Earth From Space – Lake Trasimeno

Lake Trasimeno, the fourth largest lake in Italy, is featured in this week’s Earth from Space image.

Lake Trasimeno is located in central Italy, around 20 km west of Perugia, and has an area of around 128 sq km. It is shallow, with its maximum depth of approximately 6 m, although the lake’s water level varies depending on meteorological and climatic conditions.

In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark coloured waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae.

Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno. 

Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022.

Lake Trasimeno wasn’t the only Italian water body affected by drought this summer, with the Po River hitting record-lows. The Copernicus Sentinel-2 satellites capture high-resolution imagery that provides information about the conditions on Earth, such as water quality, plant life and coastal areas. 

The mountainous terrain of the Umbrian Apennine Mountains surrounds Lake Trasimeno with many agricultural fields dotted around the area. Several other smaller lakes including Lake Montepulciano, Lake Chiusi and Lake Pietrafitta, can be seen south of Lake Trasimeno. Perugia, capital of the Umbria region, is a well-known cultural and artistic centre in Italy known for its chocolate and jazz festivals.

• Download the full high-resolution image.