Research and application of the mathematical model for extreme weather event in coastal urban areas

Extreme weather event simulation in coastal urban areas is more complex and difficult due to their special geography and climate characteristics, different kinds of land uses, close-packed buildings, and large amounts of flood control works and drainage systems. Urban Flood Simulation Model (UFSM) was integrated in this study to simulate the extreme weather events in the Pudong flood protection area (Shanghai, China). The model is established based on two-dimensional unsteady flow theory and nonstructural and irregular mesh technique. A method based on one-dimensional unsteady flow theory is proposed to deal with small-scale river and road. The calculation of the pumping stations, the water gates is indicated based on the real scheduling discipline. The extreme weather event scenarios (typhoon+rainstorm+ astronomical high tide + upstream flood) are simulated. The results show that the flood risk is higher in the coastal area and the upstream of the Huangpu Rive, and UFSM is a suitable method for simulating the flood inundation of coastal urban areas

Assessment of weather research and forecasting (WRF) physical schemes parameterization to predict moderate to extreme rainfall in poorly gauged basin

Incomplete hydro-meteorological data and insufficient rainfall gauges have caused difficulties in establishing a reliable flood forecasting system. This study attempted to adopt the remotely sensed hydro-meteorological data as an alternative to the incomplete observed rainfall data in the poorly gauged Kuantan River Basin (KRB), the main city at the east coast of Peninsula Malaysia. Performance of Weather Research and Forecasting (WRF) schemes’ combinations, including eight microphysics (MP) and six cumulus, were evaluated to determine the most suitable combination of WRF MPCU in simulating rainfall over KRB. All the obtained results were validated against observed moderate to extreme rainfall events. Among all, the combination scheme Stony Brook University and Betts–Miller–Janjic (SBUBMJ) was found to be the most suitable to capture both spatial and temporal rainfall, with average percentage error of about ±17.5% to ±25.2% for heavy and moderate rainfall. However, the estimated PE ranges of −58.1% to 68.2% resulted in uncertainty while simulating extreme rainfall events, requiring more simulation tests for the schemes’ combinations using different boundary layer conditions and domain configurations. Findings also indicate that for the region where hydro-meteorological data are limited, WRF, as an alternative approach, can be used to achieve more sustainable water resource management and reliable hydrological forecasting

La ciudad perdida vs la ciudad ganada : transformación de los barrios de promoción oficial

En la década de los 40 del siglo XX se inició en España un cambio de modelo económico y social que afectó de forma directa al crecimiento de la ciudad. Los Barrios de Promoción Oficial fueron la solución al problema de la vivienda en España, sin embargo, la ciudad ha evolucionado desde entonces y la sustitución de algunos de estos barrios ha sido inevitable. Esta sustitución no siempre ha respondido de forma adecuada ante los problemas que había presentes en el barrio. Tras un análisis de algunos de los Barrios de Promoción Oficial que se sustituyeron, se eligieron dos que por su escala, su adecuada circunscripción y su patente mejoría o manifiesto empeoramiento, eran adecuados para un estudio más en profundidad. Con el fin de definir qué criterios se han de seguir para que un barrio sea o no de buena calidad desde el punto de vista urbanístico, se analizaron tanto los barrios originales como los actuales. Basándose en el estudio, se definieron los criterios para una buena actuación: un buen tratamiento de la morfología urbana y el viario para dotar de estructura al barrio; la alternancia de la tipología con el fin de jerarquizar la estructura urbana y de aportar un ritmo claro al barrio; un adecuado tratamiento de los espacios libres, con atención a la vegetación, acompañando al viario o agrupada en jardines

Investigation on the effect of estuary shape in propagating salinity intrusion

For one-dimensional salt intrusion models to be predictive, we need predictive equations to link model parameters to observable hydraulic and geometric variables. The onedimensional model of Savenije (1993b) made use of predictive equations for the Van der Burgh Coefficient K and the dispersion at the seaward boundary D0. Here we have improved these equations by using an expanded database, including new previously unsurveyed estuaries. Furthermore, we derived a revised predictive equation for the dispersion at tidal average condition and with the boundary situated at the well identifiable inflection point where the estuary changes from wave-dominated to tidedominated geometry. We used 89 salinity profiles in 30 estuaries (including seven recently studied estuaries in Malaysia), and empirically derived a range of equations using various combinations of dimensionless parameters. We split our data in two separated data sets: (1) with more reliable data for calibration, and (2) with less reliable data for validation. The dimensionless parameters that gave the best performance depended on the geometry, tidal strength, friction and the Richardson number. The limitation of the equations is that the friction is generally unknown. In order to overcome this problem, a coupling has been made with the analytical hydraulic model of Cai et al. (2012), which makes use of observed tidal damping and by which the friction can be determined

Evaluation of Weather Research and Forecasting (WRF) Microphysics single moment class-3 and class-6 in Precipitation Forecast

In this study, the performance of two different Microphysics Scheme options in Weather Research and Forecasting (WRF) model were evaluated for the estimating the precipitation forecast. The schemes WRF single moment class-3 (WSM-3) and single moment class-6 (WSM-6) were employed to produce the minimum, medium and maximum precipitation for the selected events over the Kuantan River Basin (KRB). The obtained simulated results were compared with the observed data from eight different rainfall gauging stations. The results comparison indicate that WRF model provides better forecasting at some rainfall stations for minimum and medium rainfall events but did not produce good result during maximum rainfall overall. The WSM-6 scheme is found to produce better result compared to WSM-3. The study also found that to acquire accurate precipitation results, it is also required to test some other physics scheme parameterization to enhance the model performance

Investigation of the current salt intrusion condition in the Kuantan estuary and the efficiency of the Kuantan barrage

Kuantan River has been spotted to have a high potential rate of being affected by salt intrusion issue. A research was conducted to estimate flow discharge in the Kuantan Estuary, to test, calibrate and validate the Van der Burgh coefficient, K and dispersion coefficient, D in the 1-D analytical salt intrusion model, and to verify the salinity condition in the Kuantan Estuary before and after the construction of the barrage. Basin delineation has been done by using GIS approached in collaboration with HEC-GeoHMS. The estimation of flow discharge in the Estuary was carried out by using hydrological modelling, HEC-HMS. Besides that, the study utilised the predictive discharges from the 1-D model for comparison purposes due to data availability issues in the estuary. 1-D analytical salt intrusion model has been adopted in this study to test, calibrate and validate several parameters and the model suitability for the salinity investigation in the estuary. Thus, five field surveys have been conducted in Kuantan Estuary on 27th and 29th March, 3rd October 2017, 7th March, and 15th April 2018. The study for the estuary covered from the mouth of estuary until the reading reached 1ppt but until the Kobat barrage by using moving boat technique. In addition, the study also extended to the Belat Estuary to test the model and study the potential of the tributary. Thus, four surveys in Belat Estuary have been conducted on 26th April, 2nd October 2017, 6th March and 14th April 2018. From the salt intrusion simulation, the Van Der Burgh coefficient, K for Kuantan Estuary and Belat Estuary are 0.45 and 0.5, respectively. The dispersion in Kuantan and Belat Estuary is in the range of 100 to 250 m2/s and 50 to 200 m2/s, respectively. The future low flow in the estuaries was estimated by performing Hydrological Procedure No 12 with 7 days in 50years ARI. The low flow obtained for Kuantan and Belat Estuary is 3 and 61.5m3/s, respectively according to the fraction area. These low flow discharge then utilised in 1-D Salt Model by using the current salinity scheme. The error analyses for HEC-HMS and 1-D Salt Model are performing by using two methods which are NSE and RMSE method. In overall, the 1-D Salt Model demonstrated well in these two estuaries

Assessment of Weather Research and Forecasting (WRF) Physical Schemes Parameterization to Predict Moderate to Extreme Rainfall in Poorly Gauged Basin

Incomplete hydro-meteorological data and insufficient rainfall gauges have caused difficulties in establishing a reliable flood forecasting system. This study attempted to adopt the remotely sensed hydro-meteorological data as an alternative to the incomplete observed rainfall data in the poorly gauged Kuantan River Basin (KRB), the main city at the east coast of Peninsula Malaysia. Performance of Weather Research and Forecasting (WRF) schemes’ combinations, including eight microphysics (MP) and six cumulus, were evaluated to determine the most suitable combination of WRF MPCU in simulating rainfall over KRB. All the obtained results were validated against observed moderate to extreme rainfall events. Among all, the combination scheme Stony Brook University and Betts–Miller–Janjic (SBUBMJ) was found to be the most suitable to capture both spatial and temporal rainfall, with average percentage error of about ±17.5% to ±25.2% for heavy and moderate rainfall. However, the estimated PE ranges of −58.1% to 68.2% resulted in uncertainty while simulating extreme rainfall events, requiring more simulation tests for the schemes’ combinations using different boundary layer conditions and domain configurations. Findings also indicate that for the region where hydro-meteorological data are limited, WRF, as an alternative approach, can be used to achieve more sustainable water resource management and reliable hydrological forecasting