As Floods Ravage Sudan, Young Volunteers Revive a Tradition of Aid Men built a barrier to protect their houses from rising water in Khartoum, Sudan, this week. More than 300,000 people have been directly affected by the flooding, and dozens have died. KHARTOUM, Sudan - Their temporary headquarters are a beehive of young volunteers buzzing in and out of rooms, up and down stairs, carrying bags of donated food, medicine and large packets of plastic sheets. "What happened to your house?" one volunteer asks on the phone, as others load aid on trucks or create maps and charts on laptops. And where do you say you are? We'll have a team out there soon. They are the members of Nafeer, a volunteer, youth-led initiative that responded swiftly to the humanitarian crisis caused by heavy rains and flash floods that struck Sudan this month. The deluge has taken a heavy toll. Beyond the dozens of people killed, more than 300,000 people have been directly affected, with 74,000 homes damaged or destroyed, according to the United Nations. The spread of diseases like malaria is also reported to be on the rise. The impact of the heavy rains and floods has been felt in most of Sudan, including the camps for displaced people in the war-torn region of Darfur. In one case, six United Nations peacekeepers were swept away by a current. Four are still missing. But the area around Khartoum, the capital, suffered the hardest blow. More rain is expected, and as the Nile and the Blue Nile rise to record levels, many fear the worst is yet to come. "We saw that the heavy rains and floods were going to impact the lives of many, and we felt we had a social responsibility to help people," said Muhammad Hamd, 28, a Nafeer spokesman. The idea came out of a discussion on Facebook among friends. A "nafeer" is a Sudanese social tradition that comes from an Arabic word meaning "a call to mobilize." The group's formation was all the more important because the Sudanese government was slow to respond, some critics say. "It was a weak response," said Khalid Eltigani, the executive editor of Ilaf, a weekly newspaper. The Nafeer youth broke the silence on the flood situation. Government officials said that the level of rain this year had surpassed their expectations, but they maintained that matters were under control. "There is no need to declare a state of emergency," said Sudan's interior minister, Ibrahim Mahmoud Hamid. Mark Cutts, the head of the United Nations Office for the Coordination of Humanitarian Affairs in Sudan, described the situation as a "huge disaster," which his agency called the worst floods in 25 years. Aid has arrived from United Nations agencies, Qatar, the United States, Japan, Egypt, Ethiopia and others. The rainy season started late this year in Sudan, but when it arrived, it came with a vengeance. "We can attribute this to climate change," said Nagmeldin Elhassan of the Higher Council for Environment and Natural Resources, a government agency. Mr. Elhassan, who has contributed to reports by the Intergovernmental Panel on Climate Change, referred to studies that predicted what he called "incidents of frequent and intense droughts and incidents of high levels of rains" in the region and "shifts in rain patterns," like later start dates of the rainy season. Poor urban planning, however, may have also contributed to the immense damage caused by flash flooding, especially around Khartoum. "Khartoum is in a shallow basin that will always be prone to flooding," said Howard Bell of the United Nations Environment Program in Sudan, "and urban areas should be planned accordingly." Over 5,000 volunteers have registered to help with the Nafeer campaign, organizers said. At the hot line desk, volunteers work in two-hour shifts, receiving emergency calls, 24 hours a day. Hundreds of Sudanese living abroad have joined the Nafeer campaign, with hot lines set up to receive donations in Qatar, the United Arab Emirates, Saudi Arabia, the United States, Canada, Australia and other countries. At the hot line desk in Khartoum, volunteers are glued to their cellphones. "The phones don't stop," said Wafa Tawfig, 16, a student volunteer. People call for food, sheets and covers. After receiving calls, Nafeer sends out assessment teams to evaluate the needs of different areas. The next day, a team goes back with whatever aid it can offer.