scholarly journals An insight into pre-Columbian raised fields: the case of San Borja, Bolivian lowlands

SOIL ◽  
2016 ◽  
Vol 2 (3) ◽  
pp. 367-389 ◽  
Author(s):  
Leonor Rodrigues ◽  
Umberto Lombardo ◽  
Mareike Trauerstein ◽  
Perrine Huber ◽  
Sandra Mohr ◽  
...  

Abstract. Pre-Columbian raised field agriculture in the tropical lowlands of South America has received increasing attention and been the focus of heated debates regarding its function, productivity, and role in the development of pre-Columbian societies. Even though raised fields are all associated to permanent or semi-permanent high water levels, they occur in different environmental contexts. Very few field-based studies on raised fields have been carried out in the tropical lowlands and little is known about their use and past management. Based on topographic surveying and mapping, soil physical and chemical analysis and OSL and radiocarbon dating, this paper provides insight into the morphology, functioning and time frame of the use of raised fields in the south-western Llanos de Moxos, Bolivian Amazon. We have studied raised fields of different sizes that were built in an area near the town of San Borja, with a complex fluvial history. The results show that differences in field size and height are the result of an adaptation to a site where soil properties vary significantly on a scale of tens to hundreds of metres. The analysis and dating of the raised fields sediments point towards an extensive and rather brief use of the raised fields, for about 100–200 years at the beginning of the 2nd millennium.

2016 ◽  
Author(s):  
Leonor Rodrigues ◽  
Umberto Lombardo ◽  
Mareike Trauerstein ◽  
Perrine Huber ◽  
Sandra Mohr ◽  
...  

Abstract. Pre-Columbian raised field agriculture in the tropical lowlands of South America has received increasing attention and been the focus of heated debates regarding its function, productivity, and role in the development of pre-Columbian societies. Even though raised fields are all associated to permanent or semi-permanent high water levels, they occur in different environmental contexts. Very few field-based studies on raised fields have been carried out in the tropical lowlands and little is known about their use and past management. Based on topographic surveying and mapping, soil physical/chemical analysis and OSL and radiocarbon dating, this paper provides insight into the morphology, functioning and time frame of the use of raised fields in the south-western Llanos de Moxos, Bolivian Amazon. We have studied raised fields of different sizes that were built in an area, near the town of San Borja, with a complex fluvial history. The results show that differences in field size and height are the result of an adaptation to a site where soil properties vary significantly on a scale of tens to hundreds of meters. The analysis and dating of the raised fields sediments point towards an extensive and rather brief use of the raised fields, for about 100–200 years at the beginning of the 2nd millennium.


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 738
Author(s):  
Nicola Rossi ◽  
Mario Bačić ◽  
Meho Saša Kovačević ◽  
Lovorka Librić

The design code Eurocode 7 relies on semi-probabilistic calculation procedures, through utilization of the soil parameters obtained by in situ and laboratory tests, or by the means of transformation models. To reach a prescribed safety margin, the inherent soil parameter variability is accounted for through the application of partial factors to either soil parameters directly or to the resistance. However, considering several sources of geotechnical uncertainty, including the inherent soil variability, measurement error and transformation uncertainty, full probabilistic analyses should be implemented to directly consider the site-specific variability. This paper presents the procedure of developing fragility curves for levee slope stability and piping as failure mechanisms that lead to larger breaches, where a direct influence of the flood event intensity on the probability of failure is calculated. A range of fragility curve sets is presented, considering the variability of levee material properties and varying durations of the flood event, thus providing crucial insight into the vulnerability of the levee exposed to rising water levels. The procedure is applied to the River Drava levee, a site which has shown a continuous trend of increased water levels in recent years.


Author(s):  
Sanna Saunaluoma

Interpretations of the Amazonia prehistory have changed significantly in the last few decades, as the complexity and diversity of the Amazonian cultures are beginning to be documented and understood. Earthworking, a long-term conscious anthropogenic landscape alteration, was a widespread phenomenon throughout the South American tropical lowlands. A variety of earthworks has been documented in the Southwest Amazon, including ditches and embankments of different shapes and sizes, roads, extensive raised fields, canals, causeways, and artificial wetlands linked to adjacent mounds and forest island settlement sites. A field survey and test excavations were undertaken in the region of Riberalta, in the Bolivian Amazon. The purpose of these investigations was to study the distribution and characteristics of the pre-Columbian occupation in the region. We found different types of sites, some without visible earthworks, indicating fairly dense occupation on river bluffs and terra firme, but lacking long permanence in the same location. The earthwork tradition prevailed in the Riberalta region from at least 100 B.C. until the period of European contact. The function of the less-complex earthworks may have been to enclose the occupation areas, and in some cases, to serve as canals. Compared to the variable layout of the sites, the ceramic assemblages of the region are relatively homogeneous. A central objective for future research will be to determine if the earthwork sites correlate with a single or multiple cultural traditions.Key-words: Southwest Amazonian archaeology, earthworks, ceramic traditions.


2007 ◽  
Vol 158 (1-2) ◽  
pp. 14-21
Author(s):  
Vasyl Sabadosh ◽  
Oleg Suprunenko

The upper Theresian Valley lies along the southwest-facing ridge of the Ukrainian Carpathians. Despite expansive forestation high water levels are frequent. The forest belongs to the state and is centrally administrated. Felling is sometimes outsourced to private companies and private companies have also been founded to process the timber. Job opportunities have become fewer and illegal work is increasing. A new democratic awareness has emerged since the «Orange Revolution» in 2004. With foreign investors, however, new risks emerge. The authors recommend giving monies from forest management to the communities, the founding of new wood processing enterprises and more transparent information.


1996 ◽  
Vol 34 (12) ◽  
pp. 67-72
Author(s):  
Yukio Komai

A water sample was taken once a day for 15 months at a site near an estuary of the Kako River, Japan, to estimate nutrient loads from rivers to the sea. Total phosphorus (T-P), total nitrogen (T-N), suspended solids (SS) and electronic conductivity (EC) were measured. T-P and SS concentrations varied in proportion to the discharge, and T-P concentrations increased with those of SS, too. EC varied inversely with the discharge, but the fluctuations of T-N concentrations were less than those of T-P and SS concentrations. Water quality remained, for the most part, constant throughout the day. T-P, T-N and SS load were 181t/year, 2320t/year and 51000t/year in 1992, respectively, 54% of T-P load, 47% of T-N load and 80% of SS loads outflowed in those cases where the discharge was more than 100 m3/s, which were 36 days in 1992. 79% of T-P load, 69% of T-N load and 92% of SS load outflowed in periods of high water discharge, which were 88 in 1992. T-P and T-N loads calculated by using one day's data in every month were 151t/year and 2450t/year. But nutrient loads calculated by using the average value of data from an ordinary discharge were two or three times lower than calculated yearly loads. These results showed the importance of estimating the yearly load considering the discharge condition and sampling at a time of high water discharge.


2020 ◽  
Vol 17 (2) ◽  
pp. 88-100 ◽  
Author(s):  
Sundos Suleman Ismail Abdalla ◽  
Haliza Katas ◽  
Fazren Azmi ◽  
Mohd Fauzi Mh Busra

Fast progress in nanoscience and nanotechnology has contributed to the way in which people diagnose, combat, and overcome various diseases differently from the conventional methods. Metal nanoparticles, mainly silver and gold nanoparticles (AgNPs and AuNPs, respectively), are currently developed for many applications in the medical and pharmaceutical area including as antibacterial, antibiofilm as well as anti-leshmanial agents, drug delivery systems, diagnostics tools, as well as being included in personal care products and cosmetics. In this review, the preparation of AgNPs and AuNPs using different methods is discussed, particularly the green or bio- synthesis method as well as common methods used for their physical and chemical characterization. In addition, the mechanisms of the antimicrobial and anti-biofilm activity of AgNPs and AuNPs are discussed, along with the toxicity of both nanoparticles. The review will provide insight into the potential of biosynthesized AgNPs and AuNPs as antimicrobial nanomaterial agents for future use.


Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 378
Author(s):  
Taeyong Kwon ◽  
Seongsim Yoon ◽  
Sanghoo Yoon

Uncertainty in the rainfall network can lead to mistakes in dam operation. Sudden increases in dam water levels due to rainfall uncertainty are a high disaster risk. In order to prevent these losses, it is necessary to configure an appropriate rainfall network that can effectively reflect the characteristics of the watershed. In this study, conditional entropy was used to calculate the uncertainty of the watershed using rainfall and radar data observed from 2018 to 2019 in the Goesan Dam and Hwacheon Dam watersheds. The results identified radar data suitable for the characteristics of the watershed and proposed a site for an additional rainfall gauge. It is also necessary to select the location of the additional rainfall gauged by limiting the points where smooth movement and installation, for example crossing national borders, are difficult. The proposed site emphasized accessibility and usability by leveraging road information and selecting a radar grid near the road. As a practice result, the uncertainty of precipitation in the Goesan and Hwacheon Dam watersheds could be decreased by 70.0% and 67.9%, respectively, when four and three additional gauge sites were installed without any restriction. When these were installed near to the road, with five and four additional gauge sites, the uncertainty in the Goesan Dam and Hwacheon Dam watersheds were reduced by up to 71.1%. Therefore, due to the high degree of uncertainty, it is necessary to measure precipitation. The operation of the rainfall gauge can provide a smooth site and configure an appropriate monitoring network.


The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.


Author(s):  
Ellen M. Whitehead ◽  
Allan Farrell ◽  
Jenifer L. Bratter

ABSTRACT The racial composition of couples is a salient indicator of race’s impact on mate selection, but how well do those in intimate partnerships know the racial identities of their partners? While prior research has revealed that an individual’s race may be perceived differently than how they identify, most of what is known comes from brief interactions, with less information on established relationships. This study examines whether discrepancies in the reports of a person’s race or ethnicity can be identified even within intimate relationships, as well as which relational, social, and attitudinal factors are predictive of divergent or concordant reports. We draw on the Fragile Families and Child Wellbeing Study (n=3467), a U.S.-based dataset that uniquely provides both the father’s self-reported race and Hispanic origin and the mother’s report of the father’s race and ethnicity. We compare reports of the father’s race/Hispanic origin from both parents to assess the extent of mismatch, and we distinguish between whether mothers view the father’s race as similar to or different from her own. We find roughly 14% of mothers provide a race and Hispanic origin that is inconsistent with the father’s report, with a large share reflecting differences in the self-identified and perceived race of fathers who are reported as Hispanic. Among mismatched reports, mothers are more likely to report a race/ethnicity for the father that matches her own, depressing the number reporting interracial unions. Perceptions of racial homogamy are especially likely when mothers view racial sameness as important to marriage. Further, mismatches are more common in the midst of weak relational ties (i.e. non-marital relationships) and are less common when both parents are college-educated. These findings reveal that intimate unions are a site where race is socially constructed and provide insight into how norms of endogamy manifest within formed relationships.


2021 ◽  
Vol 9 (6) ◽  
pp. 605
Author(s):  
Craig Heatherington ◽  
Alistair Grinham ◽  
Irene Penesis ◽  
Scott Hunter ◽  
Remo Cossu

Marine renewable energy is still in its infancy and poses serious challenges due to the harsh marine conditions encountered for wave or tidal installations and the survivability of devices. Geophysical and hydrodynamic initial site surveys need to be able to provide repeatable, reliable, and economical solutions. An oscillating water column wave energy converter is to be installed on the west coast of King Island, Tasmania. The location is in a high-energy nearshore environment to take advantage of sustained shoaling non-breaking waves of the Southern Ocean and required site-specific information for the deployment. We provide insight into scalable geophysical site surveys capable of capturing large amounts of data within a short time frame. This data was incorporated into a site suitability model, utilising seabed slope, sediment depth, and water depth to provide the terrain analysis needed to match deployment-specific characteristics. In addition, short-term hydrology and geotechnical work found a highly energetic seabed (near seafloor water velocities <1 m/s) with sufficient bearing capacity (6 MPa). In a highly energetic environment, care was taken to collect the relevant data needed for an assessment of critical information to an emerging technology companies primary project. This is in addition to the malleable methodology for a site suitability model that can incorporate various weighted parameters to prioritise the location for shallow wave energy sites in general.


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