Holocene climate in the high tropical Andes was characterized by both gradual and abrupt changes, which disrupted the hydrological cycle and impacted landscapes and societies. High-resolution ...paleoenvironmental records are essential to contextualize archaeological data and to evaluate the sociopolitical response of ancient societies to environmental variability. Middle-to-Late Holocene water levels in Lake Titicaca were reevaluated through a transfer function model based on measurements of organic carbon stable isotopes, combined with high-resolution profiles of other geochemical variables and paleoshoreline indicators. Our reconstruction indicates that following a prolonged low stand during the Middle Holocene (4000 to 2400 BCE), lake level rose rapidly ~15 m by 1800 BCE, and then increased another 3 to 6 m in a series of steps, attaining the highest values after ~1600 CE. The largest lake-level increases coincided with major sociopolitical changes reported by archaeologists. In particular, at the end of the Formative Period (500 CE), a major lake-level rise inundated large shoreline areas and forced populations to migrate to higher elevation, likely contributing to the emergence of the Tiwanaku culture.
The Central Pacific (CP) flavor of El Niño/Southern Oscillation (ENSO) may account for some of the Medieval Climate Anomaly (MCA) aridity in the highland Titicaca Basin of the South Central Andes ...observed by Arnold et al. (2021 in Quaternary Science Reviews). There is urgent need for a longer record of CP presence and frequency.
In the Lake Titicaca Basin of the Andes, narratives of agricultural change have focused exclusively on a single innovation: raised fields. In this article, I examine macrobotanical remains and other ...archaeological datasets to elucidate a wider range of past farming practices that contributed to processes of agricultural change on the Taraco Peninsula, Bolivia, during the Formative Period (1500 B.C.E.–C.E. 500). This analysis reveals strong continuities in crop selection through time, with farmers gradually diversifying a basic set of cultigens—quinoa and tubers—but never abandoning them. Patterns in wild plant species indicate continuity in agropastoral land use up to the Late Formative Period (second century C.E.) when the unintended consequences of long-term tilling and camelid grazing transformed the botanical landscape into one that required a new set of practices to remove weeds and replenish nutrients to the soils. Examining how these practices and the farmers enacting them articulated with broader processes of demographic, environmental, and sociopolitical change reveals dynamic, multivariate courses of agricultural change even before the inclusion of raised fields. En la cuenca del lago Titicaca de los Andes, las narrativas del cambio agrícola se han enfocado exclusivamente en una sola innovación: los campos elevados. En este artículo, se analizan restos macrobotánicos y otros datos arqueológicos para investigar un rango más amplio de prácticas agrícolas que contribuyeron a los procesos de cambio en la península de Taraco, Bolivia a lo largo del período Formativo (1500 a.C. – 500 d.C.). Este análisis revela fuertes continuidades en la selección de cultivos a través del tiempo con la diversificación gradual del conjunto básico de quinua y tubérculos. Los patrones de las especies de plantas silvestres indican una continuidad en el uso agro-pastoral del paisaje hasta el período Formativo Tardío (segundo siglo d.C.) cuando las consecuencias no intencionadas de las precedentes actividades agrícolas y pastoriles de camélidos transformaron el paisaje botánico en uno que requería de un nuevo conjunto de prácticas agrícolas para eliminar las malezas y renovar los nutrientes de los suelos. Evaluar cómo estas prácticas y los agricultores que las llevaron adelante se articularon con procesos de cambio demográficos, medioambientales y socio-políticos revela trayectorias multivariadas y dinámicas de cambios agrícolas que antecedieron a la incorporación de campos elevados.
Las perforaciones petroleras de Ahuallani, ubicadas en el altiplano del departamento de Puno, son algunas de las más antiguas de Perú. Por más de medio siglo afloraron emulsiones de aguas de salmuera ...que desembocaron en el lago Titicaca. La información de los efectos de estas emulsiones sobre la diversidad es casi inexistente. El objetivo fue determinar la diversidad de avifauna del área degradada de la actividad petrolífera en Ahuallani (Perú). Para ello, se realizaron evaluaciones mediante puntos de conteo, cuyos registros fueron corroborados mediante revisión bibliografía para determinar la condición migratoria, el ambiente de registro y el estado de conservación según normativa peruana, IUCN y CITES. Un total de 28 especies de aves fueron registradas: 20 residentes, 7 migratorias y 1 indeterminada. Tan solo Phoenicopterus chilensis está categorizada según normativa peruana, CITES y IUCN. Los registros en Ahuallani presentan valores bajos de índices de diversidad, lo cual es evidencia de las afectaciones de la actividad petrolera sobre la comunidad aviar.
Las comunidades Indígenas Andino-bolivianas del Titicaca dependen a menudo de sus recursos naturales para garantizar su seguridad alimentaria, lo que las hace especialmente vulnerables a ...fluctuaciones ambientales y cambios en el ecosistema. Bajo ese criterio, el presente estudio aplica una metodología cualitativa para analizar la relación existente entre la seguridad alimentaria de las comunidades de la región de la bahía de Cohana (tomando como caso de estudio a la comunidad de Chojasivi) y la contaminación hídrica presente en la cuenca Katari. Los resultados revelan que dicha contaminación ha generado un efecto potencial en el acceso, disponibilidad, uso y estabilidad en el tiempo de los alimentos que componen la canasta básica de los comunarios.
Spatial distribution and interpolation methods provide a summarized overview about the pollution dispersion, concerning the environment's quality. A high-altitude lake was taken as a model to assess ...the metalloid As and metals Cr, Cu, Ni, Pb, Zn distribution in superficial sediment and classify them according to their ecotoxicological potential in the aquatic environment. Surface sediments were collected from 11 sites along Puno Bay located at the western area of Lake Titicaca, Peru, and analyzed for pseudo total-metals. Sediment concentration data and quality were plotted using the Inverse Distance Weighting (IDW) as an interpolation method. High concentrations of As were found especially in the outer bay (81.73 mg.kg−1). Spatial heterogeneity was evidenced for metal by the coefficient of variation, although no significative differences were observed between the two bays applying a Kruskall Wallis test (p < 0.05, df = 1). Sediment quality classification showed that most metal values were below TEL and toxicity was unlikely to occur, only As exceeded threefold PEL values, which categorized sediment as “Very Bad”, indicating a rather high ecotoxicological potential to the aquatic environment. In conclusion, spatial analysis connected to interpolation methods demonstrated the superficial sediment heterogeneity in Puno Bay.
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•Spatial distribution shows metal concentration dissimilarities in Puno Bay.•The Titicaca basin's geomorphology influences metal accumulation in sediment.•Arsenic shows to be potentially toxic according international sediment guidelines.•Raw water collection for drinking treatment occurs in below the PEL areas for Arsenic.
•This paper tracks pan-Titicaca basin locality dynamics via geochemical data, specific ceramic pastes and resource areas.•Decorated ceramics indicate diverse intraregional potting practices and high ...levels of exchange in the Late Formative northern basin.•Pukara was not the primary locus of centralized fineware production and distribution during the Late Formative.•In the southern basin, earlier local styles were superseded by standardized regional styles during the Middle Horizon.•In spite of social upheaval in the late Prehispanic periods, potters continued to share similar clay sources in the southern basin.
Potters in the Lake Titicaca basin produced a wide variety of ceramic styles over the last 3000 years. Archaeologists have drawn on this variety across space and time to track processes such as the development of multi-community polities during the Late Formative (200 BC-AD 600), the origins and expansion of Tiwanaku (AD 600–1000), the creation and maintenance of political boundaries during the Late Intermediate period (AD 1000–1400), and the strategies of Inca conquest and consolidation (AD 1400–1534). We report on LA-ICP-MS research into Titicaca ceramics and clays conducted at the Field Museum’s Elemental Analysis Facility (EAF), and present the first review of raw materials and pottery analyzed from across the region. Ceramic samples from the northern basin include samples from Taraco, Pukara, and neighboring sites, and speak to the diversity of intraregional potting practices during the Late Formative Period. Ceramic samples from the southern basin span the Middle Formative through the Inca periods, and index local and regional practices over two millennia. After presenting our specific case studies, we touch on how shifting scales of locality impact the chemical signatures explored here, the potential for comparative analyses across the region, and future directions for research collaborations.
Tiwanaku was a regionally significant, state level polity in the south-central Andes from ca. 500–1000 CE. The development of complex society in the region was greatly facilitated through intensified ...agricultural systems that relied on monsoonal precipitation. At the end of the first millennium CE, the Tiwanaku political regime collapsed, and their raised field systems were mostly abandoned within 200 years or less. It has been suggested that a prolonged period of aridity contributed to the collapse, but questions have remained about its chronology and severity. In this study, we investigated the relationship between δ2Hwax and δ18Ocalcite values, aridity and societal change. A period of nondeposition or erosion occurred between 915 and 1025 CE indicating a low lake stand exposing the core site. This extended and pronounced drought ending 1025 CE was recorded in the isotopic proxies extracted from lake sediments that show this period of aridity persisted into the 13th century. The broad agreement between our record and other regional paleoenvironmental archives of Holocene climate variability is consistent with Northern Hemisphere oceanic and atmospheric circulation patterns as a mechanism for driving centennial scale climate change in the Andes and supports the correspondence between prolonged drought and the collapse of Tiwanaku.
•A centuries long period of aridity during the Medieval Climate Anomaly corresponds with the collapse of the Tiwanaku Civilization.•Aridity shown in other proxy records throughout Peru is strongly reinforced by a new record from Lake Orurillo.•Our paleo-lake water reconstruction demonstrates that lake levels in Orurillo were severely reduced by evaporation during periods of high aridity.•Shifts in δ2Hwax and δ18Ocalcite values were most likely driven by changes in atmospheric and oceanic circulation patterns over the Atlantic.
Lakes have an important role in storing water for drinking, producing hydroelectric power, and environmental, agricultural, and industrial uses. In order to optimize the use of lakes, precise ...prediction of the lake water level (LWL) is a main issue in water resources management. Due to the existence of nonlinear relations, uncertainty, and characteristics of the time series variables, the exact prediction of the lake water level is difficult. In this study the hybrid support vector regression (SVR) and the grey wolf algorithm (GWO) are used to predict lake water level fluctuations. Also, three types of data preprocessing methods, namely Principal component analysis, Random forest, and Relief algorithm were used for finding the best input variables for prediction LWL by the SVR and SVR-GWO models. Before the LWL simulation on monthly time step using the hybrid model, an evolutionary approach based on different monthly lags was conducted for determining the best mask of the input variables. Results showed that based on the random forest method, the best scenario of the inputs was Xt−1, Xt−2, Xt−3, Xt−4 for the SVR-GWO model. Also, the performance of the SVR-GWO model indicated that it could simulate the LWL with acceptable accuracy (with RMSE = 0.08 m, MAE = 0.06 m, and R2 = 0.96).
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