Thousands of refugees have been forced to hurriedly relocate with their belongings after their temporary homes near the Sudanese border became flooded this week, according to the UN High Commissioner for Refugees (UNHCR).Briefing reporters in Geneva, UNHCR spokesman Ron Redmond said convoys transferring refugees to safer camps further inside Chad had to slow down Wednesday because sandstorms reduced visibility.The annual rainy season started in early June but has only now reached the northern section of the border between Chad and Sudan, cutting off roads and making it extremely difficult for humanitarian workers to deliver aid.Mr. Redmond said many refugees this week had to walk through flooded seasonal riverbeds, carrying their belongings on their heads, to find drier ground after the heavy downpours began near the border town of Bahai.UN agencies have so far managed to transfer more than 127,000 mostly black African refugees from the Sudanese region of Darfur to nine Chadian camps that are away from the border and the threat of further raids by the Arab Janjaweed militias. About 1,000 refugees are being relocated each day. Another 50,000 people still live in makeshift shelters close to the border.Meanwhile, in Western Darfur, the World Food Programme (WFP) is planning its first airdrop of emergency supplies next week because so many roads are impassable since the rains began.In South Darfur, UN agencies and non-governmental organizations (NGOs) are concerned about a sudden rise in the number of internally displaced people (IDPs) at a camp at Kalma. There are now 70,000 residents at the camp, with more people arriving every day – compared to 30,000 at the end of last month.In a separate development, delegates from the Sudanese Government and the UN today concluded the first meeting of the Joint Implementation Mechanism (JIM) – which is designed to alleviate the humanitarian crisis and stop the fighting in Darfur.The JIM was set up to make sure Khartoum and the UN meet the pledges made in a joint communiqué signed on 3 July. That agreement included a promise by Sudan to disarm the Janjaweed, end the impunity for people committing human rights abuses and remove all obstacles to humanitarian access. The UN said it would provide urgent aid relief and play its part in any peace efforts.Jan Pronk, the Secretary-General’s Special Representative for Sudan, attended the meetings for the UN and will return to New York next week, a UN spokesperson said. The next JIM meeting is scheduled for 2 August.Negotiations have also begun in Addis Ababa, Ethiopia, where the African Union (AU) is attempting to mediate between the Sudanese Government and Darfur rebel groups, who have been fighting each other since early last year. Mohamed Sahnoun, the Secretary-General’s Special Adviser for Africa, participated in the talks.