Simulating stream flow over data sparse areas – an application of internet based data

Abstract. Many hydrological modeling studies suffer from lack of robust station observed data, mainly rainfall and discharge. Where such a dearth of data exists, detailed modeling studies in estimating and assessing change in water resources become difficult when models cannot be compared against recorded observations. In addition, some river basins exist along trans-boundaries of two or more countries that problems in data sharing among them add to the difficulties in such modeling studies. Nevertheless, with the advancement in the global internet resources, access to such data has become easy. Whether such internet based data are good substitutes for station data can be ascertained only after performing some modeling research. To this end, this paper describes a hydrological modeling study that simulates the river flow of the Da River across the trans-boundary regions of China and Vietnam over a 11 yr period from 1971 to 1982. Globally available observation data used in this study include topography (from SRTM – Shuttle Radar Topography Mission), land use (from GLCC – Global Land Cover Characterization), soil (from FAO – Food and Agriculture Organization), precipitation (from APHRODITE – Asian Precipitation Highly Resolved Observational Data Integration Towards the Evaluation) and temperature (from GHCN2 – modified of Global Historical Climatology Network version 2). The study employs a hydrological model to recreate the natural flow without dam(s) built across the main river channel. The results of the study are promising and provide a wide scope to utilize internet based data for further research. This also has implications in the context of climate change applications.