Principles of Geographical Information Systems BURROUGH, PROFESSOR PETER A. (FORMER PROFESSOR OF PHYSICAL GEOGRAPHY AT UTRECHT UNIVERSITY, THE NETHERLANDS),MCDONNELL, RACHAEL A. (SCHOOL OF GEOGRAPHY AND THE EVIRONMENT, UNIVERSITY OF OXFORD AND INTERNATIONAL CENTER FOR BIOSALINE AGRICULTURE, DUBAI, UNITED ARAB EMIRATES),LLOYD, CHRISTOPHER D. (DEPARTMENT OF GEOGRAPHY AND PLANNING, UNIVERSITY OF LIVERPOOL, UK)