Hydrological modeling applications of high resolution rain radar
Annual Conference
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In many hydrological modelling applications it is considered advantageous to measure, in real time, the state of catchments and make predictions about future outflows. Precipitation data is typically fed into hydrological models from sparse gauge networks, or from just a single gauge.
An alternative to a rain gauge network is high resolution rain radar. In this paper we present results from a field campaign using our mobile X-band high resolution rain radar to image the spatial and temporal distribution of rain down to 300 m resolution over a small catchment. The project was sponsored by Mighty River Power and focused on sub-catchments of the Waikato River.
The radar data agrees well with rain gauge measurement on a point wise basis, but provides much wider coverage. The demonstrable spatial and temporal heterogeneities in real rain fields preclude the use of sparse rain-gauge networks for measurement of areal rainfall. An unmanageable number of gauges would be required to approach measurements made with radar remote sensing.
The response of a simple hydrological model to high resolution rain radar data is compared to that of rain gauge measurements.
The utility of such data in real time operations is being investigated.