Modal morphing on meteorological radar data for rainfall pattern analysis

Owing to their short duration and high intensity, flash floods are among the most devastating natural disasters in metropolises. The existing warning tools—flood potential maps and two-dimensional numerical models—are disadvantaged by time-consuming computation and complex model calibration. This study develops a data-driven, probabilistic rainfall-inundation model for flash-flood warnings. Applying a modified support vector machine (SVM) to limited flood information, the model provides probabilistic outputs, which are superior to the Boolean functions of the traditional rainfall-flood threshold method. The probabilistic SVM-based model is based on a data preprocessing framework that identifies the expected durations of hazardous rainfalls via rainfall pattern analysis, ensuring satisfactory training data, and optimal rainfall thresholds for validating the input/output data. The proposed model was implemented in 12 flash-flooded districts of the Xindian River. It was found that (1) hydrological rainfall pattern analysis improves the hazardous event identification (used for configuring the input layer of the SVM); (2) brief hazardous events are more critical than longer-lasting events; and (3) the SVM model exports the probability of flash flooding 1 to 3 h in advance.

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Influences of hydrological and hydrogeological conditions on debris flows in peri-vesuvian hillslopes

Natural Hazards and Earth System Science ◽

10.5194/nhess-2-27-2002 ◽

2002 ◽

Vol 2 (1/2) ◽

pp. 27-35 ◽

Cited By ~ 24

Author(s):

P. De Vita ◽

V. Piscopo

Keyword(s):

Hydraulic Conductivity ◽

Debris Flows ◽

Pattern Analysis ◽

Rainfall Pattern ◽

Soil Stability ◽

Strong Variation ◽

Hydraulic Flow ◽

Water Tables ◽

The Stability ◽

Pyroclastic Soil

Abstract. The paper illustrates some results of research carried out to assess factors triggering debris flows which involve the pyroclastic overburdens covering carbonate mountains around Vesuvius. The aims of the research were to reconstruct a relationship between rainfall and debris flow occurrence and to highlight empirical hydrological thresholds through rainfall pattern analysis. The research was also aimed at investigating hydrogeological features of a pyroclastic cover-carbonate bedrock system to analyse factors inducing temporary hydraulic flow, critical for pyroclastic soil stability. The results of research are the following: i) rainfall pattern highlights empirical hydrological thresholds that differentiate the Lattari and Salerno Mountains from the Sarno Mountains; ii) in some sample areas of the Sarno Mountains close to the trigger zones of the landslides of May 1998 strong variation in hydraulic conductivity has been found in the first few meters below the surface; iii) these permeability variations would seem to justify temporary perched water tables that might affect the stability of the pyroclastic mantle.

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Interpretation procedure of meteorological radar data for propagation application in heavy rain region

2014 International Symposium on Antennas and Propagation Conference Proceedings ◽

10.1109/isanp.2014.7026783 ◽

2014 ◽

Author(s):

Hong Yin Lam ◽

Jafri Din ◽

Siat Ling Jong

Keyword(s):

Heavy Rain ◽

Radar Data ◽

Meteorological Radar

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