GALVESTON, Texas — A few hundred holdouts could be forced to leave a barrier island that was leveled by Hurricane Ike, as President Bush surveyed the damage by helicopter and urged Americans to donate money to victims.

The giant storm has been blamed for the deaths of 47 people since hitting the American Gulf Coast over the weekend. It stranded more than 30,000 evacuees in shelters and left about 2 million Texans without power. The storm earlier claimed more than 80 lives in the Caribbean.

Areas such as the resort barrier island of Bolivar Peninsula, just east of Galveston, were almost completely wiped out. Authorities say holdouts there will be required to leave in the next few days, and they are prepared to impose martial law if needed to empty the barrier island.

Mr. Bush, who drew scorn for his handling of Hurricane Katrina, which killed 1,600 people in 2005, warned against letting “disaster fatigue” slow donations when the need remains great.

Mr. Bush took an aerial tour of the damage, with his helicopter flying low along the Texas coastline. From the air, he could see homes left with only foundations, roofs torn from buildings, and roads, and beaches strewn with debris.

The president’s next stop was the island of Galveston, which was torn apart when Ike made landfall on Saturday as a Category 2 storm with 110 mph winds. After a quick briefing in Galveston, Mr. Bush was leaving Texas, after spending less than three hours in the region.

On the Bolivar Peninsula, Galveston County Judge Jim Yarbrough, the county’s top elected official, said there is a “hardy bunch” of roughly 250 people still trying to live there, including some “old timers who aren’t going to want to leave.”