Applications of quantitative remote sensing to hydrology

In order to quantify the rates of the exchanges of energy and matter among hydrosphere, biosphere and atmosphere, quantitative description of land surface processes by means of measurements at different scales are essential. Quantitative remote sensing plays an important role in this respect. The session intended to provide a forum for scientists and engineers to report on the recent progresses in retrieval of bio-geophysical parameters, determination of land surface processes and assimilation of remotely sensed information in hydrological, meteorological and ecological models. Contributions dealing with the development of theories, techniques and applications of quantitative remote sensing supported by experimental evidence were mostly welcome. Issues related to scaling, aggregation, and heterogeneity and related techniques in temporal and spatial aspects were also welcome. Three themes were dealt with: (1) retrieval of bio-geophysical parameters which include but are not limited to albedo, emissivity, temperature, fractional vegetation coverage, leaf area index, bio-mass, etc., and retrieval of atmospheric parameters for the purpose of atmospheric correction; (2) determination of land surface processes using remotely sensed parameters, including evaporation, transpiration, soil moisture, snowmelt rate, CO2 fluxes, etc.; (3) assimilation of physical parameters and processes into hydrological, atmospheric and ecological models. The paper by W. Verhoef and H. Bach was presented as an invited paper. All others are contributions. We are grateful to the reviewers (see list of reviewers) who have provided timely reviews for the submitted papers. Our special thanks goes to Dr. Jun Wen who has helped throughout the whole reviewing and compilation process. Professor H. Savenije is thanked for his interest and encouragement in producing this special issue.