SERGIO GUERRA - Academia.edu (original) (raw)

Papers by SERGIO GUERRA

African Journal of Agricultural Research, Jul 14, 2016

In the Brazilian semiarid regions, underground dams can efficiently store water under possible sc... more In the Brazilian semiarid regions, underground dams can efficiently store water under possible scenarios of climate change. However, the annual humidity vector in these regions is vertical, and annual evapotranspiration exceeds annual rainfall, resulting in the accumulation of salts in groundwater reservoirs. This study investigated over the course of two agricultural years the hydrologic behavior, soil moisture and the seasonal behavior of electrical conductivity (EC) of the irrigation water from an underground dam constructed in the Jacu watershed in a Brazilian semiarid region. The underground dam retained more soil moisture than other nearby areas during the rainy season; however, during dry periods, its storage capacity was reduced by evapotranspiration occurring inside and outside of the groundwater dam and after rainfall the same level of evaporation occurred from soil as from the dam. During the dry season the underground dam raised the concentration of salts in the irrigation water which was categorized as C4, corresponding to the far too saline irrigation water; however, in subsequent rainy seasons, the electrical conductivity of irrigation water decreased to be included in a group of low salinity of 0.95 dS m-1 (C1). The irrigation water sodicity changed from the risk of sodium accumulation to without sodium risk category.

Revista Brasileira de Geografia Física

Assessing technologies based on sediment yield in watersheds is increasingly important to determi... more Assessing technologies based on sediment yield in watersheds is increasingly important to determine the delivery rate. This work aimed to determine values of sediment delivery of the hydrographic basin of the river Jacu in the semiarid of Pernambuco and its relations with the soil and vegetation. Therefore, it was calculated the rates of interrill and rill erosion by yield testing under shrub and uncovered Inceptisols conditions, and it was carried out direct measurement campaigns of suspended sediment and bedload, by means of US DH-48 e US BLH-84, respectively. The sediment yield obtained in Jacu stream was considered low. The soil loss due to interril erosion under uncovered conditions equal to 8.43 t ha-1 was considered high, as well as the same way for the values of rill erosion with erodibility equal to 0.0021142 kg N-1 s-1 and critical shear stress equal to 2.34 Pa. The mean value of sediment delivery ratio of Jacu watershed was equal to 0.165 and ranged from 0.29 in the year 2008 to 0.026 in 2010. This variation is associated with the natural variability of semiarid environment, indicating the necessity of assessment in a large period of years to improve the knowledge about the sediment delivery ratio of Jacu semiarid watershed.

Hydrological Sciences Journal

ABSTRACT Overland flow occurs on a land surface, making a sheet flow without any flow concentrati... more ABSTRACT Overland flow occurs on a land surface, making a sheet flow without any flow concentration. Under these conditions, cultivated semi-arid hillslopes experience inter-rill erosion. One objective of this study was to evaluate the hydraulic resistance caused by semi-arid crops and shrubs in two slopes’ field conditions, and the other was to learen more about the overland flow governed by Froude number. To achieve these targets, a set of rainfall simulations was performed on two slope gradients, of 4.9% and 8.9%, covered by shrubs and semi-arid crops. On these two semi-arid hillslopes, exfiltration occurred, which added flow from subsurface water by seepage. We show, for the first time, that for overland flow with Reynolds number from 1 to 100 in different crops and native Brazilian shrub, hydraulic resistance is more strongly correlated with Froude number than with Reynolds number, as were the vegetal force drag and the soil detachment rate.

Research, Society and Development, 2020

Heat stroke is part of solar energy that spreads without the need for a material medium and is re... more Heat stroke is part of solar energy that spreads without the need for a material medium and is represented by the hours of the day that the solar disk remains visible on the earth's surface. The objective is to characterize the climatic conditions of insolation using the interpolation method for the area of the hydrographic basin of the Ipojuca River and its surroundings, elaborating a monthly and annual graph for the period from 1962 to 2019. The average climatological data of the total monthly and annual sunshine were generated by the simple interpolation method, using electronic spreadsheets to extract the averages values ​​of the monthly, annual, median, standard deviation, coefficient of variance, maximum and minimum absolute values. Total sunstroke is greater than the cloud coverage in the period from August to March, totaling 1861.8 hours and tenths, while in the same period, the cloud coverage is 0.45 tenths. Low cloud cover, temperature fluctuations and low or no ground...

Research, Society and Development, 2020

Sorghum is a plant of tropical origin, of short days and with high photosynthetic rates, requirin... more Sorghum is a plant of tropical origin, of short days and with high photosynthetic rates, requiring a warm climate in order to express its production potential. The objective is to evaluate the agroclimatic aptitude of the cultivation of sorghum that allows to visualize or identify its productive potential in the state of Pernambuco. The pluviometric data were acquired from the Northeast Development Superintendence and the Pernambuco water and climate agency, the temperature data were from the National Institute of Meteorology and estimated by the estima_T software between the period 1960-2019. In the region of the high sertão and sertão there is moderate fitness due to excess water. In the agreste region full fitness was obtained with prolonged rainy season. In the Zona da Mata and Litoral regions, fitness is unrestricted. The study was carried out using information from the rainy season and without the aid of irrigation, that is, taking into account the rainfed planting.

CATENA, 2017

Heavy metal contamination has long been a water quality concern worldwide. Most studies have focu... more Heavy metal contamination has long been a water quality concern worldwide. Most studies have focused on heavy metal concentration in water through suspended sediment and bottom sediment; however, the concentration transported by river-bottom sediment, known as bedload, has not been taken into account. In order to fill this gap, this study aimed to determine the concentration of Hg, Pb, Cd, Ni, Cu, Cr, Zn, As, Fe and Mn in bedload of Ipojuca River which is an environmentally impacted river in Brazil. The use of bedload in heavy metal contamination studies raises the following question: Is the bedload an adequate indicator of heavy metal contamination? To answer this question, sediment contamination assessment was performed using sediment contamination indices, principal component analysis, and comparison with background values and sediment quality guidelines (SQGs). Comparing with sediment quality guidelines, the Probable Effect Level (PEL) and Threshold Effect Level (TEL) seem to underestimate the harmful effect on sediment-dwelling organisms, being essential either to calibrate the SQGs for site specific conditions or develop site specific guidelines. The pollution load index (PLI) indicated that the upstream and downstream sites were not polluted and polluted, respectively. Principal component analysis explained roughly 91% and 81% of the total variance in heavy metal contamination upstream and downstream, respectively, and distinguished natural and anthropogenic contributions in Ipojuca River. Multiple lines of evidence suggested that heavy metal concentrations in bedload were an adequate and feasible indicator of anthropogenic impacts.

Ecological Engineering, 2019

Vegetation is one of the main factors that compose the alluvial dynamic of the semiarid environme... more Vegetation is one of the main factors that compose the alluvial dynamic of the semiarid environment. The determination of the hydraulic roughness generated by the plant in the alluvial environment is essential to understand the behavior of the forces that describe the flow, the processes associated with the loss of energy and the sediment transport rates. The objective of this study is the characterization of the flow resistance imposed by an aquatic vegetation patch in an intermittent stream, located in Pernambuco's hinterland, Brazil, in the emerged and submerged conditions, through the parameters of vegetal drag coefficient (C D) and vegetal drag stress (τ veg) of the different intrinsic species of this alluvial environment. The sampling took place in the Cachoeira intermittent stream to monitor the channel geometry, vegetative parameters, and liquid and solid discharges. Based on the submergence ratio, the flux was divided into two distinct layers that allowed the understanding of hydrosedimentological dynamics, the first one of direct contact with the vegetation and the second one the free flow zone. The average values of C D to the aquatic vegetation patch (composed by Senna obtusifolia, Ipomoea pescaprae and Cynodon dactylon (L.) Pers.), according to the methodologies adopted in this study, were 10.97 and 3.73 m −1. The generated physical forces were in opposition to the flow and, consequently, in the condition of increase of the vegetal density, they promoted the higher values of vegetal drag stress, and retarded the flow velocity, reducing the transport rate of suspended sediment.

InTech eBooks, Dec 9, 2015

Sediment transport relates to suspended sediment and bedload. The suspended sediment plays the mo... more Sediment transport relates to suspended sediment and bedload. The suspended sediment plays the most important role on the land-ocen sediment flux. On the other hand, the bedload should be considered in order to assess the impacts of dams on sediment transport and sediment yield. Recent effects of dam construction have been widely reported. The sediment load has been reduced by more than 75% for major rives, such as Nilo, Orange, Volta, Indus, Ebro, Kizil Irmark, Colorado, and Rio Grande and more than 40% of its lux is trapped within large dams. In addition, the multiple trapping through sequential dams has impacted the sediment transfer from terrestrial to coastal zone, triggering the coastal erosion. In terms of sediment retention and transport, China stands out the most impacted country by dams, followed by United States, and continents such as Europe, Africa, and South America. Based on the foregoing, the impact of dams on sediment transport and yield of an important Brazilian watershed with multiple dams will be the focus of this chapter. Thus, a three years field sampling (2009-2011) was carried out to measure the sediment yield of Capibaribe Watershed, and also its contribution to coastal erosion. The ratio between QB and SSQ ranged from 0.12% to 27.3% with 76% of all values lower than 5%. Usually, the bedload transport rate of a river is about 5-25% of the suspended sediment transport. This ranging sheds light on the lack of bedload reaching the coastal zone and it is likely one of the reasons to yield coastal erosion. The low rates can be attributed to the presence of dams which have been admitted to have a strong effect on sediment transport. The sediment yield was equal to 3.69, 4.36, and 6.7 t km-2 ano-1 in 2009, 2010, and 2011, respectively. In comparison with bedload yield, the suspended sediment yield was higher than 95% for all studied years. Therefore, the limited bedload supply-mainly responsible for construction of coastal landform-is likely contributing to the coastal erosion along part of the northeast region, Brazil. The multiple dams along the Capibaribe River watershed produce a deficit in sediment flux to

Ecological Indicators, Nov 1, 2019

The structural parameters of vegetation have an important influence on the resistance imposed to ... more The structural parameters of vegetation have an important influence on the resistance imposed to shallow flow under the soil, being important in the control of floods, water erosion and sediment transport in the watersheds. Therefore, in order to obtain the hydraulic characteristics of overland flow, the variables of hydraulic resistance generated by the vegetation to surface flow, and the interrill erosion rates under semi-arid region led to the introduction of agricultural crops, through which shallow flows were generated on elephant grass (Pennisetum purpureum), corn (Zea mays sp.) and in a bare Entisol, placed in a toeslope landscape position. Results showed that the flow regime was slow, laminar and interrill erosion occurred (Re < 500 and Fr < 1). Nevertheless, the hydraulic characteristics of overland flow (Vm, h, q and log f) were probably affected by the proximity to the water table, a hypothesis supported by the obtained values for the infiltration. However, corn and principally elephant grass showed high hydraulic resistance to superficial flow and interrill erosion conferred by the highest ground coverage (lowest Ci = 0.198), by the effect of the sub-factors CiI, CiII and CiIII, and the lowest values of sediment concentration (CS), runoff coefficient (C), interrill detachment rate (Di), and soil loss (SL). Our results support the purpose of introducing agricultural crops in the Brazilian semi-arid region since increasing resistance to interrill erosion can be provided. Elephant grass is a more appropriate crop to be inserted under land management protocols in the semi-arid environment. where ql is the lateral flow per unit length (m 2 s −1); Q is the water discharge (m 3 s −1); x is the length in the flow direction (m); A is the

The objectives of this study were to (1) determine the status of heavy metal concentrations in su... more The objectives of this study were to (1) determine the status of heavy metal concentrations in suspended sediments, (2) distinguish between natural and anthropogenic sources of metals, and (3) evaluate the risk, to the environment, posed by the heavy metals in the river system (by comparison with SQGs).Suspended sediment samples were obtained using a depthintegrated and isokinetic sampling. The mean available metal concentration in suspended sediment followed the order Fe > Mn > Zn > Pb > Cr > Cu > Ni > As > Cd > Hg and Fe > Mn > Pb > Zn > Cr > Cu > Ni > As > Cd > Hg, upstream and downstream, respectively. The concentration of Mn (upstream) and Pb in both sites are likely to result in harmful effects on sediment dwelling organisms based on the comparison with SQGs. However, SQGs underestimate the harmful effect of studied metals on sediment-dwelling organisms. Notably, Pb is the most harmful of the heavy metals for aquatic life. The upstream portion of the Ipojuca River is moderately contaminated, with higher contaminant levels for Mn and As; and that the sediments of the downstream portion are highly contaminated with Zn, Pb, and As.

Journal of Experimental Agriculture International, 2018

Studies assessing technologies to design riparian strips using plant covers, based on sediment yi... more Studies assessing technologies to design riparian strips using plant covers, based on sediment yield in river basins, are required for environmental protection. The removal of semi-shrubby, native vegetation in the Brazilian semiarid region, has contributed to the degradation of semiarid basins. The aim of this study was to design a riparian strip for the Jacu River in the semiarid region of Pernambuco as a function of sediment yield. Experiments were conducted during the years 2008

Revista Brasileira de Engenharia Agrícola e Ambiental, 2011

A erosão hídrica é um dos principais processos responsáveis pela degradação física dos solos, em ... more A erosão hídrica é um dos principais processos responsáveis pela degradação física dos solos, em particular em áreas semiáridas, susceptíveis a chuvas de alta intensidade e com limitada cobertura vegetal, principalmente nos períodos secos. O presente trabalho teve como objetivo avaliar experimentalmente as características hidrossedimentológicas da bacia hidrográfica do Riacho Mimoso, no semiárido pernambucano, no município de Pesqueira, PE. A bacia representativa do Riacho Mimoso apresentou respostas hidrológicas com altos picos de vazão, em seção de controle com regime hidrológico intermitente. A produção de descarga sólida em suspensão do Riacho Mimoso é elevada, tendo-se registrado concentrações de sedimentos de 10,91 e 0,91 t ha-1 ano-1, para os anos de 2009 e 2010, respectivamente.

Revista Brasileira de Ciência do Solo, 2009

Pouco se conhece sobre a diferenciação pedogenética no Alto Paranaíba (MG), quando são comparados... more Pouco se conhece sobre a diferenciação pedogenética no Alto Paranaíba (MG), quando são comparados materiais de composição química tão variada, como tufitos, rochas ígneas alcalinas e ultramáficas e carbonatitos, todos de ocorrência na região. Dessa forma, este trabalho teve como objetivo caracterizar física, química e mineralogicamente os solos representativos de três topolitossequências do Alto Paranaíba. Para isso, foram descritos e coletados 11 perfis de solos, entre os municípios de Serra do Salitre, Patrocínio e Coromandel, representando as variações litológicas na faixa do contato geológico entre os grupos Bambuí, rochas vulcânicas ultramáficas e Araxá. Nas amostras de solos foram realizadas análises físicas e químicas de rotina, além de determinações de Fe, Al e Si após extração por ataque sulfúrico; Fe por DCB e oxalato; Fe, Ca, Mg, K, P, Ti e outros metais pesados após digestão total (ataque triácido); e determinação dos diferentes componentes da fração argila por difratome...

Journal of Experimental Agriculture International, 2018

Evaluation of sediment delivery ratio is important for determining watershed sediment yield. Rate... more Evaluation of sediment delivery ratio is important for determining watershed sediment yield. Rates of both interrill and rill erosion were calculated under shrub and uncovered Inceptisols conditions and were not observed to the presence by ravines and gullies in the watershed of Jacu River, in a semiarid region, Brazil. Direct measurement campaigns of suspended sediment and bedload were also carried out by means of the US DH-48 for collection of suspended sediment samples and US BLH-84used to collect samples bed load. The soil loss due to interril erosion under uncovered conditions was equal to 8.43 t ha-1 and was considered high, and the same was true for the values of rill erosion with erodibility equal to 0.0021142 kg N-1 s-1 and critical shear stress (τc) equal to 2.34 Pa. The mean value of sediment delivery ratio of Jacu watershed was equal to 0.165 and ranged from 0.29 in the year 2008 to 0.026 in 2010. This variation was associated with the natural variability of semiarid environment, indicating the necessity of assessment for a longer period to deepen our knowledge of sediment delivery ratio of the Jacu semiarid watershed.

Effects of Sediment Transport on Hydraulic Structures, 2015

Sediment transport relates to suspended sediment and bedload. The suspended sediment plays the mo... more Sediment transport relates to suspended sediment and bedload. The suspended sediment plays the most important role on the land-ocen sediment flux. On the other hand, the bedload should be considered in order to assess the impacts of dams on sediment transport and sediment yield. Recent effects of dam construction have been widely reported. The sediment load has been reduced by more than 75% for major rives, such as Nilo, Orange, Volta, Indus, Ebro, Kizil Irmark, Colorado, and Rio Grande and more than 40% of its lux is trapped within large dams. In addition, the multiple trapping through sequential dams has impacted the sediment transfer from terrestrial to coastal zone, triggering the coastal erosion. In terms of sediment retention and transport, China stands out the most impacted country by dams, followed by United States, and continents such as Europe, Africa, and South America. Based on the foregoing, the impact of dams on sediment transport and yield of an important Brazilian watershed with multiple dams will be the focus of this chapter. Thus, a three years field sampling (2009-2011) was carried out to measure the sediment yield of Capibaribe Watershed, and also its contribution to coastal erosion. The ratio between QB and SSQ ranged from 0.12% to 27.3% with 76% of all values lower than 5%. Usually, the bedload transport rate of a river is about 5-25% of the suspended sediment transport. This ranging sheds light on the lack of bedload reaching the coastal zone and it is likely one of the reasons to yield coastal erosion. The low rates can be attributed to the presence of dams which have been admitted to have a strong effect on sediment transport. The sediment yield was equal to 3.69, 4.36, and 6.7 t km-2 ano-1 in 2009, 2010, and 2011, respectively. In comparison with bedload yield, the suspended sediment yield was higher than 95% for all studied years. Therefore, the limited bedload supply-mainly responsible for construction of coastal landform-is likely contributing to the coastal erosion along part of the northeast region, Brazil. The multiple dams along the Capibaribe River watershed produce a deficit in sediment flux to

Hydrological Sciences Journal, 2013

Suspended sediment and bedload discharges in sand-bed rivers shape semi-arid landscapes and impac... more Suspended sediment and bedload discharges in sand-bed rivers shape semi-arid landscapes and impact sediment delivery from these landscapes, but are still incompletely understood. Suspended sediment and bedload fluxes of the intermittent Exu River, Brazil, were sampled by direct measurements. The highest suspended sediment concentration observed was 4847.4 mg L-1 and this value was possibly associated with the entrainment of sediment that was deposited in the preceding year. The bedload flux was well related to the stream power and the river efficiently transported all available bedload with a mean rate of 0.0047 kg m-1 s-1 , and the percentage of bedload to suspended sediment varied between 4 and 12.72. The bed sediment of Exu River was prone to entrainment and showed a proclivity for transport. Thus, sand-bed and gravel-bed rivers of arid environments seem to exhibit the same mobility in the absence of armour layer.

Revista Águas Subterrâneas, 2000

Neste trabalho será abordada a metodologia utilizada na elaboração de uma carta das condições de ... more Neste trabalho será abordada a metodologia utilizada na elaboração de uma carta das condições de infiltração que abrangeu a quase totalidade do Projeto Industrial e Portuário de Suape, localizado na porção central do litoral Pernambucano. Para confecção desta carta foram analisados, processados e interpretados produtos cartográficos que caracterizassem o meio físico da área estudada (mapa geológico, mapa pedológico, mapa fitológico, carta de declividade e a carta de Interseção da rede de drenagem com traços de fratura), utilizando-se para tal técnicas de geoprocessamento.

Environmental Science and Pollution Research, 2015

Data regarding trace element concentrations and fluxes in suspended sediments and bedload are sca... more Data regarding trace element concentrations and fluxes in suspended sediments and bedload are scarce. To fill this gap and meet the international need to include polluted rivers in future world estimation of trace element fluxes, this study aimed to determine the trace element fluxes in suspended sediment and bedload of an environmentally impacted river in Brazil. Water, suspended sediment, and bedload from both the upstream and the downstream cross sections were collected. To collect both the suspended sediment and water samples, we used the US DH-48. Bedload measurements were carried out using the US BLH 84 sampler. Concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma (ICP-OES). As and Hg were determined by an atomic absorption spectrophotometer (AA-FIAS). The suspended sediments contributed more than 99 % of the trace element flux. By far Pb and to a less extent Zn at the downstream site represents major concerns. The yields of Pb and Zn in suspended sediments were 4.20 and 2.93 kg km 2 year −1 , respectively. These yields were higher than the values reported for Pb and Zn for Tuul River (highly impacted by mining activities), 1.60 and 1.30 kg km 2 year −1 , respectively, as well as the Pb yield (suspended+dissolved) to the sea of some Mediterranean rivers equal to 3.4 kg km 2 year −1. Therefore, the highest flux and yield of Pb and Zn in Ipojuca River highlighted the importance to include medium and small rivers-often overlooked in global and regional studies-in the future estimation of world trace element fluxes in order to protect estuaries and coastal zones.

African Journal of Agricultural Research, Jul 14, 2016

In the Brazilian semiarid regions, underground dams can efficiently store water under possible sc... more In the Brazilian semiarid regions, underground dams can efficiently store water under possible scenarios of climate change. However, the annual humidity vector in these regions is vertical, and annual evapotranspiration exceeds annual rainfall, resulting in the accumulation of salts in groundwater reservoirs. This study investigated over the course of two agricultural years the hydrologic behavior, soil moisture and the seasonal behavior of electrical conductivity (EC) of the irrigation water from an underground dam constructed in the Jacu watershed in a Brazilian semiarid region. The underground dam retained more soil moisture than other nearby areas during the rainy season; however, during dry periods, its storage capacity was reduced by evapotranspiration occurring inside and outside of the groundwater dam and after rainfall the same level of evaporation occurred from soil as from the dam. During the dry season the underground dam raised the concentration of salts in the irrigation water which was categorized as C4, corresponding to the far too saline irrigation water; however, in subsequent rainy seasons, the electrical conductivity of irrigation water decreased to be included in a group of low salinity of 0.95 dS m-1 (C1). The irrigation water sodicity changed from the risk of sodium accumulation to without sodium risk category.

Revista Brasileira de Geografia Física

Assessing technologies based on sediment yield in watersheds is increasingly important to determi... more Assessing technologies based on sediment yield in watersheds is increasingly important to determine the delivery rate. This work aimed to determine values of sediment delivery of the hydrographic basin of the river Jacu in the semiarid of Pernambuco and its relations with the soil and vegetation. Therefore, it was calculated the rates of interrill and rill erosion by yield testing under shrub and uncovered Inceptisols conditions, and it was carried out direct measurement campaigns of suspended sediment and bedload, by means of US DH-48 e US BLH-84, respectively. The sediment yield obtained in Jacu stream was considered low. The soil loss due to interril erosion under uncovered conditions equal to 8.43 t ha-1 was considered high, as well as the same way for the values of rill erosion with erodibility equal to 0.0021142 kg N-1 s-1 and critical shear stress equal to 2.34 Pa. The mean value of sediment delivery ratio of Jacu watershed was equal to 0.165 and ranged from 0.29 in the year 2008 to 0.026 in 2010. This variation is associated with the natural variability of semiarid environment, indicating the necessity of assessment in a large period of years to improve the knowledge about the sediment delivery ratio of Jacu semiarid watershed.

Hydrological Sciences Journal

ABSTRACT Overland flow occurs on a land surface, making a sheet flow without any flow concentrati... more ABSTRACT Overland flow occurs on a land surface, making a sheet flow without any flow concentration. Under these conditions, cultivated semi-arid hillslopes experience inter-rill erosion. One objective of this study was to evaluate the hydraulic resistance caused by semi-arid crops and shrubs in two slopes’ field conditions, and the other was to learen more about the overland flow governed by Froude number. To achieve these targets, a set of rainfall simulations was performed on two slope gradients, of 4.9% and 8.9%, covered by shrubs and semi-arid crops. On these two semi-arid hillslopes, exfiltration occurred, which added flow from subsurface water by seepage. We show, for the first time, that for overland flow with Reynolds number from 1 to 100 in different crops and native Brazilian shrub, hydraulic resistance is more strongly correlated with Froude number than with Reynolds number, as were the vegetal force drag and the soil detachment rate.

Research, Society and Development, 2020

Heat stroke is part of solar energy that spreads without the need for a material medium and is re... more Heat stroke is part of solar energy that spreads without the need for a material medium and is represented by the hours of the day that the solar disk remains visible on the earth's surface. The objective is to characterize the climatic conditions of insolation using the interpolation method for the area of the hydrographic basin of the Ipojuca River and its surroundings, elaborating a monthly and annual graph for the period from 1962 to 2019. The average climatological data of the total monthly and annual sunshine were generated by the simple interpolation method, using electronic spreadsheets to extract the averages values ​​of the monthly, annual, median, standard deviation, coefficient of variance, maximum and minimum absolute values. Total sunstroke is greater than the cloud coverage in the period from August to March, totaling 1861.8 hours and tenths, while in the same period, the cloud coverage is 0.45 tenths. Low cloud cover, temperature fluctuations and low or no ground...

Research, Society and Development, 2020

Sorghum is a plant of tropical origin, of short days and with high photosynthetic rates, requirin... more Sorghum is a plant of tropical origin, of short days and with high photosynthetic rates, requiring a warm climate in order to express its production potential. The objective is to evaluate the agroclimatic aptitude of the cultivation of sorghum that allows to visualize or identify its productive potential in the state of Pernambuco. The pluviometric data were acquired from the Northeast Development Superintendence and the Pernambuco water and climate agency, the temperature data were from the National Institute of Meteorology and estimated by the estima_T software between the period 1960-2019. In the region of the high sertão and sertão there is moderate fitness due to excess water. In the agreste region full fitness was obtained with prolonged rainy season. In the Zona da Mata and Litoral regions, fitness is unrestricted. The study was carried out using information from the rainy season and without the aid of irrigation, that is, taking into account the rainfed planting.

CATENA, 2017

Heavy metal contamination has long been a water quality concern worldwide. Most studies have focu... more Heavy metal contamination has long been a water quality concern worldwide. Most studies have focused on heavy metal concentration in water through suspended sediment and bottom sediment; however, the concentration transported by river-bottom sediment, known as bedload, has not been taken into account. In order to fill this gap, this study aimed to determine the concentration of Hg, Pb, Cd, Ni, Cu, Cr, Zn, As, Fe and Mn in bedload of Ipojuca River which is an environmentally impacted river in Brazil. The use of bedload in heavy metal contamination studies raises the following question: Is the bedload an adequate indicator of heavy metal contamination? To answer this question, sediment contamination assessment was performed using sediment contamination indices, principal component analysis, and comparison with background values and sediment quality guidelines (SQGs). Comparing with sediment quality guidelines, the Probable Effect Level (PEL) and Threshold Effect Level (TEL) seem to underestimate the harmful effect on sediment-dwelling organisms, being essential either to calibrate the SQGs for site specific conditions or develop site specific guidelines. The pollution load index (PLI) indicated that the upstream and downstream sites were not polluted and polluted, respectively. Principal component analysis explained roughly 91% and 81% of the total variance in heavy metal contamination upstream and downstream, respectively, and distinguished natural and anthropogenic contributions in Ipojuca River. Multiple lines of evidence suggested that heavy metal concentrations in bedload were an adequate and feasible indicator of anthropogenic impacts.

Ecological Engineering, 2019

Vegetation is one of the main factors that compose the alluvial dynamic of the semiarid environme... more Vegetation is one of the main factors that compose the alluvial dynamic of the semiarid environment. The determination of the hydraulic roughness generated by the plant in the alluvial environment is essential to understand the behavior of the forces that describe the flow, the processes associated with the loss of energy and the sediment transport rates. The objective of this study is the characterization of the flow resistance imposed by an aquatic vegetation patch in an intermittent stream, located in Pernambuco's hinterland, Brazil, in the emerged and submerged conditions, through the parameters of vegetal drag coefficient (C D) and vegetal drag stress (τ veg) of the different intrinsic species of this alluvial environment. The sampling took place in the Cachoeira intermittent stream to monitor the channel geometry, vegetative parameters, and liquid and solid discharges. Based on the submergence ratio, the flux was divided into two distinct layers that allowed the understanding of hydrosedimentological dynamics, the first one of direct contact with the vegetation and the second one the free flow zone. The average values of C D to the aquatic vegetation patch (composed by Senna obtusifolia, Ipomoea pescaprae and Cynodon dactylon (L.) Pers.), according to the methodologies adopted in this study, were 10.97 and 3.73 m −1. The generated physical forces were in opposition to the flow and, consequently, in the condition of increase of the vegetal density, they promoted the higher values of vegetal drag stress, and retarded the flow velocity, reducing the transport rate of suspended sediment.

InTech eBooks, Dec 9, 2015

Sediment transport relates to suspended sediment and bedload. The suspended sediment plays the mo... more Sediment transport relates to suspended sediment and bedload. The suspended sediment plays the most important role on the land-ocen sediment flux. On the other hand, the bedload should be considered in order to assess the impacts of dams on sediment transport and sediment yield. Recent effects of dam construction have been widely reported. The sediment load has been reduced by more than 75% for major rives, such as Nilo, Orange, Volta, Indus, Ebro, Kizil Irmark, Colorado, and Rio Grande and more than 40% of its lux is trapped within large dams. In addition, the multiple trapping through sequential dams has impacted the sediment transfer from terrestrial to coastal zone, triggering the coastal erosion. In terms of sediment retention and transport, China stands out the most impacted country by dams, followed by United States, and continents such as Europe, Africa, and South America. Based on the foregoing, the impact of dams on sediment transport and yield of an important Brazilian watershed with multiple dams will be the focus of this chapter. Thus, a three years field sampling (2009-2011) was carried out to measure the sediment yield of Capibaribe Watershed, and also its contribution to coastal erosion. The ratio between QB and SSQ ranged from 0.12% to 27.3% with 76% of all values lower than 5%. Usually, the bedload transport rate of a river is about 5-25% of the suspended sediment transport. This ranging sheds light on the lack of bedload reaching the coastal zone and it is likely one of the reasons to yield coastal erosion. The low rates can be attributed to the presence of dams which have been admitted to have a strong effect on sediment transport. The sediment yield was equal to 3.69, 4.36, and 6.7 t km-2 ano-1 in 2009, 2010, and 2011, respectively. In comparison with bedload yield, the suspended sediment yield was higher than 95% for all studied years. Therefore, the limited bedload supply-mainly responsible for construction of coastal landform-is likely contributing to the coastal erosion along part of the northeast region, Brazil. The multiple dams along the Capibaribe River watershed produce a deficit in sediment flux to

Ecological Indicators, Nov 1, 2019

The structural parameters of vegetation have an important influence on the resistance imposed to ... more The structural parameters of vegetation have an important influence on the resistance imposed to shallow flow under the soil, being important in the control of floods, water erosion and sediment transport in the watersheds. Therefore, in order to obtain the hydraulic characteristics of overland flow, the variables of hydraulic resistance generated by the vegetation to surface flow, and the interrill erosion rates under semi-arid region led to the introduction of agricultural crops, through which shallow flows were generated on elephant grass (Pennisetum purpureum), corn (Zea mays sp.) and in a bare Entisol, placed in a toeslope landscape position. Results showed that the flow regime was slow, laminar and interrill erosion occurred (Re < 500 and Fr < 1). Nevertheless, the hydraulic characteristics of overland flow (Vm, h, q and log f) were probably affected by the proximity to the water table, a hypothesis supported by the obtained values for the infiltration. However, corn and principally elephant grass showed high hydraulic resistance to superficial flow and interrill erosion conferred by the highest ground coverage (lowest Ci = 0.198), by the effect of the sub-factors CiI, CiII and CiIII, and the lowest values of sediment concentration (CS), runoff coefficient (C), interrill detachment rate (Di), and soil loss (SL). Our results support the purpose of introducing agricultural crops in the Brazilian semi-arid region since increasing resistance to interrill erosion can be provided. Elephant grass is a more appropriate crop to be inserted under land management protocols in the semi-arid environment. where ql is the lateral flow per unit length (m 2 s −1); Q is the water discharge (m 3 s −1); x is the length in the flow direction (m); A is the

The objectives of this study were to (1) determine the status of heavy metal concentrations in su... more The objectives of this study were to (1) determine the status of heavy metal concentrations in suspended sediments, (2) distinguish between natural and anthropogenic sources of metals, and (3) evaluate the risk, to the environment, posed by the heavy metals in the river system (by comparison with SQGs).Suspended sediment samples were obtained using a depthintegrated and isokinetic sampling. The mean available metal concentration in suspended sediment followed the order Fe > Mn > Zn > Pb > Cr > Cu > Ni > As > Cd > Hg and Fe > Mn > Pb > Zn > Cr > Cu > Ni > As > Cd > Hg, upstream and downstream, respectively. The concentration of Mn (upstream) and Pb in both sites are likely to result in harmful effects on sediment dwelling organisms based on the comparison with SQGs. However, SQGs underestimate the harmful effect of studied metals on sediment-dwelling organisms. Notably, Pb is the most harmful of the heavy metals for aquatic life. The upstream portion of the Ipojuca River is moderately contaminated, with higher contaminant levels for Mn and As; and that the sediments of the downstream portion are highly contaminated with Zn, Pb, and As.

Journal of Experimental Agriculture International, 2018

Studies assessing technologies to design riparian strips using plant covers, based on sediment yi... more Studies assessing technologies to design riparian strips using plant covers, based on sediment yield in river basins, are required for environmental protection. The removal of semi-shrubby, native vegetation in the Brazilian semiarid region, has contributed to the degradation of semiarid basins. The aim of this study was to design a riparian strip for the Jacu River in the semiarid region of Pernambuco as a function of sediment yield. Experiments were conducted during the years 2008

Revista Brasileira de Engenharia Agrícola e Ambiental, 2011

A erosão hídrica é um dos principais processos responsáveis pela degradação física dos solos, em ... more A erosão hídrica é um dos principais processos responsáveis pela degradação física dos solos, em particular em áreas semiáridas, susceptíveis a chuvas de alta intensidade e com limitada cobertura vegetal, principalmente nos períodos secos. O presente trabalho teve como objetivo avaliar experimentalmente as características hidrossedimentológicas da bacia hidrográfica do Riacho Mimoso, no semiárido pernambucano, no município de Pesqueira, PE. A bacia representativa do Riacho Mimoso apresentou respostas hidrológicas com altos picos de vazão, em seção de controle com regime hidrológico intermitente. A produção de descarga sólida em suspensão do Riacho Mimoso é elevada, tendo-se registrado concentrações de sedimentos de 10,91 e 0,91 t ha-1 ano-1, para os anos de 2009 e 2010, respectivamente.

Revista Brasileira de Ciência do Solo, 2009

Pouco se conhece sobre a diferenciação pedogenética no Alto Paranaíba (MG), quando são comparados... more Pouco se conhece sobre a diferenciação pedogenética no Alto Paranaíba (MG), quando são comparados materiais de composição química tão variada, como tufitos, rochas ígneas alcalinas e ultramáficas e carbonatitos, todos de ocorrência na região. Dessa forma, este trabalho teve como objetivo caracterizar física, química e mineralogicamente os solos representativos de três topolitossequências do Alto Paranaíba. Para isso, foram descritos e coletados 11 perfis de solos, entre os municípios de Serra do Salitre, Patrocínio e Coromandel, representando as variações litológicas na faixa do contato geológico entre os grupos Bambuí, rochas vulcânicas ultramáficas e Araxá. Nas amostras de solos foram realizadas análises físicas e químicas de rotina, além de determinações de Fe, Al e Si após extração por ataque sulfúrico; Fe por DCB e oxalato; Fe, Ca, Mg, K, P, Ti e outros metais pesados após digestão total (ataque triácido); e determinação dos diferentes componentes da fração argila por difratome...

Journal of Experimental Agriculture International, 2018

Evaluation of sediment delivery ratio is important for determining watershed sediment yield. Rate... more Evaluation of sediment delivery ratio is important for determining watershed sediment yield. Rates of both interrill and rill erosion were calculated under shrub and uncovered Inceptisols conditions and were not observed to the presence by ravines and gullies in the watershed of Jacu River, in a semiarid region, Brazil. Direct measurement campaigns of suspended sediment and bedload were also carried out by means of the US DH-48 for collection of suspended sediment samples and US BLH-84used to collect samples bed load. The soil loss due to interril erosion under uncovered conditions was equal to 8.43 t ha-1 and was considered high, and the same was true for the values of rill erosion with erodibility equal to 0.0021142 kg N-1 s-1 and critical shear stress (τc) equal to 2.34 Pa. The mean value of sediment delivery ratio of Jacu watershed was equal to 0.165 and ranged from 0.29 in the year 2008 to 0.026 in 2010. This variation was associated with the natural variability of semiarid environment, indicating the necessity of assessment for a longer period to deepen our knowledge of sediment delivery ratio of the Jacu semiarid watershed.

Effects of Sediment Transport on Hydraulic Structures, 2015

Sediment transport relates to suspended sediment and bedload. The suspended sediment plays the mo... more Sediment transport relates to suspended sediment and bedload. The suspended sediment plays the most important role on the land-ocen sediment flux. On the other hand, the bedload should be considered in order to assess the impacts of dams on sediment transport and sediment yield. Recent effects of dam construction have been widely reported. The sediment load has been reduced by more than 75% for major rives, such as Nilo, Orange, Volta, Indus, Ebro, Kizil Irmark, Colorado, and Rio Grande and more than 40% of its lux is trapped within large dams. In addition, the multiple trapping through sequential dams has impacted the sediment transfer from terrestrial to coastal zone, triggering the coastal erosion. In terms of sediment retention and transport, China stands out the most impacted country by dams, followed by United States, and continents such as Europe, Africa, and South America. Based on the foregoing, the impact of dams on sediment transport and yield of an important Brazilian watershed with multiple dams will be the focus of this chapter. Thus, a three years field sampling (2009-2011) was carried out to measure the sediment yield of Capibaribe Watershed, and also its contribution to coastal erosion. The ratio between QB and SSQ ranged from 0.12% to 27.3% with 76% of all values lower than 5%. Usually, the bedload transport rate of a river is about 5-25% of the suspended sediment transport. This ranging sheds light on the lack of bedload reaching the coastal zone and it is likely one of the reasons to yield coastal erosion. The low rates can be attributed to the presence of dams which have been admitted to have a strong effect on sediment transport. The sediment yield was equal to 3.69, 4.36, and 6.7 t km-2 ano-1 in 2009, 2010, and 2011, respectively. In comparison with bedload yield, the suspended sediment yield was higher than 95% for all studied years. Therefore, the limited bedload supply-mainly responsible for construction of coastal landform-is likely contributing to the coastal erosion along part of the northeast region, Brazil. The multiple dams along the Capibaribe River watershed produce a deficit in sediment flux to

Hydrological Sciences Journal, 2013

Suspended sediment and bedload discharges in sand-bed rivers shape semi-arid landscapes and impac... more Suspended sediment and bedload discharges in sand-bed rivers shape semi-arid landscapes and impact sediment delivery from these landscapes, but are still incompletely understood. Suspended sediment and bedload fluxes of the intermittent Exu River, Brazil, were sampled by direct measurements. The highest suspended sediment concentration observed was 4847.4 mg L-1 and this value was possibly associated with the entrainment of sediment that was deposited in the preceding year. The bedload flux was well related to the stream power and the river efficiently transported all available bedload with a mean rate of 0.0047 kg m-1 s-1 , and the percentage of bedload to suspended sediment varied between 4 and 12.72. The bed sediment of Exu River was prone to entrainment and showed a proclivity for transport. Thus, sand-bed and gravel-bed rivers of arid environments seem to exhibit the same mobility in the absence of armour layer.

Revista Águas Subterrâneas, 2000

Neste trabalho será abordada a metodologia utilizada na elaboração de uma carta das condições de ... more Neste trabalho será abordada a metodologia utilizada na elaboração de uma carta das condições de infiltração que abrangeu a quase totalidade do Projeto Industrial e Portuário de Suape, localizado na porção central do litoral Pernambucano. Para confecção desta carta foram analisados, processados e interpretados produtos cartográficos que caracterizassem o meio físico da área estudada (mapa geológico, mapa pedológico, mapa fitológico, carta de declividade e a carta de Interseção da rede de drenagem com traços de fratura), utilizando-se para tal técnicas de geoprocessamento.

Environmental Science and Pollution Research, 2015

Data regarding trace element concentrations and fluxes in suspended sediments and bedload are sca... more Data regarding trace element concentrations and fluxes in suspended sediments and bedload are scarce. To fill this gap and meet the international need to include polluted rivers in future world estimation of trace element fluxes, this study aimed to determine the trace element fluxes in suspended sediment and bedload of an environmentally impacted river in Brazil. Water, suspended sediment, and bedload from both the upstream and the downstream cross sections were collected. To collect both the suspended sediment and water samples, we used the US DH-48. Bedload measurements were carried out using the US BLH 84 sampler. Concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma (ICP-OES). As and Hg were determined by an atomic absorption spectrophotometer (AA-FIAS). The suspended sediments contributed more than 99 % of the trace element flux. By far Pb and to a less extent Zn at the downstream site represents major concerns. The yields of Pb and Zn in suspended sediments were 4.20 and 2.93 kg km 2 year −1 , respectively. These yields were higher than the values reported for Pb and Zn for Tuul River (highly impacted by mining activities), 1.60 and 1.30 kg km 2 year −1 , respectively, as well as the Pb yield (suspended+dissolved) to the sea of some Mediterranean rivers equal to 3.4 kg km 2 year −1. Therefore, the highest flux and yield of Pb and Zn in Ipojuca River highlighted the importance to include medium and small rivers-often overlooked in global and regional studies-in the future estimation of world trace element fluxes in order to protect estuaries and coastal zones.