For climate change scenarios, there is a high degree of complexity, with impacts on the future availability of water resources. In this context, studies related to changes in rainfall time series are essential in order to identify environmental vulnerability. The objective of this study was to analyze trends in the rainfall regime, number of rainy days and temperature for stations located at different continentality and altitude conditions in Northeast Brazil. Meteorological data of the Instituto Nacional de Meteorologia were used, being classified according to the location in relation to the continent: coastal strip (14 stations), strip of 150-300 km up to 300 m altitude (14 stations) and above 300 m (five stations), between 400 and 600 km from the coast up to 300 m (four stations) and above 300 m (eight stations). All the 45 stations used have a historical series with a data period of more than 30 years. The trend of rainfall and rainy days was obtained through the Mann-Kendall and regression analyses, at significance levels of 0.01 and 0.05, respectively. There were trends of reduction in the number of rainy days, in the coastal strip, as well as reduction in rainfall and rainy days, both in the strip of 150-300 km from the coast and in the Sertão region, with no significant effect of continentality in the strip of 400-600 km from the coast. For temperature, except for Maceió, AL, Brazil, there is a trend of increase in near future.

Understanding small-scale hydrologic processes and the impact of soil conservation techniques are crucial in reducing runoff and sediment losses in semi-arid regions. This study was conducted in the Alto Ipanema River Basin, in Pernambuco State (Brazil). Soil and water dynamics were intensely monitored in twelve experimental plots with different coverage conditions (plot with bare soil—Bare; plot with natural vegetation—Natur; plot with mulch—Mulch; plot with Cactus Palma—Palma). By far, bare soil conditions produced higher runoff and soil losses. Mulch cover was close to natural vegetation cover, but still presented higher runoff and sediment losses. Palma, which is a very popular spineless cactus for animal feed in the Brazilian semi-arid region, presented an intermediate hydrologic impact in controlling runoff, enhancing soil moisture, and also reducing soil losses. Experiments were conducted in one hydrologic year (2016/2017) at three different sites. They were intensely monitored and had the same number of plots. This enabled us to carry out a robust performance assessment of the two soil conservation practices adopted (Mulch and Palma), compared to natural vegetation cover and bare soil conditions. Such low-cost alternatives could be easily adopted by local farms in the region, and, hence, improve soil reclamation and regional resiliency in a water-scarce environment.

BALANÇO HÍDRICO EM FUNÇÃO DE REGIMES PLUVIOMÉTRICOS NA REGIÃO DE PETROLINA-PE IUG LOPES¹; MIGUEL JULIO MACHADO GUIMARÃES¹; JULIANA MARIA MEDRADO DE MELO¹ E CLOVIS MANOEL CARVALHO RAMOS² ¹ Departamento de Engenharia Agrícola, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, Dois Irmão, CEP: 52171-900 – Recife, PE, Brasil. iuglopes@hotmail.com; mjmguimaraes@hotmail.com; medrado.juliana@gmail.com² Colegiado de Engenharia Agrícola e Ambiental, Universidade Federal do Vale do São Francisco – Campus Juazeiro, Av. Antônio Carlos Magalhães, 510 Country Club, CEP: 48.902-300 – Juazeiro, BA, Brasil. clovis.ramos@univasf.edu.br 1 RESUMO O estudo das condições climáticas da região de Petrolina se faz necessário devido sua importância no cenário agrícola nacional. O objetivo do trabalho foi caracterizar os perfis pluviométricos, classificar por meio da utilização de técnica quantílica e a realização de balanço hídrico para diferentes regimes hídricos observados. Foram utilizados da estação meteorológica convencional (OMM: 81991) localizada no município de Petrolina-PE, os dados de precipitação pluvial e temperatura média do ar condensada. Além do uso da técnica de Quantis que classifica os anos de acordo com o índice pluviométrico anual como muito seco, seco, normal, chuvoso e muito chuvoso, foi utilizado o balanço hídrico pelo método de Thornthwaite e Mather. Na caracterização pluviométrica observou-se um quantitativo anual, variando entre 107,20 e 1023,50 mm, com média de 496,83 mm, a cada dois anos é possível observar uma precipitação pluvial igual ou inferior a 462,92 mm. Ao avaliar o balanço hídrico para os distintos regimes pluviométricos obtidos, pode-se verificar que todos os regimes pluviométricos apresentaram uma deficiência que se estende por todo o ano, com exceção para anos chuvoso e muito chuvoso que apresentam reposição nos meses iniciais do ano. Palavras-chave: ciclo hidrológico, climatologia, planejamento agrícola LOPES, I; GUIMARÃES, M. J. M.; MELO, J. M. M.; RAMOS, C. M. C. WATER BALANCE FOR PRECIPITATION REGIMES IN THE PETROLINA, PE REGION 2 ABSTRACT The study of the climatic conditions of the Petrolina region is necessary due to its importance in the national agricultural scenario. The objective of this work was to characterize the rainfall profiles, to classify by means of the use of quantile regression technique and the achievemnt of water balance for different water regimes observed. Data for rainfall and average temperature of the condensed air were provided by the conventional meteorological station (OMM: 81991) located in the city of Petrolina, PE. In addition to the Quantis technique, which classifies years according to the annual rainfall index as very dry, dry, normal, rainy and very rainy, the water balance according to the Thornthwaite & Mather method was used. In the pluviometric characterization, an annual quantitative one, varying between 107.20 mm and 1023.50 mm, with an average of 496.83 mm. Every two years, it is possible to observe a rainfall equal to or less than 462.92 mm. When assessing the water balance for the different pluviometric regimes obtained, it can be verified that all pluviometric regimes have a deficiency that extends throughout the year, except for rainy and very rainy years, which present replacement in the initial months of the year. Keywords: hydrological cycle, climatology, agricultural planning

Spatial variability analysis of meteorological elements and precise identification of possible causes of thermal stress in poultry housing help producers in the decision making process. The objective of this study was to evaluate the internal environment of poultry houses in the downtime (sanitary void) and in the production phase, to characterize spatial thermal variability and to identify critical control points. The study was carried out in the Alluvial Valley of the Mimoso River, municipality of Pesqueira, PE, Brazil. The data of air temperature, wind speed and illuminance were recorded in November (spring season), at 155 points within each poultry facility (10 x 90 m), spaced in a 3.0 x 2.5 m grid and subjected to descriptive statistical analysis and geostatistics. There was a strong spatial dependence for the variables air temperature, wind speed and illuminance. The ranges obtained for the air temperature in the facilities were from 48.22 to 114.52 m, while for the wind speed and illuminance were less than 10 m, thus revealing the need for greater homogeneity of the studied variables and meeting of the thermal requirement of the poultry.

The use of organic mulch as a natural practice to enhance water retention and absorption is underexplored, highlighting the need for a deeper understanding of its effectiveness under varying conditions. The aim of this study was to investigate the process of interception, retention, and absorption of rainwater by different types, sizes, and densities of some organic mulch covers. Six organic mulches of various sizes were used, all largely available in the Brazilian semiarid: coconut leaf (cc), cashew leaf (ca), elephant grass (el), corn leaf (co), Brachiaria grass (br), and sugar cane leaf (su), under simulated rainfall conditions. The experimental scheme consisted of a factorial of six types of mulches, three sizes (50, 100, and 200 mm), and four densities (1, 2, 4, and 8 t ha⁻¹). Water adsorption and retention curves were constructed, and the interception capacity of different vegetation materials was estimated. Analysis of variance, Tukey Test, Regression polynomial, and Principal Components Analysis were applied. It was observed that increasing density systematically led to an increase in water retention and absorption. For 8 t ha⁻¹ the values were 11 to 23% for water retention and 7 to 16% for water absorption of the gross rainfall depth. When comparing 8 t ha⁻¹ and 2 t ha⁻¹ densities, rainfall retention and absorption increased more than 100%. Higher values were obtained for cashew and Brachiaria grass, improving water retention and cashew leaves for absorption. Coconut leaves promoted only 83% retention and 67% water absorption, when compared to the cashew leaf and Brachiaria grass.

A caracterização morfométrica de bacias hidrográficas utilizando dados SRTM, em ambiente SIG, pode proporcionar um auxilio no âmbito da gestão e do gerenciamento de recursos hídricos, principalmente para regiões em que há uma menor disponibidade hídrica. O objetivo deste estudo foi de realizar a caracterização morfométrica da Bacia Hidrográfica do Rio Pontal através de dados do Shuttle Radar Topography Mission (SRTM) processados em Sistema de Informações Geográficas (SIG), com o auxílio dos softwares livres Quantum GIS (QGIS) 2.8 e Terrain Análise Ucantar Digital Elevation Modelos (TauDEM) V.5. A bacia hidrográfica em questão possui 6046,23 km², considerada de 6º ordem, com densidade de drenagem de 0,42 km km-2. Observou-se que a declividade média foi de 4,45% e mais de 92% da área da bacia apresentou declividades menores que 8%. Apresentou ainda fator de forma de 0,41 m m-1, coeficiente de compacidade de 0,72 e índice de circularidade de 0,32, indicando que a bacia possui formato muito alongado e por conseguinte, baixa tendência a enchentes. Os softwares livres se mostraram uma ferramenta eficiente, podendo auxiliar na gestão e no gerenciamento dos recursos hídricos.