The WATER (Watershed Allied Telemetry Experimental Research) experiment, which was a simultaneous airborne, satellite-borne and ground-based remote sensing experiment aiming to improve the observability, understanding, and predictability of hydrological and related ecological processes at a catchment scale, was taken place in the Heihe River Basin, China’s second largest inland river basin in 2007-2009.

　　The field campaigns of WATER (hereafter referred as WATER I) have been completed. Airborne sensors including microwave radiometers at L, K and Ka bands, imaging spectrometer, thermal imager, CCD and LIDAR were used. Various satellite data were collected. Ground measurements were carried out at various scales with the participations of more than 280 scientists and students. The goals of WATER I have been mostly achieved.

　　The WATER II has been planned in the framework of the Eco-Hydrology Science Program in the Heihe River Basin, which was initialized by the National Science Foundation of China and will be kicked off soon.

　　The overall objective of WATER II is to close the water cycle at the catchment-scale by integrating remote sensing and in-situ observations and modeling. The immediate goals are to carry out multi-scale remote sensing and ground-based experiments for observing catchment-scale water cycle and hydrological processes in different ecological regions, to build a comprehensive dataset for integrated watershed models, and to establish a watershed observing system for watershed science and integrated river basin management.

　　WATER II will be composed by a cold region experiment in the upper stream area, an oasis experiment in the middle stream area, and an arid region experiment in the down stream area.

　　The key objectives of the cold region experiment are:

　　  To improve the understanding of the cold region water cycle.

　　  To assimilate multi-scale remote sensing data in distributed hydrological models for improving  the hydrological predictability.

　　  To improve the understanding of the relationship between freeze/thaw and carbon cycle

　　Remote sensing will be used for 1)measuring/estimating of precipitation, soil moisture, evapotranspiration, snow water equivalent, and runoff, 2) mapping of snow cover extent, permafrost and seasonal frozen soil, and river ice. 

　　The key objectives of the oasis experiment are:

　　　 Flux scaling and its uncertainty quantification for heterogeneous surface

　　　 Interactions among surface water, groundwater and evaporation

　　　 Effects on water conservation from wetland and river-bank ecosystem

　　　 Ecological effects of condensation water

　　　 Influences on hydrological processes from human activities such as the land use and water resource management

　　Remote sensing will be used for 1)estimating of evapotranspiration and other components of energy balance, 2) Mapping of rivers, wetlands, and landscape; 3) monitoring of water quality. 

　　The key objectives of the arid region experiment are:

　　  Interaction between groundwater and natural oasis ecosystem

　　  Scaling of evapotranspiration

　　　 Quantification of the interactions between ecology and hydrology

　　　 Development and verification of the carbon-water coupled model

　　  The remote sensing will be used for 1) estimating of evapotranspiration, 2)measuring Forest and shrub structure parameters, 3) retrieval of carbon cycle related biogeophysical parameters.

　　  The intensive field campaign of WATER II is proposed to be carried out during the period from mid 2012 to the end of 2013, for at least one full year observations.