ABU SHOUK CAMP, Sudan — Water wells at this giant Darfur refugee camp are drying up.

Women wait as long as three days for water, using jerrycans to save their places in perpetual lines that snake around pumps. A year ago, residents could fill a five-gallon plastic can in a few minutes, but lately the flow is so slow it takes half an hour.

“The water is running out,” said Mariam Ahmed Mohammed, 35, sweating at the pump with an infant strapped to her back. “As soon as I fill one jerrycan, I put another at the back of the line.”

Water isn’t the only endangered resource. Forests were chopped down long ago, and the roots were dug up for firewood. Thousands of displaced families are living atop prime agricultural land, preventing farmers from growing food.

As the Darfur conflict approaches its fifth year, the environmental strain of the world’s largest displacement crisis is quickly depleting western Sudan’s already-scarce natural resources. Experts say the situation is exacerbating chronic shortages of land and water that contributed to the fighting in the first place.

“There is a massive resource problem in Darfur,” said environmentalist Muawia Shaddad, head of the Sudanese Environment Conservation Society. “We’ve been shouting about this for years, but no one listened.”

In the struggle to bring peace to Darfur, 200,000 people have died and 2.5 million have been displaced. Questions about dwindling natural resources have largely been brushed aside as emergency efforts have focused on saving lives and feeding the hungry.

But with reports bubbling up from Darfur camps about water shortages, overstressed land and increasing deforestation, aid workers and Sudanese activists say finding long-term solutions to the region’s environmental woes is just as crucial as restoring security and reaching a political compromise.

“The clashes could all stop tomorrow, and we won’t have moved any closer to solving the real problems of Darfur, which I think come down to the environment,” said Cate Steains, acting head of U.N. humanitarian operations in El Fasher, capital of the region’s northern province.

For decades, western Sudan has grappled with climatic changes, particularly in northern Darfur, which lies along the edge of the encroaching Sahara.

Over the past 50 years, annual rainfall in El Fasher has been down 34 percent, turning millions of acres of grazing land into desert, a recent United Nations Environment Program study found.

Tree coverage in Darfur has dropped as low as 18 percent, from 48 percent in 1956, Sudanese forestry researcher Kamil Shawgi said. During the same period, the population of the region — a territory one-quarter the size of California — swelled fivefold to 6.5 million; the number of grazing animals increased from 30 million to 130 million.

For generations, Darfur’s farmers and herders managed to share the land. Clashes were settled through tribal mediation. But after unprecedented droughts in the 1970s and 1980s, Darfurians found it more difficult to occupy the same space.

The Sudanese government is accused of exploiting these tensions. After Darfur rebels attacked government facilities and personnel in 2003, officials in Khartoum, the Sudanese capital, allegedly responded by arming herders, mostly members of Arab tribes, and allowing them to attack farming villages believed loyal to the rebels. The Arab militias, known as janjaweed, were promised they could keep land as part of the bargain, U.S. and U.N. officials say.

The U.S. government has described the ethnically charged conflict as “genocide.” But at its root, many say, Darfur also is a resource-based conflict, fueled by competition for land and water amid a changing climate. With its fragile ecology and political instability, Africa should brace for more such clashes, experts say. “What we’re seeing in Darfur could happen in many other places,” said Shaddad, the conservation-society chief.

Abu Shouk, long viewed as one of the best-planned and well-equipped camps in Darfur, could become one of the first environmental casualties. If engineers don’t find a solution to the water shortage, Abu Shouk might be abandoned, forcing a costly and traumatic second displacement for the 54,000 people here.

Haydar Nasser, head of UNICEF’s El Fasher office, which helps provide water to the camp, said three of the 33 wells at Abu Shouk are completely dry, and nine are losing production.

Part of the problem, experts say, is that no one is monitoring how much water residents take. It was assumed that each person would use about four gallons a day, but average consumption is six gallons, and some residents take 15.

Water is intended to be used for drinking and washing, but as the conflict drags on, residents are using it to generate income. Some are filling up donkey-drawn steel drums with free water from Abu Shouk and selling it in El Fasher, according to a recent report by Tearfund, a British-based Christian relief group. Even more ends up poured into dirt pits to create mud for a booming brickmaking enterprise.

The presence of more than 12,000 aid workers and 7,000 African Union peacekeepers in Darfur is adding to the strain because foreigners tend to use four times as much water as locals. Finding enough water for the 26,000-member U.N. peacekeeping force approved this summer will be yet another drain.

Hoping to offer a solution to the water shortage, a U.S. scientist recently said he had detected a vast underground lake in northern Darfur. Sudanese scientists say they already knew about the underground water; the problem is finding the money and political will to drill for it.