The Lost Woodlands of Ancient Nasca

2011 ◽  
Author(s):  
David Beresford-Jones
Keyword(s):  
Native Americans ◽  
Environmental Impact ◽  
Cultural Change ◽  
El Niño ◽  
New World ◽  
Climatic Factors ◽  
El Nino ◽  
Dry Forest ◽  
Desert Ecosystem ◽  
Human Environmental Impact

This book presents an archaeological case of prehistoric human environmental impact: a study of ecological and cultural change from the arid south coast of Peru, beginning around 750 bc and culminating in a collapse during the Middle Horizon, around ad 900. Its focus is the lower Ica Valley — today depopulated and bereft of cultivation and yet with archaeological remains attesting to substantial prehistoric occupations — thereby presenting a prima facie case for changed environmental conditions. Previous archaeological interpretations of cultural changes in the region rely heavily on climatic factors such as El Niño floods and long droughts. While the archaeological, geomorphological, and archaeobotanical records presented here do indeed include new evidence of huge ancient flood events, they also demonstrate the significance of more gradual, human-induced destruction of Prosopis pallida (huarango) riparian dry-forest. The huarango is a remarkable leguminous hardwood that lives for over a millennium and provides forage, fuel, and food. Moreover, it is crucial to the integration of a fragile desert ecosystem, enhancing microclimate and soil fertility and moisture. Its removal exposed this landscape to the effects of El Niño climatic perturbations long before Europeans arrived in Peru. This case study therefore contradicts the popular perception that Native Americans inflicted barely perceptible disturbance upon a New World Eden. Yet, it also records correlations between changes in society and degrees of human environmental impact. These allow inferences about the specific contexts in which significant human environmental impacts in the New World did, and did not, arise.

scholarly journals El Niño and the shifting geography of cholera in Africa

2017 ◽  
Vol 114 (17) ◽  
pp. 4436-4441 ◽  
Author(s):  
Sean M. Moore ◽  
Andrew S. Azman ◽  
Benjamin F. Zaitchik ◽  
Eric D. Mintz ◽  
Joan Brunkard ◽  
...  
Keyword(s):  
West Africa ◽  
East Africa ◽  
El Niño ◽  
Climatic Factors ◽  
El Nino ◽  
Southern Oscillation ◽  
Climate Patterns ◽  
Southern Central ◽  
Major Shift ◽  
Mapping Techniques

The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases ranging from dengue to cholera. In Africa, El Niño conditions are associated with increased rainfall in East Africa and decreased rainfall in southern Africa, West Africa, and parts of the Sahel. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between ENSO patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa. Using high-resolution mapping techniques, we find that the annual geographic distribution of cholera in Africa from 2000 to 2014 changes dramatically, with the burden shifting to continental East Africa—and away from Madagascar and portions of southern, Central, and West Africa—where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall, suggesting a complex relationship between rainfall and cholera incidence. Here, we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño years, likely mediated by El Niño’s impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with ENSO forecasting could be used to notify countries in Africa when they are likely to see a major shift in their cholera risk.

Introduction

2011 ◽  
Author(s):  
David Beresford-Jones
Keyword(s):  
Human Impact ◽  
Cultural Change ◽  
Environmental Conditions ◽  
El Niño ◽  
El Nino ◽  
Prima Facie ◽  
South Coast ◽  
Archaeological Remains ◽  
Prima Facie Case

This introductory chapter first sets out the book's purpose, which is to present a new archaeological case for prehistoric human impact on the environment: a study of ecological and cultural change from the arid south coast of Peru, beginning around 700 bc and culminating in a collapse by about ad 1000. Its focus is the lower Ica Valley, today largely depopulated and bereft of cultivation, but whose abundant archaeological remains attest to substantial prehistoric occupations and thereby present a prima facie case for changed environmental conditions. This is a place of extreme environmental juxtaposition: one of the world's oldest and driest deserts, crossed by lush riverine oases, and sporadically impacted by El Niño floods or long droughts. An overview of the subsequent chapters is also presented.

“El Niño” events recorded in dry-forest species of the lowlands of northwest Peru

2005 ◽  
Vol 22 (3) ◽  
pp. 181-186 ◽  
Author(s):  
Rodolfo Rodríguez ◽  
Antonio Mabres ◽  
Brian Luckman ◽  
Michael Evans ◽  
Mariano Masiokas ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Dry Forest ◽  
Forest Species ◽  
El Niño Events ◽  
El Nino Events

scholarly journals Lag effect of climatic variables on dengue burden in India

2019 ◽  
Vol 147 ◽  
Author(s):  
Satya Ganesh Kakarla ◽  
Cyril Caminade ◽  
Srinivasa Rao Mutheneni ◽  
Andrew P Morse ◽  
Suryanaryana Murty Upadhyayula ◽  
...  
Keyword(s):  
El Niño ◽  
Climatic Factors ◽  
El Nino ◽  
Southern Oscillation ◽  
Seasonal Pattern ◽  
Climatic Conditions ◽  
Transmission Risk ◽  
Surveillance Program ◽  
Lag Period ◽  
The Relationship

AbstractDengue is a widespread vector-borne disease believed to affect between 100 and 390 million people every year. The interaction between vector, host and pathogen is influenced by various climatic factors and the relationship between dengue and climatic conditions has been poorly explored in India. This study explores the relationship between El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD) and dengue cases in India. Additionally, distributed lag non-linear model was used to assess the delayed effects of climatic factors on dengue cases. The weekly dengue cases reported by the Integrated Disease Surveillance Program (IDSP) over India during the period 2010–2017 were analysed. The study shows that dengue cases usually follow a seasonal pattern, with most cases reported in August and September. Both temperature and rainfall were positively associated with the number of dengue cases. The precipitation shows the higher transmission risk of dengue was observed between 8 and 15 weeks of lag. The highest relative risk (RR) of dengue was observed at 60 mm rainfall with a 12-week lag period when compared with 40 and 80 mm rainfall. The RR of dengue tends to increase with increasing mean temperature above 24 °C. The largest transmission risk of dengue was observed at 30 °C with a 0–3 weeks of lag. Similarly, the transmission risk increases more than twofold when the minimum temperature reaches 26 °C with a 2-week lag period. The dengue cases and El Niño were positively correlated with a 3–6 months lag period. The significant correlation observed between the IOD and dengue cases was shown for a 0–2 months lag period.

The Role ofProsopisin Ecological and Landscape Change in the Samaca Basin, Lower Ica Valley, South Coast Peru from the Early Horizon to the Late Intermediate Period

2009 ◽  
Vol 20 (2) ◽  
pp. 303-332 ◽  
Author(s):  
David G. Beresford-Jones ◽  
Susana Arce T. ◽  
Oliver Q. Whaley ◽  
Alex J. Chepstow-Lusty
Keyword(s):  
El Niño ◽  
Landscape Change ◽  
El Nino ◽  
Dry Forest ◽  
South Coast ◽  
Intermediate Period ◽  
Early Intermediate Period ◽  
El Niño Events ◽  
The Impact ◽  
El Nino Events

AbstractThe lower Ica Valley on the hyperarid south coast of Peru is today largely depopulated and bereft of cultivation, yet its extensive archaeological remains attest to substantial prehispanic populations. This paper describes archaeological investigations to retrace changes in geomorphology, ecology, and land-use in Samaca, one of the riparian oasis basins of the lower Río lea, with the aim of investigating when, how, and why such changes took place. Archaeological interpretations of culture change in the region often invoke the impacts of major ENSO perturbations (El Niño). While our investigations confirm that major El Niño events around the end of the Early Intermediate Period likely offer part of the explanation for marked landscape change in the Samaca Basin, we also demonstrate the significance of more gradual, human-induced destruction of Prosopis pallida (huarango) riparian dry-forest. Huarango is a remarkable leguminous hardwood that lives for over a millennium and provides forage, fuel, and food. Moreover, it plays a crucial role in integrating fragile desert ecosystems, enhancing soil fertility and moisture, and accomplishing desalination and microclimatic amelioration. We propose that south coast valleys remained densely forested well into the Early Intermediate Period, attenuating the impact of El Niño events and supporting hitherto underappreciated agroforestry adaptations. Gradual deforestation eventually crossed an environmental threshold: river and wind erosion increased dramatically and precipitated radical desertification, feeding back into cultural changes in the Middle Horizon. Thus we argue Prosopis-human ecological relationships merit proper recognition in our archaeological interpretations of the south coast of Peru.

scholarly journals Determinación de áreas naturales de Sesbania (Sesbania punicea), abono verde, en el bosque seco a consecuencia del evento de El Niño Costero, como aporte a la agricultura piurana – 2017 (Determination of natural areas of Sesbania (Sesbania punicea), fertilizer green, in the dry forest as a result of the event of the coastal child, as a contribution to the Piura agriculture – 2017)

2017 ◽  
Vol 20 (2) ◽  
pp. 7
Author(s):  
Alex García ◽  
Rodman Souza
Keyword(s):  
El Niño ◽  
El Nino ◽  
Dry Forest ◽  
Sesbania Sesban ◽  
Natural Areas

Los eventos de El Niño en Piura, Perú, se presentan con una frecuencia entre 8 y 15 años, como han sido los tres últimos fenómenos considerados como muy fuertes, 1983, 1998, 2016. Estos fenómenos traen consigo presencia de lluvias que ocasionan daños significativos en la infraestructura de la región, muchos son los parámetros para evaluar los daños ocasionados, sin embargo la historia de nuestro País nos demuestra que los antepasados aprovecharon de la mejor manera la presencia de las lluvias. Los estudios de investigación actuales demuestran la gran importancia que tiene la presencia de estas lluvias, ambas teorías la ancestral y la moderna coinciden con la apuesta de la naturaleza por demostrarnos la teoría de GAIA, especialmente en la conservación de la biodiversidad existente en los bosques secos de nuestra región. La agricultura de nuestra zona se ve muy afectada por la presencia del fenómeno del niño, este tipo de agricultura tiene una cedula de cultivos que son para el auto consumo y la creciente siembra de especies que las demanda el mercado de exportación con clientes que cada vez son más exigentes en cultivos producidos con tecnología orgánica.Los paquetes tecnológicos con los que contamos en la región siempre han estado orientados a un tipo de producción solamente con insumos químicos esto por diferentes motivos, uno de ellos es que no se dispone de variables prácticas que sean incluidas en este paquete tecnológico. Durante la presencia del último fenómeno del niño costero se organizó tareas de incursión al bosque seco con el objetivo de observar que nos brinda el bosque seco para mejorar el paquete tecnológico de la cedula de cultivos actuales. Como experiencia del autor se tenía que en el año 1984, observó la presencia de una especie de leguminosa con alto grado de nodulación en sus raíces, Hoy 2017, se ha determinado la presencia de áreas significativas de leguminosa conocida como Sesbania sesban, que nos podría facilitar el recojo de semilla para ser introducida como variable en el paquete tecnológico actual. La Sesbania sesban es una especie reconocida en el ámbito internacional como una excelente fuente de abono verde y el uso complementario a través de energía calorífica, forraje para el ganado y alimentación (flores) en los seres humanos.

scholarly journals Dendroecology of Macrolobium acaciifolium (Fabaceae) in Central Amazonian floodplain forests

2018 ◽  
Vol 48 (4) ◽  
pp. 311-320 ◽  
Author(s):  
Eliane Silva BATISTA ◽  
Jochen SCHÖNGART
Keyword(s):  
El Niño ◽  
Climatic Factors ◽  
El Nino ◽  
Ring Width ◽  
Tree Age ◽  
Diameter Increment ◽  
Annual Growth Rings ◽  
Significant Difference ◽  
The Mean ◽  
Hydrological Variables

ABSTRACT The forest dynamics in the Amazonian floodplains is strongly triggered by the flood pulse. Trees respond to unfavorable growth conditions during the flood period by cambial dormancy, which results in the formation of annual growth rings. We determined tree age and compared the mean annual rates of increase in the diameter of Macrolobium acaciifolium with hydrological and climatic factors in three regions of central Amazonian floodplain forest. A wood sample was obtained from each tree using an increment borer. Ring growth was assessed by marginal parenchyma bands to determine tree age and the mean diameter increment. Ring widths were indexed to construct cross-dating chronologies and correlated with climatic and hydrological variables. The analyses demonstrate that the mean annual diameter increment did not differ between the three study sites. The chronologies correlated significantly with the terrestrial phase. There was no significant difference in the ring-width index between El Niño years and other years, and between La Niña and other years. These results show that the hydrological variables can be considered crucial to the rates of tree growth and diameter increment in floodplains, and El Niño signals were not detected in the tree-ring chronologies.

scholarly journals Temperature Surface of Guaíba Lake, RS, from time series of MODIS images

RBRH ◽  
2017 ◽  
Vol 22 (0) ◽  
Author(s):  
Glenio Antonio da Luz ◽  
Laurindo Antonio Guasselli ◽  
Daniela Rocha
Keyword(s):  
Air Temperature ◽  
El Niño ◽  
Climatic Factors ◽  
El Nino ◽  
Rio Grande ◽  
Equatorial Pacific ◽  
La Niña ◽  
Metropolitan Region ◽  
Rio Grande Do Sul ◽  
La Nina

ABSTRACT The Guaíba lake is located in an area of complex weather variation and is influenced by many atmospheric circulation systems, bringing about violent occluded fronts, and, sometimes, intense precipitation. In Rio Grande do Sul, during El Niño, air temperatures and the precipitation index are higher, contrary to La Niña. Moreover, the Guaíba Lake receives water from the Guaíba's Hydrographical Region, which corresponds to 1/3 of Rio Grande do Sul State, and is thus an important water body to the metropolitan region of Porto Alegre. Methods that seek to understand the behavior of Guaíba lake surface water temperature (LSWT) may lead to relevant information to identify periods of more or less water warming, as well as the relations between LSWT, water quality deterioration and risks to human health. This paper aims to comprehend the behavior of Guaíba LSWT during periods of climatic anomalies (El Niño/La Niña). Therefore, 418 sea surface temperature (SST) images from the MODIS sensor were processed with SeaDas 7.2 software. The quarterly averages of LSWT were obtained and compared to the climatological anomalies in Equatorial Pacific Ocean. LSWT behavior is more complex in El Niño/La Niña periods. The results show that during climatic abnormality periods there are no direct relationship between the warming/cooling of Guaíba LSWT and the warming/cooling of Equatorial Pacific Ocean’s SST. The precipitation indices were more significant to the behavior of LSWT during El Niño periods, but for all periods (of climatic normality and abnormality), air temperature is what most influences LSWT. This relation occurs with climatic factors of water retention time, water entry and precipitation, and air temperature. There is a major correspondence during La Niña periods with the cooling of Guaíba LSWT only for some years. On the other hand, during El Niño periods there are no correspondences of this phenomenon with the warming of Guaíba LSWT. There are only more intense oscillations in surface temperatures than during regular and La Niña periods, but with a tendency to LSWT warming.

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