scholarly journals Evaluation of monotonic trends for streamflow in austral Amazon, Brazil: a case study for the Xingu and Tapajós rivers

2015 ◽  
Vol 371 ◽  
pp. 125-130 ◽  
Author(s):  
L. Z. Moura
Keyword(s):  
River Basin ◽  
Confidence Level ◽  
Statistical Tests ◽  
River Basins ◽  
Annual Average ◽  
Southwestern Part ◽  
Southeastern Part ◽  
Xingu River ◽  
Increasing Trends

Abstract. This paper has the goal of evaluating monotonic trends in the Xingu and Tapajós river basins in the Austral Amazon region, Brazil. Non-parametric statistical tests such as Mann–Kendall, Bootstrap Mann–Kendall, Sen and Bootstrap Sen are applied on streamflow gauging stations data, to determine the significance and magnitude of possible trends. Data in these river basins is relatively scarce, with time series ranging from twenty to forty years, having many gaps. Former studies indicate a decreasing trend for both annual average and minimum streamflow values in the Tapajós river basin, with 99% confidence level, and a decrease in maximum values in the Xingu river basin, with 90% confidence level. However, past analyses have only used one station near the basin outlet. This study uses data from 7 gauging stations in the Xingu basin and 14 stations in the Tapajós basin. Results indicate opposite trends at the 95% confidence level for different regions in the basins, and for different flow regimes. For the Xingu river basin, trends in the minimum flow for different sub-basins even out at the Altamira station, near its outlet. For the Tapajós river, the southeastern part of the basin has increasing trends, while the southwestern part decreases. At the Itaituba station, they also balance out.

Another Way of Early Pottery Distribution in Eastern Europe? Case Study of the Pezmog 4 Site, European Far Northeast

Radiocarbon ◽  
2014 ◽  
Vol 56 (2) ◽  
pp. 733-741 ◽  
Author(s):  
Victor N Karmanov ◽  
Natalia E Zaretskaya ◽  
Alexander V Volokitin
Keyword(s):  
Eastern Europe ◽  
River Basin ◽  
Radiocarbon Dating ◽  
Early Stage ◽  
River Basins ◽  
Ural Region ◽  
Time Range ◽  
Forest Zone ◽  
Early Pottery

A case study of the Neolithic comb ceramic site Pezmog 4 of the Kama culture presents a situation when results of radiocarbon dating change long-existing concepts concerning the development of archaeological events. Until the early 2000s, the chronology of the Kama culture, distributed mainly in the Kama and Vychegda River basins, has been based on comparative-typological analysis. Estimates of the age of this culture changed from the 3rd millennium BC in the 1950s to the 1st half of the 4th millennium BC by the 1990s. Research concerning the Pezmog 4 site in the central Vychegda River basin in 1999–2002 has abruptly changed this chronological understanding. The data obtained put the age of the early stage of Kama culture within the time range 5750–5620 cal BC and allowed us to propose the existence of another way of early pottery distribution in the forest zone of eastern Europe at the beginning of the 6th millennium BC. This innovation probably penetrated from the trans-Ural region.

scholarly journals New records of fishes (Actinopterygii: Ostariophysi) from the Upper Tapajós River Basin

Check List ◽  
2012 ◽  
Vol 8 (3) ◽  
pp. 592 ◽  
Author(s):  
Fernando C. P. Dagosta ◽  
Murilo N. L. Pastana ◽  
André L. H. Esguícero
Keyword(s):  
River Basin ◽  
New Records ◽  
River Basins ◽  
Amazon River ◽  
First Report ◽  
Xingu River ◽  
Coastal Rivers

The first report of Sartor (Anostomidae) and Tatia intermedia (Auchenipteridae) for the Upper Tapajós River Basin are presented here. Sartor is very rare on collections, and is reported only from the Trombetas, Tocantins and Upper Xingu river basins. Tatia intermedia is registered in the upper reaches of the Araguaia, Tocantins, Xingu, and Capim rivers, tributaries of the lower Amazon River in Brazil, northwards to the Suriname coastal rivers and the Essequibo River in Guyana.

scholarly journals Land Use/Cover Change Effects on River Basin Hydrological Processes Based on a Modified Soil and Water Assessment Tool: A Case Study of the Heihe River Basin in Northwest China’s Arid Region

2019 ◽  
Vol 11 (4) ◽  
pp. 1072 ◽  
Author(s):  
Xin Jin ◽  
Yanxiang Jin ◽  
Xufeng Mao
Keyword(s):  
Land Use ◽  
River Basin ◽  
Assessment Tool ◽  
River Basins ◽  
Climatic Conditions ◽  
Hydrological Processes ◽  
Heihe River ◽  
Distributed Models ◽  
The Subject ◽  
Increasing Trends

Land use/cover change (LUCC) affects canopy interception, soil infiltration, land-surface evapotranspiration (ET), and other hydrological parameters during rainfall, which in turn affects the hydrological regimes and runoff mechanisms of river basins. Physically based distributed (or semi-distributed) models play an important role in interpreting and predicting the effects of LUCC on the hydrological processes of river basins. However, conventional distributed (or semi-distributed) models, such as the soil and water assessment tool (SWAT), generally assume that no LUCC takes place during the simulation period to simplify the computation process. When applying the SWAT, the subject river basin is subdivided into multiple hydrologic response units (HRUs) based on the land use/cover type, soil type, and surface slope. The land use/cover type is assumed to remain constant throughout the simulation period, which limits the ability to interpret and predict the effects of LUCC on hydrological processes in the subject river basin. To overcome this limitation, a modified SWAT (LU-SWAT) was developed that incorporates annual land use/cover data to simulate LUCC effects on hydrological processes under different climatic conditions. To validate this approach, this modified model and two other models (one model based on the 2000 land use map, called SWAT 1; one model based on the 2009 land use map, called SWAT 2) were applied to the middle reaches of the Heihe River in northwest China; this region is most affected by human activity. Study results indicated that from 1990 to 2009, farmland, forest, and urban areas all showed increasing trends, while grassland and bare land areas showed decreasing trends. Primary land use changes in the study area were from grassland to farmland and from bare land to forest. During this same period, surface runoff, groundwater runoff, and total water yield showed decreasing trends, while lateral flow and ET volume showed increasing trends under dry, wet, and normal conditions. Changes in the various hydrological parameters were most evident under dry and normal climatic conditions. Based on the existing research of the middle reaches of the Heihe River, and a comparison of the other two models from this study, the modified LU-SWAT developed in this study outperformed the conventional SWAT when predicting the effects of LUCC on the hydrological processes of river basins.

scholarly journals GEOSPATIAL ASSESSMENT OF VULNERABILITIES OF CROPLANDS TO FLOODING RISKS: A CASE STUDY OF PHILIPPINE RIVER BASINS

2019 ◽  
Vol XLII-4/W19 ◽  
pp. 173-180
Author(s):  
D. M. G. dela Torre ◽  
P. K. A. dela Cruz ◽  
R. P. Jose ◽  
N. B. Gatdula ◽  
A. C. Blanco
Keyword(s):  
Adaptive Capacity ◽  
River Basin ◽  
River Basins ◽  
High Poverty ◽  
Analytic Hierarchical Process ◽  
Vulnerability Maps ◽  
Flooding Risk ◽  
Agricultural Areas ◽  
Agricultural Regions

Abstract. This study utilized the Analytic Hierarchical Process and spatial analysis using various datasets to produce sub-provincial vulnerability maps with 20 km resolution. Five (5) indicators for exposure, four (4) for sensitivity and seven (7) for adaptive capacity were selected and weighted using aggregated rankings from twenty-three (23) experts. Based on these indicators, gridded maps of exposure, sensitivity, adaptive capacity, and vulnerability were produced. Using river basins as the unit of analysis, the Pampanga River Basin was determined to be the most vulnerable, followed by the Agus River Basin, having the highest sensitivity, and Buayan River Basin, having the lowest adaptive capacity. These areas have large agricultural regions and river systems with high flooding risk. Coastal regions in southern Mindanao and eastern Visayas were also highly vulnerable to flooding. High poverty rates with high dependence on agricultural incomes and low adaptive capacities characterize these areas. Vulnerability hotspots can easily be identified through these maps, which have value in planning initiative to reduce potential damages of floods to agricultural areas.

scholarly journals Evapotranspiration and Precipitation over Pasture and Soybean Areas in the Xingu River Basin, an Expanding Amazonian Agricultural Frontier

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1112
Author(s):  
Gabriel de Oliveira ◽  
Jing M. Chen ◽  
Guilherme A. V. Mataveli ◽  
Michel E. D. Chaves ◽  
Jing Rao ◽  
...  
Keyword(s):  
River Basin ◽  
Climate Impacts ◽  
Primary Forest ◽  
Annual Average ◽  
Agricultural Frontier ◽  
Xingu River ◽  
Primary Finding ◽  
Northern Portion ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer

The conversion from primary forest to agriculture drives widespread changes that have the potential to modify the hydroclimatology of the Xingu River Basin. Moreover, climate impacts over eastern Amazonia have been strongly related to pasture and soybean expansion. This study carries out a remote-sensing, spatial-temporal approach to analyze inter- and intra-annual patterns in evapotranspiration (ET) and precipitation (PPT) over pasture and soybean areas in the Xingu River Basin during a 13-year period. We used ET estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS) and PPT estimates from the Tropical Rainfall Measurement Mission (TRMM) satellite. Our results showed that the annual average ET in the pasture was ~20% lower than the annual average in soybean areas. We show that PPT is notably higher in the northern part of the Xingu River Basin than the drier southern part. ET, on the other hand, appears to be strongly linked to land-use and land-cover (LULC) patterns in the Xingu River Basin. Lower annual ET averages occur in southern areas where dominant LULC is savanna, pasture, and soybean, while more intense ET is observed over primary forests (northern portion of the basin). The primary finding of our study is related to the fact that the seasonality patterns of ET can be strongly linked to LULC in the Xingu River Basin. Further studies should focus on the relationship between ET, gross primary productivity, and water-use efficiency in order to better understand the coupling between water and carbon cycling over this expanding Amazonian agricultural frontier.

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