A local resident stumbles as he wades through flood water on a residential street in Carlisle, Britain December 6, 2015. British police have declared a major incident in northern England after prolonged heavy rain caused widespread flooding and forced emergency services to evacuate residents from their homes. (Photo by Phil Noble/Reuters)

When he's driving, New York-based painter Gregory Thielker takes in the views that change from moment to moment: the road, the sky, other cars. “Inside the car it's easy to forget the outside temperature, humidity, the noise of the road”, he says. “But something happens when rain interrupts the view: the lens through which we are seeing is revealed. Water both obscures and highlights the landscape”. Gregory Thielker's exhibition “Between here and now” will be at Castor Gallery in lower Manhattan from early March. Here: “Complete Stop”. (Painting by Gregory Thielker)

Two men help each other cross a street covered in deep mud in Copiapo, Chile, Thursday, March 26, 2015. Unusually heavy thunder storms and torrential rains that began on Tuesday have blocked roads, caused power outages and affected some 600 people on this normally dry region. (Photo by Aton Chile/Marcelo Hernandez/AP Photo)

Ban Gioc – Detian Falls are two waterfalls on the Quây Sơn River, in Chinese Guichun River, straddling the Sino-Vietnamese border, located in the Karst hills of Daxin County, Guangxi (Chinese side), and in Trùng Khánh District, Cao Bằng province on the Vietnamese side, 272 km (169 mi) north of Hanoi. In Vietnamese, the two falls are considered as two parts of one waterfall with the sole name Bản Giốc. The two parts are called as: thác chính (Main waterfall) and thác phụ (Subordinate waterfall). Chinese texts sometimes name both falls from the Détiān falls on the Chinese side. During the summer rains the two waterfalls may join together.

A man driving a vintage car reacts as he passes by crabs crossing a highway on their way to spawn in the sea in Playa Giron, Cuba on April 25, 2017. Each year, after the first spring rains, millions of red, yellow and black landcrabs march for days from the surrounding forests to the bay on Cuba's southern coast to spawn in the sea. (Photo by Alexandre Meneghini/Reuters)

Tim Laman is a field biologist and wildlife photojournalist. His pioneering research in the rain forest canopy in Borneo led to a PhD from Harvard and his first National Geographic article in 1997. Since then, he has pursued his passion for exploring wild places and documenting little-known and endangered wildlife by becoming a regular contributor to National Geographic. He has eighteen articles to his credit to date, all of which have had a conservation message. Some have focused on endangered species such as Orangutans or Hornbills, while others, such as a series of articles on Conservation International’s Biodiversity Hotspots, have highlighted regions under intense pressure.

A cenote is a natural phenomenon, a sinkhole in the Earth’s surface. The Yucatan Peninsula in Mexico has an estimated 7,000 cenotes because it is primarily made up of porous limestone. For millions of years, rainfall slowly ate away at the limestone and a huge system of underground caves and caverns was formed. Many filled with water from rain or from the underground water table. When the roof of a water filled cave collapses, a cenote is born. The water found in a cenote may be fresh water, salt water, or both. Structurally it may be completely open, like a lake, almost completely closed with just a small opening at the top, or somewhere in between.

The sign above the door of restaurant and hotel “Am Paulusbogen” is partially submerged in the flooded centre of the Bavarian town of Passau, about 200 km (124 miles) north-east of Munich June 3, 2013. (Photo by Michaela Rehle/Reuters)