Performance assessment of the database downscaled ocean waves (DOW) on Santa Catarina coast, South Brazil

ABSTRACT: This work presents a validation of wave parameters from the new sixty years Downscaled Ocean Waves (DOW) reanalysis database. This study compares quantiles of the Gumbel distribution of Hs (significant wave height) and Tp (peak period) from simulated data with an 11 months' time series obtained from a buoy moored seaward on the Santa Catarina coast. Analysis by means of Gumbel distribution quantiles allows more weight to be given to the highest values of the time series, which are especially important in design projects. The statistical parameters used to verify the fit between the measured and the modeled data included: RMSE, BIAS, Scatter Index and Pearson Correlation Coefficient. Mean direction (9m) validation was conducted qualitatively. The database showed good fit of the mean conditions, especially Hs which was well Reproduced by the wave model. Underestimation of Tp, related mainly to the low spatial and temporal resolution of wind data used to generate waves, highlights this general modeling problem. Based on calculated statistical parameters, DOW data were considered comparable to the values obtained by measurements; however, such data must be cautiously used for extreme events analysis and in areas of bimodal sea conditions, where major deficiencies in the database were observed.The authors are also thankful to the Brazilian government through the Ministério do Meio Ambiente (MMA) and the Agência Brasileira de Cooperação (ABC) for the financial support of this research (within the project Transference of Methodologies and Tools to Support the Brazilian Coastal Management)

Irrigation with treated wastewater affected the minor components of virgin olive oil from cv. Chemlali in Tunisia

Water limitation for agriculture is a problem in many countries and irrigation with treated wastewater (TWW) can be a tool to face the decreasing availability of water for important domestic crops such as olive. Taking into account this aspect, a research was carried out for 13 years in an olive grove (Chemlali cultivar) located in the area of Sfax (Tunisia). Two different irrigation treatments were applied: (a) irrigation with good quality water (GQW) and (b) irrigation with TWW. The main objective of this 13-year study was to verify the effects of the irrigation with TWW vs. GQW on some minor parameters of the virgin olive oil. Many oil parameters significantly increased in the TWW irrigated plot, in particular lutein, total tocopherols, squalene, campesterol and stigmasterol whereas β-carotene, α-tocopherol, δ-tocopherol, β-sitosterol and total sterols decreased with respect to the GQW treatment. Irrigation with TWW can be a possible tool to irrigate olive groves with two positive effects: saving of freshwater and production of olive oil of good quality