Areal rainfall estimation using moving cars as rain gauges - A modelling study
Creators: name: Haberlandt, Uwe
name: Sester, Monika
Publisher: name: Göttingen : Copernicus GmbH
Year: 2010
Subjects: subject: Accuracy level
subject: Different scale
subject: Discrete numbers
subject: Dynamic network
subject: Germany
subject: Harz mountains
subject: High-time resolution
subject: Hydrological modelling
subject: Indicator kriging
subject: Memory chips
subject: Modelling studies
subject: New approaches
subject: Ordinary kriging
subject: Point data
subject: Radar data
subject: Radar observations
subject: Rain gauge networks
subject: Rain gauges
subject: Rainfall data
subject: Rainfall estimations
subject: Rainfall fields
subject: Rainfall rates
subject: Research questions
subject: River basins
subject: Spatial assessment
subject: Time step
subject: Traffic model
subject: Estimation
subject: Gages
subject: Interpolation
subject: Meteorological instruments
subject: Optimization
subject: Radar
subject: Rain gages
subject: Sensors
subject: Watersheds
subject: Rain
subject: accuracy assessment
subject: automobile
subject: data set
subject: GPS
subject: interpolation
subject: kriging
subject: optimization
subject: precipitation (climatology)
subject: radar
subject: rainfall-runoff modeling
subject: raingauge
subject: river basin
subject: sensor
subject: spatial analysis
subject: Harz Mountains
subject: Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften
subject: Dewey Decimal Classification::500 | Naturwissenschaften::551 | Geologie, Hydrologie, Meteorologie

description: Optimal spatial assessment of short-time step precipitation for hydrological modelling is still an important research question considering the poor observation networks for high time resolution data. The main objective of this paper is to present a new approach for rainfall observation. The idea is to consider motorcars as moving rain gauges with windscreen wipers as sensors to detect precipitation. This idea is easily technically feasible if the cars are provided with GPS and a small memory chip for recording the coordinates, car speed and wiper frequency. This study explores theoretically the benefits of such an approach. For that a valid relationship between wiper speed and rainfall rate considering uncertainty was assumed here. A simple traffic model is applied to generate motorcars on roads in a river basin. Radar data are used as reference rainfall fields. Rainfall from these fields is sampled with a conventional rain gauge network and with several dynamic networks consisting of moving motorcars, using different assumptions such as accuracy levels for measurements and sensor equipment rates for the car networks. Those observed point rainfall data from the different networks are then used to calculate areal rainfall for different scales. Ordinary kriging and indicator kriging are applied for interpolation of the point data with the latter considering uncertain rainfall observation by cars e.g. according to a discrete number of windscreen wiper operation classes. The results are compared with the values from the radar observations. The study is carried out for the 3300 km 2 Bode river basin located in the Harz Mountains in Northern Germany. The results show, that the idea is theoretically feasible and motivate practical experiments. Only a small portion of the cars needed to be equipped with sensors for sufficient areal rainfall estimation. Regarding the required sensitivity of the potential rain sensors in cars it could be shown, that often a few classes for rainfall observation are enough for satisfactory areal rainfall estimation. The findings of the study suggest also a revisiting of the rain gauge network optimisation problem.