Sensitivity of IDF Curves to Rainfall Gauge Type

The primary objectives of the study was to evaluate the effect of using tipping bucket rain gauges of different types of computing Intensity-Duration-Frequency Curves. Data were used from two tipping bucket rain gauges installed in an upstream sub basin of Numan catchment in Saudi Arabia. With the help of the probability distribution of Gumbel. Records of gauges for the period 2006–2017 were used to develop IDF curves. Comparison of the resulting IDF curves indicated that the Hydrological Services (HS) gauge produced IDF curves with higher rainfall intensities compared to the Texas Electronics (TEMM) gauge. This can be ascribed to fact that the HS gauge are fitted with a siphon tube which decreases undercatchment in the course of intense rainfall events.