Observational date is integral in our understanding of present climate, its natural variability and any change due to anthropogenic effects. This study incorporates a brief overview of sampling requirements using data from the first ISLSCP Field Experiment (FIFE) in 1987 which was a multidisciplinary field experiment over a 15 km grid in Konza Prairie, USA. Sampling strategies were designed for precipitation and soil moisture measurements and also detecting land cover type. It was concludes that up to 8 raingages would be needed for valuable precipitation measurements covering the whole FIFE catchment, but only one soil moisture station. Results show that as new gages or station are added to the catchment then the sampling error is reduced, but the improvement in error performance is less as the number of gages or stations increases. Sampling from remotely sensed instruments shows different results. It can be seen that the sampling error at larger resolution sizes are small due to competing error contribution from both commission and omission error.

• Chul-Sang Yoo(Division of Environmental, Ocean and Water resources Engineering Department of civil Engineering Texas A & M University Colleges Station)