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Title: Agricultural drought in Chile From the assessment toward prediction using satellite data.
Other Titles: Sequía Agrícola en Chile, de la evaluación hacía la predicción usando datos satelitales.
Authors: Lillo Saavedra, Mario; supervisor de grado
Zambrano Bigiarini, Francisco Javier
Keywords: Sequía - Chile;Cambios de la Temperatura Global;Calentamiento Global;Agricultura - Efecto del Calentamiento Global.
Issue Date: 2017
Publisher: Universidad de Concepción.
Abstract: Climate change is occurring and there is a scientific consensus that human being is playing a key role by pouring greenhouses gases to the atmosphere. Temperature has been increasing globally and the precipitation patterns are changing. Regionally, since the year 2010 Chile has been experiencing which has been called a mega drought, however, it has been seen mostly in meteorological terms by analyzing precipitation deficits. Further, the future projection for Chile indicates that the precipitation will decrease in Central-South Chile, this addded to the increase on temperature likely could increase drought frequency and intensity. Also, in this regard crop yield of corn and wheat decreases are forecasted by 2050 for Chile. The study on how climate variability and human activity impact agriculture has been known as agricultural drought. One of the main factors that trigger this drought conditions is precipitation deficit, thus is crucial to understand how this depletion relates to agriculture development. Although, since 2010 Chile has been facing water shortage mostly as results of the analysis of annual precipitation, but still there is a lack of knowledge about how this mega drought is affecting agriculture over Chile. Moreover, during the growing season 2007-2008 a large part of the country experienced decreases in crop yield for which these areas were declared under drought emergency by the government. However, by analyzing the total amount of annual precipitation these years are not seen as relevant drought years. This happens in part because for vegetation is more important the timing of the rainfall deficit rather than the cumulative over a year. Thus, the study and understanding of agricultural drought and methods that could help to anticipate it are challenging. The study of agricultural drought at regional and global scale brings the problem of having enough data that allow to analyze it spatially and temporally. Nonetheless, since the 70’s the use of remote sensing data obtained from satellite to monitor the environment at global and regional scale has been highly improved, and nowadays are a key data source to support climatic and environmental studies. In that regard, there is an important amount of satellite-derived data publicly available. One of this dataset that provided useful data for the monitoring of vegetation is provided for the National Aeronautics and Space Administration (NASA) and its sensor the Moderate-Resolution Imaging Spectroradiometer (MODIS) which is coupled to the TERRA and AQUA satellites. Further, multiple microwave and infrared satellites have allowed the development of precipitation estimates products at different temporal and spatial resolutions Between them, highlight the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) having data since 1998, and also has been derived long-term precipitation products such as the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks - Climate Data Record (PERSIANNCDR) with data since 1983, and the Climate Hazards Group InfraRed Precipitation with Station data version 2 (CHIRPS v2) providing estimates since 1981. These vegetation and precipitation satellite products are valuable data sources for agricultural drought studies, allowing to evaluate the interaction vegetationprecipitation at regional and global scale. Accordingly, in this thesis was studied the usefulness of satellite data for the assessment and prediction of agricultural drought over Chile. The main research question is: How well the satellite data of vegetation and precipitation together with climatic oscillation indices can be used to predict agricultural drought before the end of the growing season? To achieve this, the work was developed in three stages: 1) assessment of vegetation response to water shortage in the BioBío Region of Chile, 2) the evaluation of long-term satellite precipitation data over Chile for use in drought studies, and 3) prediction of agricultural drought in Chile from one to four month before the end of the growing season for 2000-2016. For the first stage, was used
Description: Tesis para optar al grado de Doctor en Ingeniería Agrícola, mención Recursos Hídricos en la Agricultura.
metadata.dc.identifier.other: 233068
Appears in Collections:Ingeniería Agrícola - Tesis Doctorado

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