Marcelo dos Santos Targa

Influência das cavas de extração de areia no balanço hídrico do vale do Paraíba do Sul

The extraction of sand in the valley of the Paraiba do Sul River, carried out in a vulnerable environment, is responsible for significant environmental impacts. This work had the objective of investigating the increase of the total area of lakes created in the mining process for a period of 11 years and of verifying the influence of the evaporation from these lakes on the regional water balance. Thus, a Geographic Information System data basis was implemented using the GIS software package, SPRING, and Landsat imagery. Scenes 218/76 and 219/76 were used for the quantification of the mining areas and for the assessment of the evolution of the activity in the area for a period of 11 years. With data from a local climatological station (UNITAU/INMET-83784) integrated into the database and with the total area of artificial lakes resultant from sand mining activity, it was possible to estimate the increase of the evaporation rate due to this activity. An increase of 591 ha, in 1993 to 1,726 ha in 2003 in the area of lakes was observed. The resulting increase in the evaporating rate was 203% with 19,157,022 m³ evaporated in 2003 correspondent to the consumption of a city with more than 326,000 inhabitants, considering the average consumption for the State of Sao Paulo which is greater than the Brazilian average.

Variação espectral e eficiência de uso da radiação fotossinteticamente ativa em ensaio com genótipos de trigo

Field radiometry measurements are used to quantify the spectral variation and the solar radiation use efficiency of biomass production (eF), in an experiment with 20 wheat genotypes cultivated at the experimental site of the University of Taubate in Taubate, Sao Paulo State, Brazil, during the period from May to October of 1999. The crop was irrigated on a weekly basis in order to supply water close to soil field capacity. Eight radiometric measurements were taken with the field spectroradiometer Spectron SE-590, from plant emergency through physiological grain maturity. These measurements were transformed into the normalized difference vegetation index (NDVI) that, along with the photosynthetic active radiation (PAR) data, were used to calculate the accumulated absorbed PAR (AAPAR) over the crop growing season in order to estimate the values of eF. The result showed that eF presented a significant variation among genotypes and that the field radiometric technique is a promising tool to identify genotypes with high eF, and furthermore, for biomass production, the use of solar radiation, in the photosynthetic process, is much more relevant than AAPAR.

Allometric equations for the estimation of Jatropha curcas biomass.

This paper describes the estimation of biomass and carbon stock in Jatropha crops in the Vale do Paraiba region, Brazil, using allometric equations developed based on regression analysis which considered the biomass as a variable dependent on easily obtainable dendrometric measurements. The biomass estimated using allometric equations was validated by the destructive direct method based on the cutting of trees of different heights and structures. When compared with other models, the linear equation Y = 1.3 (h²d), where Y is the biomass (kg), h is the height (m), and d is the crown projection (m) showed reliable results and no significant errors to estimate trees up to 3.2 m tall. For the 4 × 3 m plant spacing, result evaluations showed that the stock of dry matter ranged from 0.5 to 6 Mg ha–1, while the carbon stored in the area could reach 3 Mg C ha–1.

Equações Alométricas para Estimativa de Fitomassa em Cultivo de Pinhão Manso / Allometric Equations for the Estimation of Jatropha Curcas Biomass

This paper describes the estimation of biomass and carbon stock in Jatropha crops in the Vale do Paraiba region, Brazil, using allometric equations developed based on regression analysis which considered the biomass as a variable dependent on easily obtainable dendrometric measurements. The biomass estimated using allometric equations was validated by the destructive direct method based on the cutting of trees of different heights and structures. When compared with other models, the linear equation Y = 1.3 (h²d), where Y is the biomass (kg), h is the height (m), and d is the crown projection (m) showed reliable results and no significant errors to estimate trees up to 3.2 m tall. For the 4 × 3 m plant spacing, result evaluations showed that the stock of dry matter ranged from 0.5 to 6 Mg ha–1, while the carbon stored in the area could reach 3 Mg C ha–1.

Estimativa do escoamento superficial em área residencial

This study aimed to estimate the watershed runoff caused by extreme events that often result in the flooding of urban areas. The runoff of a residential area in the city of Guaratingueta, Sao Paulo, Brazil was estimated using the Curve-Number method proposed by USDA-NRCS. The study also investigated current land use and land cover conditions, impermeable areas with pasture and indications of the reforestation of those areas. Maps and satellite images of Residential Riverside I Neighborhood were used to characterize the area. In addition to characterizing land use and land cover, the definition of the soil type infiltration capacity, the maximum local rainfall, and the type and quality of the drainage system were also investigated. The study showed that this neighborhood, developed in 1974, has an area of 792,700 m2, a population of 1361 inhabitants, and a sloping area covered with degraded pasture (Guaratingueta-Piagui Peak) located in front of the residential area. The residential area is located in a flat area near the Paraiba do Sul River, and has a poor drainage system with concrete pipes, mostly 0.60 m in diameter, with several openings that capture water and sediments from the adjacent sloping area. The Low Impact Development (LID system) appears to be a viable solution for this neighborhood drainage system. It can be concluded that the drainage system of the Guaratingueta Riverside I Neighborhood has all of the conditions and characteristics that make it suitable for the implementation of a low impact urban drainage system. Reforestation of Guaratingueta-Piagui Peak can reduce the basin’s runoff by 50% and minimize flooding problems in the Beira Rio neighborhood.

Compensatory forestation for soil water retention in watersheds of Campos do Jordão municipality, SP, Brazil

O Florestamento Compensatorio e uma tecnica importante para estimar a area de cobertura florestal necessaria para compensar as perdas de agua por escoamento superficial em uma bacia hidrografica e assim orientar intervencoes de recomposicao florestal. O estudo tem como principal objetivo quantificar a area de florestamento compensatorio necessario para melhorar a retencao de agua nas sub-bacias hidrograficas do Ribeirao das Perdizes e do Ribeirao Fojo, no municipio de Campos do Jordao, SP. As estimativas foram baseadas na metodologia do Florestamento Compensatorio para Retencao de Agua em Microbacias (FCRAM). Dessa forma, a estimativa da retencao de agua em microbacias foi feita considerando: o valor medio mundial de destino da agua no ciclo hidrologico, os usos e a ocupacao do solo, bem como, a estimativa da permeabilidade. As sub-bacias tem uma area total de 2.666,6 ha, correspondendo a 9,3% da area do Municipio de Campos do Jordao. Os principais usos e ocupacao do solo sao: area de floresta com 1.257,9 ha, area urbanizada com 434,4 ha, area de reflorestamento com 432,5 ha, area de campos de altitude com 265,1 ha, area de pasto com 126,8 ha e area de outras classes com 149,9 ha. Estimativas de campo da infiltracao de agua em Cambissolo Haplico resultaram em taxas elevadas (298 mmh-1) para o solo com cobertura do tipo floresta, de 289 mmh-1para a cobertura vegetal do tipo reflorestamento, 94 mmh-1 para o campo e 63 mmh-1para a cobertura vegetal do tipo pasto. Com base na recomendacao de que 20,55% de toda a agua que precipita sobre a bacia deve infiltrar no solo, calculou-se por meio do FCRAM que a area de floresta necessaria para compensar as perdas de agua por escoamento superficial nas demais coberturas do solo (campo, pasto, reflorestamento e urbana) existentes nessas sub-bacias e de 1.318,1 ha (51,8%). Dessa forma, concluiu-se que 60,2 ha (2,3%), adicionais de floresta devam ser plantados para compensacao de 1,096 milhoes de m³/ano de agua perdida nessas sub-bacias.

Drenagem urbana do Parque Residencial Beira Rio I no município de Guaratinguetá, SP

The objective of this work is to analyze flooding events that frequently affect the residential area called Parque Residencial Beira Rio I in the municipality of Guaratingueta, State of Sao Paulo. Data obtained from existing maps and recorded precipitation were used for calculating effective precipitation and surface runoff based on infiltration coefficients derived from the land cover mosaic and related impervious surfaces. Results show that this neighborhood has an area of 330,000m2, a population of 1,361 inhabitants, a sloping area without vegetation cover facing the residential area, an open drainage system of 0.60m diameter tubes, several open pits that capture rain water that descends from the surrounding area allowing a sediment load to enter the tubes. The residential area is located in a low lying plain with cemented curbs, lawn yards, and crossing roads around the lawns that are located in a higher elevation level than the drainage system. Lowering the level of those lawn yards and curbs, as well as recovering the surrounding slopes with forest vegetation should minimize the flooding problems in this neighborhood. Palavras-chave: Sustentabilidade da drenagem urbana, escoamento superficial, low impact development. INTRODUCAO Guaratingueta, municipio localizado no medio Vale do Paraiba Paulista, desenvolveu-se as margens do Rio Paraiba do Sul, entre as Serras da Mantiqueira e do Quebra-Cangalha. Embora, em 1630, a ocupacao urbana tenha ocorrido nas colinas ao redor da Igreja Matriz de Santo Antonio, a maior concentracao populacional se encontra nas planicies aluviais do Rio Paraiba do Sul. Segundo Cardoso Neto (1998), a ocupacao urbana se da apos o desmatamento e tem como consequencias o aumento do escoamento superficial e da erosao do solo, comprometendo os canais e galerias pluviais atraves de assoreamento. A ocupacao das areas naturais da bacia de inundacao do rio Paraiba do Sul e ribeirao Guaratingueta intensificou a ocorrencia de enchentes nessas regioes, aumentando os danos sociais e materiais causados pelas fortes chuvas. Esses locais em geral, sao ocupados irregularmente e sao as areas mais prejudicadas por cheias e inundacoes quando ocorrem chuvas intensas, como a de janeiro de 2000 que ocasionou muitas perdas (PONTES e BERNADES, 2000). O sistema de drenagem na maioria das cidades brasileiras e conhecido como sistema de microdrenagem e sao compostos por conjunto de dutos pluviais ou canais em nivel de loteamento ou de rede primaria urbana. Este tipo de sistema de drenagem e projetado para atender a drenagem de precipitacoes com risco moderado. (TUCCI, 2002). O presente trabalho tem como objetivo determinar a precipitacao efetiva e as condicoes em que ocorre o escoamento superficial na drenagem do Bairro Beira Rio I no municipio de Guaratingueta, SP. METODOLOGIA O Bairro Beira Rio em Guaratingueta, SP (Figura1), a margem esquerda do Rio Paraiba do Sul, foi inaugurado em 1981 com 734 lotes e cuja implantacao foi administrada pela Companhia de Desenvolvimento de Guaratingueta (CODESG). Essa area, no passado, pertencia a fazenda da familia Bygton que produziam cafe junto ao Espigao Guartingueta-Piagui. A area destinada ao atual bairro Beira Rio I (Figura 2) era um local com diversas nascentes, lagos, corregos e vegetacao diversificada.