Résumé/Abstract In this study, runoff and soil erosion processes due to natural convective rainst... more Résumé/Abstract In this study, runoff and soil erosion processes due to natural convective rainstorms on a 0.025 ha undisturbed experimental plot have been analysed. The plot was instrumented to monitor rainfall overland flow runoff and erosion. Automatic devices were ...
In this paper the main goal was to analyze the effect of spatial variability of rainfall on runof... more In this paper the main goal was to analyze the effect of spatial variability of rainfall on runoff in an experimental monitored watershed (2.108 km2) located on a semiarid region (Seridó Potiguar), Rio Grande do Norte-Brazil. To accomplish this, a rainfall-runoff-sediment hydrologic model was used. The study area was divided into 143 elements (planes and channels). Rainfall spatial distribution, estimated using the inverse of distance method, was used as input to calculate rainfall spatial variability index for three observed storm events and different combinations of recording gauge arrangements. This index was considered in this study as an indicator used to evaluate the capacity of rainfall spatial characteristics measurement. The impact of spatial rainfall variability on catchment hydrologic response was analyzed and permitted to obtain the following conclusions: (a) rainfall data input provided by gage combination [1-2] best described rainfall distribution, although station 1 i...
Hydrological modeling of the unsaturated soil zone fluxes allows the transfer processes simulatio... more Hydrological modeling of the unsaturated soil zone fluxes allows the transfer processes simulation through the hydrological active soil zone. The pedotransfer functions (FTP) are useful tools in the modeling process. They contain analytical functions derived through statistic optimization process using a large amount of soil information data. This paper aims to analyze the level of reliability of two different pedotransfer functions [Wsten et al. (2001); Hodnett and Tomasella (2000)] by using field measurement of soil properties and experimental infiltration data through a disc infiltrometer in an experimental catchment at northeastern semi arid zone of Brazil. FTP's used in this study were derived on previous studies by taking into account soils of different origins. The former FTP considers a large range of soil classes from temperate climate regions; the latter was derived through a selection of soils from tropical climate regions. The use of these pedotransfer functions show...
The enhancement of the Water Resources Management System depends mostly on good governance. It is... more The enhancement of the Water Resources Management System depends mostly on good governance. It is crucial for water resources protection at the long term and the current generations. In Brazil, the implementation of a water resources management model is still an unconsolidated process. In order to make implementation a reality, the consolidation of the basis of the governance needs to be framed, and it is linked to many factors: adequate institutional basis, efficient institutional arrangement, management and implementation organisms need political autonomy in the decision-making process, institutional integration between different levels, public political engagement, and environmental education.
In the Brazilian semi arid region, a combination between human activities and
climatic factors pr... more In the Brazilian semi arid region, a combination between human activities and climatic factors produces an increase in the ecosystem susceptibility to soil erosion. In this study, runoff and soil erosion processes due to natural rainstorm events on a 0.025 ha undisturbed experimental plot is analyzed. The site was instrumented to monitor rainfall, overland flow, runoff and erosion. Automatic devices were installed to monitor rainfall and the level of a 5 m3 tank at a 1-minute time step. The sediment transported by the flow was collected after each event. Plot average slope is 2.5%, vegetated of both permanent and annual plants, composed by a combination of xerophytes shrubs, brushes and grass species, whose patterns change with growing season as a result of its natural development dynamics. It was observed that runoff and soil erosion was controlled by rainfall pattern, antecedent soil moisture and vegetation. Also, vegetation height and density is influenced by soil structure and faunal activity, increasing both soil storage capacity and surface roughness. Wetting up period data (February 13 to April 25/2007) showed that runoff generation is the result of a non-linear interdependency of rainfall pattern, soil wetness condition and vegetation characteristics. Runoff coefficients less than 0.1 occurred at approximately 82 per cent of the observed events. Moreover, a positive feedback was observed involving vegetative species dynamics, soil properties and faunal activity producing annual plants regeneration. Also, annual plants distribution within the plot seemed to be controlled by permanent trees canopy, where density was higher. Finally, it was obtained an empirical relationship between short-term sediment production and rainstorm amount valid for 2006-2007 wetting up period individual rainstorm events. Hence, this approach has provided a continuous record of rainfall-runoff-sediment production field monitoring data which can be used to analyze hydrologic and vegetative dynamics at plot scale. Also, it highlights the role of vegetative cover as a controlling factor on erosion protection management.
This work aims at presenting an automatic low cost water sampler prototype.
Data provided by this... more This work aims at presenting an automatic low cost water sampler prototype. Data provided by this equipment can be used in water resources management and control. Prototype has an electronic system which controls a peristaltic pump functioning, five solenoid valves and an ultrasonic sensor that provides water level measurement data. An interface with the user provided by a board and LCD display allows sampling parameters input and a report output when sampling is over. Hydraulic module uses a peristaltic 12V pump connected to five solenoid valves, which distribute sample and clean PVC tubes once each sampling is produced. Storage module contains four plastic bottles, 1.95 . Prototype structure is made of acrylic, 0.72 m height and 0.38 m diameter. Experimental laboratory runs have showed a successful performance.
A collaborative approach under a power-sharing institutional structure, coupled with a shift in p... more A collaborative approach under a power-sharing institutional structure, coupled with a shift in paradigms, sustainable water resources management often implies a political-institutional reform to achieve its goals. Most of Brazil’s river basins are subject to rapid urbanization; however, basin stakeholders generally lack sufficient institutional capacity to address the attending water resource issues. Subject to urbanisation, the Pitimbu River basin supplies potable water to approximately 280 000 people in Brazil’s Natal region. This study investigated how current institutional models influence both water management and fluvial contamination by metals. Sediment samples collected at eight sites along the river revealed elevated levels of Pb, Fe, Al, Ni and Zn, whose sources were linked to industries, vehicles, as well as agricultural and construction wastes. Aluminium enrichment of surface waters was mainly linked to inadequate sanitation infrastructure. In light of this, the region’s poor institutional capacity must be addressed through institutional reform, including a new management structure open to public collective water management planning. In so doing, Brazil’s water policies should acknowledge capacity building as a critical element of institutional reform.
Résumé/Abstract In this study, runoff and soil erosion processes due to natural convective rainst... more Résumé/Abstract In this study, runoff and soil erosion processes due to natural convective rainstorms on a 0.025 ha undisturbed experimental plot have been analysed. The plot was instrumented to monitor rainfall overland flow runoff and erosion. Automatic devices were ...
In this paper the main goal was to analyze the effect of spatial variability of rainfall on runof... more In this paper the main goal was to analyze the effect of spatial variability of rainfall on runoff in an experimental monitored watershed (2.108 km2) located on a semiarid region (Seridó Potiguar), Rio Grande do Norte-Brazil. To accomplish this, a rainfall-runoff-sediment hydrologic model was used. The study area was divided into 143 elements (planes and channels). Rainfall spatial distribution, estimated using the inverse of distance method, was used as input to calculate rainfall spatial variability index for three observed storm events and different combinations of recording gauge arrangements. This index was considered in this study as an indicator used to evaluate the capacity of rainfall spatial characteristics measurement. The impact of spatial rainfall variability on catchment hydrologic response was analyzed and permitted to obtain the following conclusions: (a) rainfall data input provided by gage combination [1-2] best described rainfall distribution, although station 1 i...
Hydrological modeling of the unsaturated soil zone fluxes allows the transfer processes simulatio... more Hydrological modeling of the unsaturated soil zone fluxes allows the transfer processes simulation through the hydrological active soil zone. The pedotransfer functions (FTP) are useful tools in the modeling process. They contain analytical functions derived through statistic optimization process using a large amount of soil information data. This paper aims to analyze the level of reliability of two different pedotransfer functions [Wsten et al. (2001); Hodnett and Tomasella (2000)] by using field measurement of soil properties and experimental infiltration data through a disc infiltrometer in an experimental catchment at northeastern semi arid zone of Brazil. FTP's used in this study were derived on previous studies by taking into account soils of different origins. The former FTP considers a large range of soil classes from temperate climate regions; the latter was derived through a selection of soils from tropical climate regions. The use of these pedotransfer functions show...
The enhancement of the Water Resources Management System depends mostly on good governance. It is... more The enhancement of the Water Resources Management System depends mostly on good governance. It is crucial for water resources protection at the long term and the current generations. In Brazil, the implementation of a water resources management model is still an unconsolidated process. In order to make implementation a reality, the consolidation of the basis of the governance needs to be framed, and it is linked to many factors: adequate institutional basis, efficient institutional arrangement, management and implementation organisms need political autonomy in the decision-making process, institutional integration between different levels, public political engagement, and environmental education.
In the Brazilian semi arid region, a combination between human activities and
climatic factors pr... more In the Brazilian semi arid region, a combination between human activities and climatic factors produces an increase in the ecosystem susceptibility to soil erosion. In this study, runoff and soil erosion processes due to natural rainstorm events on a 0.025 ha undisturbed experimental plot is analyzed. The site was instrumented to monitor rainfall, overland flow, runoff and erosion. Automatic devices were installed to monitor rainfall and the level of a 5 m3 tank at a 1-minute time step. The sediment transported by the flow was collected after each event. Plot average slope is 2.5%, vegetated of both permanent and annual plants, composed by a combination of xerophytes shrubs, brushes and grass species, whose patterns change with growing season as a result of its natural development dynamics. It was observed that runoff and soil erosion was controlled by rainfall pattern, antecedent soil moisture and vegetation. Also, vegetation height and density is influenced by soil structure and faunal activity, increasing both soil storage capacity and surface roughness. Wetting up period data (February 13 to April 25/2007) showed that runoff generation is the result of a non-linear interdependency of rainfall pattern, soil wetness condition and vegetation characteristics. Runoff coefficients less than 0.1 occurred at approximately 82 per cent of the observed events. Moreover, a positive feedback was observed involving vegetative species dynamics, soil properties and faunal activity producing annual plants regeneration. Also, annual plants distribution within the plot seemed to be controlled by permanent trees canopy, where density was higher. Finally, it was obtained an empirical relationship between short-term sediment production and rainstorm amount valid for 2006-2007 wetting up period individual rainstorm events. Hence, this approach has provided a continuous record of rainfall-runoff-sediment production field monitoring data which can be used to analyze hydrologic and vegetative dynamics at plot scale. Also, it highlights the role of vegetative cover as a controlling factor on erosion protection management.
This work aims at presenting an automatic low cost water sampler prototype.
Data provided by this... more This work aims at presenting an automatic low cost water sampler prototype. Data provided by this equipment can be used in water resources management and control. Prototype has an electronic system which controls a peristaltic pump functioning, five solenoid valves and an ultrasonic sensor that provides water level measurement data. An interface with the user provided by a board and LCD display allows sampling parameters input and a report output when sampling is over. Hydraulic module uses a peristaltic 12V pump connected to five solenoid valves, which distribute sample and clean PVC tubes once each sampling is produced. Storage module contains four plastic bottles, 1.95 . Prototype structure is made of acrylic, 0.72 m height and 0.38 m diameter. Experimental laboratory runs have showed a successful performance.
A collaborative approach under a power-sharing institutional structure, coupled with a shift in p... more A collaborative approach under a power-sharing institutional structure, coupled with a shift in paradigms, sustainable water resources management often implies a political-institutional reform to achieve its goals. Most of Brazil’s river basins are subject to rapid urbanization; however, basin stakeholders generally lack sufficient institutional capacity to address the attending water resource issues. Subject to urbanisation, the Pitimbu River basin supplies potable water to approximately 280 000 people in Brazil’s Natal region. This study investigated how current institutional models influence both water management and fluvial contamination by metals. Sediment samples collected at eight sites along the river revealed elevated levels of Pb, Fe, Al, Ni and Zn, whose sources were linked to industries, vehicles, as well as agricultural and construction wastes. Aluminium enrichment of surface waters was mainly linked to inadequate sanitation infrastructure. In light of this, the region’s poor institutional capacity must be addressed through institutional reform, including a new management structure open to public collective water management planning. In so doing, Brazil’s water policies should acknowledge capacity building as a critical element of institutional reform.
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climatic factors produces an increase in the ecosystem susceptibility to soil erosion. In this
study, runoff and soil erosion processes due to natural rainstorm events on a 0.025 ha
undisturbed experimental plot is analyzed. The site was instrumented to monitor rainfall,
overland flow, runoff and erosion. Automatic devices were installed to monitor rainfall and
the level of a 5 m3 tank at a 1-minute time step. The sediment transported by the flow was
collected after each event. Plot average slope is 2.5%, vegetated of both permanent and
annual plants, composed by a combination of xerophytes shrubs, brushes and grass species,
whose patterns change with growing season as a result of its natural development
dynamics. It was observed that runoff and soil erosion was controlled by rainfall pattern,
antecedent soil moisture and vegetation. Also, vegetation height and density is influenced
by soil structure and faunal activity, increasing both soil storage capacity and surface
roughness. Wetting up period data (February 13 to April 25/2007) showed that runoff
generation is the result of a non-linear interdependency of rainfall pattern, soil wetness
condition and vegetation characteristics. Runoff coefficients less than 0.1 occurred at
approximately 82 per cent of the observed events. Moreover, a positive feedback was
observed involving vegetative species dynamics, soil properties and faunal activity
producing annual plants regeneration. Also, annual plants distribution within the plot
seemed to be controlled by permanent trees canopy, where density was higher. Finally, it
was obtained an empirical relationship between short-term sediment production and
rainstorm amount valid for 2006-2007 wetting up period individual rainstorm events.
Hence, this approach has provided a continuous record of rainfall-runoff-sediment
production field monitoring data which can be used to analyze hydrologic and vegetative
dynamics at plot scale. Also, it highlights the role of vegetative cover as a controlling factor
on erosion protection management.
Data provided by this equipment can be used in water resources management and control.
Prototype has an electronic system which controls a peristaltic pump functioning, five
solenoid valves and an ultrasonic sensor that provides water level measurement data. An
interface with the user provided by a board and LCD display allows sampling parameters
input and a report output when sampling is over. Hydraulic module uses a peristaltic 12V
pump connected to five solenoid valves, which distribute sample and clean PVC tubes once
each sampling is produced. Storage module contains four plastic bottles, 1.95 . Prototype
structure is made of acrylic, 0.72 m height and 0.38 m diameter. Experimental laboratory
runs have showed a successful performance.
climatic factors produces an increase in the ecosystem susceptibility to soil erosion. In this
study, runoff and soil erosion processes due to natural rainstorm events on a 0.025 ha
undisturbed experimental plot is analyzed. The site was instrumented to monitor rainfall,
overland flow, runoff and erosion. Automatic devices were installed to monitor rainfall and
the level of a 5 m3 tank at a 1-minute time step. The sediment transported by the flow was
collected after each event. Plot average slope is 2.5%, vegetated of both permanent and
annual plants, composed by a combination of xerophytes shrubs, brushes and grass species,
whose patterns change with growing season as a result of its natural development
dynamics. It was observed that runoff and soil erosion was controlled by rainfall pattern,
antecedent soil moisture and vegetation. Also, vegetation height and density is influenced
by soil structure and faunal activity, increasing both soil storage capacity and surface
roughness. Wetting up period data (February 13 to April 25/2007) showed that runoff
generation is the result of a non-linear interdependency of rainfall pattern, soil wetness
condition and vegetation characteristics. Runoff coefficients less than 0.1 occurred at
approximately 82 per cent of the observed events. Moreover, a positive feedback was
observed involving vegetative species dynamics, soil properties and faunal activity
producing annual plants regeneration. Also, annual plants distribution within the plot
seemed to be controlled by permanent trees canopy, where density was higher. Finally, it
was obtained an empirical relationship between short-term sediment production and
rainstorm amount valid for 2006-2007 wetting up period individual rainstorm events.
Hence, this approach has provided a continuous record of rainfall-runoff-sediment
production field monitoring data which can be used to analyze hydrologic and vegetative
dynamics at plot scale. Also, it highlights the role of vegetative cover as a controlling factor
on erosion protection management.
Data provided by this equipment can be used in water resources management and control.
Prototype has an electronic system which controls a peristaltic pump functioning, five
solenoid valves and an ultrasonic sensor that provides water level measurement data. An
interface with the user provided by a board and LCD display allows sampling parameters
input and a report output when sampling is over. Hydraulic module uses a peristaltic 12V
pump connected to five solenoid valves, which distribute sample and clean PVC tubes once
each sampling is produced. Storage module contains four plastic bottles, 1.95 . Prototype
structure is made of acrylic, 0.72 m height and 0.38 m diameter. Experimental laboratory
runs have showed a successful performance.