Efeitos de cenários de uso do solo sobre o regime hidríco e produção de sedimentos na bacia do Ribeirão Concórdia - SC

Abstract

RESUMO -O uso inadequado dos solos agrícolas vem causando a perda gradual da sua capacidade produtiva e a degradação dos recursos hídricos por sedimentos e poluentes. O uso do solo pode afetar os processos hidrológicos e a erosão do solo na bacia. O objetivo do trabalho foi simular diferentes cenários de uso do solo para a bacia hidrográfica do ribeirão Concórdia, utilizando o modelo SWAT, e analisar os efeitos dessas mudanças no fluxo de água e de sedimentos. Os cenários gerados foram agricultura, mata nativa e pastagem. A bacia está localizada no sul do Brasil e possui uma área de drenagem de 30,74 km 2 . Na etapa de calibração, obteve-se coeficente de eficiência Nash-Sutcliffe mensais de 0,82 para escoamento e 0,83 para sedimento. O cenário mata nativa apresentou o maior decréscimo na vazão média, em relação ao cenário atual, cerca de 8,70%. O cenário agricultura produziu a maior taxa de produção de sedimentos, aproximadamente 3 vezes maior que o cenário atual.Observou-se que alterações no uso do solo impactam o regime e a disponibilidade hídrica da bacia.Palavras-chaves: Uso do solo; Modelo SWAT; Regime hídrico. EFFECTS OF SCENARIOS OF LANDUSE ON WATER REGIME AND SEDIMENT TRANSPORT IN THE CONCÓRDIA RIVER BASIN, SC

INFLUENCE OF LAND USE CHANGE ON SEDIMENT YIELD: A CASE STUDY OF THE SUB-MIDDLE OF THE SÃO Francisco River Basin

“…Considering that the rainfall patterns has undergone no changes, surface conditions have improved the transfer process of water flow from the rains. In this same line of research, PERAZZOLI et al (2013) analyzed the effects of different land use scenarios on sediment yield in the Ribeirão Concordia River Basin, in the state of Santa Catarina (Brazil), and observed that the farming scenario showed the highest sediment production rate, being about 3 times larger than the current scenario. However, in the present study, the greatest sediment production rate was observed when replacing the grazing areas for bare soil.…”

“…Whereas the Linacre method was used in view of the availability of weather data in the other rain gauge stations within the study area. From potential evapotranspiration, actual evapotranspiration was estimated taking into account the evaporative demand of rainfall intercepted by vegetation, plant transpiration and soil evaporation (PERAZZOLI et al, 2013). Moreover, sediment yield derived from rain and runoff was estimated using the Modified Universal Soil Loss Equation (MUSLE), as follows: (2) In which, sed is the sediment yield after a rainfall event, in tons;…”

Sediment Losses in Watersheds in the Western-Center Meso-Region Rio-grandense

“…discussed the lack of planning and proper use of land in agrarian reform settlements as the preservation of natural areas, generating environmental conflict classes. For Perazzoli et al (2013) the impacts of soil use in hydrological and sediment transport conditions affect surface runoff, maximum flood flow, baseline flows, underground recharge, soil moisture and erosion and sedimentation volume. Ran et al (2012) observed that rainfall hydrologic patterns, particularly peak intensities and durations, are of high relevance affecting runoff and sediment transport.…”

Water Quality in Micro-watersheds Under Different Land Uses in the Municipality of Alegre, Espírito Santo

“…These innumerable interventions in natural cycles and their consequences have stimulated studies into water quality related to land use and occupation. Through these studies, it has been possible to observe how different soil uses interfere in differently with water quality (Perazzoli et al, 2013;Pinto et al, 2012;Vanzela et al, 2010).…”