This 1982 book consists of papers presented at the World Climate Research Programme study conference on land surface processes held in Greenbelt, Maryland from 5 to 10 January 1981. The papers cover the following: the state of knowledge of the sensitivity of atmospheric general circulation models on hydrology and other land surface processes: assessment of the state of knowledge of numerical modelling of hydrology and other land surface processes at the scale of atmospheric general circulation models; recommendations for research activities; establishment of data requirements for initialization, validation, and parameter evaluation. This book will continue to be of interest to atmospheric scientists, soil physicists, hydrologists and climatologists.