Modelling flash flood using LiDAR and high resolution satellite imagery: a case study of West Creek, Toowoomba

Australia is one of the most heavily exposed countries in the world to different natural hazards, such as floods. In December 2010 and January 2011, large areas of the south and central Queensland were affected by flooding. On Monday 10th January 2011 heavy rains continued from 12:30 pm to 2:00 pm in the City of Toowoomba catchment area. Flash flooding occurred suddenly and unexpectedly making it difficult to prevent or predict before it occurred. This led to a rise in water levels in streets and roads, disrupting traffic and causing loss of life and properties. To reduce the effect of flood disasters and minimize the damages, flood inundation maps can be used to determine the locations of threat. This research used an integration of the HEC-Hydrologic Modelling System (HEC-HMS), HEC-River Analysis System (HEC-RAS) with Geographic Information Systems (GIS) to develop an improved model of the West Creek flood extent and flood event in the city of Toowoomba. The flood extent and depth in the different flow conditions of the West Creek channel was described in this study. The Hydrologic model (HEC-HMS) was used for 15 minutes time series data to create the flow rate at West Creek catchment from 12:00 pm to 4:00 pm. HEC-RAS with HEC-GeoRAS extension in ArcGIS was applied to simulate the flash flood in West Creek from Spring Street to Long Street. Digital Elevation Model (DEM) derived from high density LiDAR data and land cover data extracted from high resolution remote sensing imagery were used to model the flood inundation in the study area. The HEC-GeoRAS extension was used to prepare data sets for the stream centreline, banks, flow paths and cross-sections for import to the HEC-RAS hydraulic model. The downstream boundary conditions were defined in HEC-RAS. The hydrological results from HEC-HMS showed the maximum discharge value of West Creek Catchment at different periods of time. These results were comparable with Toowoomba Regional Council Report (TRCR). The flood inundation maps showed the maximum flood width and depth of West Creek Channel (starting from Spring Street and ending at Long Street) at 1:00 pm to 3:00 pm, which was greater than any previous floods in Toowoomba. The validation between the modelled flood extent at peak time and flood extent in the Nearmap aerial photo showed a high degree of correlation. Therefore, the model can provide a sound basis on which to analyse similar scenarios

Flood inundation mapping using hydraulic modelling and GIS: a case study in the West Creek sub-catchment

In recent years, climate change has caused extreme climate conditions. This intensifies and increases the amount of rainfall that caused floods in many regions of the world. The recent floods in Queensland, Australia provide evidence of the effects of increased climate change to the state and its population. The flash flood that occurred on the 10th of January 2011 in the West Creek catchment in the City of Toowoomba was a sudden and unexpected event making it difficult to implement flood mitigating/preventive measures. To reduce the impact of flood damage, this study aimed to develop an improved flood inundation model in the part of West Creek catchment using Geographic information systems (GIS) and the HEC-RAS hydraulic model. A digital elevation model (DEM) derived from LiDAR data was the primary data source for flood modelling. The geometric data (e.g. stream centreline, banks, flow path centreline and cross-sections, etc.) were extracted from the DEM and used in the analysis. A high resolution satellite image was used to classify land cover. Roughness coefficients were assigned according to different land cover types. Field measurements were also conducted to support the modelling process. These include measuring culverts, stream cross-sections, etc. The result was flood inundation map that clearly shows the spatial extent of the flooded area along part of West Creek and lower elevation areas within the catchment

KEYWORDS Fulorescent Pseudomonas Carbendazim Spent mushroom compost Solarized soil Fusarium oxysporum Wilt diseases IPM APPROACH FOR THE MANAGEMENT OF WILT DISEASE CAUSED BY Fusarium oxysporum f. sp. lycopersici ON TOMATO (Lycopersicon esculentum)

ABSTRACT This study was conducted to find out the effect of combined application of fluorescent Pseudomonas, spent mushroom compost and the fungicide (Carbendazim 50 % W.P) on Fusarium wilt disease infected tomato plants grown in solarized and non-solarized soil. Results of study revealed that inoculation of fluorescent Pseudomonas and spent mushroom compost have significant effect on the number and weight of tomato fruits per replicate with cost benefit ratio as compared to the control treatment having Fusarium oxysporum f.sp. lycopersici infection. No significance differences was reported among the various treatments imposed, and highest tomato fruit per plant (8.75 fruits/plant) was reported from the treatment containing only sterilized soil after 150 days of plantation this was followed by treatment containing P. fluorescens (7.35 fruits/plant), spent mushroom compost (7.00 fruits/plant), Carbendazim (7.00 fruits/plant) and spent mushroom compost with Pseudomonas fluorescens (6.90 tomato fruit/plant). Similar trends was reported in case of fruit weight and net return and treatment containing only sterilized soil show highest fruit weight (158.60g), maximum net return (113329 Rs/ha) and incremental cost benefit ratio (1:4.50). While minimum net return (0 Rs/ha) was observed in the treatment containing non sterilized soil and F. oxysporum infection

Proceedings of International Web Conference in Civil Engineering for a Sustainable Planet

This proceeding contains articles of the various research ideas of the academic community and practitioners accepted at the "International Web Conference in Civil Engineering for a Sustainable Planet (ICCESP 2021)". ICCESP 2021 is being Organized by the Habilete Learning Solutions, Kollam in Collaboration with American Society of Civil Engineers (ASCE), TKM College of Engineering, Kollam, and Baselios Mathews II College of Engineering, Kollam, Kerala, India. Conference Title: International Web Conference in Civil Engineering for a Sustainable PlanetConference Acronym: ICCESP 2021Conference Date: 05–06 March 2021Conference Location: Online (Virtual Mode)Conference Organizer: Habilete Learning Solutions, Kollam, Kerala, IndiaCollaborators: American Society of Civil Engineers (ASCE), TKM College of Engineering, Kollam, and Baselios Mathews II College of Engineering, Kollam, Kerala, India