The Adda River in Brivio, a town near Imbersago, Italy on April 18, 2023. This month, the government established a task force to tackle the scarcity of rainfall, which has also hit the Adda, where swans glide on water so low that islands have emerged, rowboats are beached and the last of what the town calls “Leonardesque” ferries has become a stationary landmark. (Alessandro Grassani/The New York Times).