This paper discussed national and external some researches of late years in remote sensing application to the estimation of surface water resources and the calculation and forecast of flood. The application of remote sensing to surface water resources is mainly the calculation of annual runoff

which includes methods of multielement statistic and water balance. There are methods of geomorpho-climatic unit hydrograph model

rational model

and infiltration model in the application to the calculation and forecast of flood. Mathematic deduction of these models is not concerned in this paper

and on the basis of principle of the model stated

extracting characteristic information close related to runoff

which comes from the characteristics of ground surface in basin and of geometric shape in river network analysed by remotely sensed data

is mainly discussed

and the characteristics extracted are taken for input parameters of model. Examples are given for each method

which expersses that it is able ont only to increase the precision of hydrologic calculation and also to make up deficiency existed in current hydrologic models. Therefore

these methods can be of great value to hydrologic calculation in the areas of lack data.