Vander Kaufmann

Assessing the impact of climate change scenarios on water resources in southern Brazil

Abstract The SWAT hydrological model was applied to analyse the impacts of climate changes on the flow and sediment production regimes in the Concórdia River drainage basin, in southern Brazil. Climate scenarios A2 and B2 of the IPCC were used to simulate basin behaviour over the period 2071–2100 and to compare it with that in the baseline period (1961–1990). Runoff and sediment yield calculated on a monthly basis in the calibration period gave Nash-Sutcliffe coefficients of 0.82 and 0.83, respectively, showing good model fit. Comparison of simulations for scenarios A2 and B2 with the baseline showed a reduction in flow of 39.2% and 41.2%, respectively. Analysis of daily values and extreme events suggested that flood peaks could reach more extreme values in the future, especially under Scenario A2. Time series of rainfall do not show significant departures from basin mean values, although Scenario B2 and, in particular, Scenario A2, show greater maximum values. Sediment production follows the same pattern as basin streamflow. Editor Z.W. Kundzewicz Citation Perazzoli, M., Pinheiro, A., and Kaufmann, V., 2013. Assessing the impact of climate change scenarios on water resources in southern Brazil. Hydrological Sciences Journal, 58 (1), 1–11.

Transporte de glifosato pelo escoamento superficial e por lixiviação em um solo agrícola

Glyphosate was determined in runoff and leaching waters in agricultural soil that received an application of active ingredient and was exposed to simulated intensive rain conditions. The concentrations decreased during the simulation period and the concentrations of the runoff were higher than those achieved in the samples of leaching waters. The concentrations were lower than the pattern in the Brazilian Regulation MS N. 518/2004 for drinking water. The transported load of the applied active ingredient by the leaching was of 15.4% (w/w) and for the runoff was of 1.7% (w/w).

Simulating transport of nitrogen and phosphorus in a Cambisol after natural and simulated intense rainfall.

Intense rainfall adversely affects agricultural areas, causing transport of pollutants. Physically-based hydrological models to simulate flows of water and chemical substances can be used to help decision-makers adopt measures which reduce such problems. The purpose of this paper is to evaluate the performance of SWAP and ANIMO models for simulating transport of water, nitrate and phosphorus nutrients, during intense rainfall events generated by a simulator, and during natural rainfall, on a volumetric drainage lysimeter. The models were calibrated and verified using daily time series and simulated rainfall measured at 10-minute intervals. For daily time-intervals, the Nash-Sutcliffe coefficient was 0.865 for the calibration period and 0.805 for verification. Under simulated rainfall, these coefficients were greater than 0.56. The pattern of both nitrate and phosphate concentrations in daily drainage flow under simulated rainfall was acceptably reproduced by the ANIMO model. In the simulated rainfall, loads of nitrate transported in surface runoff varied between 0.08 and 8.46 kg ha(-1), and in drainage form the lysimeter, between 2.44 and 112.57 kg ha(-1). In the case of phosphate, the loads transported in surface runoff varied between 0.002 and 0.504 kg ha(-1), and in drainage, between 0.005 and 1.107 kg ha(-1). The use of the two models SWAP and ANIMO shows the magnitudes of nitrogen and phosphorus fluxes transported by natural and simulated intense rainfall in an agricultural area with different soil management procedures, as required by decision makers.

Efeitos de cenários de uso do solo sobre o regime hidríco e produção de sedimentos na bacia do Ribeirão Concórdia - SC

The inappropriate use of agricultural land is causing a gradual loss of its productive capacity and degradation of water resources by sediments and pollutants. Land use can affect the hydrological processes and soil erosion in the basin. The objective of this work was to simulate different scenarios of land use in the Concordia River basin using the SWAT model, and to analyze the effects of changes in stream flow and sediment yield, making comparisons with the present land use classification. The scenarios generated were agriculture, native forest and pasture. The basin is located in southern Brazil and has a drainage area of 30.74 km2. In the calibration state, it was obtained the month efficiency coefficient of Nash-Sutcliffe of 0.82 and 0.83 for outflow and sediment yield, respectively. Native forest had the highest decrease in average stream flow, in relation to the present scenario, about 8.70%. Agriculture produced the highest sediment loads, approximately 3 times larger than the present scenario. It was observed that changes in land use can impact the regime and water availability in the basin.

Uso do solo na zona ripária de bacias agrícolas de pequeno a médio porte

RESUMO – As zonas riparias situam-se as margens dos sistemas de drenagens de aguas superficiais, afetando processos hidrologicos. O Codigo Florestal Brasileiro estabelece um afastamento minimo ao longo dos cursos de aguas, considerado como area de preservacao permanente. Este trabalho objetivou determinar a distribuicao do uso do solo em bacias agricolas com varias dimensoes para diferentes afastamentos em relacao ao sistema de drenagem de aguas superficiais. A metodologia utilizada compreendeu o uso de imagens do satelite SPOT-5, para classificacao do uso de solo em seis bacias com areas variando de 14 a 600 km 2 . A precisao da classificacao foi determinada pela acuracidade e o nivel de acerto, determinado pelo coeficiente Kappa. A partir do sistema de drenagem foram tracadas linhas paralelas aos cursos de aguas, denominados buffers, com afastamento das margens de 20, 30, 50, 100 e 200 m. Em cada buffer foi determinada a distribuicao da ocupacao do uso do solo. Os valores obtidos com a classificacao indicaram acerto com coeficiente Kappa medio de 0,96. Os temas classificados em todas as imagens apresentaram boa acuracidade, com valores maiores que 96%. Os resultados apontaram que o uso da terra predominante em todas as bacias e a mata nativa com valores medios de 46,8%, seguida de culturas agricolas com 24,7% e pastagens com 21,7%. As areas de matas nativas apresentavam tendencia de reducao a medida que se afastavam dos cursos de agua, enquanto os reflorestamentos tendiam a aumentar o percentual da area ocupada com o afastamento das margens dos rios. Palavras-chave: Zona riparia, Uso e ocupacao do solo e Bacia agricola. LAND USE OF RIPARIAN ZONES IN SMALL AND MEDIUM SIZED RURAL WATERSHEDS

Runoff from soils under different management and simulated rainfall regimes in southern Brazil

Abstract Surface runoff and drainage were evaluated for southern Brazilian soils subjected to different rainfall intensities and management practices. Soils received up to four applications of simulated rainfall in sequences with one application per day. Seven lysimeters, each of 1 m3 volume, were used to measure drainage volume, with measurement of initial and final water content, times at which surface runoff and lysimeter drainage began, and the volume rates of flow. At the end of the second test, soils were subjected to two levels of disturbance (denoted by low and high soil movement) by opening furrows. These cultivation treatments altered the times at which lysimeter surface runoff and drainage were initiated, the rates of surface runoff, the final infiltration and internal drainage, and the components of the water balance throughout the series of trials. Mean times at which surface runoff was initiated in lysimeters subjected to greater soil disturbance were longer than those with little soil disturbance. Final infiltration rates were greater in lysimeters with little soil disturbance. It was also found that lysimeter surface runoff generation was influenced by the state of development of maize grown in the lysimeter. Editor D. Koutsoyiannis; Associate editor G. Mahé

Concentrações e cargas de nitrato e fosfato na Bacia do Ribeirão Concórdia, Lontras, SC

This study presents concentrations and loads of nitrate and total inorganic phosphate in surface runoff infiltrating water and subsurface flow in the basin of Ribeirao Concordia, Lontras, SC - Brazil . Over a 109-day period, 102 samples were collected from three river sections, three lysimeters and three piezometric wells in the interior of the basin. Concentrations were compared with the standards given in the CONAMA Resolutions 357/2005 and 420/2009. Concentrations of nitrate and phosphate in lysimeter drainage water and flows were greater than those in river sections and piezometric wells. In the river sections and in surface flow from the lysimeter under pasture, nitrate concentrations were lower than the benchmarks set for such waters. Phosphate concentrations in the river sections and in both lysimeter surface runoff and in drainage water, and in the piezometers, all exceeded the standards defined in CONAMA Resolutions 357/2005 and 420/2009. Drainage waters in the lysimeters transported nitrate and phosphate loads greater than those in surface runoff, which in turn transported loads of the same order of magnitude as in river flow.

Relações entre diversidade íctia e fatores hidrodinâmicos de um riacho na bacia do rio Uruguai

article+bn00809012009. Abstract: Physical, chemical and environmental factors in watercourses can exert influence on the structure and diversity of species of aquatic biota. Among the physical factors there are hydrodynamic conditions. Disposal variations result into complex dynamics of fish populations and communities. This study aims at assessing the correlation between hydrodynamic variables in the Fortaleza stream, affluent of Uruguay River, and species diversity. The methodology included the collection of hydrodynamic (average depth of the water column, average water flow speed and discharged water in the pluvial metric section) and biological (fish collection in the areas of influence on pluvial metric sections) data. Shannon diversity indices, equitability and the similarity index were calculated with biological data. It has been collected a sample with 527 fishes. There were 25 species, being 4 exotic ones and 4 species not-yet-classified. Such species included 4 orders, 7 families and 13 genera classified. The Shannon index ranged from 1.43 to 2.68 nats/individual. The equitability index was always above 0.8 indicating that individuals are well distributed among different species. The similarity index of Jaccard ranged between 20 and 80%. The lowest figures were obtained from the sample area located near the source. The correlations between the Shannon index and hydrodynamic features resulted in R 2 coefficients ranging between 0.59 and 0.83. These results show that diversity of species is influenced by the hydrodynamic characteristics. Nevertheless, either depth of water column or discharge average speed is not significant enough to explain the spatial variability of the diversity of species.

Influence of hydroclimatic variations on solute concentration dynamics in nested subtropical catchments with heterogeneous landscapes

Despite global efforts to monitor water quality in catchments worldwide, tropical and subtropical zones still lack data to study the influence of human activities and climate variations on solute dynamics. In this study, we monitored ten solutes every two weeks for six years (2010-2015) in three nested catchments (2 to30 km2), which contained heterogeneous landscapes composed of forests and agricultural land, and one small neighboring forested catchment (0.4 km2). Data analysis revealed that i) rainfall, discharge and solute concentrations displayed no clear seasonal patterns, unlike many catchments of the temperate zone; ii) solute concentrations in the agricultural area were higher than those in the forested area, but both areas displayed similar temporal patterns due to a common hydroclimatic driver; iii) all four catchments displayed a chemostatic export regime for most of the solutes, similar to catchments of the temperate zone; and iv) a positive correlation was observed between anion concentrations and ENSO (El Niño-Southern Oscillation) index. ENSO appeared to influence both hydroclimatic and anion dynamics in these subtropical catchments.

EVOLUÇÃO E MAGNITUDE DAS CONCENTRAÇÕES DE CÁTIONS, ÂNIONS E CARBONO NO DEJETO LÍQUIDO DE SUÍNOS EM FASE DE TERMINAÇÃO

Swine liquid wastes are an important nutrient source for physical, chemical and biological soil improvement. Characteristics change through time according to the management of animals and to farm treatment system. Anion, cation and carbon species have the greatest concentration changes in time. Current study evaluates concentration size and anion, cation and carbon evolution in finishing swine liquid wastes through anaerobic treatment system. Swine liquid wastes were collected from three farms characterized by integrated breeding system during the animals´ finishing phase. Collection occurred in the waste gut entrance and exit of the treatment system during 120 days in which the animals were installed. Retrieval occurred monthly within the bays. Anion, cation and carbon concentrations were analyzed by Ion Exchange Chromatograph, whilst total carbon was determined by Total Carbon Analyzer. Results revealed that Cl-, NH4+ and CI did not show any chemical difference between the farms. However, other chemical species had significant differences. The manure heap was highly efficient in the removal of NO2- and NO3- ions and had low efficiency for NH4+ ions. Concentration of ions Cl-, NH4+ and Ca+2 increased during the animals´ finishing period, whereas the other chemical species decreased or maintained concentrations.