BEIJING, Oct. 30 (Xinhua) -- The State Administration of Cultural Heritage (SACH) is organizing a large-scale investigation into the length of the Great Wall, said a cultural heritage official on Monday.

    "The thorough investigation will be completed in two or three years. We will use remote sensing, aviation and information technology. Scientific analysis allows us to grasp the current condition of the Great Wall and update the current regulations on its protection," Tong Mingkang, vice director of the SACH, said at www.gov.cn, the government portal website, on Monday morning, answering netizens' questions on-line.

    Tong said SACH is in charge of the investigation and the provincial governments along the Great Wall will be responsible for carrying it out.

    "Since 1980s, some local governments have conducted many surveys on the Great Wall, gaining a general view of the ancient cultural heritage," Tong said, noting that a large portion of the Great Wall is not under proper protection because of the lack of the information.

    It's imperative to hold such a large-scale investigation in order to build up a scientific and integral record for the Great Wall, he said.

    The Great Wall is a unique historical site that meanders thousands of miles, passing through a dozen of provinces, municipalities and autonomous regions. A large portion of the Great Wall is located in poor and remote areas where few people reside.