Pluvial Precipitation Research Articles

Constraining the Capacity of Global Croplands to CO2 Drawdown via Mineral Weathering.

Terrestrial enhanced weathering of alkaline silicate minerals is a promising climate change mitigation strategy with the potential to limit the global temperature rise. The formation and accumulation of pedogenic carbonate and bicarbonate in soils/subsoils and groundwater offers a large sink for C storage; the amount of soil inorganic carbon (SIC) presently held within soils has been estimated to be 720-950 Gt of C. These values can be augmented by the addition of a variety of calcium and magnesium silicates via enhanced weathering. While the concept of the application of finely milled silicate rocks for faster weathering rates is well established, there has been limited discussion on the role of local climate, natural SIC content (i.e., the SIC innately present in the soil), and soil pH (among other important agronomic factors) on silicate weathering when applied to croplands, especially in view that the aim is to establish terrestrial enhanced weathering as a carbon dioxide removal (CDR) strategy on a global scale. In this work, we emphasized the importance of soil pH and soil temperature on silicate weathering and looked to estimate an upper limit of (i.e., constrain) the global capacity until the year 2100 for enhanced rock weathering (ERW) to draw down CO2 in the form of accumulated pedogenic carbonate or soluble bicarbonate. We assessed the global spatial distribution of cropland soil pH, which serves as a proxy for local innate SIC; annual rate of pluvial (rainfall) precipitation; and soil temperature, and found that the potential CO2 drawdown difference between faster and slower weathering silicates is narrower in Asia, Africa, and South America, while the gap is larger for Europe, North America, and Oceania.

Hydrology of the palmar state reserve, yucatán, México: hydrological budget of petenes

Throughout the coastal zone of Yucatan state (Mexico), between the coastal sandbar, and the land with low dry forest, are the flooded low forest, mangroves, and swamps. It is within these swampy lands, where are found numerous arboreal islands or petenes (local name). It has been outlined that its importance is because the water contribution from springs to the basin. As a contribution to the knowledge of the petenes, it was developed a hydrological monitoring system to estimate the hydrological budget of a petén located 3 km southwest of the population of Sisal in the restoration zone of the Palmar Reserve, Yucatan. The analysis showed that the groundwater inflow represented 92 % of the total of inflow to the system, with the net precipitation representing only 6 % and the surface inflow 2 %. By the other side, the surface outflow represented 40 % of the total of the outflow of the system, the groundwater outflow 20 % and the evapotranspiration 40 %. The annual total balance resulted negative (it means fluxes out of the petenes) with a volume from storage of about – 129,288.28 m3. The springs in the interior of the petenes can become more determinant in the hydrologic balance of the community than the contribution of the pluvial precipitation, the hydrodynamics of swamps, or the influence of the waters of the sea.

Influence of Mediterranean climate and lunar calendar on milk production in Lacaune breed ewes

Environmental factors affect daily milk production in dairy animals. The aim of this study was to quantify the effects of environmental factors, specifically mean temperature (°C), relative humidity (%), temperature-humidity index (THI), solar radiation (°), pluvial precipitation (mm) and lunar calendar (full moon, waxing quarter, waning quarter, new moon), on milk production (kg/d). The analysis was based on 96,195 morning and evening milking records documented on 109 consecutive days, from 869 Lacaune ewes. Ewes were housed in groups of 174 individuals. The analysis was performed in two independent procedures, a Pearson correlation analysis and a multivariate analysis of the ewe's interrelationships, which was based on the total variance estimate and a Varimax-rotated factorial analysis. Milk yield (kg/d) was significantly (p < 0.05) negatively correlated with mean temperature (-0.24), relative humidity (-0.16), THI (-0.24), and radiation (-0.18), which suggests that the higher these environmental factors, the lower the milk yield. Lunar calendar had a significant (p < 0.01) effect on milk production yield; specifically, yields were higher on the full moon and new moon (2.25 ± 0.05kg/day) than they were on the crescent or waning moon (2.17 ± 0.05kg/day). In conclusion, ewes that had been exposed to higher mean temperature, relative humidity, THI and solar radiation had the lowest milk yield, and milk yields are highest on full and new moons. The results of this work may be helpful in making predictions for milk production in Lacaune ewes in the Mediterranean region throughout the year.

Saltwater intrusion in estuaries with different dynamic depths

Sea-level rise threatens to increase saltwater intrusion in low-lying coastal communities worldwide. In addition, changing patterns of evaporation and precipitation are expected to modify the lengths of saltwater intrusion in estuaries. This study aims to define the length of saltwater intrusion among distinct estuaries with contrasting responses to variations in river discharge and water level. A Markov-chain Monte Carlo model was used as a supervised machine learning of the relationship among saltwater intrusion length, river discharge, water level, wind velocity and pluvial precipitation in three estuaries The supervised learning provided a relationship to project saltwater intrusion for different climatic conditions in the estuaries. The length of saltwater intrusion and river discharge were proportional for the dynamically deep Dee River estuary (UK) and Capibaribe River estuary (Brazil). Increased river discharge in those two estuaries was followed by increased limit of saltwater intrusion. For these two cases, however, it is hypothesized that beyond a threshold of river discharge, both estuaries will show a decreased saltwater intrusion with increased river discharge and transition to dynamically shallow estuaries. The dynamically shallow St. Johns River estuary (USA) had the typically expected response of decreased saltwater intrusion after increases in river discharge.

Efecto de los factores climáticos en las fases fenológicas de Mauritia flexuosa Lf. en plantaciones de terraza baja en Ucayali, Perú

The aim of this study was to determine the influence of air temperature and rainfall on the phenological development of Mauritia flexuosa in plantations located in Ucayali, Peru. For this, during a 24-month period, 191 19-year-old palm trees were evaluated, distributed in three plantations established on low terrace soils. The results showed that the 45% of palm trees did not manifest their sexual maturity, meanwhile, 42% and 13% of individuals with male and female sex, respectively, were verified. It was found that the phenological cycle was biannual, with overlapping phenophases and staggered events. In female individuals, maximum flowering was observed in phenophase FLA1 (4-5%) from September to November 2018 and maximum fruiting FRM1 (4-6%) from October 2018 to January 2019; In male individuals, the FLA2 flowering phenophase occurs in two periods between September 2018 and February 2020, meanwhile, the open flower phenophase of both sexes is synchronous in a higher proportion between September and November. It was determined that pluvial precipitation and air temperature (maximum and minimum) did not show correlation (p ≤ 0.05) with the productive phenophases of Mauritia flexuosa. The pluvial precipitation, the maximum temperature and the minimum air temperature showed null association with each one of the phenological phases of the Mauritia flexuosa palm trees during the evaluation period. In order to obtain information for the planning of silvicultural management activities for the conservation of the species, it is recommended to evaluate for more years the influence of climatic elements on the productive development of Mauritia flexuosa.

Yield components and crop estimation for wheat cultivars at different sowing times

The objective of this study was to evaluate the yield and yield components of wheat cultivars, and compare the productivity obtained in the field and estimated with Jensen model, at different sowing dates, in Cascavel and Palotina cities, Parana state, Brazil. The experiments were carried out in the field at the COODETEC Research Center, located in Cascavel and Palotina. The experiment was conducted in a randomized blocks design in a 7 × 3 factorial, with plots consisting of six lines spaced at 5 × 0.17 meters, with seven wheat cultivars and three sowing dates, with three repetitions. The pluvial precipitation higher than crop evapotranspiration in all cultivation cycles analyzed did not prevent water deficiencies, which occurred predominantly in the heading and physiological maturation stages. The smallest water deficiencies in Cascavel (31.2 mm; April 22) and Palotina (7.2 mm; March 31), from sowing to heading, reduced grain yield by 41.7% and 42.8%, respectively, in relation to the higher productivity of each location. Small differences in yield components (NEM, NGE and MMG) provide differences in grain yield between the cultivars tested. The sowing carried out at the end of April and in May tended to have a higher yield. The best performances with Jensen model to estimate wheat grains yield were obtained for CD 1440 and QUARTZO cultivars. The Jensen model overestimated the grain yield of the CD 108, CD 1104, CD 150 and CD 154 cultivars, since the model do not consider losses due to excessive rainfall and/or pests and diseases.

Bidimensional geostatistics as an alternative for modeling time series under climate change scenarios

The objective of this work was to verify the use of semivariogram models and ordinary kriging to characterize and to represent the temporal dependence of the pluvial precipitation and air temperature, by using years and months with coordinates. The observed the forecast data of future scenarios of climatic changes, from 2000 to 2099, of the municipal district of Juiz de Fora – MG, for the pluvial precipitation and air temperature were analyzed. The semivariograms were adjusted by considering isotropy and anisotropy conditions. The wave model presented better adjustment than the Gaussian and spherical models when the two-dimensional grid was used. The structure and the magnitude of temporal dependence of the two variables were characterized by considering the 0º (months) and 90º (years) directions. The pattern of the temporal variability of the precipitation and the air temperature was represented by using kriging. Possible changes in the patterns of the pluvial precipitation and the air temperature for the future scenarios were verified by using a two-dimensional grid and kriging. The greatest changes in the pattern of the two variables were verified in the most pessimist future scenario.

Performance of the WRF model with different physical parameterizations in the precipitation simulation of the state of Puebla

In Mexico, intense rains generated by tropical cyclones, cold fronts, and mesoscale convective systems can cause floods and landslides, causing damage to social, service, economic and financial sectors, among others, leaving the population with fewer resources and in greater vulnerability. Given this scenario, disaster prevention has relevance in the civil protection agenda, which recognizes that it is essential to establish long-range strategies and programs focused on preventing and reducing their effects, beyond only paying attention to emergencies and disasters. The objective of this work is to evaluate the performance of the WRF model for the simulation of accumulated pluvial precipitation in 24 hours in the state of Puebla, considering 768 different combinations of physical parameters, compared to rain records of weather stations for the period from June 1 to August 20, 2017. In addition, as part of the research, optimal configurations are defined to obtain the best performance of the model at local and state levels.

Eventos extremos no estado do Ceará, Brasil: uma análise estatística de episódios pluviométricos no mês de março de 2019

Nesta investigação, foram analisados acumulados diários expressivos de precipitação pluvial que ocorreram em março de 2019 no estado do Ceará, com o intuito de identificar se os mesmos foram considerados extremos (a partir da Metodologia Estatística dos Máximos de Precipitação), além de analisar os sistemas atmosféricos que deflagraram tais eventos e possíveis danos ocasionados. Foram selecionados os dez maiores acumulados diários de março registrados nos postos da Fundação Cearense de Meteorologia e Recursos Hídricos - FUNCEME e identificados os sistemas atmosféricos atuantes que contribuíram para tais episódios pluviométricos a partir de imagens de satélites disponibilizadas pelo Instituto Nacional de Pesquisas Espaciais - INPE. Os acumulados diários foram, ao menos, um dos três maiores já registrados nos postos (cinco foram recordes) e estavam associados à atuação conjunta de dois ou mais sistemas atmosféricos. As TSMs do Atlântico (próximo à costa) apresentaram um padrão favorável à ocorrência de precipitações. Os acumulados diários foram pontuais e contribuíram para um considerável aporte de água apenas em algumas reservas hídricas do estado, pois as chuvas não apresentaram uma distribuição espaço-temporal homogênea.&#x0D; &#x0D; Abstract&#x0D; &#x0D; EXTREME EVENTS IN THE STATE OF CEARÁ, BRAZIL: A STATISTICAL ANALYSIS OF RAINFALL EPISODES IN MARCH 2019&#x0D; &#x0D; In this investigation, we analyzed expressive daily accumulated of pluvial precipitation that occurred in March 2019 in the State of Ceará, in order to identify if they were considered extreme (from the Statistical Methodology of the Maximum Precipitation), and to analyze the atmospheric systems that started such events and possible damage caused by them. The ten largest daily accumulations of March recorded in the posts of the Foundation for Metereological and Hydric Resources of Ceará State (FUNCEME) were selected. At the same time, the atmospheric systems that contributed to these pluviometric episodes were identified from satellite images provided by the National Institute of Space Research (INPE). Daily accruals were at least one of the three largest already registered at the stations (five were records) and were associated with joint performance of two or more atmospheric systems. Atlantic TMSM (near the coast) showed a favorable pattern for precipitation. The daily accumulations were punctual and allowed a considerable contribution only in some water reserves of the Ceará State, because the rain did not present a homogeneous spatial/temporal distribution.

Phenological and physiological evaluation of first and second cropping periods of sorghum and maize crops

AbstractEnvironmental conditions influence phenology and physiological processes of plants. It is common for maize and sorghum to be sown at two different periods: the first cropping (spring/summer) and the second cropping (autumn/winter). The phenological cycle of these crops varies greatly according to the planting season, and it is necessary to characterize the growth and development to facilitate the selection of the species best adapted to the environment. The aim of this study was to characterize phenological phases and physiological parameters in sorghum and maize plants as a function of environmental conditions from the first cropping and second cropping periods. Two parallel experiments were conducted with both crops. The phenological characterization was based on growth analyses (plant height, leaf area and photoassimilate partitioning) and gas exchange evaluations (net assimilation rate, stomatal conductance, transpiration and water‐use efficiency). It was found that the vegetative stage (VS) for sorghum and maize plants was 7 and 21 days, respectively, longer when cultivated during the second cropping. In the first cropping, the plants were taller than in the second cropping, regardless of the crop. The stomatal conductance of sorghum plants fluctuated in the second cropping during the development period, while maize plants showed decreasing linear behaviour. Water‐use efficiency in sorghum plants was higher during the second cropping compared with the first cropping. In maize plants, in the second cropping, the water‐use efficiency showed a slight variation in relation to the first cropping. It was concluded that the environmental conditions as degree‐days, temperature, photoperiod and pluvial precipitation influence the phenology and physiology of both crops during the first and the second cropping periods, specifically cycle duration, plant height, leaf area, net assimilation rate, stomatal conductance and water‐use efficiency, indicating that both crops respond differentially to environmental changes during the growing season.

Variación temporal de la morfología funcional del fitoplancton en una planicie inundable del Caribe Colombiano

Analizamos la variación temporal de los grupos funcionales basados en la morfología del fitoplancton (GFBM) en el sistema inundable de Ayapel a través de la comparación de dos muestreos previos realizados entre los 2005 y 2007 y uno nuevo hecho en el 2015. Se estimó el biovolumen (mm3.l-1) y los rasgos morfológicos como volumen, relación superficie/volumen (S/V) y dimensión linear máxima (DLM). El análisis temporal fue realizado acorde con los niveles de precipitación pluvial, y mediante un análisis de agrupamiento se definieron dos períodos previos (época seca y época de transición) y uno nuevo correspondiente al año 2015 (msENSO: época seca con influencia ENSO). En las épocas seca y de transición, el grupo predominante fue el GFBM III con altas DLM (108.77 µm) y relaciones S/V (1.44 µm), mientras que en el msENSO se observaron bajos biovolumenes (0.016 mm3.l-1) y la predominancia del GFBM V. La comparación de la morfología funcional entre los años evidenció la transición de formas filamentosas a formas flageladas del fitoplancton, permitiéndole un mejor ajuste ante las presiones ambientales del área de estudio.

Climatic hazard indicators for rainfed maize in a developing country: the case of Bajo Balsas, Mexico

Introduction: Rainfed agriculture is one of the most vulnerable forms of crop to the effects of climate change producing either drought or excess moisture and thus damaging crops and causing substantial economic damage. In developing countries with scarce resources for technological investment, rainfed agriculture is extremely important for the food production. The sowing of seasonal maize in the Bajo Balsas is for self-consumption, thence the importance of identifying climatic hazard indicators that threaten agricultural production of this culture. The purpose of this study was to build and validate climatic hazard indicators considering the different phenological stages of the plant. Method: First, we identify the climatic variables and characterize the phenological cycle of maize variety that is cultivated in the region; then we elaborate a database with the following daily and monthly climatic parameters: pluvial precipitation, maximum temperature and minimum temperature. We applied data mining with the WEKA software to validate and classify the maize production of 18 years, then, the years were classified by production defining three classes: 1) low hazard: a sinister area from 0 to 10%, without drought reports; 2) moderate hazard: a sinister area from 11 to 50%, with moderate drought reports; 3) high hazard: a sinister area from 51 to 100%, with reports of severe drought. Results: We determined ten climatic hazard indicators of which four correspond to the number of days with precipitation lower than zero in the months of June, July, August and September (DDE0jun, DDE0jul, DDE0aug, DDE0sep); two indicators with rainfall equal to 5 mm for June and August (DDL5jun, DDL5aug); two indicators associated with the maximum temperature of July and August (TX38jul, TX38aug), and two indicators with precipitation equal to or greater than 10 mm in October and November (WDH10oct, WDH10nov). The result of the Kappa statistic was 0.91, indicating a high reliability in the classification of three hazardness categories: high, moderate and low. Conclusion: The proposed method on the validation of climatic hazard with the WEKA software allowed to identify the most important indicators that affect the maize phenological cycle and therefore its yield; the mathematical validation of the method shows three primary indicators, which indicates that there are primary and secondary variables that determine its climatic hazard. The indicators of climatic hazard were automated and adjusted using ICC® (Indicators of Climatic Change) which offers a useful tool for future research on climate hazard analysis of other rainfed crops.

Diversity of Leafhoppers (Hemiptera: Cicadellidae) Associated with Border Grasses and Maize During the Wet and Dry Seasons in Mexico.

Leafhoppers constitute one of the largest groups of pests causing damage to crops worldwide. Edge grasses, which are border crops (also known as border grasses), contain diverse plant species and maintain large populations of leafhoppers during the tropical dry and wet seasons. However, little is known about the diversity of leafhoppers on these grasses. The objective of this study was to characterize the diversity of leafhoppers on maize and on surrounding border grasses during the dry and wet seasons. Leafhopper adults were collected with a sweep net from border grasses during the dry season, when maize is absent. During the wet, maize-growing season, leafhoppers were collected in both the maize fields and their surrounding edge grasses. A highly diverse (H' = 1.97 ± 2.03) leafhopper population was seen on the edge grasses during the dry season, and during the wet season, leafhopper diversity was higher in the edge grasses (H'= 1.79 ± 1.72) than in the maize fields themselves (H'= 1.67 ± 1.12). Throughout the wet season, the most abundant leafhopper species in border grasses were Stirellus bicolor (Van Duzee) (Hemiptera: Cicadellidae), Graminella sonora (Ball) (Hemiptera: Cicadellidae), and Balclutha incisa (Matsumura) (Hemiptera: Cicadellidae), whereas Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae) was the most abundant species in maize fields. All of these species were from the subfamily Deltocephalinae. Canonical Component Analysis showed that leafhopper abundance of Sibovia compta (Fowler) (Hemiptera: Cicadellidae), Graphocephala aurolineata (Fowler) (Hemiptera: Cicadellidae), D. maidis, and S. bicolor was associated with abiotic factors such as relative humidity, soil moisture, temperature, and pluvial precipitation. Nevertheless, for most leafhopper species, abundances were not significantly correlated with the abiotic variables measured.

Detection of precipitation infiltration in buildings by infrared thermography: a case study

Infrared thermography has recently been used in civil work inspection to detect various types of pathological manifestations due to its speed, easy handling, and capability to cover large areas and detect hidden faults, among other advantages. The specific implementation for humidity detection in buildings still presents some uncertainties, since parameters that influence results are present, for example: mechanisms that generate humidity, specific conditions of premises being studied and constructive characteristics of the building. This work is intended to evaluate the infrared thermography technique for moisture detection originated by pluvial precipitation. In this sense, a building with pathological manifestations caused by precipitation was selected to be inspected at different times of the day in order to observe behavior of this problem during rainy season. Results showed that infrared thermography was sensitive to detect areas affected by precipitation humidity presenting lower temperatures than those sectors without any problem. Furthermore, the higher the temperature difference, the better definition of the area affected by the humidity was, thus allowing the location of potential spots. Infrared thermography was presented as an auxiliary tool for inspections, as it provided more information than a simple visual inspection; however, some factors must be considered in order for the inspection to be effective.

RICE SEED TREATMENT AND RECOATING WITH POLYMERS: PHYSIOLOGICAL QUALITY AND RETENTION OF CHEMICAL PRODUCTS

ABSTRACT The use of chemical seed treatment is an important tool in the protection of seedlings and has contributed to the increase of rice yield (Oryza sativa L.). The objective of this study was to evaluate the physiological quality and quantify the retention of chemical products in rice seeds treated with insecticide and fungicide coated with polymers. Six seed treatments were used: control, phytosanitary treatment and phytosanitary treatment and coating with the polymers, Florite 1127®, GV5® Solid Resin, Polyseed CF® and VermDynaseed®. The physiological quality was evaluated by the test of germination and vigor by first count tests, germination speed index, shoot length, radicle length, seedling dry mass and sand emergence. To determine the retention of the active ingredients metalaxyl-M and thiamethoxam, an equipment called extractor was used. The experiment was organized in a completely randomized design (DIC) and the averages were separated by the Scott Knott test (p≤0.05). Seed treatment with the fungicide and insecticide, coated with the polymers, Florite 1127®, Solid Resin GV5®, Polyseed CF® and VermDynaseed®, did not affect the physiological quality of rice seeds. Solid Resin GV5®, Polyseed CF® and VermDynaseed® polymers were efficient at retaining thiamethoxam in the rice seeds, preventing some of the active ingredients of the insecticide from being leached through the sand columns immediately after the simulated pluvial precipitation.

CLIMA E DISTRIBUIÇÃO DOS SOLOS ZONAIS NO RIO GRANDE DO SUL – BRASIL

O clima tem grande influência na formação dos solos, além da ação integrada de fatores como material de origem, relevo, organismos e tempo. Os solos zonais são formados quando o clima é o fator preponderante no intemperismo. Neste estudo objetivou-se evidenciar os solos zonais do Rio Grande do Sul e determinar sua localização. A espacialização das disponibilidades climáticas para o desenvolvimento de solos zonais foi realizada utilizando-se as médias anuais, as médias dos totais anuais de precipitação pluvial e as médias anuais de temperatura do ar, entre 1931 e 1960, de 41 estações meteorológicas do 8° Distrito de Meteorologia (8º DISME). Constatou-se que os solos zonais do Rio Grande do Sul compreendem solos Lateríticos e solos Pedalférricos. Solos de clima muito úmido situam-se na metade norte do Estado com médias anuais de precipitação pluvial acima de 1.500mm e são representados pelos solos Lateríticos, predominantemente, os Latossolos. Os Pedalférricos ocorrem, preferencialmente, em regiões de clima temperado e são descritos como solos com pronunciada lixiviação, que ocorrem em condições de intemperismo químico com índices de precipitação anual acima de 600mm. No Rio Grande do Sul as condições climáticas ideais para a formação desses solos são registradas nas estações meteorológicas localizadas na Depressão Central (com exceção das estações de Santa Maria e Santa Cruz do Sul), no Escudo Sul-Riograndense (com exceção de Caçapava do Sul), na Planície Costeira e no Planalto Norte-rio-grandense (apenas a região de Vacaria). São representados, predominantemente pelos Neossolos e Cambissolos. Palavras-Chave: Lateríticos; Pedalférricos; Latossolos.

Nosemosis in worker bees and their relationship with environmental factors in Jalisco, Mexico

La nosemosis es causada por el microsporidio Nosema spp que parasita el intestino medio de abejas melíferas adultas, es mortal en su forma aguda y ello ocasiona pérdidas económicas muy importantes al productor apícola. El conocimiento de la infección por N. spp en abejas melíferas puede ayudar a prevenir la propagación o controlar la infección entre colonias. El objetivo del presente trabajo fue determinar la presencia e intensidad de infección de N. spp en colonias de abejas melíferas y su relación con la temperatura, precipitación pluvial y altitud de esta región. Se obtuvieron 352 muestras de abejas Apis mellifera de colonias de ocho municipios del sur sureste de Jalisco. Para el diagnóstico se utilizó el método de macerado de abdómenes (Cantwell) y método de Jaycox para obtener el número de esporas de N. spp por abeja. El 100 % de las muestras fueron positivas; en 83.75 % de ellas se presentó entre 1 a 5 millones de esporas por abeja. Se obtuvieron correlaciones débiles entre la intensidad de infección con la altitud (r= -0.35), la temperatura (r= 0.44) y la precipitación pluvial (r= -0.12), por lo que se sugiere que estos parámetros no influyen mayormente en la presencia de la enfermedad. Con los resultados obtenidos de nosemosis se puede sugerir la utilización de antibióticos o hacer control biológico, retirando cada año los panales más viejos en las colonias y el cambio anual de reinas.

Densidad poblacional, distribución espacial y mortalidad natural del erizo de mar Toxopneustes roseus (Camarodonta: Toxopneustidae) en tres sitios de Oaxaca, México

The sea urchin Toxopneustes roseus is widely distributed along the east coast of the tropical Pacific, from Mexico to northern Peru. In our study we evaluated population features of this species, such as population density, spatial distribution pattern and natural mortality, as well as the relationship between population density and several environmental variables. From October 2009 to September 2011 monthly sampling was carried out using belt transects in three localities of the coast of Oaxaca, Mexico: Estacahuite, Dos Hermanas and Isla Cacaluta. Additionally we recorded in situ temperature, salinity and pH in each locality. Records of irradiation and pluvial precipitation were obtained from databases. Distribution pattern of the urchins was characterized using the Morisita´s Index and the models of Poisson´s probability and Negative Binomial Distribution. Natural mortality was estimated using the modified method of Berry. A step by step analysis of Multiple Lineal Regression was applied to evaluate the relationship between population density and the recorded environmental variables. Mean (± SD) density was 0.12 ± 0.02 ind·m-2 (Estacahuite), 0.05 ± 0.01 ind·m-2 (Dos Hermanas) and 0.04 ± 0.01 ind·m-2 (Isla Cacaluta). The pattern of spatial distribution of T. roseus was aggregated in most of the sampled months in all the localities. In Estacahuite natural mortality was 0.45 and in Dos Hermanas it was 0.46, it was not possible to calculate mortality for Isla Cacaluta. Of the recorded environmental variables, pluvial precipitation showed a direct but not determinant relationship with population density of T. roseus only in Isla Cacaluta. As a result of the differences observed in the three localities we assume that the factors that could determine the population dynamics of T. roseus are: A larger extension of the area in general, and the contribution of sediments by the presence of rivers in the localities, since Isla Cacaluta was the only locality where there was evidence of an important relationship with pluvial precipitation, and this locality undergoes the influence of the rivers Copalita and Coyula, which produce an important increase in sedimentation rates at this community, affecting the entire benthic community during the rainy season.

CLIMATE CHANGE AND RAINFALL VARIABILITY IN THE CITY OF CAMPINA GRANDE-PB: ANALYSIS FROM HISTORICAL SERIES OF PRECIPITATION

Currently, the climate changes have generated many discussions, constituting one of the major concerns with regard to their effects. Several are the impacts arising from climate change, whether in social, economic and environmental context. Some climate models have shown trends of reduction of rains to the northeast in the wettest months, which could increase the frequency and intensity of droughts and reduce the availability of water resources. Thus, the objective of this work was to analyze the trends and variability of climatological precipitation series in the city of Campina Grande-PB, using daily series of pluvial precipitation over a period of 50 years. The statistical analysis and the preparation of the graphics were made with the ClimAp Software, which have been assessed the extremes of precipitation (days with rainfall ≥ 1 mm; days with rainfall ≥ 10 mm; days with rainfall ≥ 20 mm); Per95p and Pr99p (number of days with precipitation ≥ 95% and the 99%) of significant rainfall, highest rainfall in 1 day rain, annual total and its standardized deviation, monthly and quarterly averages of precipitation, annual total-linear regression, and sequential Mann-Kendall test. Through this research was possible to conclude that the city of Campina Grande presents annual distributions of irregular precipitation, with a slight increase in year-to-year variability, but without statistical significance

ANÁLISE DA VARIAÇÃO ESPACIAL E TEMPORAL DO ÍNDICE DE VEGETAÇÃO E SUA RELAÇÃO COM PARÂMETROS CLIMÁTICOS NA BACIA HIDROGRÁFICA DO ALTO CURSO DO RIO PARAÍBA, ESTADO DA PARAÍBA, BRASIL

This study aimed to analyze the spatial and temporal variation of the normalized difference vegetation index (NDVI) and the soil-adjusted vegetation index (SAVI), as well as the relationship among climate parameters in the basin of the upper reaches of the River Paraiba, which includes all or some of the eighteen municipalities, distributed in the regions of Western and Eastern Cariri of Paraiba state. 168 MODIS images were used (moderate resolution imaging spectroradiometer), corresponding to the twelve months of the year from 2000 to 2013, to obtain the vegetation indexes, which were then correlated with rainfall and average air temperature data. We used the kriging method of spatial data and thematic maps. The main results show that the average score of the vegetation index decreases from the northwest and northeast to the central portion of the basin, with the minimum score in the municipality of Congo. The vegetation index was spatially and temporally heterogeneous, corresponding to regional climate characteristics. The dry year 2013 presented vegetation index values below the rainy year of 2008, but still there is intra-annual and space-time variations. There were negative correlations between vegetation indexes and the air temperature, as well as positive correlations, most significantly, with pluvial precipitation. Keywords: caatinga, rainfall, air temperature, remote sensing.