Mapping potential impacts of dams and reservoirs in South America

2021 ◽  
Author(s):  
Bolivar Paredes-Beltran ◽  
Alvaro Sordo-Ward ◽  
Luis Garrote
Keyword(s):  
South America ◽  
Water Storage ◽  
Annual Runoff ◽  
Eastern Region ◽  
Total Water ◽  
The South ◽  
Flow Alteration ◽  
Continental Scale ◽  
The North ◽  
Resource Managers

<p>We present a continental-scale evaluation of the distribution of dams and reservoirs in South America. This analysis is relevant to estimate potential impacts on water supply and flow alteration. A combined total of 808 of the largest dams across the continent, which can store about 1,003 cubic kilometres of water, were evaluated. We divided the area of study into 27 hydrological regions and for each region we determined necessary inputs to assess the potential impacts of dams and reservoirs such as: total area, mean annual runoff, total storage volume, population, or equipped area for irrigation. Although the storage capacity of the reservoirs represents around 10% of the region's total mean annual runoff, the potential impacts for flow alteration differ considerably between hydrological regions because dams and reservoirs are not evenly distributed in South America. Whilst in some hydrological regions in the north, including the Amazon river, water storage from reservoirs represents less than 5% of their mean annual runoff, some hydrological regions in the south of the continent can store the equivalent of 2 to 3 years of their mean annual runoff. The region with the highest potential for hydrological impacts is the Rio Colorado basin in Argentina, where storage from reservoirs can be almost 3.5 times the region’s mean annual runoff. The observed variations in water storage can be explained by the diversity in hydrology and water demands of the different hydrological regions of the continent. For example, water storage for hydropower purposes represents about 85% of the total water storage in the continent. Also, the highest number of dams exclusively allocated for hydropower production are located in the east of the continent in Argentina and Brazil. The hydrological region with the highest ratio of water storage is “La Plata” in the southeast of the continent with approximately 35% of the total water storage of the continent.  In addition, almost 70% of dams are located in humid or sub-humid areas. In average, the dams in the continent can store 9,700 m<sup>3</sup> of water per person and 161,000 m<sup>3</sup> of water per hectare equipped for irrigation. The regions with the highest concentration of dams are Venezuela and the eastern region of Brazil, while the regions with the least number of dams per area are found in the northeast of Brazil and the south of the continent. These ratios may be useful to understand the potential effects of dams and reservoirs on a regional and continental scale, considering that development plans in several countries include many new dams across the continent. With this study, we expect to provide valuable insights to researchers and water resource managers about the current and future potential impacts of dams and reservoirs in South America.</p>

The Status of Economic Entomology in Peru

1929 ◽  
Vol 20 (2) ◽  
pp. 225-231
Author(s):  
George N. Wolcott
Keyword(s):  
South America ◽  
Ocean Current ◽  
High Mountains ◽  
The South ◽  
Humboldt Current ◽  
The North ◽  
The Status

The map of South America shows Peru as a rather long, narrow country, broadening at the north, and presumably tropical in climate judging by its position just south of the Equator, but with high mountains close to the coast. But it does not show the cold ocean current coming from the south—the Humboldt Current—or ar least we are not accustomed to noticing such presumably minor features, even though in the case of Peru, this is equal in importance with the mountains in determining the climate of the country and every factor that the climate may affect.

scholarly journals Precipitation and Water Vapor Transport in the Southern Hemisphere with Emphasis on the South American Region

2009 ◽  
Vol 48 (9) ◽  
pp. 1902-1912 ◽  
Author(s):  
Josefina Moraes Arraut ◽  
Prakki Satyamurty
Keyword(s):  
Water Vapor ◽  
South America ◽  
North Atlantic ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
The South ◽  
Meridional Transport ◽  
Moisture Flow ◽  
The North ◽  
The North Atlantic

Abstract December–March climatologies of precipitation and vertically integrated water vapor transport were analyzed and compared to find the main paths by which moisture is fed to high-rainfall regions in the Southern Hemisphere in this season. The southern tropics (20°S–0°) exhibit high rainfall and receive ample moisture from the northern trades, except in the eastern Pacific and the Atlantic Oceans. This interhemispheric flow is particularly important for Amazonian rainfall, establishing the North Atlantic as the main source of moisture for the forest during its main rainy season. In the subtropics the rainfall distribution is very heterogeneous. The meridional average of precipitation between 35° and 25°S is well modulated by the meridional water vapor transport through the 25°S latitude circle, being greater where this transport is from the north and smaller where it is from the south. In South America, to the east of the Andes, the moisture that fuels precipitation between 20° and 30°S comes from both the tropical South and North Atlantic Oceans whereas between 30° and 40°S it comes mostly from the North Atlantic after passing over the Amazonian rain forest. The meridional transport (across 25°S) curve exhibits a double peak over South America and the adjacent Atlantic, which is closely reproduced in the mean rainfall curve. This corresponds to two local maxima in the two-dimensional field of meridional transport: the moisture corridor from Amazonia into the continental subtropics and the moisture flow coming from the southern tropical Atlantic into the subtropical portion of the South Atlantic convergence zone. These two narrow pathways of intense moisture flow could be suitably called “aerial rivers.” Their longitudinal positions are well defined. The yearly deviations from climatology for moisture flow and rainfall correlate well (0.75) for the continental peak but not for the oceanic peak (0.23). The structure of two maxima is produced by the effect of transients in the time scale of days.

Geodynamic study of the north of the Andes block (Colombia, Panama, Ecuador and Venezuela) through gnss-gps: models of displacements, models of deformation and definition of local and regional geodynamic structures.

2020 ◽  
Author(s):  
Berrocoso Manuel ◽  
Del Valle Arroyo Pablo Emilio ◽  
Colorado Jaramillo David Julián ◽  
Gárate Jorge ◽  
Fernández-Ros Alberto ◽  
...  
Keyword(s):  
South America ◽  
Seismic Activity ◽  
Great Part ◽  
Velocity Model ◽  
South American ◽  
The South ◽  
South American Plate ◽  
Northern Andes ◽  
Velocity Models ◽  
The North

<p>The northwest of South America is conformed by the territories of Ecuador, Colombia and Venezuela. Great part of these territories make up the Northern Andes Block (BAN). The tectonic and volcanic activity in the northwest of South America is directly related to the interaction of the South American plate, and the Nazca and Caribbean plates, with the Maracaibo and Panama-Chocó micro plates. The high seismic activity and the high magnitude of the recorded earthquakes make any study necessary to define this complex geodynamic region more precisely. This work presents the velocity models obtained through GNSS-GPS observations obtained in public continuous monitoring stations in the region. The observations of the Magna-eco network (Agustín Codazzi Geographic Institute) are integrated with models already obtained by other authors from the observations of the GEORED network (Colombian Geological Service). The observations have been processed using Bernese software v.52 using the PPP technique; obtaining topocentric time series. To obtain the speeds, a process of filtering and adjustment of the topocentric series has been carried out. Based on this velocity model, regional structures have been defined within the Northern Andes Block through a differentiation process based on the corresponding speeds of the South American, Nazca and Caribbean tectonic plates. Local geodynamic structures within the BAN itself have been established through cluster analysis based on both the direction and the magnitude of each of the vectors obtained. Finally, these structures have been correlated with the most significant geodynamic elements (fractures, faults, subduction processes, etc.) and with the associated seismic activity.</p>

Growing multicentennial-scale precipitation variability in Eastern Brazil during the late Holocene

2020 ◽  
Author(s):  
André Bahr ◽  
Stefanie Kaboth-Bahr ◽  
Andrea Jaeschke ◽  
Christiano Chiessi ◽  
Francisco Cruz ◽  
...  
Keyword(s):  
South America ◽  
North Atlantic ◽  
Precipitation Amount ◽  
Moisture Distribution ◽  
The South ◽  
The Past ◽  
The North ◽  
Eastern Brazil ◽  
Future Global Warming ◽  
The North Atlantic

<p>Eastern Brazil belongs to the ecologically most vulnerable regions on Earth due to its extreme intra- and inter-annual variability in precipitation amount. In order to constrain the driving forces behind this strong natural fluctuations we investigated a high-resolution sediment core taken off the Jequitinhonha river mouth in central E Brazil to reconstruct Holocene river run-off and moisture availability in the river’s catchment. Modern day climate in the hinterland of the Jequitinhonha is influenced by the South American Summer Monsoon (SASM), in particular by the manifestation of the South Atlantic Convergence Zone (SACZ) during austral summer. Variations in the position and strength of the SACZ will have immediate impact on the moisture balance over the continent and hence influence sediment and water delivery. Our multi-proxy records, comprising XRF core-scanning, grain size, mineralogical (XRD), as well as organic biomarker analyses indicate abrupt centennial scale variations between dry and wet conditions throughout the past ~5 kyrs. Our results document a gradual weakening of the SASM over the past ~2,7 kyrs driven by changes in the intertropical heat distribution. This long-term trend is superposed by centennial to millennial-scale spatial shifts in moisture distribution that result from migrations of the SACZ. The combination of both processes caused increasingly pronounced aridity spells in eastern South America over the past 2 kyrs. As the spatial fluctuations were triggered by freshwater anomalies in the North Atlantic, we surmise that enhanced meltwater input into the North Atlantic due to future global warming might severely increase the risk for mega-droughts in tropical South America.</p>

Ecogeography and the Great American Interchange

Paleobiology ◽  
1991 ◽  
Vol 17 (3) ◽  
pp. 266-280 ◽  
Author(s):  
S. David Webb
Keyword(s):  
North America ◽  
South America ◽  
North American ◽  
Mammalian Fauna ◽  
The South ◽  
Land Bridge ◽  
Southern Mexico ◽  
The North ◽  
Land Mammal ◽  
The Impact

When the isthmian land bridge triggered the Great American Interchange, a large majority of land-mammal families crossed reciprocally between North and South America at about 2.5 Ma (i.e., Late Pliocene). Initially land-mammal dynamics proceeded as predicted by equilibrium theory, with roughly equal reciprocal mingling on both continents. Also as predicted, the impact of the interchange faded in North America after about 1 m.y. In South America, contrary to such predictions, the interchange became decidedly unbalanced: during the Pleistocene, groups of North American origin continued to diversify at exponential rates. Whereas only about 10% of North American genera are derived from southern immigrants, more than half of the modern mammalian fauna of South America, measured at the generic level, stems from northern immigrants. In addition, extinctions more severely decimated interchange taxa in North America, where six families were lost, than in South America, where only two immigrant families became extinct.This paper presents a two-phase ecogeographic model to explain the asymmetrical results of the land-mammal interchange. During the humid interglacial phase, the tropics were dominated by rain forests, and the principal biotic movement was from Amazonia to Central America and southern Mexico. During the more arid glacial phase, savanna habitats extended broadly right through tropical latitudes. Because the source area in the temperate north was six times as large as that in the south, immigrants from the north outnumbered those from the south. One prediction of this hypothesis is that immigrants from the north generally should reach higher latitudes in South America than the opposing contingent of land-mammal taxa in North America. Another prediction is that successful interchange families from the north should experience much of their phylogenetic diversification in low latitudes of North America before the interchange. Insofar as these predictions can be tested, they appear to be upheld.

scholarly journals Seasonal variability and anomalies of the currents of the cyclonic gyre in the northeastern sector of Caspian sea

2019 ◽  
Vol 46 (5) ◽  
pp. 485-495
Author(s):  
A. K. Ambrosimov
Keyword(s):  
Experimental Data ◽  
Caspian Sea ◽  
Cold Water ◽  
Eastern Region ◽  
Cyclonic Gyre ◽  
Southern Slope ◽  
The South ◽  
Near Surface ◽  
The North ◽  
North Eastern

The experimental data presented in the article show that in the North-Eastern sector of the Middle Caspian sea in the area of Peschanomyssky uplift there is a disturbance of currents caused by the interaction of the cyclonic cycle with the southern slope of the uplift. As a result of this interaction, the waters of the cyclonic cycle are divided into branches – the lower and upper. The lower bottom branch is thrown by the uplift in the South-Western direction, where at the Cape of the uplift it collides with the waters flowing down the bottom of the South-Buzachinsky deflection in the South-Eastern direction, and the upper branch, consisting of near-surface and intermediate cold waters, is pushed up and passes through the uplift. As a result of the rise of cold water in the surface layer formed upwelling, which extends to the entire North-Eastern region of the sea.

scholarly journals Water Vapor Changes Affect Cross-Seasonal Strong Drought Events in the Eastern Region of Northwest China

2021 ◽  
Vol 9 ◽  
Author(s):  
Yu Zhang ◽  
Kang Liu ◽  
Yaohui Li ◽  
Wei Shen ◽  
Yulong Ren ◽  
...  
Keyword(s):  
Water Vapor ◽  
Global Climate ◽  
Northwest China ◽  
Water Vapor Transport ◽  
Eastern Region ◽  
The South ◽  
Vapor Flux ◽  
Weather Forecasts ◽  
The North ◽  
Depth Study

Drought in eastern Northwest China (ENC) is severely affected by water vapor conditions. An in-depth study of the primary sources of water vapor and its characteristics, at intraseasonal and interannual timescales, was conducted. This information is crucial for further study of the causes and mechanisms of extreme droughts and floods in the ENC. This study evaluated the spatial distribution and transport characteristics of water vapor over ENC during the 1981–2019 period based on the fifth generation of the European Center for Medium-Range Weather Forecasts atmospheric reanalyzes data of the global climate (ERA5). We studied the water vapor transport routes, water vapor convergence, water vapor budgets as well as the changes in water vapor fluxes and budgets over time in four areas surrounding ENC. The Mediterranean Sea, Black Sea, Caspian Sea, Indian Ocean, Bay of Bengal, and the South China Sea were the main sources of water vapor in ENC, supplemented by mid to high-latitude continental sources. The monthly change in water vapor flux in ENC exhibited the peak on July. The transport of water vapor in ENC was mainly toward the east and north. For most cross-seasonal drought events, the water vapor output is the main way in the south boundary and the west boundary. However, for the longest duration of cross-seasonal strong drought events, it is characterized by that the water vapor output is the main way in the south boundary, while the water vapor input in the north boundary is obviously weak. Water vapor paths in cross-seasonal strong drought events are analyzed, by which the Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT). The intensity of the subtropical high in the western Pacific is weak and the position is south, which corresponds to the occurrence of cross-seasonal strong drought in the ENC.

DISTRIBUTION AND BIOLOGY OF INVASIVE SPECIES OF BEAN BRUCHID ACANTHOSCELIDES OBTECTUS (INSECTA, COLEOPTERA, BRUCHIDAE)

2021 ◽  
Vol 14 (4) ◽  
pp. 54-76
Author(s):  
V. G. Kaplin
Keyword(s):  
South America ◽  
Common Bean ◽  
Climate Warming ◽  
Anthropogenic Factors ◽  
Acanthoscelides Obtectus ◽  
The South ◽  
The North ◽  
Literary Sources ◽  
European Part Of Russia ◽  
Primary Habitat

The review of literary sources on ecology, biology, distribution of bean bruchid ( Acanthoscelides obtectus ) and its main food plant - Phaseolus vulgaris in North and South America; Europe, Africa, Asia, Australia and more details in Russia; the influence of abiotic, biotic and anthropogenic factors on the invasive process, phytosanitary condition of common bean crops in Russia is presented. Some aspects of the invader management are shown. The main stages and areas of cultivation of common bean and invasion of bean bruchid from their primary habitat in South America and in the south of North America are traced; the vectors and reasons causing them are considered. In Russia, the economic importance of bean bruchid has increased since the mid-1980s, which coincided with the climate warming; there was an expansion of its distribution in the eastern and north-western directions. At the last decades of the 20th century, it had penetrated in Smolensk and in the south part of the Tver and the Tomsk regions. With the increase in production of beans in Russia, the lack of systemic protection from bean bruchid and further increase of climate warming will contribute to the extension of its range to the north in the European part of Russia and the Urals to 57-58° N. Lat., where the conditions of the summer period are favorable for development of common bean and bean bruchid. To the east, it may spread to Tyva, Buryatia, the Trans-Baikal territory, the Amur region, the Jewish Autonomous region, and the southern part of the Khabarovsk territory. With the introduction of strict internal quarantine and a system of protection of common bean from this pest, which prevents the spread of infected dry bean, on the contrary, it is possible to reduce the distribution range of the bean bruchid, with its disappearance in the Siberian, Ural districts, Bashkortostan and Tatarstan.

scholarly journals Effects of a Groundwater Scheme on the Simulation of Soil Moisture and Evapotranspiration over Southern South America

2016 ◽  
Vol 17 (11) ◽  
pp. 2941-2957 ◽  
Author(s):  
J. Alejandro Martinez ◽  
Francina Dominguez ◽  
Gonzalo Miguez-Macho
Keyword(s):  
South America ◽  
Land Surface ◽  
Climate Model ◽  
Soil Column ◽  
Water Storage ◽  
Surface Model ◽  
Southern South America ◽  
La Plata ◽  
Continental Scale ◽  
La Plata Basin

Abstract The effects of groundwater dynamics on the representation of water storage and evapotranspiration (ET) over southern South America are studied from simulations with the Noah-MP land surface model. The model is run with three different configurations: one including the Miguez-Macho and Fan groundwater scheme, another with the Simple Groundwater Model (SIMGM), and the other with free drainage at the bottom of the soil column. The first objective is to assess the effects of the groundwater schemes using a grid size typical of regional climate model simulations at the continental scale (20 km). The phase and amplitude of the fluctuations in the terrestrial water storage over the southern Amazon are improved with one of the groundwater schemes. An increase in the moisture in the top 2 m of the soil is found in those regions where the water table is closer to the land surface, including the western and southern Amazon and the La Plata basin. This induces an increase in ET over the southern La Plata basin, where ET is water limited. There is also a seasonal increase in ET during the dry season over parts of the southern Amazon. The second objective is to assess the role of the horizontal resolution on the effects induced by the Miguez-Macho and Fan groundwater scheme using simulations with grid sizes of 5 and 20 km. Over the La Plata basin, the effect of groundwater on ET is amplified at the 5-km resolution. Notably, over parts of the Amazon, the groundwater scheme increases ET only at the higher 5-km resolution.

scholarly journals BURIALS OF THE EARLY BRONZE AGE IN MOUNTAIN REGIONS OF THE SOUTH-EAST OF AZERBAIJAN

2021 ◽  
Vol 17 (2) ◽  
pp. 387-402
Author(s):  
Anar Mirsamid Agalarzade
Keyword(s):  
Bronze Age ◽  
Breeding Population ◽  
Early Bronze Age ◽  
Mountainous Area ◽  
Eastern Region ◽  
The South ◽  
Cattle Breeding ◽  
South Eastern ◽  
The North ◽  
Burial Customs

The paper deals with the results of excavations carried out in recent years in the Early Bronze Age kurgans in the mountainous part of the south-eastern region of Azerbaijan. It has been determined that there are several types of burial customs of this period in these small kurgans located on the Komani plateau between Kurekchi and Arvana villages of Yardimly district, on the Azerbaijan - Iran border. Although the Early Bronze Age Telmankend kurgans were excavated in the foothills of the region in the 1960s, such monuments were not excavated or even registered in the highlands. at these grave monuments, which were first discovered by us in the summer pastures in 2014, archaeological excavations began in 2018, and four kurgans were excavated here. Komani kurgans, built at an altitude of 2000 m above sea level, are important in terms of studying the burial customs of the Early Bronze Age semi-nomadic cattle-breeding population. Excavations of Komani kurgans have revealed that the high mountainous area of the south-eastern region of Azerbaijan had been used by the cattle-breeding population since the Early Bronze Age, where they were engaged in seasonal farming and carried out their burials. The lack of grave goods during the burial is explained by their temporary residence in the summer pastures. Undoubtedly, the presence of short-term settlements of cattle-breeding tribes near the kurgans is no exception. Building of Early Bronze Age Komani kurgans in the afore-said area from the chronological viewpoint is distinguished due to their small size. As for the later stages of the Bronze Age, dozens of big kurgans can be found here. However, no archeological excavations have been carried out in any of them so far. Similar burial customs and materials of Komani kurgans are mostly found in the Early Bronze Age monuments of Nakhchivan. Similar burials can be found in other coeval grave monuments of Azerbaijan and in the north-eastern provinces of Iran.

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