The FLASH project: improving the tools for flash flood monitoring and prediction across the United States

This study introduces the Flooded Locations and Simulated Hydrographs (FLASH) project. FLASH is the first system to generate a suite of hydrometeorological products at flash flood scale in real-time across the conterminous United States, including rainfall average recurrence intervals, ratios of rainfall to flash flood guidance, and distributed hydrologic model–based discharge forecasts. The key aspects of the system are 1) precipitation forcing from the National Severe Storms Laboratory (NSSL)’s Multi-Radar Multi-Sensor (MRMS) system, 2) a computationally efficient distributed hydrologic modeling framework with sufficient representation of physical processes for flood prediction, 3) capability to provide forecasts at all grid points covered by radars without the requirement of model calibration, and 4) an open-access development platform, product display, and verification system for testing new ideas in a real-time demonstration environment and for fostering collaborations. This study assesses the FLASH system’s ability to accurately simulate unit peak discharges over a 7-yr period in 1,643 unregulated gauged basins. The evaluation indicates that FLASH’s unit peak discharges had a linear and rank correlation of 0.64 and 0.79, respectively, and that the timing of the peak discharges has errors less than 2 h. The critical success index with FLASH was 0.38 for flood events that exceeded action stage. FLASH performance is demonstrated and evaluated for case studies, including the 2013 deadly flash flood case in Oklahoma City, Oklahoma, and the 2015 event in Houston, Texas—both of which occurred on Memorial Day weekends

CASES OF INTEGRATING THERMAL TRANSMITTANCE PROCESSES INTO VENTILATION EQUIPMENT / VĖDINIMO ĮRENGINIO ŠILUMINIO PRALAIDUMO PROCESŲ INTEGRAVIMO ATVEJAI

The paper analyzes the influence of integrating the processes taking place in the ventilation equipment of a public building on the thermal transmittance of heat exchangers. Pinch analysis helped with determining changes in the thermal transmittance of heat exchangers per year. The article examines the dependency of the thermal transmittance of heat exchangers on the disposed quantity of streams. The total thermal transmittance of heat exchangers is higher if several streams of lower parameters are used. Without additional economical calculations, the thermal transmittance of heat exchangers can assess their size, price and be used for the purposes of comparing the obtained results showing that designing such systems is useful for evaluating the possibilities of integrating the processes taking place in ventilation equipment. Santrauka Analizuojama viešosios paskirties pastato vėdinimo įrenginyje vykstančių procesų integracijos įtaka šilumokaičių šiluminiam pralaidumui. Taikant Pinch analizės metodą, nustatyta, kaip kinta šilumokaičių šiluminis pralaidumas per metus. Išnagrinėta, kaip nuo disponuojamų srautų kiekio priklauso šilumokaičių šiluminis pralaidumas. Suminis šilumokaičių šiluminis pralaidumas didesnis tada, kai naudojami keli žemesnių parametrų srautai. Pagal šilumokaičių šiluminį pralaidumą neatliekant papildomų ekonominių skaičiavimų galima įvertinti jų dydį, kainą ir palyginti skaičiavimų rezultatus. Gauti rezultatai parodė, kad projektuojant šias sistemas naudinga vertinti vėdinimo įrenginiuose vykstančių procesų integravimo galimybes. Raktiniai žodžiai: vėdinimo sistema; šilumogrąža; šilumos pralaidumas; procesų integracija; Pinch analiz