Evaluation of hydrology, suspended sediment and Nickel loads in a small watershed in Basque Country (Northern Spain) using eco-hydrological SWAT model

Abstract

-Suspended sediment transportation and associated pollutants from catchment to stream networks are responsible for aquatic habitat degradation, reservoir sedimentation and the transportation of sediment bound pollutants. Quantifying suspended sediment loads from lands to watercourses is essential in controlling soil erosion and in implementing appropriate mitigation practices to reduce stream sediment and associated pollutant loads, and hence improve surface water quality downstream.The main objective of this study is to evaluate the temporal variability of hydrology, sediment and nickel loads using Soil and Water Assessment Tool in Oka watershed located in north Spain. Model simulation was completed using 11 years historical records (2001-2009 for validation and 2009-2012 for calibration) of streamflow and suspended sediment concentration (SSC). Thestreamflow, SSC and sediment load estimated from the model were compared with observed data using statistical parameters, which indicates a successful simulation. The annual production of simulated sediments shows variability between 662 and 1515 t, with a mean specific yield of 33 t km x2 y x1 . The annual load of nickel simulated ranged from 32 to 72 kg, representing a mean specific of 1.63 kg km x2 year x1 . The information obtained from this research is of interest to understand long term interannual variability of suspended sediment and nickel yield.

Modeling environmental services in rivers at catchment scale

“…De Girolamo et al (2015) have tested an approach aimed at supporting the ecological quality assessment at river reach scale of intermittent streams in the Salsola and Celone river basins in south-east Italy, by using integrated hydrological modeling and analyzing the hydrological alterations due to anthropogenic pressures. Peraza-Castro et al (2015) have evaluated the temporal variability of hydrology, sediment and nickel loads using the Soil Water Assessment Tool (SWAT) in the Oka watershed (32 km 2 ), located in northern Spain in oceanic climatic conditions. Wang et al (2015) have used SWAT in a study conducted in the Shibetsu River watershed (672 km 2 ) in Hokkaido, Japan to understand the dynamics of sediment, particulate organic nitrogen (PON) and particulate organic phosphorous (POP).…”