The Alviela is a small river born near Alcanena and flows into the Tagus in Vale de Figueira, Santarem. The region crossed by the river is limestone. Rainwater quickly infiltrates the soil and forms underground lakes and rivers, which rise to the surface at certain points, giving rise to surface rivers such as the Alviela.

The climate is of the Mediterranean type, with hot summers, relatively mild winters, infrequent but torrential rains, and many sunny days a year. On the banks of the Alviela, we find riverside trees, such as ash trees, without leaves in winter but with superb green foliage in summer.

Walking along the banks of the Alviela a few days ago, on a morning with a clear sky and bright sun, I was fascinated by the contrast of sun and shadows, the green of the foliage and the blue reflections of the sky in the water, and the extraordinary roots of the trees, fixing them solidly in the soil and not letting them be carried away by the powerful river currents in winter.

I put myself in the water with the Hasselblad X1D mounted on a tripod and used a neutral density filter and a low shutter speed (1/2 second). I obtained this image with the trunks and roots of the trees very sharp and focused, and the current of the river flowing, contrasting the strength of the roots and the longevity of the trees with the transience of the river water, always in current, always new and different.