scholarly journals Avaliação da aplicação de modelos de desprendimento em bacia experimental do semiárido brasileiro

2021 ◽  
Vol 14 (1) ◽  
pp. 396
Author(s):  
Paulo Roberto De Souza Silveira ◽  
George Leite Mamede
Keyword(s):  
Arid Region ◽  
Daily Precipitation ◽  
Drainage Network ◽  
Catchment Basin ◽  
Caatinga Biome ◽  
Slope Sediment ◽  
Main Factors ◽  
Semi Arid Region ◽  
Experimental Basin ◽  
Semi Arid

Granulometria é um dos principais fatores que afetam a dinâmica de sedimentos em bacias hidrográficas, desde seu desprendimento do solo matriz até o transporte ou deposição pela rede e reservatório. Objetivou-se com esse trabalho analisar o comportamento granulométrico dos sedimentos em uma bacia do semiárido brasileiro, no bioma Caatinga e analisar a eficiência da aplicação de modelos de estimativa do padrão granulométrico do sedimentos desprendido das encostas. O estudo foi realizado na bacia hidrográfica do Pentecoste, situada no semiárido do Ceará. A parte experimental da pesquisa foi realizada na Bacia Experimental do Vale do Curú (BEVC) com coleta de dados pluviométricos e hidrossedimentológicos, amostras de solo da bacia de captação, precipitação diária e de escoamentos superficiais, durante a quadra chuvosa entre os anos de 2015 e 2017. Modelos de desprendimento de sedimentos divulgados na literatura foram testados e aplicados para a área de estudo. Os resultados mostraram que o modelo de desprendimento de sedimento da encosta proposto por Foster et al. (1981) apresentou os melhores resultados quando comparado aos demais, com coeficiente de Nash e Sutcliff (NS) de 0,99, em ambiente de cobertura vegetal mista. Evaluation of the application of detachment models in the experimental basin of the Brazilian semi-arid region A B S T R A C TSize grain is one of the main factors that affect sediment dynamics in watersheds, from its detachment from the soil to the transport or deposition through the drainage network and reservoir. The objective of this research was to analyze the granulometric behavior of the sediments in a Brazilian semi-arid basin in the Caatinga biome and to analyze the efficiency of the application of models for the estimation of the granulometric pattern of sediments detached on slopes. The study was carried out in the Pentecost basin, located in the semi-arid region of Ceará. The experimental part of the research was conducted in the Curú Valley Experimental Basin (BEVC) with rainfall and hydrosedimentological data collection, soil samples from the catchment basin, daily precipitation and surface runoff during the rainy season between 2015 and 2017. Models of sediment release disclosed in the literature were tested and applied to the study area. The results showed that the slope sediment detachment model proposed by Foster et al. (1981) presented the best results when compared to the others, with Nash and Sutcliff coefficient (NS) of 0.99, under mixed vegetation cover.Keywords: size grain, Foster model, Experimental Basin of the Curú Valley, Caatinga biome.

scholarly journals Complexity and predictability of daily precipitation in a semi-arid region: an application to Ceará, Brazil

2006 ◽  
Vol 13 (6) ◽  
pp. 651-659 ◽  
Author(s):  
M. E. S. Silva ◽  
L. M. V. Carvalho ◽  
M. A. F. da Silva Dias ◽  
T. de M. B. S. Xavier
Keyword(s):  
Arid Region ◽  
Daily Precipitation ◽  
Large Degree ◽  
Inter Tropical Convergence Zone ◽  
Periodic Sequences ◽  
Precipitation Regimes ◽  
Ocean Topography ◽  
Semi Arid Region ◽  
Precipitation Records ◽  
Semi Arid

Abstract. Complexity and predictability of daily precipitation in a tropical semi-arid region (Ceará State, Brazil) is assessed by applying entropy concepts. Precipitation regimes in that region depend on several dynamical forcings, the most important being the displacement and activity of the Inter-tropical Convergence Zone in the Atlantic Ocean. Topography is another important factor that influences the spatial distribution of rainfall in the region. A hierarchical approach based on sequences of events of different lengths is used to estimate complexity of daily precipitation records. It is shown that precipitation in Ceará exhibit more random than periodic sequences, which indicates a large degree of complexity. Nevertheless, there is indication of potentially inherent rules in the precipitation time-series that could ultimately improve prediction on time-scales between 9–11 days. It is suggested that synoptic-scale disturbances (1–8 days) represent important sources of rules in the precipitation regimes in this region.

scholarly journals Spatial-temporal variation in coiled and straight morphotypes of Cylindrospermopsis raciborskii (Wolsz) Seenayya et Subba Raju (Cyanobacteria)

2010 ◽  
Vol 24 (2) ◽  
pp. 585-591 ◽  
Author(s):  
Ênio Wocyli Dantas ◽  
Maria do Carmo Bittencourt-Oliveira ◽  
Ariadne do Nascimento Moura
Keyword(s):  
Arid Region ◽  
Thermal Stratification ◽  
Cylindrospermopsis Raciborskii ◽  
Temporal Behavior ◽  
Mixed Condition ◽  
Ecological Success ◽  
Main Factors ◽  
Semi Arid Region ◽  
Sampling Times ◽  
Semi Arid

This study reports the spatial and temporal behavior of straight and coiled morphotypes of C. raciborskii in a reservoir in Brazil's semi-arid region as well as the main factors responsible for the variability. Two set of samples were collected from the subsurface and bottom in the central region of a reservoir in two seasonal periods (dry - January 2005; rainy - June 2005) over 20-hour sampling periods during daylight (8 am, 12 pm and 4 pm) and dark (8 pm, 12 am and 4 am) hours. Measurements of abiotic parameters were determined concurrently to the sampling of biotic variables. Two C. raciborskii morphotypes were found in the reservoir: straight and coiled. There was no difference in density of the straight and coiled C. raciborskii morphotypes between the different sampling times for either season. Vertical differences were found in the distribution of both morphotypes in both seasons, with greater densities recorded at the subsurface. Densities of the two C. raciborskii morphotypes were greater in the dry season, with the density of the coiled morphotype at the surface two-fold greater than that of the straight morphotype and that found in the rainy season. The ecological success of the coiled morphotype was due to thermal stratification, whereas a mixed condition was determinant in the success of the straight morphotype.

scholarly journals Spatial variability of soil attributes in an experimental basin in the semi-arid region of Pernambuco, Brazil

2018 ◽  
Vol 22 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Diego C. dos S. Araújo ◽  
Suzana M. G. L. Montenegro ◽  
Abelardo A. de A. Montenegro ◽  
Valdemir de P. e Silva Junior ◽  
Sylvana M. dos Santos
Keyword(s):  
Bulk Density ◽  
Spatial Dependence ◽  
Arid Region ◽  
Spatial Dynamics ◽  
Chemical Properties ◽  
Soil Attributes ◽  
Semi Arid Region ◽  
Physical And Chemical ◽  
Experimental Basin ◽  
Semi Arid

ABSTRACT This study aimed to evaluate the spatial patterns of physical and chemical properties of a soil in an experimental basin with an area of 149 km2, located in the municipality of Pesqueira, in the semi-arid region of Pernambuco state (Brazil). Samples were taken in the layers of 0-0.10 and 0.10-0.20 m, at 35 monitoring points distributed in an irregular grid, encompassing the three soil classes present in the basin and commonly found in the semi-arid region. For the attributes of soil texture, organic carbon and bulk density in the layer of 0.10-0.20 m, spatial dependence from medium to strong was detected, ranging from 0.03 to 49.98%. Bulk density in the layer 0-0.10 m, as well as the electrical conductivity, in both layers, showed pure nugget effect, possibly due to insufficient sampling distance to capture spatial dependence. However, geostatistics represented well the spatial dynamics of soil attributes at points where the mapping is possible.

scholarly journals Determining the Soil Erodibility for an Experimental Basin in the Semi-Arid Region Using Geoprocessing

2017 ◽  
Vol 08 (12) ◽  
pp. 3174-3188 ◽  
Author(s):  
Erich Celestino Braga Pereira ◽  
Fernando Bezerra Lopes ◽  
Francisco Emanoel Firmino Gomes ◽  
Aldênia Mendes Masceno de Almeida ◽  
Ana Caroline Messias de Magalhães ◽  
...  
Keyword(s):  
Arid Region ◽  
Soil Erodibility ◽  
Semi Arid Region ◽  
Experimental Basin ◽  
Semi Arid

Gaya xiquexiquensis (Malvaceae, Malvoideae), a new species from Bahia state, Brazil

Phytotaxa ◽  
2015 ◽  
Vol 207 (2) ◽  
pp. 205
Author(s):  
Catia Takeuchi ◽  
Gerleni Lopes Esteves
Keyword(s):  
New Species ◽  
Arid Region ◽  
Conservation Status ◽  
The State ◽  
Morphological Description ◽  
Ecological Data ◽  
Caatinga Biome ◽  
Semi Arid Region ◽  
A New Species ◽  
Semi Arid

Gaya xiquexiquensis is a new species from the state of Bahia, Brazil. This species is known only from the municipality of Xique-Xique, growing in the Caatinga biome of the Brazilian semi-arid region. Gaya xiquexiquensis is morphologically similar to Gaya aurea A. St.-Hil. We here in present its morphological description, illustrations, as well as ecological data and conservation status.

scholarly journals Agro-economic performance of the association of beet with green cowpea in different amounts of hairy woodrose

2018 ◽  
Vol 22 (3) ◽  
pp. 194-199 ◽  
Author(s):  
Daciano M. de Sousa ◽  
Francisco Bezerra Neto ◽  
Jailma S. S. de Lima ◽  
Grace K. L. de Lima ◽  
Aridênia P. Chaves ◽  
...  
Keyword(s):  
Economic Performance ◽  
Green Manure ◽  
Arid Region ◽  
Block Design ◽  
Arid Conditions ◽  
Randomized Complete Block Design ◽  
Caatinga Biome ◽  
Semi Arid Region ◽  
Brazilian Northeast ◽  
Semi Arid

ABSTRACT Intercropping systems of beet and green cowpea are beginning to be implemented in the northeastern semi-arid region in Brazil. The great challenge is to know if there is agro-economic efficiency in these systems when fertilized with organic matter produced by spontaneous species of the Caatinga biome. Thus, the objective of this research was to evaluate the effect of green manuring using different amounts of hairy woodrose (Merremia aegyptia) in the association of beet with green cowpea under the semi-arid conditions. The experiment was carried out at the Rafael Fernandes Experimental Farm, rural area of Mossoró, RN, Brazil, in the period of September-December 2015, in a randomized complete block design with four treatments and five replicates. The treatments consisted of hairy woodrose amounts incorporated into the soil (10, 25, 40, 55 t ha-1 on a dry basis). The cultivars of beet and green cowpea planted were ‘Early Wonder’ and ‘BRS Itaim’, recommended for the semi-arid conditions of the Brazilian Northeast. The best agro-economic performance for intercropping system of beet and green cowpea was obtained with 55 t ha-1 of hairy woodrose incorporated in the soil. The use of the hairy woodrose species as green manure is agronomically viable in intercropped systems with beet and green cowpea.

scholarly journals Vascular flora of semi-arid region, São José do Piauí, state of Piauí, Brazil

Check List ◽  
2009 ◽  
Vol 6 (1) ◽  
pp. 039 ◽  
Author(s):  
Maura Rejane de Araújo Mendes ◽  
Antonio Alberto Jorge Farias Castro
Keyword(s):  
New Species ◽  
Sea Level ◽  
Arid Region ◽  
Northeastern Brazil ◽  
Local Conditions ◽  
Caatinga Biome ◽  
Semi Arid Region ◽  
A New Species ◽  
Semi Arid

The Caatinga biome is located in the semi-arid region of northeastern Brazil and covers about 37 % of Piauí state. The main objective of the present study was a characterization of the Caatinga flora of the farm of Morro do Baixio, in state of Piauí, Brazil (06°51’13” S; 41°28’15” W, at 400 to 540 m above sea level) in view of the fact that very few such surveys were conducted in the state. The flora of the farm was surveyed monthly, during a year, to gather herbs, epiphytes, parasites, sub shrubs, shrubs and trees. We encountered 136 species belonging to 46 families, including a new species of Bauhinia. The richest families were Caesalpiniaceae (15 spp.), Fabaceae (11 spp.), Bignoniaceae and Mimosaceae (both with nine spp.). We observed a higher frequency of typical species from sedimentary Caatinga. However, local conditions favor the appearance of species that occur in Carrasco and Cerrado.

scholarly journals New records of Auriculariales, Hymenochaetales and Polyporales (Fungi: Agaricomycetes) for the Caatinga Biome

Check List ◽  
2013 ◽  
Vol 9 (4) ◽  
pp. 800 ◽  
Author(s):  
Elisandro Ricardo Drechsler-Santos ◽  
Leif Ryvarden ◽  
José Luiz Bezerra ◽  
Tatiana Baptista Gibertoni ◽  
C. A. Salvador-Montoya ◽  
...  
Keyword(s):  
Arid Region ◽  
New Records ◽  
Auricularia Polytricha ◽  
Caatinga Biome ◽  
Semi Arid Region ◽  
Semi Arid

Macrofungi from exclusive Brazilian biome of semi-arid region are poorly known and more efforts are necessary to document the diversity and distribution of this group among all the different ecosystems of the Caatinga. Sixty one exsiccata kept at ALCB, CEPEC, HUVA and IPA herbaria were revised which corresponded to 36 species. Fourteen of these, Auricularia polytricha, Amauroderma partitum, A. sprucei, Dichomitus cavernulosus, Flabellophora parva, Flaviporus hydrophilus, Ganoderma resinaceum, Hexagonia papyracea, Perenniporia aurantiaca, Phellinus shaferi, Polyporus ianthinus, Rigidoporus lineatus, R. ulmarius, and Steccherinum reniforme, are first records for the Caatinga biome.

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