Abstract Introduction. Corn is one of the oldest known food grains. With climate change and frequent and severe droughts, the water available in the soil will be considerably reduced. Water deficit affects maize crop development to varying degrees, and sensitivity to this stress varies at different development stages. Objective. To identify the phenological stages most sensitive to water deficit in maize. Materials and methods. The experiment was conducted during two growing seasons in 2020 and 2021 in El Ejido, Los Santos province, Panama, under semi-controlled conditions in the greenhouse facilities of the Instituto Coronel Segundo de Villarreal. The commercial corn hybrid ADV-9293 was used and agronomic management was carried out according to the recommendations of the Institute for Agricultural Innovation of Panamá (IDIAP). Plant height, leaf length and width, stem diameter, biomass and yield components, such as number of rows per ear, number of grains per row and 100-grain mass, were determined throughout the crop cycle. Soil moisture was also determined by the gravimetric method. Water deficit at different stages was generated by drought simulation. Results. The grain yields of the control were higher than the different treatments evaluated with 12.83 t ha-1, followed by the treatment with grain filling stress with 10.31 t ha-1. Two periods were determined to be more sensitive to water deficit; these were the stages from 20 to 35 and 40 to 55 days after planting. Water deficit in the different phenological stages of the crop had a negative impact on the relative chlorophyll content. Conclusion. The pre-flowering and flowering stages were more sensitive to water deficiency in maize.

Resumen Introducción. El maíz es uno de los granos alimenticios más antiguos conocido. Con el cambio climático y las sequías severas y frecuentes, se reducirá en gran medida el agua disponible en el suelo. El déficit hídrico afecta en diversos grados el desarrollo del cultivo de maíz y la sensibilidad a este estrés varía en las diferentes etapas de desarrollo. Objetivo. Identificar las etapas fenológicas más sensibles al déficit hídrico en el cultivo de maíz. Materiales y métodos. El experimento se realizó durante dos ciclos en los años 2020 y 2021 en El Ejido, Provincia de Los Santos, Panamá. Se desarrolló bajo condiciones semicontroladas en la casa de cultivo del Instituto Coronel Segundo de Villarreal. Se utilizó el híbrido de maíz comercial ADV-9293. El manejo agronómico se realizó según las recomendaciones del Instituto de Innovación Agropecuaria de Panamá (IDIAP). Durante todo el ciclo del cultivo, se determinaron las variables altura de planta, largo y ancho de hojas, diámetro del tallo, biomasa y los componentes del rendimiento como número de hileras por mazorca, número de granos por hilera y peso de cien granos. También, se determinó la humedad del suelo por el método gravimétrico. El déficit hídrico en distintas etapas se generó a través de la simulación de sequía. Resultados. El rendimiento de grano del testigo superó los diferentes tratamientos evaluados con 12,83 t ha-1, seguido por el tratamiento con estrés en el llenado de grano con 10,31 t ha-1. Se determinaron dos períodos más sensibles al déficit hídrico; los cuales son las etapas comprendidas desde los 20 a 35 y 40 a 55 dds. El déficit hídrico, durante las diferentes etapas fenológicas del cultivo, tuvo un impacto negativo en el contenido relativo de clorofilas. Conclusión. Las etapas de prefloración y floración resultaron más sensibles a la deficiencia hídrica en el cultivo del maíz.

Resumen Nos basamos en la teoría gramsciana de la hegemonía y en la teoría del valor de David Graeber para explorar las posibilidades de una contra-hegemonía al manejo ambiental del agua en la provincia argentina de Córdoba. Se analizan conflictos entre dos posiciones contrarias en la zona de Sierras Chicas. Por un lado, las propuestas hegemónicas de soluciones por medio de grandes y medianas obras de infraestructura para lidiar con las sequías e inundaciones en relación al desarrollo; por otro, a propuestas que ponderan soluciones adecuadas a las formas bio-físicas del ciclo hidrológico de un ambiente serrano. contrahegemonía contra Córdoba Chicas lado desarrollo otro biofísicas bio físicas serrano

Abstract We draw on Gramscian hegemony theory and David Graeber’s theory of value to explore the possibilities of a counter-hegemony to environmental water management in the Argentine province of Córdoba. Conflicts between two opposing positions in the Sierras Chicas area are analyzed. On the one hand, the hegemonic proposals of solutions by means of large and medium-sized infrastructure works to deal with droughts and floods; on the other hand, proposals that emphasize solutions adequate to the bio-physical forms of the hydrological cycle in a mountain environment. Graebers Graeber s counterhegemony counter Córdoba analyzed hand mediumsized medium sized floods biophysical bio physical environment

Resumo O noroeste pacífico da Costa Rica é uma região com uma estacionalidade no regime de chuvas muito marcada. Somado a essa sazonalidade, esta área da Costa Rica é propensa a fenômenos hidroclimáticos extremos como secas e inundações, por exemplo. A distribuição limitada de pluviômetros ou a falta de disponibilidade de informações relevantes fazem com que os dados complementares obtidos de satélites e suas respectivas reanálises sejam fundamentais para obter informações cruciais e, assim, embasar as ações de gestão dos recursos hídricos e suas repercussões nos ecossistemas, tanto naturais quanto produtivos. Para analisar os padrões de precipitação, foram analisadas as séries temporais de precipitação do produto CHIRPS para cinco ecorregiões delimitadas na Área de Conservação Guanacaste, no Pacífico noroeste da Costa Rica. Estas curvas foram correlacionadas com as séries temporais das regiões de monitoramento da temperatura superficial do mar nas regiões Niño 1.2, Niño 3, Niño 3.4 e Niño 4. Todas as ecorregiões analisadas correlacionaram de forma negativa e forte com a região do Niño 1.2, com valores de R entre -0.72 e -0.74. Além disso, foi detectado um atraso na curva do Niño 4 de quatro a cinco meses, em relação à curva da região Niño 1.2. O estudo sugere que a anomalia do El Niño 4, com um desfasamento de aproximadamente 4 a 5 meses, pode ser utilizada como indicador de possíveis impactos nos padrões de precipitação nas diferentes ecorregiões estudadas. Este tempo é suficiente para planejar ações, especialmente no setor agroprodutivo. Neste trabalho, é demonstrado o potencial de previsibilidade dos efeitos do fenômeno ENOS sobre o padrão de precipitação em áreas extensas e com certa homogeneidade ecossistêmica, como as ecorregiões na Área de Conservação Guanacaste.

Abstract The Pacific Northwest of Costa Rica is a region with marked seasonality in rainfall patterns. This area of Costa Rica is prone to extreme hydroclimatic phenomena such as droughts and floods. Due to the limited distribution of rainfall gauges and the unavailability of relevant information, complementary data obtained from satellites and their respective reanalyzes become imperative for acquiring crucial information. This information can support water resource management actions and their impacts on both natural and productive ecosystems. To analyze the precipitation patterns, we utilized the CHIRPS product’s precipitation time series for five ecoregions within the Guanacaste Conservation Area, located in the northwestern Pacific region of Costa Rica. These curves were strongly and negatively correlated with time series from sea surface temperature monitoring regions, including Niño 1.2, Niño 3, Niño 3.4, and Niño 4. All analyzed ecoregions exhibited strong negative correlations with the Niño 1.2 region, with correlation coefficients (R values) ranging between -0.72 to -0.74. Additionally, a lag of four to five months was observed in the Niño 4 curve compared to the Niño 1.2 region. This study suggests that the Niño 4 anomaly, with a lag of approximately 4 to 5 months, can serve as an indicator of possible impacts on precipitation patterns in different ecoregions. This provides sufficient time to plan actions, particularly within the agricultural sector. This study demonstrates the potential predictability of the effects of ENSO phenomenon on precipitation patterns for large areas with a certain eco-systemic homogeneity, such as the ecoregions in the Guanacaste Conservation Area.

Resumen El pacífico noroeste de Costa Rica es una región con una estacionalidad en el régimen de lluvias muy marcada. Sumado a dicha estacionalidad, esta área de Costa Rica es propensa a fenómenos hidroclimáticos extremos como sequías e inundaciones, por ejemplo. La escasa distribución de pluviómetros o bien, la no disponibilidad de información pertinente, hacen que los datos complementarios obtenidos de satélites y sus respectivas reanálisis, sean fundamentales para disponer de información crucial y así poder fundamentar las acciones de gestión del recurso hídrico y sus repercusiones en los ecosistemas, tanto naturales como productivos. Para analizar los patrones de precipitación, se analizaron las series de tiempo de precipitación del producto CHIRPS para cinco ecorregiones delimitadas en el Área de Conservación Guanacaste, en el Pacífico noroeste de Costa Rica. Estas curvas se correlacionaron con las series de tiempo de las regiones de monitoreo de la temperatura superficial del mar en las regiones Niño 1.2, Niño 3, Niño 3.4 y Niño 4. Todas las ecorregiones analizadas correlacionaron de forma negativa y fuertemente con la región del Niño 1.2, con valores de R entre -0.72 y -0.74. Por otra parte, se detectó un rezago en la curva de Niño 4 de cuatro a cinco meses, con la curva de la región Niño 1.2. El estudio sugiere que la anomalía del Niño 4, con un desfase de aproximadamente 4 a 5 meses, puede ser utilizada como indicador de posibles impactos en los patrones de precipitación en las diferentes ecorregiones estudiadas. Este tiempo es suficiente para planear acciones, sobre todo en el sector agroproductivo. En este trabajo se muestra el potencial de predictibilidad de los efectos del fenómeno ENOS sobre el patrón de la precipitación para áreas extensas y con cierta homogeneidad ecosistémica, como son las ecorregiones en el Área de Conservación Guanacaste.

Abstract Forest pests are one of the primary disturbance factors in the temperate forests of Mexico. Ips confusus attacks Pinus cembroides trees, especially after intense droughts. The aim of this study was to assess the impact of I. confusus on the annual radial growth of a P. cembroides forest in the Carichí municipality, state of Chihuahua, México. Additionally, the influence of climatic variables was determined. Increment cores were extracted from both attacked (AA) and non-attacked P. cembroides trees (ANA). A total of 53 increment cores were dated, spanning from 1776 to 2012 (AA=24 and ANA=29). Starting from 1998, differential basal area growth was observed between AA and ANA. By the time of tree mortality in 2012, a difference of over 100 % was recorded (AA=8.03±1.53 cm2 year⁻¹, and ANA=17.7±1.74 cm2 year⁻¹, p<0.001). However, ANA exhibited greater sensitivity to climatic variables than AA, displaying increased synchrony in recent years. At the canopy level, a correlation was found between Normalized Difference Vegetation Index (NDVI, r=0.51, p<0.05) and ANA, exclusively. Nonetheless, AA demonstrated a high sensitivity to drought conditions, particularly with the Palmer Drought Severity Index (PDSI, r=0.53, p<0.05). This suggests that prior drought conditions (up to 10 years) are linked to reduced growth in P. cembroides, predisposing them to forest pest infestations.

Resumen Las plagas forestales representan una de las principales causas de disturbio en los bosques templados de México. Ips confusus ataca a Pinus cembroides después de intensas sequías. El objetivo del presente estudio fue evaluar tanto el impacto por I. confusus, como del clima en el crecimiento radial de un bosque de P. cembroides en el municipio Carichí, Chihuahua, México. Se obtuvieron núcleos de crecimiento de árboles atacados (AA) y de no atacados (ANA) de la misma especie. Se dataron 53 series dendrocronológicas con una extensión máxima de 1776 a 2012 (AA=24 y ANA=29). A partir de 1998, se observó un crecimiento diferencial en el área basal entre AA y ANA. Al momento de la muerte del arbolado (2012), se registró una diferencia de más de 100 % (AA=8.03±1.53 cm2 año-1, y ANA=17.7±1.74 cm2 año-1, p<0.001). Los ANA mostraron una sensibilidad superior a variables climáticas que los AA, con una mayor sincronía en los últimos años. A nivel dosel, se determinó una correlación con el Índice de Vegetación de Diferencia Normalizada (NDVI, r=0.51, p<0.05) exclusivamente para ANA. Sin embargo, los AA fueron más sensibles a condiciones de sequía, con base en el Índice de Severidad de Sequia de Palmer (PDSI, r=0.53, p<0.05). Esto sugiere que condiciones de sequía previas (hasta 10 años) predisponen menor crecimiento radial de P. cembroides y favorece el ataque de plagas.

ABSTRACT Population growth has led to an exponential demand for agricultural products, to meet this demand it is necessary to improve management and achieve efficient use of resources without compromising the sustainability of ecosystems, particularly agricultural ones. One of the technologies that facilitate these tasks is precision agriculture (PA), which focuses on the optimization of resources and inputs based on the compilation of precise and timely geo-information of variables of agricultural interest with high spatio-temporal variability, obtained through remote sensors of three types: images captured by satellites or airplanes, images obtained from manned and unmanned aerial vehicles (UAVs) and specific information with sensors mounted on machinery or in the field. These limitations were overcome by using multispectral images, which has increased applications for agricultural purposes. Currently, multispectral images allow quantifying soil moisture, monitoring the presence of droughts and the degree of crop water stress, estimating the temporal and spatial variability of evapotranspiration, monitoring phenology, detecting nutritional deficiencies, estimating the degree of weed infestation. and insects, calculate organic carbon and soil salinity, and estimate yields and agricultural production. The use of geospatial technologies in the PA has changed the paradigm of agriculture and today constitutes a viable alternative to face the challenges that food production demands in a world with high climate variability.

RESUMEN El crecimiento poblacional ha derivado en una demanda exponencial de productos agrícolas, para cubrir esta demanda se requiere mejorar la gestión y lograr un uso eficiente de recursos sin comprometer la sustentabilidad de los ecosistemas, en particular los agrícolas. Una de las tecnologías que facilitan estas tareas es la agricultura de precisión (AP), que se enfoca en la optimización de recursos e insumos basado en la compilación de geo información precisa y oportuna de variables de interés agrícola de alta variabilidad espacio-temporal, obtenida mediante sensores remotos de tres tipos: imágenes capturadas por satélites o aviones, imágenes obtenidas desde vehículos aéreos tripulados y no tripulados (VANT’s) e información puntual con sensores montados en maquinaria o en campo. Estas limitantes se superaron al usar imágenes multiespectrales, lo que ha incrementado las aplicaciones con fines agrícolas. Actualmente, las mágenes multiespectrales permiten cuantificar la humedad del suelo, monitorear la presencia de sequías y el grado de estrés hídrico de cultivos, estimar la variabilidad temporal y espacial de la evapotranspiración, dar seguimiento fenológico, detectar deficiencias nutricionales, estimar grado de infestación de malezas e insectos, calcular carbono orgánico y salinidad del suelo y estimar rendimientos y producción agrícola. El uso de tecnologías geoespaciales en la AP ha cambiado el paradigma de la agricultura y hoy en día constituye una alternativa viable para afrontar los retos que demanda la producción de alimentos en un mundo con alta variabilidad climática.

Abstract Anthropogenic activities have added enough to cause important alterations in the climate at a global level; in the last 20 years, a phenomenon of extreme characteristics called ‘climate change’ has worsened, which has been responsible for causing climate variability, the level of affectation of which extends to all geographical scales. This research was carried out in 2022 with the aim of knowing the impacts of climate change on the productive system of the corn crop in Mexico, given its great nutritional, cultural, and economic relevance. It describes the climate variability and extreme events that occur in Mexico and that in some way have a direct relationship with corn production, such as precipitation, temperature, frosts, hailstorms, droughts, and floods. Worldwide, Mexico stands out in the first places in production and consumption of corn; the current population exceeds 126 million people, and it is a condition that manifests a great demand, having to make a strong export of the grain year after year, showing the unsustainability of the country’s food security. This situation is aggravated when climate change and climate variability directly affect the most important requirements for the establishment of a crop, and that directly affect all stages of growth and development, presenting a decrease in current and future yield.

Resumen Las actividades antropogénicas han sumado lo suficiente para ocasionar alteraciones importantes en el clima a nivel global, en los últimos 20 años se ha pronunciado un fenómeno de características extremas denominado ‘cambio climático’, el cual ha sido encargado de causar una variabilidad climática, cuyo nivel de afectación se extiende en todas las escalas geográficas. Esta investigación se realizó en al año 2022, teniendo como objetivo conocer los impactos del cambio climático en el sistema productivo del cultivo de maíz en México, dada su gran relevancia nutricional, cultural y económica. Se describe la variabilidad climática y los eventos extremos que ocurren en México y que de alguna manera tienen una relación directa con la producción del maíz, como la precipitación, temperatura, heladas, granizadas, sequías e inundaciones. A nivel mundial, México destaca en los primeros lugares en producción y consumo de maíz, la población actual supera los 126 millones de personas y resulta una condición que manifiesta una gran demanda, teniendo que realizar una fuerte exportación del grano año con año, poniendo en manifiesto la insostenibilidad de la seguridad alimentaria del país. Esta situación se agrava cuando el cambio climático y la variabilidad climática, afectan directamente en los requerimientos de mayor importancia para el establecimiento de un cultivo y que afectan directamente con todas las etapas de crecimiento y desarrollo, presentando una disminución del rendimiento actual y futuro.

Abstract Soil moisture content can be used to predict drought impact on agricultural yield better than precipitation. Remote sensing is viable source of soil moisture data in instrument-scarce areas. However, space-based soil moisture estimates lack suitability for daily and high-resolution agricultural, hydrological, and environmental applications. This study aimed to assess the potential of the random forest machine learning technique to enhance the spatial resolution of remote soil moisture products from the SMAP satellite. Models were built using random forest for spatial downscaling of SMAP-L3-E, then visually and statistically evaluated for disaggregation quality. The impact of topography, soil properties, and precipitation on the downscaled soil moisture was examined. The relationship between downscaled soil moisture and in-situ soil moisture was analyzed. The results indicate that the proposed method demonstrated spatial and hydrological coherence, along with a satisfactory downscaling quality. Statistical validation indicated suitable generalization error for scientific and practical use (RMSE < 0.05 cm3 cm-3). Random forest effectively achieved spatial downscaling of SMAP-L3-E in the study area. Principal component and spatial analysis revealed dependence of downscaled soil moisture on elevation, soil organic carbon content, clay content, and saturated hydraulic conductivity, mainly under near-saturation conditions. Regarding validation against in-situ data, downscaled soil moisture explained in-situ soil moisture well under low soil water content (ρ = 0.624). Downscaling performance deteriorates for water contents between 0.40 to 0.50 cm3 cm-3, suggesting inadequacy under near saturation conditions at a daily temporal frequency. However, coarser temporal aggregations (7 to 10 days) yielded an average 0.98 correlation coefficient, regardless of saturation conditions. These results could potentially be applied in irrigation planning, soil physics studies and hydrology monitoring, to forecasting the occurrence of droughts, leaching of contaminants, surface runoff modeling, carbon cycle studies, soil's capacity to store and provide nutrients. Our results could mainly be applied to understanding the impact of droughts on crop yield.

Abstract The study investigated ash development in an arid region, focusing on its invasive spread mechanisms at organismic and ecosystem levels under varying moisture conditions. Conducted in the Northern Caspian region’s Volga-Urals interfluve, it examined the effects of arid climate, soil salinity, and limited moisture on plant communities. The features of ash functioning at the organismal and ecosystem levels with permanent and partial deficiency of productive moisture in the soil, as well as with its optimal availability, were investigated. It is shown that on automorphic soil types, ash cultures, subject to appropriate forestry technologies, can exist for many decades even during periodic soil droughts due to premature harmless dumping of leaf mass. In hydromorphic floodplain conditions, ash is not only well preserved in cultures, but also effectively introduced into meadow and forest ecosystems by lowering the relief. Trees in a new place, especially in meadows, begin to bear fruit after 6-10 years and spread the seeds to other territories. Such a nomadic strategy of stepwise dispersed multiple dispersal of ash contributes to the rapid formation of its secondary invasive areas and eliminates the possibility of effective control against it. Therefore, the use of ash in industrial plantings in floodplains is highly inadvisible. region conditions regions s VolgaUrals Volga Urals interfluve climate salinity communities availability types cultures technologies mass relief place meadows 610 6 10 6-1 territories Therefore inadvisible 61 1 6-

Resumo O presente estudo investigou o desenvolvimento do freixo da Pensilvânia em uma região árida, concentrando-se nos mecanismos de sua propagação invasiva a nível organísmico e ecossistêmico, sob condições variáveis de umidade. Realizado no interflúvio Volga-Urais da região norte do Cáspio, foram examinados os efeitos do clima árido, da salinidade do solo e da umidade limitada nas comunidades vegetais. As características do funcionamento do freixo a nível de organismo e de ecossistema foram investigadas tanto em relação à deficiência permanente e parcial de umidade produtiva no solo, quanto a sua disponibilidade ideal. Foi possível observar que culturas de freixo sujeitas a tecnologias florestais apropriadas podem existir por muitas décadas em solos não-hidromórficos, mesmo durante secas periódicas, devido ao seu processo de desfolha precoce e inofensiva. Além de apresentar uma boa adaptação em culturas com condições de solos hidromórficos em planícies aluviais, a introdução do freixo em ecossistemas de prados e florestas é igualmente bem-sucedida após a nivelação do relevo. Árvores plantadas em um novo local, especialmente em prados, começam a frutificar após 6-10 anos e assim disseminam suas sementes para outros territórios. Tal estratégia nômade de dispersão múltipla e gradual contribui para a sua rápida invasão de áreas secundárias e elimina a possibilidade de um controle eficaz contra o freixo. Portanto, o plantio de freixo em cultivos para fins industriais em planícies aluviais é altamente desaconselhável. árida concentrandose concentrando se ecossistêmico VolgaUrais Volga Urais Cáspio árido vegetais ideal nãohidromórficos, nãohidromórficos não hidromórficos, não-hidromórficos periódicas inofensiva bemsucedida bem sucedida relevo local 610 6 10 6-1 territórios Portanto desaconselhável 61 1 6-

Resumen La Región Hidrográfica del Río Paraná es de gran relevancia socioeconómica para Brasil. Debido a la historia de sequías en la región, el presente estudio tuvo como objetivo analizar la variabilidad espacial y temporal de las precipitaciones, así como las características de la sequía con base en el Índice Porcentual Normal (IPN) con el fin de contribuir a la gestión del agua en el Alto Río Paraná (ARP). El área de estudio comprende 14 unidades hídricas distribuidas en los estados de Goiás, Mato Grosso do Sul, Minas Gerais y São Paulo. Los datos climático se obtuvieron de la Red Hidrometeorológica Nacional. Se realizó un análisis geoestadístico de las precipitaciones, a partir de la serie anual de 408 estaciones, y posteriormente el cálculo del IPN para clasificar la severidad de las sequías. Todos los períodos (1990-2020) mostraron dependencia espacial (moderada-alta), lo que permitió la elaboración de mapas de sequías. Los períodos y áreas secas y lluviosas no indicaron influencia directa de El Niño-Oscilación del Sur (ENOS). Mato Grosso do Sul y São Paulo fueron las principales contribuyentes a las sequías. Los datos mostraron que 2010-2020 fue la década más seca, con mayor contribución del 2019/2020, donde las sequías superaron el 60% del área, evento nunca identificado en las últimas 3 décadas. Las curvas IPN referidas a “sequía inicial” y “leve” permitieron verificar años de crisis hídrica cuando sus porcentajes sumados alcanzaron al menos el 50% de la región. La metodología utilizada es versátil, permitiendo su uso en cualquier cuenca hidrográfica. Brasil región precipitaciones (IPN ARP. ARP . (ARP) 1 Goiás Nacional 40 estaciones 19902020 1990 2020 (1990-2020 moderadaalta, moderadaalta moderada alta , (moderada-alta) NiñoOscilación Niño Oscilación ENOS. ENOS (ENOS) 20102020 2010 2010-202 seca 20192020 2019 2019/2020 60 décadas inicial leve “leve 50 versátil hidrográfica (ARP 4 1990202 199 202 (1990-202 (moderada-alta (ENOS 2010202 201 2010-20 2019202 2019/202 6 5 199020 19 20 (1990-20 201020 2010-2 201920 2019/20 19902 2 (1990-2 20102 2010- 20192 2019/2 (1990- 2019/ (1990 (199 (19 (1 (

Abstract The Paraná River Hydrographic Region is of great socioeconomic relevance for Brazil. Therefore, due to the history of droughts in the region, the aims of the current study were to assess rainfall spatial and temporal variability, as well as to analyze drought features based on using the Normalized Percentage Index (NPI) to contribute to water management processes in Upper Paraná River (UPR). The study area encompasses 14 Planning and Management Units, distributed in Goiás, Mato Grosso do Sul, Minas Gerais and São Paulo states. Climate data were obtained from the National Hydrometeorological Network database. A geostatistical analysis of rainfall was carried out, based on the annual series of 408 stations, and subsequently the calculation of NPI for classifying the droughts severity. All periods analyzed (1990-2020) showed spatial dependence (moderate to high), allowing the elaboration of droughts maps. The dry and rainy periods and areas did not indicate direct influence of El Niño-Southern Oscillation (ENSO). Mato Grosso do Sul and São Paulo units were the main contributors to the identified droughts. The data showed that 2010-2020 was the driest decade of the period, with a greater contribution from the 2019/2020 period, where droughts exceeded 60% of the area for two consecutive years, an event never identified in the last 3 decades. The NPI curves referring to “initial drought” and “mild” allowed verifying years of water crisis when their summed percentages reached at least 50% of the region. The methodology used is versatile, allowing its use in any watershed. Brazil Therefore region variability (NPI UPR. UPR . (UPR) 1 Units Goiás states database out 40 stations severity 19902020 1990 2020 (1990-2020 moderate high, high , high) maps NiñoSouthern Niño Southern ENSO. ENSO (ENSO) 20102020 2010 2010-202 period 20192020 2019 2019/202 60 decades initial mild “mild 50 versatile watershed (UPR 4 1990202 199 202 (1990-202 (ENSO 2010202 201 2010-20 2019202 2019/20 6 5 199020 19 20 (1990-20 201020 2010-2 201920 2019/2 19902 2 (1990-2 20102 2010- 20192 2019/ (1990- (1990 (199 (19 (1 (

Resumo A Região Hidrográfica do Rio Paraná possui grande relevância socioeconômica para o Brasil. Devido ao histórico de secas na região, o objetivo do presente estudo foi avaliar a variabilidade espacial e temporal das chuvas, bem como analisar as características das secas com base no Índice de Porcentagem Normal (IPN) de modo a contribuir com a gestão da água no Alto Rio Paraná (ARP). A área de estudo compreendeu 14 unidades hídricas de planejamento, distribuídas nos estados de Goiás, Mato Grosso do Sul, Minas Gerais e São Paulo. Os dados climáticos foram obtidos junto a Rede Hidrometeorológica Nacional. Efetuou-se a análise geoestatística dos dados de precipitação, a partir das séries anuais de 408 estações, e posteriormente o cálculo do IPN para classificação da severidade das secas. Todos os períodos analisados (1990-2020) indicaram dependência espacial (moderada-alta), possibilitando a elaboração dos mapas de secas. Os períodos e áreas secas e chuvosas não indicaram influência direta do El Niño-Oscilação Sul (ENOS). Mato Grosso do Sul e São Paulo foram os maiores contribuintes nas secas. Os dados indicaram que 2010-2020 foi o decênio mais seco do período, com maior contribuição em 2019/2020, onde as secas superaram 60% da área, evento nunca identificado nas últimas 3 décadas. As curvas IPN referente a “seca inicial” e “suave” permitiram verificar anos de crise hídrica quando seus percentuais somados atingiram pelo menos 50% da bacia do ARP. A metodologia utilizada mostrou versatilidade permitindo seu uso em qualquer escala hidrográfica, apresentando-se como alternativa em regiões com escassez de dados. Brasil região chuvas (IPN ARP . (ARP) 1 planejamento Goiás Nacional Efetuouse Efetuou se precipitação 40 estações 19902020 1990 2020 (1990-2020 moderadaalta, moderadaalta moderada alta , (moderada-alta) NiñoOscilação Niño Oscilação ENOS. ENOS (ENOS) 20102020 2010 2010-202 período 20192020 2019 2019/2020 60 décadas seca inicial suave “suave 50 hidrográfica apresentandose apresentando (ARP 4 1990202 199 202 (1990-202 (moderada-alta (ENOS 2010202 201 2010-20 2019202 2019/202 6 5 199020 19 20 (1990-20 201020 2010-2 201920 2019/20 19902 2 (1990-2 20102 2010- 20192 2019/2 (1990- 2019/ (1990 (199 (19 (1 (

ABSTRACT One of the impacts of climate change is an increase in the frequency and intensity of hydrometeorological disasters such as prolonged droughts. Borneo is one of the areas threatened by drought due to climate change. Therefore, it is important to identify and implement appropriate mitigation and adaptation measures. This study used the dynamical downscaling method by the Conformal Cubic Atmospheric Model (CCAM) to evaluate the potential for drought events in Borneo based on the RCP 4.5 scenario. The annual rainfall in Borneo for 2021-2050 is projected to increase compared to 1991-2020. However, the increase in annual rainfall does not free Borneo from the possibility of drought events in the future. This study’s results indicate that areas in southern Borneo, such as Banjarmasin, Pangkalan Bun, and Pontianak, will have a higher frequency of meteorological drought events and are also expected to experience longer periods of consecutive dry days between 2021-2050 compared to 1991-2020.

RESUMEN Uno de los efectos del cambio climático es el aumento de la frecuencia e intensidad de los desastres hidrometeorológicos, como las sequías prolongadas. Borneo es una de las zonas amenazadas por la sequía debido al cambio climático. Por lo tanto, es importante identificar e implementar medidas apropiadas de mitigación y adaptación. Este estudio utilizó el método dinámico de reducción de escala “Conformal Cubic Atmospheric Model (CCAM)” para evaluar el potencial de eventos de sequía en Borneo según el escenario RCP 4.5. Se prevé que la precipitación anual en Borneo para 2021-2050 aumente en comparación con 1991-2020. Sin embargo, el aumento de las precipitaciones anuales no libera a Borneo de la posibilidad de eventos de sequía en el futuro. Los resultados de este estudio indican que las áreas del sur de Borneo, como Banjarmasin, Pangkalan Bun y Pontianak, tendrán una mayor frecuencia de sequías meteorológicas entre 2021 y 2050 en comparación con 1991 y 2020.

Abstract For nearly three centuries, the “Gerais” of the upper-middle São Francisco River were occupied by production systems adapted to the tablelands, veredas and wetlands. Common land takeovers, deforestation, and drainage stimulated by the “agricultural modernization” of the 1970s drastically reduced water sources, and then droughts began to affect domestic and productive supplies. This article analyzes the experience of the “great drought” of 2011/2019 in three communities in the Gerais region, investigating public programs, water supply, and agricultural production from the perspective of rural people. The methodology relied on the local classification of agro-environments, using focus groups, interviews with community leaders, and sampled families according to different compositions. It concludes that the disappearance of historical conditions of access to resources led the population to reorganize agriculture and water consumption. Experiencing new situations, the memory of the abundance of land and water is the inspiration to claim, negotiate and adapt public policies to the culture and needs of communities. centuries “Gerais uppermiddle upper middle tablelands wetlands takeovers deforestation modernization s sources supplies great drought 20112019 2011 2019 2011/201 region programs supply people agroenvironments, agroenvironments agro environments, environments agro-environments groups leaders compositions consumption situations claim 2011201 201 2011/20 201120 20 2011/2 20112 2 2011/

Resumo Durante quase três séculos o “gerais” do Alto-Médio rio São Francisco foi ocupado com sistemas de produção adaptados às chapadas, veredas e brejos. As tomadas de terras comuns, desmates e drenagens estimuladas pela “modernização agrícola” dos anos 1970 reduziram drasticamente as fontes e o acesso às águas, e então as secas passaram a afetar o abastecimento doméstico e produtivo. Este artigo analisa a travessia da “grande seca” de 2011/2019 em três comunidades do gerais, investigando programas públicos, abastecimento de água e produção agrícola na perspectiva da população rural. A metodologia foi referenciada na classificação local de agroambientes, usando grupos focais, entrevistas com lideranças comunitárias e famílias amostradas segundo diferentes composições. Conclui que o desaparecimento das condições históricas de acesso aos recursos levou a população a rearranjar a agricultura e o consumo de água. Vivendo novas situações, a lembrança da abundância de terras e águas é a inspiração para reivindicar, negociar e adequar programas públicos à cultura e às necessidades das comunidades. gerais “gerais AltoMédio Alto Médio chapadas brejos comuns modernização 197 produtivo grande seca 20112019 2011 2019 2011/201 rural agroambientes focais composições situações reivindicar 19 2011201 201 2011/20 1 201120 20 2011/2 20112 2 2011/

Abstract Drought is a natural phenomenon that cause severely impacts on different sectors of society. To assess drought, indices are used that allow comparing events in different regions and time scales. SPEIbase is a gridded database that provides global-scale SPEI estimates with an extensive temporal coverage (1901 to 2022), 0.5° x 0.5° spatial resolution, and is currently being updated. This study aimed to evaluate SPEIbase v2.9 in representing the spatio-temporal patterns of drought in the Southeastern Brazil Region. For this, SPEIbase values were compared to values calculated from data from eight conventional meteorological stations (CMS), for the period from 1961 to 2010. SPEIbase showed satisfactory results for the Southeastern Brazil Region. The gridded data presented a positive linear trend for all eight CMS in the study, with a strong correlation (0.70 < r < 0.90) for more than 50% of the stations. Additionally, SPEIbase performed satisfactorily in identifying the frequency and intensity of droughts. SPEIbase is an important tool for drought analysis in the Southeastern Brazil Region. society scales globalscale global scale 1901 (190 2022, 2022 , 2022) 05 0 5 0.5 resolution updated v29 v v2 9 v2. spatiotemporal spatio Region this CMS, (CMS) 196 2010 0.70 070 70 (0.7 0.90 090 90 50 Additionally droughts 190 (19 202 0. (CMS 19 201 0.7 07 7 (0. 0.9 09 (1 20 1 (0 ( 2

Resumo A seca é um fenômeno natural, que causa impactos severos em diferentes setores da sociedade. Para avaliar a seca, são utilizados índices que permitem comparar eventos em diferentes regiões e escalas temporais. O SPEIbase é uma base de dados em grade que fornece estimativas do SPEI em escala global, com ampla abrangência temporal (1901 a 2022), resolução espacial de 0,5° x 0,5° e segue em processo de atualização. O objetivo deste estudo foi avaliar o SPEIbase v2.9 na representação dos padrões espaço-temporal da seca na Região Sudeste Brasileira. Para isso, foram comparados os valores da SPEIbase via dados de oito estações meteorológicas convencionais (EMC), para o período de 1961 a 2010. A SPEIbase apresentou resultados satisfatórios para a Região Sudeste Brasileira. Os dados em grade apresentaram tendência linear positiva para todas as oito EMC, com correlação forte (0,70 < r < 0,90) para mais de 50% das estações. Além disso, a SPEIbase apresentou desempenho satisfatório na identificação da frequência e intensidade das secas. O SPEIbase é um importante produto que pode ser usado para a análise de secas na Região Sudeste Brasileira. natural sociedade temporais global 1901 (190 2022, 2022 , 2022) 05 0 5 0,5 atualização v29 v v2 9 v2. espaçotemporal espaço Brasileira isso EMC (EMC) 196 2010 0,70 070 70 (0,7 0,90 090 90 50 disso 190 (19 202 0, (EMC 19 201 0,7 07 7 (0, 0,9 09 (1 20 1 (0 ( 2

ABSTRACT Extreme weather events (e.g., droughts, excessive precipitation) are expected to increase in frequency and severity in the coming decades due to climate change, causing significant impacts on society and ecosystems. Because these events are rare and complex, they have been studied with manipulative experiments. Littorinidae snails inhabit a complex and variable environment in which they must deal with periodic extreme events and are thus considered excellent ecological models for these studies. Therefore, this study aimed to understand the effects of extreme climatic events on the survival and weight of the species Littorina fabalis and Littorina littorea in Spain and Littoraria angulifera and Littoraria flava in Brazil. Higher mortality rates and greater weight loss were observed in the desiccation resistance treatment compared to the control treatment in both countries. The results showed dependence on the species’ body size. The submergence tolerance treatment indicated that the species from Spain are more susceptible to mortality in response to excessive rainfall and/or coastal flooding. Each species tested for the effect of extreme climatic events using an integrated response strategy with clear latitudinal differences. Understanding the organisms’ responses at different latitudes is essential for conservation biology on a global scale. e.g., eg e g (e.g. droughts precipitation change ecosystems experiments studies Therefore Brazil countries size andor or flooding differences organisms scale e.g. (e.g e.g

Resumo: Identificar e explicar as relações entre sociedade e meio ambiente apresenta muitos desafios para o historiador. Este artigo apresenta alguns desses desafios usando um estudo de caso da Arábia romana tardia no século anterior ao surgimento do Islã. A primeira metade do século VI EC na Arábia foi particularmente marcada pelo desaparecimento de Himyar, a potência dominante na região até 525 EC. Os registros hidroclimáticos do sul da Arábia e seus arredores, incluindo um novo registro de estalagmite de alta resolução do norte de Omã, lançam nova luz sobre o contexto desses desenvolvimentos. Eles indicam claramente uma seca sem precedentes, com a aridez mais severa persistindo entre aproximadamente 500 e 530 EC. Será que essas secas contribuíram para minar a resistência dos Himyaritas e, portanto, para o surgimento do contexto ambiental no qual o Islã emergiu posteriormente? O artigo discute os desafios de integrar e interpretar os dados históricos e paleoclimáticos. Resumo historiador Himyar 52 arredores Omã desenvolvimentos precedentes 50 53 portanto posteriormente paleoclimáticos 5

Abstract: Identifying and explaining the relationships between society and environment presents many challenges to the historian. This article sets out some of these using a case study from late Roman Arabia in the century preceding the rise of Islam. The first half of the 6th century CE in Arabia was particularly marked by the demise of Himyar, the dominant power in the region until 525 CE. Hydroclimate records from and around Southern Arabia, including a new high-resolution stalagmite record from Northern Oman, throw new light on the background to these developments. They clearly indicate an unprecedented drought, with the most severe aridity persisting between ~500 and 530 CE. Did such droughts contribute to undermining Himyarite resilience - and thus to the appearance of the environmental context in which Islam later emerged? The article discusses the challenges in integrating and interpreting the historical and palaeoclimate data. Abstract historian th Himyar 52 highresolution high resolution Oman developments drought 500 ~50 53 emerged data 5 50 ~5 ~

For more than two centuries, Beaufort West has been an essential stopover for people traversing an arid and sparsely populated region. Throughout its existence, the town has been plagued by water problems, whether they be drought, flash floods, or sanitary in origin. Many factors contributed to Beaufort West’s sanitary woes. Situated in the semi-arid central Great Karoo with an average rainfall of a mere 250mm, Beaufort West’s unique geographical positioning renders it climatologically vulnerable and because its water supply is heavily reliant on rainfall, regular droughts are inevitable. Groundwater extracted from boreholes has played an increasingly important role in the development of Beaufort West. Since the 1850s, it has been reliant on a very rudimentary potable water reticulation system of open street furrows, and a sewage system comprising cesspools and pail removals. Until the first half of the twentieth century many of the residents were self-sustaining and on their properties they kept farm animals such as pigs, sheep, goats, fowl and cows as food and horses as draught animals. These conditions created almost unsurmountable sanitation problems. The council minutes and sanitation reports of the Beaufort West Municipality frequently note the prevalence of two diseases – typhoid and diphtheria. This article investigates the root causes, manifestation, and health impact of these diseases on the community of Beaufort West. It traces the municipal initiatives to combat their occurrence, and the efforts made to improve the town’s general sanitary conditions. This case study of Beaufort West corroborates a hypothesis that modern-day outbreaks of water-borne diseases and sanitation in South Africa have a long historical antecedent.

Oor twee eeue heen, was Beaufort-Wes 'n noodsaaklike rushalte vir reisigers wat deur 'n droë en ylbevolkte omgewing gereis het. Sedert sy stigting is die dorp deurlopend geteister deur waterprobleme, hetsy droogte, vloedwater of besoedeling. Baie faktore het tot die dorp se gesondheidsprobleme bygedra. As gevolg van sy unieke geografiese ligging is die dorp klimatologies baie kwesbaar. Beaufort-Wes is in die sentrale Groot Karoo se semi-woestyn geleë, met 'n gemiddelde jaarlikse reënval van slegs 250 mm. Watervoorsiening aan die dorp is grotendeels van reënval afhanklik en gereelde droogtes is onvermydelik. Grondwater, wat deur middel van boorgate onttrek word, het deur die jare heen 'n toenemend belangrike rol in die ontwikkeling van Beaufort-Wes gespeel. 'n Baie rudimentäre waterverspreidingstelsel, wat oorspronklik uit oop straatleivore bestaan het, asook 'n rioolstelsel, bestaande uit nagemmer verwydering en putlatrines, is ontwikkel. Baie dorpenaars was selfonderhoudende inwoners wat plaasdiere soos varke, skape, bokke, hoenders en koeie as voedselbronne op hul eiendomme aangehou het. Hierdie situasie het byna onoorkomelike gesondheidsprobleme opgelewer. Twee waterdraende siektes -ingewandskoors en witseerkeel - het vir baie jare met reëlmaat opgeduik in die notules en gesondheidsverslae van Beaufort-Wes se munisipaliteit. Die studie ondersoek die oorsake, manifestering en gesondheidsimpak van hierdie siektes op die gemeenskap van Beaufort-Wes, asook die munisipale inisiatiewe wat aangewend is om die voorkoms daarvan te bestry en pogings om die dorp se algemene gesondheidstoestand te verbeter. Die gevallestudie van Beaufort-Wes bevestig die hipotese dat moderne uitbrekings van waterdraende siektes en sanitasie in Suid-Afrika 'n lang historiese aanloop het.