) sandblasted and acid etched surface (SLA), (2) hydroxyapatite (HA) and tricalcium phosphate (TCP) blasted surface (HA/TCP), and (3) HA-blasted and non-etching acid washed surface (HA + AW). In addition, an in vitro viability study of MG-63 osteoblast cells was performed with a JC-1 test. To complete the study, an in vivo study was conducted in New Zealand rabbits. The study analyzed the histometric characteristics of the bone formed around the implants at the level of area, volume, bone density, accumulated bone density, and bone–implant contact (BIC). The rabbits were sacrificed at 6 weeks after implants were placed in the tibial metaphysis. No statistically significant differences were observed at the level of cell viability or histometric parameters between the different study groups (p &gt; 0.05). SLA and HA/TCP surfaces were the ones that obtained a higher BIC value. Taking into account the limitations of this study, it can be concluded that the different implant surfaces analyzed favor a good bone response.

ORGANIZATION OF THE LIVING SPACE ON THE SEVERIAN VODYANE HILL-FORT

The organization of the living space in the Romenska culture part of Vodyane hill-fort in Zmiiv district of Khakiv oblast is analyzed in the paper. The hill-fort occupies the edge of plateau and a high cape of the right bank of Uda River; it existed during two periods: the Early Iron Age — mid. 5th—4th cent. BC (the forest-steppe culture of Sсythian Age) and Early Middle Ages — the Romenska archaeological culture. In the latter period only the northern part of the site was inhabited (0,5 ha). The Severian neighboring community lived here for 50—60 years (within the 10th — beginning of 11th centuries). A total of 11 dwellings, 2 household buildings, 3 open heating systems (cookhouses), vault, 6 household pits (one of which was used for food storing) were discovered on the hill-fort.&#x0D; In the Severian time the hill-fort was built by rows/lines of houses from the southern east to the northern west with the consideration of the topographic level of each separate row. Three building lines are watched and the southern one was probably the earliest. First researchers recorded the entrance to the hill-fort on the west edge of the cape with a rampart. The absence of objects and, practically, of cultural layer in the south-western corner of the yard and along the considerable part of the western edge of the cape provide an opportunity to offer the organization of the living space of the settlement. From the entrance to the hill-fort, the road ran along the western edge of the cape, and the passes between rows of houses were located to the south from this road.&#x0D; At least 6 homesteads stand out on the hill-fort. 3 more homesteads can be defined based on the presence of cavities on the site surface. It points to the fact that the organization of the living space on Vodyane hill-fort in the end of the 1st millennium is defined by linear character (by rows) with elements of homestead building. It corresponds to the late period of the Severians’ development, when clan community was replaced by neighboring one.

Sleep and resting-state functional magnetic resonance imaging connectivity in middle-aged adults and the elderly: A population-based study.

Sleep problems increase with ageing. Increasing evidence suggests that sleep problems are not only a consequence of age-related processes, but may independently contribute to developing vascular or neurodegenerative brain disease. Yet, it remains unclear what mechanisms underlie the impact sleep problems may have on brain health in the general middle-aged and elderly population. Here, we studied sleep's relation to brain functioning in 621 participants (median age 62years, 55% women) from the population-based Rotterdam Study. We investigated cross-sectional associations of polysomnographic and subjectively measured aspects of sleep with intrinsic neural activity measured with resting-state functional magnetic resonance imaging on a different day. We investigated both functional connectivity between regions and brain activity (blood-oxygen-level-dependent signal amplitude) within regions, hierarchically towards smaller topographical levels. We found that longer polysomnographic total sleep time is associated with lower blood-oxygen-level-dependent signal amplitude in (pre)frontal regions. No objective or subjective sleep parameters were associated with functional connectivity between or within resting-state networks. The findings may indicate a pathway through which sleep, in a 'real-life' population setting, impacts brain activity or regional brain activity determines total sleep time.

Comprehensive assessment of spatial soil variability related to topographic parameters in sugarcane fields

Landscapes are intrinsically related to spatial soil variability. Understanding soil chemical fertility based on topographic parameters is essential to ensuring sustainable agronomic management through the rational use of inputs. The aim of this study was to perform a comprehensive assessment of soil organic matter (OM), pH, sum of bases (SB) and cation exchange capacity (CEC) according to topographic parameters, with the goal of identifying spatial patterns and better understanding the relationship between them to capture the soil variability in sugarcane fields. A soil dataset from nine sugarcane experimental fields was evaluated. Approximately 3000 soil samples collected between 2008 and 2017 were evaluated. The topographic parameters of vertical and horizontal curvatures were related to the variability in the soil attributes. The results showed that the horizontal morphometric classes (HConv, HPlan and HDiv) associated with vertical concave areas (VConc) presented higher levels of OM, SB and CEC, which indicated that these areas have higher soil chemical fertility. The VConcHDiv showed the highest soil chemical fertility; regardless of site, topographic level and inherent soil fertility. For all vertical morphometric classes (VConc, VRet and VConv), soil pH levels were higher in horizontal divergent areas (HDiv) and lower in convergent areas (HConv), suggesting that stricter soil acidity management was needed in the HConv areas. The VConvHConv areas, where lower soil chemical fertility was observed, should be sampled with greater accuracy for adequate spatial soil characterization because it had a higher coefficient of variation (CV) than the other morphometric classes. The results showed that the detected spatial patterns were temporally stable. With high spatial and temporal stability, topographic parameters could be excellent sources of economically feasible and easily assessed information to support farmers in soil chemical fertility characterization. Finally, topographic attributes proved to be an excellent source about soil spatial variability for farmers to use in their fields aiming a site-specific management or an additional layer of data for management zones delineation.

TOPOGRAPHY AND SEASONALITY PROMOTES TAXONOMIC BETA DIVERSITY OF SEEDLINGS IN A TROPICAL WETLAND

Spatial and temporal beta diversity of seedlings in tropical wetland remain poorly understood. We assessed the ecological pattern of taxonomic beta diversity of seedling assemblages along a topographic gradient, seasonally flooded disturbance, and sampling years in a tropical wetland. We tested that seasonally flooded disturbance on seedling assemblage promotes a high taxonomic beta diversity due to a high taxonomic turnover along the topographical gradient. Here we examined a large database from 200 plots (each having 0.5 × 0.5 m), across eight seasonally flooded grasslands in the Pantanal of central-west Brazil. We selected data on ponds for four years at two characteristic hydrological phases per year: post-flood (July and August), and post-dry season (October and November). We classified the topographical gradient into three levels 1) low—longer duration of flood; 2) mid—intermediate level; and 3) high—short duration of flood (dry soil). For both post-flood and post-dry seasons, we counted the number of seedlings within five plots at each topographic level. Additionally, taxonomic beta diversity was examined via novel abundance-based metrics (including both turnover and nestedness patterns). Overall, taxonomic beta diversity was consistently higher in high topographic level and post-dry season plots. We observed differences in beta diversity components between topographical levels, seasons and years. Topographical gradient and seasonally flooded promotes more variation in taxonomic turnover and beta diversity; due to these environmental filters we presume that the resulting beta diversity can be decisive in the species diversity in this tropical wetland.

Evolution of the Edea‐Eseka geomorphic units: A 'natural laboratory' of a prototype active rifting cross‐cutting the Southern Cameroon (West African) passive margin

The SW Cameroonian passive margin, a part of the Cameroon Low‐Plateau, presents several topographic levels cross‐cut by the Sanaga Fault (SF), Benue Triple Junction and Cameroon Volcanic Line (CVL), three pre‐ and syn‐rift tectonic features that are still active. This study carried out on the Edea‐Eseka Region (EER) a portion of this margin (3°30′–4°N, 10°–10°55′E) aims to constrain the relationships between these features and the development of the morphology. Geomorphic indices, combined with field observations and supported by literature data show that the interactive activity of these structures constitutes the main force that controls the EER morphology. From West to East, EER consists of three morphotectonic units: the Coastal, Intermediate and Upper units. The Coastal unit built on the Douala‐Kribi/Campo Basin (&lt;65 Ma) and assigned to the Aptian South Atlantic rifting, exhibits low reliefs deeply incised. The Intermediate and Upper units are developed on the Nyong and Oubanguide crystallophyllian complexes during the Eburnean/Trans‐Amazonian (2,400–1,750 Ma) and Pan‐African (650–540 Ma) orogenies, respectively. The Intermediate unit with moderate reliefs registers a strong differential erosion, whilst the Upper unit records high‐reliefs. Geomorphic indices, tectonic and recent seismic data reveal that the EER has been rejuvenated, experienced uplifts and tiltings synchronously with the main active phases of these features. The timing and magnitude of these activities vary from one unit to another. The morphotectonic model is consistent to the crucial tectonic phases: emplacement of SF (Palaeozoic), the breakup of Gondwana and erection of CVL (Cretaceous).

An integrated study of electrical resistivity tomography and infiltration method in deciphering the characteristics and potentiality of unsaturated zone in crystalline rock

To assess the shallow subsurface conditions in a granitic terrain, Electrical Resistivity Tomography (ERT) and double ring infiltrometer studies were conducted in Hyderabad city, India. Electrical Resistivity Tomography responses were monitored continuously with, Wenner and Schlumberger array with an electrode spacing of 1 and 5 m. Double ring infiltrometer hydrogeological test was equally done on the same ERT profile to image the subsurface resistivity distribution for shallow depths only. ERT has exemplified highly weathered and weathered zones and the infiltrometer study illustrated, the rate at which the water is infiltrating from the topsoil to the subsurface weathered zone. The data acquired from ERT and infiltration tests were analyzed and it is depicted that the rate of infiltration is increasing gradually concerning time i.e. at the 100th minute there is an anomaly showing a rapid increase in the rate of infiltration and the same is revealed in its depth calculation graph. Results indicating that the infiltrated water is tending to flow laterally rather than vertical, up to a depth of 17 m, thus concluding that this zone might be dominated by sheeting joints which play a vital role as a water carrier to enhance groundwater quality as well as quantity. These sheeting zones are generally flat, sometimes curved and nearly parallel to the topographic level which is formed mainly in granitoid rocks. A comprehensive study reveals the near surface information and its potentiality in terms of groundwater recharge. The findings and approach has implication towards selecting suitable sites and implementing best recharge techniques to improve the aquifer condition in all the sectors and can be upscale on a regional level in granitic terrain.

Groundwater dynamics, land cover and salinization in the dry Chaco in Paraguay

A two-year experimental study on saline groundwater dynamics in the Paraguayan dry Chaco is reported. This study was designed to better understand dryland salinity as a natural phenomenon and a potential consequence of land use changes, in order to avoid adverse economic and environmental impacts. A total of 28 wells at two study sites located nearby Loma Plata were monitored approximately every two weeks for groundwater conductivity and water table level, following transects from sown pasture to native forest and topographic gradients from bush or pasture to a nearby temporarily flooded lagoon. Results show a relation among topography, land cover, precipitation, groundwater salinity and surface salinization. Under pasture, groundwater was less saline in the average and the water table was slightly higher than under adjacent forest. Under forest, infiltrating rainwater never reached groundwater level, whereas under pasture, rainwater diluted the groundwater at several occasions during the observation period. Along the topographic gradients, there was a fringe prone to surface salinization along the borderline of the lagoon. At higher topographic levels, the saline ground water was low enough to not reach the surface by capillary ascension. On the other hand, high water table in the center of the lagoon fed by inflowing rainwaters (which had a slightly higher altitude level than the water table under adjacent land covers), displaced the saline groundwater vertically and horizontally. These findings provide information for land use planning in the region, which is prone to dryland salinity due to a generally high saline water table.

Dense georadar survey for a large‐scale reconstruction of the archaeological site of Pyrgi (Santa Severa, Rome)

AbstractThe Etruscan site of Pyrgi extended over 10 ha along the Tyrrhenian coastline. Fieldwork has so far brought to light the sanctuary and a ceremonial complex at the southern edge of the settlement, whereas additional evidence is provided by a section cut by sea erosion across the site. The archaeological layer is about 2 m thick and includes dry masonry buildings arranged into lots; the most superficial features are disturbed by deep agricultural activities and the top layer includes scattered building material (limestone and tuff blocks). At this site, the efficacy of geophysical prospections are generally affected by the nearby presence of the beach's magnetic sand and the railway line. The use of dense ground penetrating radar (GPR) data proved to be the most suitable method in the mapping of buried archeological structures and made it possible to map out the topographic layout of the area which is currently under excavation. The dense three‐dimensional georadar (GPR) data highlight the presence of structures implanted at different topographic levels and provide preliminary information about the main building interventions and planimetric modifications inside the urban lots. The work was extremely useful for the future planning of the archaeological excavation as it makes it possible to reduce the costs and environmental impact of the archaeological activity. The georadar anomalies were confirmed by an archaeological test‐trench conducted in the surveyed area.

Nutrient scarcity strengthens soil fauna control over leaf litter decomposition in tropical rainforests.

Soil fauna is a key control of the decomposition rate of leaf litter, yet its interactions with litter quality and the soil environment remain elusive. We conducted a litter decomposition experiment across different topographic levels within the landscape replicated in two rainforest sites providing natural gradients in soil fertility to test the hypothesis that low nutrient availability in litter and soil increases the strength of fauna control over litter decomposition. We crossed these data with a large dataset of 44 variables characterizing the biotic and abiotic microenvironment of each sampling point and found that microbe-driven carbon (C) and nitrogen (N) losses from leaf litter were 10.1 and 17.9% lower, respectively, in the nutrient-poorest site, but this among-site difference was equalized when meso- and macrofauna had access to the litterbags. Further, on average, soil fauna enhanced the rate of litter decomposition by 22.6%, and this contribution consistently increased as nutrient availability in the microenvironment declined. Our results indicate that nutrient scarcity increases the importance of soil fauna on C and N cycling in tropical rainforests. Further, soil fauna is able to equalize differences in microbial decomposition potential, thus buffering to a remarkable extent nutrient shortages at an ecosystem level.

Pesawat Terbang Tanpa Awak (PTTA) sebagai Pengembangan Media Sistem Informasi Geospasial

&lt;p&gt;&lt;em&gt;As we know, Indonesia has a dynamic structure of the earth's surface layer. This topographic differences level was results in land variations and it impacts on the material contained in it. This certainly will growth an enrich amount of natural land resources and the quality of plant vegetation and the sea. All of them are natural resources that are beneficial for human survival and the other habitats.&lt;/em&gt; &lt;em&gt;To monitoring its management from the surface, we need a method that serves to inform the potential region conditions, one of them is the Geospatial Information System (GIS). Generally, taken data for GIS could be obtained through aerial photography of satellite images. However, the results are less accurate, so that, we look for the other alternatif instruments, which could made a GIS map better, using the design of unmanned aircraft vehicle (PTTA) or commonly known as drones. For now, Unmanmed Aircraft Vehicle is a currently technology which that is growing rapidly. On this occasion, the author will introduce UAV technology that can be designed by itself according to needed, and could be able to answer every problems in which related to image mapping from geospatial information systems.&lt;/em&gt;&lt;/p&gt;&lt;p&gt; &lt;/p&gt;