Commercial microwave links in urban rainfall-runoff modelling: Two different approaches to removing the bias

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F20%3A00341797" target="_blank" >RIV/68407700:21110/20:00341797 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.5194/egusphere-egu2020-9384" target="_blank" >https://doi.org/10.5194/egusphere-egu2020-9384</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5194/egusphere-egu2020-9384" target="_blank" >10.5194/egusphere-egu2020-9384</a>

Result language

angličtina

Original language name

Commercial microwave links in urban rainfall-runoff modelling: Two different approaches to removing the bias

Original language description

Commercial microwave links (CMLs) are point-to-point radio connections widely used as cellular backhaul and thus very well covering urbanized areas. They can provide path-integrated quantitative precipitation estimates (QPEs) as they operate at frequencies where radio wave attenuation caused by raindrops is almost proportional to rainfall intensity. We demonstrated the feasibility of using CML QPEs to predict rainfall-runoff in a small urban catchment. Unfortunately, runoff volumes were highly biased, mostly for QPEs from short CMLs, although the temporal runoff dynamics were predicted very well, especially during heavy rainfall events. Current understanding is that the bias in CML QPEs is often caused by imprecise estimation of wet antenna attenuation (WAA), which is a complex process influenced by many physical phenomena, including radome hardware or positioning of the outdoor unit. However, traditional WAA estimation methods are typically unable to take into account all the individual-level factors. We proposed to estimate WAA separately for each of the examined CMLs by using discharge measurements at the outlet of a small urban catchment. In the presented study, we evaluate the effect of the method we proposed (method i) in more detail and compare it to the method of Fencl et al. (2017) (method ii). For a case study in Prague, a calibrated rainfall-runoff model is used to predict discharges at the outlet of the small urban catchment (1.3 km2) using QPEs from 16 CMLs. First results confirm that minimizing the bias in CML QPEs using method i is convenient mainly for heavy rainfalls. Moreover, method i preserves the information about the rainfall temporal dynamics during heavy rainfalls better than method ii for most of the individual CMLs (correlation coefficient with observed runoffs on average 0.83 for method i and 0.78 for method ii).

Czech name

—

Czech description

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Type

O - Miscellaneous

CEP classification

—

OECD FORD branch

10501 - Hydrology

Project

<a href="/en/project/GC20-14151J" target="_blank" >GC20-14151J: Spatial rainfall estimates using improved observations from commercial microwave links and statistical data fusion (SpraiLINK)</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů