Browsing by Subject "semiarid"

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    Relaciones agua-suelo-vegetación.-Assessing diffuse and concentrated recharge in average- and dry-rainfall year in a semiarid carbonate sloping aquifer, a preliminary report
    Alcalá, F.J.; Were, A.; Serrano-Ortiz, P.; Cantón, Y.; Solé, A.; Villagarcía, L.; Contreras, S.; Kowalski, A.S.; Marrero, R.; Puigdefábregas, J.; Domingo, F.; Universidad de Murcia
    ABSTRACT The chloride mass balance (CMB) method was applied in the unsaturated zone to estimate potential recharge (RT) by rainfall in two small catchments of southern mid-to-high slope of Sierra de Gádor carbonate aquifer (SE Spain), in the average hydrological year 2003-04 and the unusually dry 2004-05. Unknown fractions of diffuse (RD) and concentrated recharge (RC) into RT were firstly evaluated to fit average and lower RT thresholds for modeling further longterm recharge. Daily rainfall and actual evapotranspiration (AET) from the Eddy Covariance (EC) technique provided yearly RT of 189 mm year-1 in 2003-04 and 8 mm year-1 in 2004-05. Difference on RT among CMB method and EC technique is ~5% in year 2003-04, increasing to ~25% in year 2004-05. RD from soil-moisture field data was 65 mm year-1 (~34% of RT) in 2003-04 and negligible in 2004-05. The use of complementary methods checks low RT rates and identifies RD and RC fractions mixing in the unsaturated zone before RT reaches the regional water-table top. The results can explain long-term variations on groundwater storage and hydrochemistry and validate lower RT ~ RC yearly rates from the EC technique.
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    Relaciones agua-suelo-vegetación.-Soil fertility dynamics in a semiarid basin: impact of scale level in weighing the effect of the landscape variables
    Ruiz-Navarro, A.; Barberá, G.G; Albaladejo, J.; Universidad de Murcia
    ABSTRACT Arid and semi-arid Mediterranean soils are particularly sensitive to degradation processes, and soil fertility could play important role in restoration/conservation practices. Our objective was to study the relationships between soil and landscape at different scales in order to understand the main drivers of soil fertility on a semiarid catchment. A stratified sampling plan was carried out to take soil and landscape representative variability. Multivariate statistic techniques were used to elucidate the relationship between both. The results showed that soil fertility are positively related with density of vegetation and topographical conditions favourable to soil moisture at small scale, while negatively with topographical factors that contributed erosion dynamic on erodebility lithologies at medium and large scale.