Roberto Pizarro

• Director of HR at University of Talca

Wildfires pose an escalating threat to ecosystems and human settlements, making accurate forecasting essential for early mitigation. This study compared three deep learning models for wildfire prediction: Deep Reinforcement Learning (DRL) with Actor–Critic architecture, Convolutional Neural Network (CNN), and Transformer-based models. The models we...

Water is a fundamental resource for Chile’s productive structure, which is more important in arid areas, and especially with agricultural uses. This study was based on two basins (Cogotí and Illapel) located in the Coquimbo Region of north-central Chile. In this region, surface water rights were closed in 2002 and the only current option is the use...

Land surface temperature (LST) is one of the most important variables in the physical processes of surface energy and water balance. The temporal behavior of LST was analyzed between the latitudes 32°00′ S and 34°24′ S (Valparaíso and Metropolitana regions of Chile) for three summer months (December, January, and February) in the 2000–2017 period,...

Specific algorithms are developed to solve the equations that define the physical dimensions under various conditions. In this sense, the storm index method was incorporated for the variable precipitation intensity, expanding the number of rainfall stations with the intensity duration frequency (IDF) curves from 9 to 31 within the considered territ...

Estimating intensity−duration−frequency (IDF) curves requires local historical information of precipitation intensity. When such information is unavailable, as in areas without rain gauges, it is necessary to consider other methods to estimate curve parameters. In this study, three methods were explored to estimate IDF curves in ungauged areas: Kri...

The availability of water in Chile has shown signs of decline in recent decades. This is problematic because Chile’s economy depends on mining, forestry, and agricultural activities, all limited by the availability of water resources. In this study, daily, monthly and annual flows in 31 basins located in the arid–semiarid zones (29°12′ S–33°58′ S)...

Sediment production and transport in a basin are generally a function of the degree of soil protection, normally represented by plant cover. In this study, two basins located at similar latitudes but with different hydrological regimens and plant covers were studied, one with a pluvial regimen and forest plantations (Ñuble) and another one with the...

This paper reviews the current knowledge of hydrological processes in Chilean temperate forests which extend along western South America from latitude 29° S to 56° S. This geographic region includes a diverse range of natural and planted forests and a broad sweep of vegetation, edaphic, topographic, geologic, and climatic settings which create a un...

This paper reviews the current knowledge of hydrological processes in Chilean temperate forests which extend along western South America from latitude 29° S to 56° S. This geographic region includes a diverse range of natural and planted forests and a broad sweep of vegetation, edaphic, topographic, geologic, and climatic settings which create a un...

El recurso agua es limitado en la zona norte de Chile por tratarse de una zona árida, de ahí la importancia de estudiar si en ellas se están verificando cambios hidrológicos que pudiesen alertar sobre un incremento de tal situación. Para ello, se estudiaron las tendencias de los caudales punta (caudal máximo instantáneo) de la Región de Coquimbo, a...

Forest ecosystems play an important role in surface and subsurface runoff, as well as the availability of water. Therefore, it is important to have a greater understanding of the interactions between forests and the production of water in watersheds. In this sense, this study evaluates the long-term effect of native forests and forest plantations o...

The arid Coquimbo region of Chile has experienced a significant economic growth in recent decades, fueled in large part by water-intensive activities such as mining and agriculture. Under this context, a monthly and annual trend analysis of precipitation, streamflow, and piezometric levels was carried out. Thus, 43 pluviometric stations, 11 fluviom...

Several studies have focused on why the Aculeo Lagoon in central Chile disappeared, with a recent one concluding that a lack of precipitation was the main cause, bringing tremendous political consequences as it supported the argument that the government is not responsible for this environmental, economic, and social disaster. In this study, we eval...

Maximum rainfall intensity is an interesting factor to analyze when determining whether temporal and spatial changes have occurred. Data gathered from 11 rain gauges were used to determine annual maximum rainfall intensities for the Maule Region (central Chile), for durations from 15-minute to 24-hour durations, between 1974 and 2009. Statistical t...

The Purapel watershed in central Chile has experienced drastic land‐use changes since the 1950s, beginning with the conversion of native forests to forest plantations. Controversy exists on the effects of reforestation on sediment production in watersheds. The temporal evolution of stage–discharge curves and sediment production was evaluated and co...

To develop intensity-duration-frequency (IDF) curves, it is necessary to calculate annual maximum rainfall intensities for different durations. Traditionally, these intensities have been calculated from the analysis of traces recorded by rain gauges on pluviograph strip charts (PSCs). For many years, these charts have been recorded and analyzed by...

Maqui, Aristotelia chilensis (Molina) Stuntz, is a Chilean native species with a fruit with the most antioxidant content in the world. Today, it presents a growing demand in international markets, with Chile the only country exporting the fruit from natural formations. In the present book, we present a novel combination of rainwater harvesting syst...

Toxic metal content were measured in samples of mollusc Concholepas concholepas obtained from the Chilean coast. Samples were collected during two periods, one before and one after the earthquake-tsunami which occurred in the Maule Region, Chile, February 27th, 2010 as a result of an earthquake with a magnitude of 8.8. Quantification of toxic metal...

The lack of reliable continuous rainfall records can exacerbate the negative impact of extreme storm events. The inability to describe the continuous characteristics of rainfall from storm events increases the likelihood that the design of hydraulic structures will be inadequate. To mitigate extreme storm impacts and improve water governance at the...

p>La erosión de sedimentos es un problema serio, con aproximadamente 75.000 millones de toneladas de suelo erosionadas anualmente en todo el mundo (Pimentel y Kounang, 1998). Aunque la erosión es un proceso natural, ésta puede acelerarse debido a la actividad humana y a los cambios en el uso de la tierra. El incremento de la erosión del suelo más a...

This study aims to determine if there is variation in precipitation concentrations in Chile. We analyzed daily and monthly records from 89 pluviometric stations in the period 1970–2016 and distributed between 29°12′ S and 39°30′ S. This area was divided into two climatic zones: arid–semiarid and humid–subhumid. For each station, the Gini coefficien...

Balocchi, F., Pizarro, R., Meixner, T., & Urbina, F. (November- December, 2017). Annual and monthly runoff analysis in the Elqui River, Chile, a semi-arid snow-glacier fed basin. Water Technology and Sciences (in Spanish), 8(6), 23-35, DOI: 10.24850/j-tyca-2017-06-02. Climate change and its relationship to temperature are critical factors affect...

Trees have been around for more than 370 million years, and today there are about 80 thousand species of them, occupying 3.5 billion hectares worldwide, including 250 million ha of commercial plantations. While forests can provide tremendous environmental, social, and economic benefits to nations, they also affect the hydrologic cycle in different...

Mining is the most important economic activity in Chile; causing significant degradation of the environment in the arid regions. The Coquimbo Region has suffered serious soil and water pollution because of heavy metals from mining, particularly copper. Implementation of measures that help to minimize the environmental impact of mining tailings requ...

PIZARRO-TAPIA, R., CABRERA-JOFRE, C., MORALES-CALDERÓN, C., & FLORES-VILLANELO, J.P. Temporal variations of rainfall and flows in the Maipo River Basin, central Chile, and the influence of glacier melting on water yield (1963-2006). Water Technology and Sciences, formerly Hydraulic engineering in Mexico (in Spanish). Vol. II, No. 3, July-September,...

Precipitation is the most critical climatic element that directly affects the availability of water resources. The objective of this study was to describe and discuss spatio-temporal patterns of annual precipitation, its aggressiveness, and its concentration in the southwest coast of South America (36°–49°S) from 1930 to 2006. An annual and multi-d...

Intensity-duration-frequency (IDF) relationships are the tools for obtaining design rainfall estimation. Their calculation requires rainfall data not commonly available in time. The scarce spatial information makes it difficult to perform a Regional Frequency Analysis (RFA). The objective of this paper was to establish a new method to obtain more e...

Most of meteorological stations in Chile register rainfall amounts once every 24 h. The creation of intensity–duration–frequency (IDF) curves requires continuous recorded data, and this insufficiency of proper instrumentation has resulted in a lack of IDF curves nationwide. The objective of this study is to further develop and evaluate the feasibil...

L arge-scale climate changes have occurred naturally throughout Earth's history, including changes in global vegetation patterns and the waxing and waning of the extent of deserts (e.g., Beerling and Woodward 2001). These natural variations have occurred as a con-sequence of changes in the Earth's orbit, solar cycles, plate tectonics, volcanic mega...

Fire is a natural component of forest ecosystems in parts of North America, South America, Europe, Australia, Africa and the Mediterranean region. These fires are usually uncontrolled wildfires in areas of ignitable vegetation but can also be prescribed fires set for vegetation management purposes. Wildfires are commonly characterised based on caus...

En el presente estudio se analizaron cuatro modelos matemáticos de estimación de caudales recesivos, con el fin de determinar cuál de ellos obtiene los mejores resultados en una cuenca andina del Maule, zona mediterránea de Chile central. Esto se realizó a través del análisis de 25 crecidas en la época estival 1971-2003, en donde se consideró el ap...

This study analyzed four mathematical models for recessive flow estimation in order to determine which one would provide the best results for an Andean basin in Maule, central Chile. This was accomplished through the analysis of 25 summer floods occurring between 1971 and 2003, which identified groundwater as the exclusive supply as of the third in...

Chile has a unique geography that provides an extraordinary variety of climatic conditions and availability of water resources. The objective of this manuscript was to describe and analyze the spatial and temporal distribution patterns, as well as the management of water resources, along a country with a narrow distance from the Andes Mountains to...

Air pollution in Santiago is a serious problem every winter, causing thousands of cases of breathing problems within the population. With more than 6 million people and almost two million vehicles, this large city receives rainfall only during winters. Depending on the frequency of storms, statistics show that every time it rains, air quality impro...

This paper compares three methods to obtain synthetic unit hydrographs (SUH). The Snyder (modified for Chile by Astorga and Benítez), the US Bureau of Reclamation, and the Témez methods are analyzed on two watersheds located in Mediterranean areas of Chile. To do so, each watershed was characterized in terms of its morphology and vegetation type. I...

This study analyzed the influence of climate change on peak flow behavior in the metropolitan region, Libertador Bernardo O'Higgins region and the area of Maule, central Chile. To this end, the Gumbel's PDF was applied, with which the best results for fitting peak flows were obtained, considering return periods of 10, 20, 30, 40, and 50 years. Than...

Abstract In determining the possible influence of climate change, it is important to understand the temporal and spatial variability in streamflow response for diverse climate zones. Thus, the aim of this study was to determine the presence of changes in annual maximum peak flow for two climate zones in Chile over the past few decades. A general a...

Abstract This study analyzed the influence of climate change on peak flow behavior in the metropolitan region, Libertador Bernardo O’Higgins region and the area of Maule, central Chile. To this end, the Gumbel’s PDF was applied, with which the best results for fitting peak flows were obtained, considering return periods of 10, 20, 30, 40, and 50 y...

Abstract Analysis of precipitation observations from Chile indicated that man-made water reservoirs might be affecting the intensity of extreme precipitation events. Fifty rain gauges were used to evaluate rainfall intensities under different climates, using the Gumbel method (T = 5 and 100 years) and average maximum recorded rainfall intensities...

Chile se caracteriza por tener una amplia variedad de condiciones climáticas y topográficas en sus más de 4.000 km de largo, que van entre las latitudes 17° y 56°S. Como elementos topográficos destacan la Cordillera de los Andes en su límite oriental, con alturas máximas superiores a los 6800 msnm y la Cordillera de la Costa hacia el poniente, con...

As a way to contribute to proper use of IDF curves in Chile, this chapter describes the relationship among four crucial climatic variables: rainfall intensity, storm duration, rainfall frequency and rainfall distribution. Graphical and mathematical representations of IDF curves were developed towards the selection of 1-, 2-, 6-, 12-, and 24-hr dura...

The manuscript refl ects the opinion of the authors about the need for a hydromorphological approach for the management of Chilean rivers. A brief state-of-the-art of the recent scientifi c advances on hydromorphological approach to river management is presented, as well as a general overview of the conditions of Chilean rivers and the mayor distur...

The manuscript reflects the opinion of the authors about the need for a hydromorphological approach for the management of Chilean rivers. A brief state-of-the-art of the recent scientific advances on hydromorphological approach to river management is presented, as well as a general overview of the conditions of Chilean rivers and the mayor disturba...

This guide contains the methodology and main results of the the project "Natural Disasters Footprint: A tool for assessing environmental-economic impact of natural disasters to prioritize resources and reconstruction activities. Pilot implementation in communes of O'Higgins, Maule and Biobío Regions of Chile" (in Spanish). It also explains how to a...

The study and analysis of precipitation has become a crucial tool in understanding the temporal and spatial behavior of water resources, in terms of availability and impact on extreme events. The objective of this study was to evaluate different rainfall parameters (intensities for 1-h duration D = 1 h and return periods of T = 5 and 100 yr, and me...

The study and analysis of precipitation has become a crucial tool in understanding the temporal and spatial behavior of water resources, in terms of availability and impact on extreme events. The objective of this study was to evaluate different rainfall parameters (intensities for 1-h duration D = 1 h and return periods of T = 5 and 100 yr, and me...

This study compared the behavior of an Oak-Hualo secondary forest, where the dominant species are Nothofagus obliqua and Nothofagus glauca, with that of a 12-year-old Pinus radiata D. Don plantation in the precipitation-interception process. The study was conducted at the El Picazo Experimental Station in the town of San Clemente, Maule region, bet...

A wildfire burned around 15,000 ha of Monterrey Pine (Pinus radiata) plantations near Yungay, Chile, in January of 2007. Post-fire water repellency (hydrophobicity) was measured using the water-drop-penetration-time (WDPT) method at depths of 0, 5, and 10 mm from the soil surface. These measurements were collected on burned sites of both young (4-y...

A rainfall simulator is an important tool for the study of runoff generation and soil loss because it can be used either under laboratory conditions, or in disturbed or natural soil. The objective of this study was to describe the design and operation of a rainfall simulator to evaluate soil loss in situ. The rainfall simulator has four full-cone s...

A rainfall simulator is an important tool for the study of runoff generation and soil loss because it can be used either under laboratory conditions, or in disturbed or natural soil. The objective of this study was to describe the design and operation of a rainfall simulator to evaluate soil loss in situ. The rainfall simulator has four full-cone s...

El suelo se encuentra sometido a una creciente presión medioambiental en todo el planeta Tierra, provocada principalmente por la actividad humana ligada a usos agrícolas, forestales o mineros, los que no siempre aplican las adecuadas medidas de conservación. Asimismo, las actividades industriales, relacionadas con el movimiento de suelos o la ocupa...

Este estudio evalúa la aplicabilidad de distintos métodos para la estimación de datos faltantes de precipitación puntual, en ocho estaciones pluviográficas de la Región del Maule, Chile. Estos métodos corresponden a correlación lineal, completación por razones de distancia, completación por promedios vecinales, completación por razones promedio y c...

Temporal and spatial rainfall distribution were analyzed in the central zone of Chile in order to define the level of rainfall aggressiveness and concentration. Monthly and annual precipitation data from 63 rain gauge stations were used for calculating the Fournier Index (FI), the Fournier Modified Index (MFI) and the Maule-Fournier Modified index...

Esta investigación propuso un diseño hidrológico para la construcción de zanjas de infiltración, en faenas forestales del secano costero e interior de Chile central. Así, se evaluaron cuatro ensayos (Hidango, Región de O'Higgins; Name, Región del Maule; y Llohué y Manzanares, Región del Bío-Bío) con dos tipos de zanjas de infiltración, establecidos...

In this research a hydrologic design is defined for infiltration ditches in forest works, for arid, and semiarid regions in central Chile. In this context, four plots were evaluated (Hidango, in O'Higgins Region; Name, in Maule Region; and Llohué and Manzanares, in Bio-Bio Region), including two types of infiltration ditches, established in May 200...

In Tutuvén river basin, central Chile, instantaneous runoff coefficient (C), defined as the rate between runoff and rainfall, and its influence on different vegetation cover considering previous soil moisture were studied. Coefficients were calculated for intervals of 1, 2 and 4 hours in three different vegetation covers and three different moistur...

The distribution of peak river flows was studied over the period 1960 2000 in the watershed of Purapel River (Maule Region, Chile) in order to evaluate the relationship of these flows to vegetation cover. Maximum annual and summer flows, between decades and between periods, monthly and yearly were compared with multi-temporal analysis for 1955, 197...

Resumen En la cuenca del río Tutuvén, VII región de Chile, se estudió el comportamiento del coeficient e de escorrentía instantáneo (C), definido como la relac ión entre las precipitaciones efectivas y las precipitaciones totales caídas, y la influencia sob re éste de diversas situaciones de vegetación y condiciones precedentes de humedad del suelo...

La presente Guía constituye uno de los productos preliminares del Proyecto liderado por el Centro del Agua para Zonas Áridas y Semiáridas de América Latina y El Caribe (CAZALAC), para la elaboración del Mapa de Zonas Áridas, Semiáridas y Subhúmedas secas de América Latina y El Caribe. Esta iniciativa representa el esfuerzo de diferentes institucion...

Se calibraron y validaron dos modelos de simulación integral de cuenca, Modelo T (de 2 parámetros) y Modelo Témez (de 4 parámetros), para las cuencas del río Purapel (264.6 km2), y del río Achibueno (943 km2), respectivamente, en la Región del Maule, Chile. La calibración consideró el planteamiento original de los modelos, pero diferenciando paráme...

Este artículo analiza la influencia que tienen las masas boscosas en la producción de agua de la cuenca del río Purapel, ubicada en la zona central de Chile. Esta cuenca tiene una superficie de 264,6 km2 y se ha visto afectada por procesos de sustitución vegetacional, pasando de bosques nativos a una forestación masiva, principalmente de la especie...

This study approaches the problems of mean areal rainfall estimation in three longitudinal sectors of the VII Region of Chile: the Andes mountain range, the central valley, and coastal mountain range. The methods used were the Mean Arithmetic (MA), Thiessen’s Polygons (Th), Isohyets (Iso), Modified Thiessen (ThM) and Inverse Squared Distance (IDC)....

SUMMARY In this research a hydrologic design is defined for infiltration ditches in forest works, for arid and semiarid regions in central Chile. In this context, four plots were evaluated (Hidango, in O'Higgins Region; Name, in Maule Region; and Llohué and Manzanares, in Bío-Bío Region), including two types of infiltration ditches, established in...

SUMMARY RESUMEN Se estudió el comportamiento de los caudales punta para el periodo 1960 -2000, en la cuenca del río Purapel, región del Maule, Chile; y el efecto p rovocado por los cambios en la cobertura vegetal presente en la cuenca. Para ello se realizaron comp araciones estadísticas entre décadas y por periodos (1960/1978, 1979/2000), a nivel m...

RESUMEN En la zona central de Chile, se analiza la distribución y la agresividad de las precipitaciones, a partir de registros procedentes de 63 estaciones meteorológicas. Se utilizaron las precipitaciones mensuales y anuales, como información base para el cálculo de los índices de Fournier (FI) y Modificado de Fournier (MFI), el Índice de Concentr...