Avaliação de impactos de mudanças climáticas sobre a agricultura e os recursos hídricos na bacia do alto paranapanema, são paulo: um enfoque de dinâmica de sistemas
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Data
2022-11-04
Autores
Gonzalez, Alba Maria Guadalupe Orellana
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Universidade Estadual Paulista (Unesp)
Resumo
Esta pesquisa teve o objetivo de formular um modelo geral utilizando a metodologia de Dinâmica de Sistemas e o software STELLA, composto por submodelos específicos, para avaliar os impactos causados por mudanças climáticas globais, manifestadas em alterações na pluviosidade, sobre a agricultura irrigada e os recursos hídricos na Bacia Hidrográfica do Alto Paranapanema (BH do ALPA), SP. O processo de desenvolvimento do modelo foi dividido em três etapas: conceitualização, formalização e simulação. Na última etapa foram efetuadas a avaliação, exploração e simulações de diferentes cenários divididos em dois grupos: a) cenários de referência ou tendenciais (BaU) no período de 2016 até 2070, elaborados sem incorporar alterações provocadas pelas mudanças climáticas globais (MCG); b) cenários em que foram incorporados os efeitos das MCG no nível médio da precipitação na BH do ALPA, o que permitiu a avaliação comparativa dos impactos. No modelo geral da Bacia Hidrográfica do Alto do Paranapanema (MGBALPA), foram gerados 10 submodelos divididos em três grupos principais: de demanda, de oferta e aqueles que realizam cálculos específicos para simular os diferentes elementos estudados. Para avaliar os resultados, foram utilizados os Índices de Falkenmark, Keller e o Índice de Sustentabilidade de Xu. Nos cenários Business as Usual (BaU) os três índices avaliados indicam que existe na BH do ALPA uma oferta adequada de água que permite satisfazer a demanda da população (Índice de Falkenmark). Quanto ao uso de água, o Índice de Keller mostra que dentro das fases de desenvolvimento, a bacia do ALPA está na Fase de Exploração, estágio I e II, usando até 60% da água disponível, sendo considerada uma bacia aberta. Por outro lado, segundo o Índice de Sustentabilidade, o sistema de recursos hídricos da bacia não apresenta situações de estresse ou vulnerabilidade. Os resultados do cenário combinado que incorpora variações nas precipitações, na taxa de crescimento das terras irrigadas e na vazão ecológica, mostram, de forma geral, uma deterioração nos três índices, indicando que essas variações combinadas afetam a disponibilidade de água para a população, tornando a bacia do ALPA um sistema fechado e indicando uma sobre- explotação da oferta de água disponível.
This research aimed to formulate a general model using System Dynamics methodology and STELLA software, composed of specific sub-models, to assess the impacts caused by global climate change, manifested in changes in rainfall, on irrigated agriculture and water resources in the Upper Paranapanema Watershed (ALPA Watershed), SP. The model development process was divided into three stages: conceptualization, formalization, and simulation. In this last stage, the evaluation, exploration, and simulations of different scenarios, divided into two groups, were performed. In group A, the reference or trend scenarios (BaU) in the period from 2016 to 2070 were elaborated without incorporating changes caused by global climate change (GCC) while in the scenarios of group B, the effects of GCC on the average level of precipitation in the ALPA B were incorporated, which allowed the comparative evaluation of the impacts. In the general model of the Upper Paranapanema Watershed (MGBALPA), 10 submodels were generated, divided into three main groups: demand, supply, and those that perform specific calculations to simulate the different elements studied. To evaluate the results, the Falkenmark, Keller, and Xu Sustainability Index were used. In the Business as Usual (BaU) scenarios, the three indices evaluated indicate that there is an adequate supply of water in the ALPA basin to satisfy the demand of the population (Falkenmark Index). As for water use, the Keller Index shows that within the development phases, the ALPA basin is in the Exploration Phase, stage I and II, using up to 60% of the available water, being considered an open basin. On the other hand, according to the Sustainability Index, the basin's water resources system does not present situations of stress or vulnerability. The results of the combined scenario that incorporates variations in precipitation, the growth rate of irrigated land, and the ecological flow show, in general, a deterioration in the three indices, indicating that these combined variations affect the availability of water for the population, making the ALPA basin a closed system and indicating an overexploitation of the available water supply.
This research aimed to formulate a general model using System Dynamics methodology and STELLA software, composed of specific sub-models, to assess the impacts caused by global climate change, manifested in changes in rainfall, on irrigated agriculture and water resources in the Upper Paranapanema Watershed (ALPA Watershed), SP. The model development process was divided into three stages: conceptualization, formalization, and simulation. In this last stage, the evaluation, exploration, and simulations of different scenarios, divided into two groups, were performed. In group A, the reference or trend scenarios (BaU) in the period from 2016 to 2070 were elaborated without incorporating changes caused by global climate change (GCC) while in the scenarios of group B, the effects of GCC on the average level of precipitation in the ALPA B were incorporated, which allowed the comparative evaluation of the impacts. In the general model of the Upper Paranapanema Watershed (MGBALPA), 10 submodels were generated, divided into three main groups: demand, supply, and those that perform specific calculations to simulate the different elements studied. To evaluate the results, the Falkenmark, Keller, and Xu Sustainability Index were used. In the Business as Usual (BaU) scenarios, the three indices evaluated indicate that there is an adequate supply of water in the ALPA basin to satisfy the demand of the population (Falkenmark Index). As for water use, the Keller Index shows that within the development phases, the ALPA basin is in the Exploration Phase, stage I and II, using up to 60% of the available water, being considered an open basin. On the other hand, according to the Sustainability Index, the basin's water resources system does not present situations of stress or vulnerability. The results of the combined scenario that incorporates variations in precipitation, the growth rate of irrigated land, and the ecological flow show, in general, a deterioration in the three indices, indicating that these combined variations affect the availability of water for the population, making the ALPA basin a closed system and indicating an overexploitation of the available water supply.
Descrição
Palavras-chave
balanço hídrico, impactos climáticos, pensamento sistêmico, STELLA, gestão de recursos hídricos, water balance, climate Impacts, systems thinking, water resources management