Environmental risk factors of leishmaniasis in Bahia State, Brazil using NASA Earth observation satellites / Fatores de risco ambientais para leishmanioses no estado da Bahia, Brasil, utilizando satélites da NASA de observação da Terra

NASA’s Earth Observing Satellites (EOS) were used to calculate three vegetation indices, extract precipitation and elevation data, and then evaluate their applicability for assessing risk of visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) in Bahia State, Brazil. Regression models showed that either form of leishmaniasis can be predicted by NDVI, NDMI, NDWI data products and TRMM) precipitation data (R2 = 0.370; p<0.001). Elevation was not significantly associated with the distribution of either VL or CL. In areas of high annual precipitation, CL was 3.6 times more likely to occur than VL. For vegetative moisture (NDMI), CL was 2.11 times more likely to occur than VL. Odds of CL occurrence increased to 5.5 times when vegetation (NDVI) and 13.5 times when liquid water content of vegetation canopies (NDWI) was considered. Areas at risk of CL and VL were mapped based on the selected explanatory variables. Accuracy of models were assessed using area under the receiver operating characteristic curve (AUC=0.72). We propose that statewide scale risk models based on use of EOS products will be a useful tool at 1 km2 spatial resolution to enable health workers to identify and target high risk areas to prevent transmission of leishmaniasis.

Os satélites de observação da Terra (SOT) da NASA foram usados para calcular três índices de vegetação, extrair dados de precipitação e elevação e avaliar sua aplicabilidade para identificar o risco para leishmaniose visceral (LV) e leishmaniose tegumentar (LT) no Estado da Bahia, Brasil. Modelos de regressão mostraram que ambas as formas de leishmaniose podem ser preditas pelos NDVI, NDMI, NDWI e precipitação TRMM (R2 = 0,370; p<0,001). A elevação não foi significativamente associada à distribuição de LV ou LT. Em áreas de alta precipitação anual, a LT foi 3,6 vezes mais provável de ocorrer do que a LV. Para a umidade vegetativa (NDMI), a LT apresentou 2,11 maior probabilidade de ocorrer do que a LV. As chances de ocorrência de LT aumentaram para 5,5 vezes em relação com a vegetação (NDVI) e 13,5 vezes quando o conteúdo de água líquida dos dosséis da vegetação (NDWI) foi considerado. Áreas em risco de LT e LV foram mapeadas com base nas variáveis explicativas selecionadas. A precisão dos modelos foi avaliada usando a área sob curva característica de operação do receptor (Curva COR=0,72). Propusemos que os modelos de risco em escala estadual baseados no uso de produtos SOT são uma ferramenta útil na resolução espacial de 1 km2 por permitir que profissionais de saúde identifiquem e direcionem áreas de alto risco para evitar a transmissão da leishmaniose.

Asociaciones polínicas de sedimentos superficiales del norte de la región chaqueña argentina / Pollen assemblages of surface sediments from the North of the Argentine Chaco region

Resumen La vegetación chaqueña esta condicionada por diversas presiones ambientales que afectan la fisionomía del paisaje. Con el objetivo de reconocer cambios espaciales de la vegetación y distinguir indicadores de disturbios naturales (inundaciones, sequías) y/o antrópicos (incendios, malezas de cultivos y pastoreo), se analizó la composición y distribución de las asociaciones polínicas de sedimentos superficiales sobre un gradiente ambiental al norte de la región chaqueña argentina (23°-27° S & 59°63° W). Se tomaron 35 muestras en un gradiente de 600 km en dirección SE-NO. El análisis se realizó con métodos multivariados y el índice de valor de importancia (IVI). La zonación mostró un reemplazo gradual de biotipos y taxones. En la zona oriental dominó el polen de palmeras (Copernica alba), hierbas (Poaceae) y árboles altos (Schinopsis balansae). Hacia la zona central predominó el polen de árboles bajos (Schinus, Prosopis ruscifolia, Pisonia zapallo), arbustos (Celtis, Castela) y hierbas (Amaranthaceae/Chenopodiaceae, Poaceae). La zona occidental presentó altos contenidos de polen de árboles altos (Schinopsis balansae, Schinopsis lorentzii, Astronium). Se detectaron conjuntos polínicos que permitieron discernir contingencias ambientales, como las inundaciones (Copernicia alba, Juncaginaceae, Cyperaceae) y actividades antrópicas, tales como incendios (Trithrinax, Shinus, Aspidosperma quebracho-blanco), malezas de cultivos (Amaranthaceae/ Chenopodiaceae, Gomphrena, Urticaceae, Ambrosia) y pastoreo (Prosopis ruscifolia, Prosopis kuntzei, Capparicordis, Cerciduim praecox). Los tipos polínicos más importantes fueron: Schinopsis balansae (9 %), Celtis (8.4 %), Poaceae (7.5 %), Schinus (6.9 %), Copernicia alba (3.7 %), entre otros. Se diferenciaron tres asociaciones polínicas que representaron las comunidades de: 1) palmares y sabanas, 2) bosques bajos y matorrales y 3) bosques altos, que se distribuyeron en umbrales de precipitación de 1 100 - 1 000, 1 000 -850 y 850 - 700 mm respectivamente. Los resultados amplían el conocimiento sobre las asociaciones polínicas de la región chaqueña argentina, ofreciendo una buena perspectiva para interpretar la dinámica del paisaje durante el Holoceno en la región.(AU)

Abstract Chaco vegetation is conditioned by several environmental pressures affecting the physiognomy of the landscape. With the aim to recognize the spatial changes of vegetation and distinguish indicators of natural (floods, droughts) and/or anthropogenic disturbances (fires, weeds of crops and grazing), we analyzed the composition and distribution of pollen assemblages of surface sediments along an environmental in the north of Argentine Chaco region (23°-27° S, 59°-63° W). Thirty-five samples were taken into an environmental gradient comprising 600 km length in SE-NW direction. The analyses was performed by multivariate methods and the importance value index (IVI). Zonation showed a gradual replacement of biotypes and taxa. In the Eastern zone, the pollen of palms (Copernica alba), herbs (Poaceae) and high trees (Schinopsis balansae) were dominant. Towards the middle zone, the pollen of low trees (Schinus, Prosopis ruscifolia, Pisonia zapallo), shrubs (Celtis, Castela) and herbs (Amaranthaceae/Chenopodiaceae, Poaceae) were dominant. The western zone recorded the highest content of pollen of high trees (Schinopsis balansae, Schinopsis lorentzii, Astronium). Pollen types were detected that allowed to discern environmental contingencies, such as floods (Copernicia alba, Juncaginaceae, Cyperaceae) and anthropic activities, such as fires (Trithrinax, Shinus, Aspidosperma quebracho-blanco), weeds of crops (Amaranthaceae/Chenopodiaceae, Gomphrena, Urticaceae, Ambrosia) and grazing (Prosopis ruscifolia, Prosopis kuntzei, Capparicordis, Cerciduim praecox). The most important pollen types were: Schinopsis balansae (9 %), Celtis (8.4 %), Poaceae (7.5 %), Schinus (6.9 %), Copernicia alba (3.7 %), among others. Three pollen assemblages were differentiated which represent the follow communities: 1) palms and savannas, 2) low forests and scrublands and 3) high forests, that are distributed in precipitation thresholds corresponding to, 1 100 - 1 000, 1 000 - 850 and 850 - 700 mm respectively. Results expand the knowledge about the pollen assemblages of the Argentine Chaco region, offering a good perspective to interpret the dynamic of the landscape during the Holocene in the region.(AU)

Caracterización y modelado hidrometeorológico en la cuenca del río Atulapa, Guatemala / Characterization and hydrometeorological modeling in the Atulapa River basin, Guatemala

Los modelos hidrometeorológicos, facilitan el control, monitoreo y planificación del recurso agua en cuencas hidrográficas, representando variables meteorológicas de forma distribuida. El objetivo del estudio, es proponer modelos hidrometeorológicos bidimensionales para cuantificar de forma precisa, las variables básicas que determinan la dinámica del recurso hídrico en la cuenca del río Atulapa, Esquipulas, departamento de Chiquimula, Guatemala. Se generaron y recopilaron datos hidrometeorológicos, con estaciones digitales instaladas y estaciones locales. Para el desarrollo de los modelos se elaboró una correlación entre altitud de las estaciones meteorológicas, como variable explicativa y registros climáticos como variable de respuesta. El modelo de escorrentía es una correlación entre alturas limnimétricas en la estación hidrométrica, como variable explicativa y el caudal óptimo de los aforos como variable de respuesta. La precipitación media de la cuenca obtenida con los modelos generados, es de 1,884 mm/año y la temperatura media de 18.92°C. El cambio de temperatura entre la parte baja y alta disminuye a razón de 1°C por cada 175 m.snm. El caudal medio anual es a razón de 0.5 m3 /seg en la estación hidrométrica del Puente. Los modelos hidrometeorológico generados en la cuenca del río Atulapa representaron la variabilidad climática en forma bidimensional, permitiendo un control y monitoreo del recurso hídrico en la cuenca, para la planificación del uso sostenible. La orografía en la cuenca, definió la estrecha relación con las variables meteorológicas precipitación y temperatura obteniendo modelos de regresión lineal precisos.

The hydrometeorological models facilitate the control and monitoring of the water resource in watersheds, representing meteorological variables in a distributed way, for the planning of the water resource. The objective of the study is to propose two-dimensional hydrometeorological models to accurately quantify the basic variables that determine the dynamics of water resources in the Atulapa River basin, Esquipulas, department of Chiquimula, Guatemala. Hydrometeorological data were generated and collected, with installed digital stations and local stations. For the development of the models, a correlation was made between the altitude of the meteorological stations, as an explanatory variable and climatic records as a response variable. The runoff model is a correlation between limnimetric heights in the hydrometric station, as an explanatory variable and the optimum flow of the gauging as a response variable. The average precipitation of the basin obtained with the generated models is 1,884 mm/ year and the average temperature is 18.92°C. The temperature change between the low and high part decreases at a rate of 1°C for every 175 masl. The average annual flow is at a rate of 0.5 m3 /sec at the Puente hydrometric station. The hydrometeorological models generated in the Atulapa River basin represented the climatic variability in two-dimensional form, allowing a control and monitoring of the water resource in the basin, for the planning of the sustainable use. The orography in the basin, defined the close relationship with meteorological variables precipitation and temperature obtaining accurate linear regression models.

Hydroclimatic variables associated with El Nino and La Nina events at the Curuá-Una hydroelectric reservoir, Central Amazonia / Variáveis hidroclimáticas associadas com eventos de El-Niño e La-Niña no reservatório hidrelétrico de Curuá-Una, Amazônia Central

The anomalies of Sea Surface Temperature (SST) influence rainfall and therefore the regime of the rise and fall in the level of the rivers in the Amazon region. The aim of this study was to investigate the influence of the El Nino-Southern Oscillation (ENSO) on hydroclimatic variables and identify the existence of trends on these variables in the Curuá-Una hydroelectric reservoir in the West of the State of Pará. It was used 27 years of monthly precipitation and water flow data to identify possible trends using a non-parametric test (Mann Kendall, p<0.05), and the standardized precipitation index (SPI) was also calculated. The results indicate a positive tendency of the influence of the ENSO on hydroclimatic variables, although it was observed that the rainfall did not increase over the period of 1977 to 2004. The SPI indicates that extreme events of precipitation are related to El Nino and La Nina and that lower precipitation periods were more intense in the decades of the 80´s and 90's. The results show that El Nino events can directly affect the water balance at the micro-watershed of Curuá-Una, as was observed in 2015.

As anomalias da temperatura da superfície do mar (TSM) influenciam as chuvas e consequentemente o regime de subida e descida do nível dos rios na região amazônica. O objetivo deste estudo foi verificar a influência de eventos El Niño Oscilação Sul (ENSO) sobre algumas variáveis hidroclimáticas e identificar a existência de tendência sobre essas variáveis para o reservatório de Curuá-Una no oeste do Pará. Utilizaram-se 27 anos de dados mensais de precipitação e vazão para identificar possíveis tendências utilizando um teste não paramétrico (Mann Kendall, p<0.05) e calculado o índice de precipitação normalizado (SPI). Os resultados apresentam tendência positiva da influência do ENOS sobre as variáveis hidroclimáticas, embora não foi observado um aumento na precipitação para o período de 1977 a 2004. O índice de precipitação normalizado revela que os eventos extremos de seca e precipitação estão relacionados com eventos de El Niño e La Niña e que os eventos de baixa precipitação foram mais intensos nas décadas de 80 e 90. Os resultados revelam ainda que eventos de El Niño afetam diretamente o balanço hídrico da micro bacia do reservatório de Curuá-Una, como recentemente em 2015.

Global Model selection for evaluation of Climate Change projections in the Eastern Tropical Pacific Seascape / Selección del Modelo Global para la evaluación de las proyecciones de Cambio Climático en el Paisaje Marino del Pacífico Tropical Oriental

Two methods for selecting a subset of simulations and/or general circulation models (GCMs) from a set of 30 available simulations are compared: 1) Selecting the models based on their performance on reproducing 20th century climate, and 2) random sampling. In the first case, it was found that the performance methodology is very sensitive to the type and number of metrics used to rank the models and therefore the results are not robust to these conditions. In general, including more models in a multi-model ensemble according to their rank (of skill in reproducing 20th century climate) results in an increase in the multi-model skill up to a certain point and then the inclusion of more models degrades the skill of the multi-model ensemble. In a similar fashion when the models are introduced in the ensemble at random, there is a point where the inclusion of more models does not change significantly the skill of the multi-model ensemble. For precipitation the subset of models that produces the maximum skill in reproducing 20th century climate also showed some skill in reproducing the climate change projections of the multi-model ensemble of all simulations. For temperature, more models/simulations are needed to be included in the ensemble (at the expense of a decrease in the skill of reproducing the climate of the 20th century for the selection based on their ranks). For precipitation and temperature the use of 7 simulations out of 30 resulted in the maximum skill for both approaches to introduce the models.

Se emplearon dos métodos para escoger un subconjunto a partir de treinta simulaciones de Modelos de Circulación General. El primer método se basó en la habilidad de cada uno de los modelos en reproducir el clima del siglo XX y el segundo en un muestreo aleatorio. Se encontró que el primero de ellos es muy sensible al tipo y métrica usada para categorizar los modelos, lo que no arrojó resultados robustos bajo estas condiciones. En general, la inclusión de más modelos en el agrupamiento de multi-modelos ordenados de acuerdo a su destreza en reproducir el clima del siglo XX, resultó en un aumento en la destreza del agrupamiento de multi-modelos hasta cierto punto, y luego la inclusión de más modelos/simulaciones degrada la destreza del agrupamiento de multi-modelos. De manera similar, en la inclusión de modelos de forma aleatoria, existe un punto en que agregar más modelos no cambia significativamente la destreza del agrupamiento de muti-modelos. Para el caso de la precipitación, el subconjunto de modelos que produce la máxima destreza en reproducir el clima del siglo XX también mostró alguna destreza en reproducir las proyecciones de cambio climático del agrupamiento de multi-modelos para todas las simulaciones. Para temperatura, más modelos/simulaciones son necesarios para ser incluidos en el agrupamiento (con la consecuente disminución en la destreza para reproducir el clima del siglo XX). Para precipitación y temperatura, el uso de 7 simulaciones de 30 posibles resultó en el punto de máxima destreza para ambos métodos de inclusión de modelos.