Estimation of alluvial recharge in the semiarid

Abstract

ABSTRACT:In areas where there is irrigated agriculture, the recuperation of water reserves in alluvial aquifers may occur preferentially due to precipitation. Recharging can be evaluated from variation information of water depth measured in piezometers or observation wells. Thus, the aim of this research is to study the recharge in the alluvial aquifer formed by the Mimoso temporary stream in the semiarid region of Pernambuco (PE), Brazil, using the method of the fluctuation of the water level. This system is typical on the Brazilian Northeast semiarid region, using groundwater for domestic supply and for irrigation on small scale agriculture. Monthly potentiometric levels and rainfall data were used. The selected period for the study, from January 2002 to October 2009, involved extreme events of flooding and droughts as well as regular years, providing a better understanding of the behavior of the alluvial recharge. It was found that the system responds significantly to precipitation events. It was also observed that even with different soil textures in the study area, recharge factors were not significantly different. The study provided a better understanding of the behavior of aquifer recharge and its relationship with the soil and the rainfall events in the region.KEYWORDS: recharge factor, groundwater, monitoring. ESTIMATIVA DE RECARGA EM ALUVIÃO NO SEMIÁRIDORESUMO: Em áreas onde se pratica agricultura irrigada, a recuperação das reservas hídricas do aquífero aluvial pode ocorrer devida, preferencialmente, à precipitação. A recarga pode ser avaliada a partir de informação da variação da profundidade da água. Desta forma, o objetivo do presente trabalho é estudar a recarga no aquífero aluvial formado pelo riacho temporário do Mimoso, na região semiárida de Pernambuco, utilizando o método da flutuação do nível da água. Esse sistema é típico de sistemas do semiárido do Nordeste do Brasil, com uso da água subterrânea para abastecimento de populações difusas que residem nesses vales aluviais e para irrigação em agricultura familiar ou de pequena escala. Foram utilizados dados mensais do monitoramento dos níveis potenciométricos e dados de precipitação pluviométrica. O período selecionado, janeiro de 2002 a outubro de 2009, envolveu eventos extremos de cheia, seca e anos regulares. Foi verificado que o sistema responde significativamente a eventos de precipitação. Embora haja solos com diferentes texturas, estas não provocam diferenças significativas nos fatores de recarga do aquífero. O estudo permitiu melhor conhecimento do comportamento da recarga do aquífero aluvial e suas relações com o solo e com os eventos de chuva da região. PALAVRAS-CHAVE: fator de recarga, água subterrânea, monitoramento.

Temporal dependence of potentiometric levels and groundwater salinity in alluvial aquifer upon rainfall and evapotranspiration

“…The C 0 value was low and equal to half of the first semivariance, representative is the time variation of ETo within a month. This dispersion can be explained by soil texture and transmissivity heteroneneity (MONTEIRO; MONTENEGRO; ANDRADE et al, 2014), and significant decrease and increase of groundwater level over time affect groundwater parameters and might contribute to secondary soil salinization, surface water salinization and reduction of soil fertility (AMIRATAEE; ZEINALZADEH, 2016;ARSLAN, 2017) This dispersion could be a result of flow low dilution of salt in the unsaturated and saturated zone (MONTENEGRO, 1997), due to Loam and Sandy loam textures in alluvial valley and diffuse recharge processes which tend to be slower than infiltration due to flooding (ALMEIDA; FRISCHKORN, 2015). Figure 4 shows the temporal mapping of groundwater levels ( Figure 4A, B and C) and the average map of the monthly means levels for stable piezometers ( Figure 4D).…”

“…Nevertheless, the alluvial aquifers are strategic resources for coping with long droughts periods. Such aquifers are usually of restricted storage capacity, requiring rational explotation for their sustainability (ANDRADE et al, 2014).…”

Comparative hydrology: relationships among physical characteristics, hydrological behavior, and results of the SWAT model in different regions of Brazil (Hidrologia comparativa: relações entre características físicas, comportamento hidrológico e ....)

“…The basin is inserted in a semiarid region with annual precipitation, in average, about 700 mm. Several investigations considering groundwater recharge patterns and spatiotemporal variability of groundwater levels and salinity have been developed in the aforementioned valley (Andrade et al, 2012;Fontes Júnior et al, 2012;Andrade et al, 2014).…”

Governance of alluvial aquifers and community participation: a social-ecological systems analysis of the Brazilian semi-arid region

“…Alluvial aquifers, which are formed on the beds and banks of rivers, from the deposition of sediments carried by the action of runoff, are an important source of water in arid and semi-arid regions (Dahlin and Owen 2005;Morin et al 2009;Andrade et al 2014;Mvandaba et al 2018;Walker et al 2018) . These aquifers, although small and shallow, compose an important water system, which smallholder farmers rely on for irrigation and livestock feeding (Owen et al 1989;Mackay et al 2005;Burte et al 2011;Alves et al 2018;Rêgo 2012).…”