The environmental impact of a pre-Columbian city based on geochemical insights from lake sediment cores recovered near Cahokia

2018 ◽  
Vol 91 (2) ◽  
pp. 714-728 ◽  
Author(s):  
David P. Pompeani ◽  
Aubrey L. Hillman ◽  
Matthew S. Finkenbinder ◽  
Daniel J. Bain ◽  
Alexander Correa-Metrio ◽  
...  

AbstractCahokia is the largest documented urban settlement in the pre-Columbian United States. Archaeological evidence suggests that the city, located near what is now East St. Louis, Illinois, began to rapidly expand starting around AD 1050. At its height, Cahokia extended across 1000 ha and included large plazas, timber palisade walls, and hundreds of monumental earthen mounds. Following several centuries of occupation, the city experienced a period of gradual abandonment from about AD 1200 to 1400. Here, we present geochemical data from a 1500-year-old sediment core from nearby Horseshoe Lake that records watershed impacts associated with the growth and decline of Cahokia. Sedimentary analysis shows a distinctive 24-cm-thick, gray, fine-grained layer formed between AD 1150 and 1220 and characterized by low carbonate δ13C, elevated sorbed metal concentrations, and higher organic matter δ15N. The deposition of this layer is contemporaneous with archaeological evidence of increased agricultural activity, earthen mound construction, and higher populations surrounding the lake. We hypothesize that these human impacts increased soil erosion, producing new sediment sources from deeper soil horizons, and shifted dissolved transport to the lake, producing lower carbonate δ13C values, higher concentrations of lead, copper, potassium, and aluminum, and increased δ15N, likely due to contributions of enriched nitrogen from sewage.

The Holocene ◽  
2018 ◽  
Vol 29 (3) ◽  
pp. 505-517 ◽  
Author(s):  
Aubrey L Hillman ◽  
Alice Yao ◽  
Mark B Abbott ◽  
Daniel J Bain

Landscapes have been shaped by human activities for millennia and there is a pressing need to characterize pre-industrial impacts in order to mitigate present-day effects. We present the analysis of two sediment cores from Dian Lake in Yunnan, China, which span 4000 years. We compare cores from the northern and southern ends of the lake to investigate spatial variability in natural and anthropogenic environmental changes in this large (300 km2) lake. To document the initiation of human impacts on the landscape and characterize the attendant changes in the lake water and sediment quality, we rely on organic and inorganic geochemical measurements as well as sedimentology and stratigraphy. The character and magnitude of proxy changes are coherent between the two core sites with slight differences in the timing of events. At both core sites, we find definitive evidence for substantial anthropogenic change beginning AD 100 (1850 yr BP), coincident with the introduction of terraced agriculture. Sedimentological shifts are distinctive and characterized by an increase in magnetic susceptibility values and a visible change to red, fine-grained clay. The geochemistry of this sediment suggests that it was sourced from the eastern catchment of the lake and delivered into the basin following intensive agriculture and soil erosion. Anthropogenic impacts intensify after AD 900 through hydrologic modification and cultural eutrophication resulting from increased nutrient loading. This study presents evidence that human-affected landscapes have been present in this region of China for longer than previously believed and that ‘small-scale’ land use change can have measureable impacts on lakes.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Kang Liu ◽  
Ling Yin ◽  
Meng Zhang ◽  
Min Kang ◽  
Ai-Ping Deng ◽  
...  

Abstract Background Dengue fever (DF) is a mosquito-borne infectious disease that has threatened tropical and subtropical regions in recent decades. An early and targeted warning of a dengue epidemic is important for vector control. Current studies have primarily determined weather conditions to be the main factor for dengue forecasting, thereby neglecting that environmental suitability for mosquito breeding is also an important factor, especially in fine-grained intra-urban settings. Considering that street-view images are promising for depicting physical environments, this study proposes a framework for facilitating fine-grained intra-urban dengue forecasting by integrating the urban environments measured from street-view images. Methods The dengue epidemic that occurred in 167 townships of Guangzhou City, China, between 2015 and 2019 was taken as a study case. First, feature vectors of street-view images acquired inside each township were extracted by a pre-trained convolutional neural network, and then aggregated as an environmental feature vector of the township. Thus, townships with similar physical settings would exhibit similar environmental features. Second, the environmental feature vector is combined with commonly used features (e.g., temperature, rainfall, and past case count) as inputs to machine-learning models for weekly dengue forecasting. Results The performance of machine-learning forecasting models (i.e., MLP and SVM) integrated with and without environmental features were compared. This indicates that models integrating environmental features can identify high-risk urban units across the city more precisely than those using common features alone. In addition, the top 30% of high-risk townships predicted by our proposed methods can capture approximately 50–60% of dengue cases across the city. Conclusions Incorporating local environments measured from street view images is effective in facilitating fine-grained intra-urban dengue forecasting, which is beneficial for conducting spatially precise dengue prevention and control.


1995 ◽  
Vol 6 (4) ◽  
pp. 310-334 ◽  
Author(s):  
William J. Folan ◽  
Joyce Marcus ◽  
Sophia Pincemin ◽  
María del Rosario Domínguez Carrasco ◽  
Laraine Fletcher ◽  
...  

In this paper we summarize more than a decade of interdisciplinary work at Calakmul, including (1) the mapping project, which has covered more than 30 km2; (2) the excavation project, which has uncovered major structures and tombs in the center of the city; (3) the epigraphic project, whose goal is to study the hieroglyphic texts and relate them to the archaeological evidence; (4) the analysis of the architecture, ceramics, and chipped stone to define sacred and secular activity areas and chronological stages; and (5) a focus on the ecology, hydrology, and paleoclimatology of Calakmul and its environs with the aim of understanding more fully its periods of development and decline.


Author(s):  
Douglas Nelson ◽  
Alan Heyvaert ◽  
Laurent Meillier ◽  
Jae Kim ◽  
Xiaoping Li ◽  
...  

2019 ◽  
pp. 84-91
Author(s):  
Yurii Solohub ◽  
Sergey Uliganets ◽  
Olha Bezpala

Main goal: To analyze the level of the urban settlement system development of the Capital Socio-Geographical region by means of a cluster analysis method and by selecting the optimal number of capacitive indicators. It is assumed that the most significant characteristics, may be the most important and have a determining function. Methodology: The use of special statistical and mathematical methods of research, in particular, the method of cluster analysis is the basis of the study. This method has gained wide popularity for the study of both the general socio-economic development of the administrative-territorial units of the state and the corresponding systems of settlement of different taxonomic ranks. Cluster analysis is a research tool for analyzing data to solve classification problems. Its purpose is to sort cases into groups or clusters in such a way that the degree of dependency is strong between members within one cluster and weak between members of different clusters. The process of clustering involves the selection of optimal indicators, which most fully and objectively reflect the situation of the manifestation of a phenomenon in the studied area.Results: It is established that the presence of agglomerated settlements around the agglomeration center, namely the city of Kyiv, significantly increase its concentration potential, which leads to an increase in the area of both direct and indirect influence of the city center. Thus, the zone of influence of the city of Kyiv is not limited to the boundaries of the administrative Kyiv region, but extends beyond it, involving the territories of Chernihiv, Zhytomyr, Cherkasy and, to a lesser extent, Vinnitsa and Poltava regions. Scientific novelty: The clusterization of administrative-territorial units of the Capital Socio-Geographical region is carried out. Clustering was based on the degree of manifestation in them of the main indicators of the development of regional urban settlement systems.It is revealed that the presence of agglomerated settlements around the agglomeration center, the city of Kiev, significantly increase its concentration potential, which leads to an increase in the area of both direct and indirect influence of the city center. Thus, the zone of influence of the city of Kyiv is no longer confined to the boundaries of the administrative Kyiv region, but extends beyond it, involving the territories of Chernihiv, Zhytomyr, Cherkasy and, to a lesser extent, Vinnytsia and Poltava regions. The degree of localization of the urban population of the district and the cluster analysis of its administrative-territorial units in accordance with the levels of development of their settlement systems were considered to present the situation regarding the concentration of urban population of the Capital Socio-Geographical region. Practical relevance: Publication materials can be used in the development of measures to optimize the settlement system of the Capital Socio-Geographical region and to adjust the administrative and territorial reform of the state.


2014 ◽  
Vol 344 ◽  
pp. 64-74 ◽  
Author(s):  
Young Shin Lim ◽  
Jin Kwan Kim ◽  
Jong Wook Kim ◽  
Sei Sun Hong

2018 ◽  
Vol 17 (4) ◽  
pp. 433-450 ◽  
Author(s):  
Alexandra Crosby ◽  
Kirsten Seale

As urban renewal agendas are fortified in cities globally, ‘creativity’ – as contained within discourses of the creative industries, the Creative City and the creative economy – is circulated as the currency of secure post-industrial urban futures. Using the nexus between creativity and the urban as a starting point, the authors investigate how local enterprises visually communicate the urban in a neighbourhood that is characterized by the interface between manufacturing and creative industries. This research takes a fine-grained approach to the notion of creativity through an audit and qualitative analysis of the visual presentation, material attributes and semiotic meaning of street numbers. The authors do this by collecting data on and analysing how street numbers have been made, selected, used, replaced and layered in a contested industrial precinct in Australia’s largest city, Sydney. They contend that street numbers, as a ubiquitous technology within the city that is both operational and creative, are metonyms for what they understand to be urban. In arguing for vernacular readings of the city, they make use of a top-down, governmental mode of reading the city – the operational legibility of street numbering – as an intervention in current discourses of the urban and of creativity in the city.


Author(s):  
Ibrahima Thiaw

This chapter examines how slavery was imprinted on material culture and settlement at Gorée Island. It evaluates the changing patterns of settlement, access to materials, and emerging novel tastes to gain insights into everyday life and cultural interactions on the island. By the eighteenth century, Gorée grew rapidly as an urban settlement with a heterogeneous population including free and enslaved Africans as well as different European identities. Interaction between these different identities was punctuated with intense negotiations resulting in the emergence of a truly transnational community. While these significant changes were noted in the settlement pattern and material culture recovered, the issue of slavery — critical to most oral and documentary narratives about the island — remains relatively opaque in the archaeological record. Despite this, the chapter attempts to tease out from available documentary and archaeological evidence some illumination on interaction between the different communities on the island, including indigenous slaves.


Author(s):  
Simon James

Archaeological evidence indicates that, during the final halfcentury of the life of the city, the area directly annexed by the military was significantly larger than the original excavators realized. In addition to concentrations of soldiers around the gates and defences, and at various places within the ‘civil’ town, the military came to control a single continuous swathe of the urban interior, comprising the entire N part of the walled area from the W defences to the river cliffs, and extending as far as the S end of the Citadel, plus the floor of the inner wadi right down to Lower Main St opposite the (by Durene standards) showy C3 bath, which it also apparently built. This area totals c.13.5 ha (c.33 acres)—a literal quarter of the intramural area which today covers c.52 ha (c.118 acres, measured from the CAD plan of the city by Dan Stewart; both city and base were slightly bigger in antiquity, before loss of the River Gate and parts of the Citadel). In its final form, the base included several distinct zones (Pl. XXIII). The NW part of the city had become a military enclosure, bounded on the E side by a continuous wall down the W side of G St, incorporating the street facades of the E3 bath and E4 house. On the S it was defined by the ‘camp wall’ from the city defences to D St; with no sign of a wall across blocks F5 or F7, the perimeter between D and F Sts is inferred. It must be presumed that, as to the W, the 8th-St-fronting properties of the two blocks were taken over, but that the party walls comprising the boundary with civil housing to the S was not further elaborated. These lines converged on the amphitheatre, which formed the corner of the enclosure. This perimeter of the NW enclosure involved physically blocking Wall, A, C, D, and 10th Sts. A major entrance was on 8th St, at G St between the amphitheatre and the E4 house.


Radiocarbon ◽  
2020 ◽  
Vol 62 (2) ◽  
pp. 289-311
Author(s):  
Alex da Silva de Freitas ◽  
Javier Helenes Escamilla ◽  
Cintia Ferreira Barreto ◽  
Alex Cardoso Bastos ◽  
Estefan Monteiro da Fonseca ◽  
...  

ABSTRACTMicropaleontological and geochemical data were applied to sediments from southeastern Brazil to study the hydrodynamics associated with the Holocene sea level rise. Sediment cores were taken around Vitória Bay, examined for dinoflagellate cysts and subjected to isotopic analysis. The cyst assemblage mainly dominated by autotrophic species most notably O. centrocarpum, L. machaerophorum and T. vancampoae. The influence of the marine transgression and subsequent regression observed during the Holocene along the coast of Brazil could have initially favored the establishment of an oligotrophic and higher energy environment. The inflow of continental water from tributaries combined with a higher inflow of saline water into the estuarine system could have favored the establishment and subsequent deposition of the dinocysts.


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