A significant part of Hong Kong has hilly terrain with relatively short flow concentration time and, hence, is susceptible to the threat of flash floods and landslides during intense convective thunderstorms and tropical cyclones. For places like Hong Kong, a rainfall model that could adequately capture small-scale temporal and spatial variations would be highly desirable. The main challenge in rain-field modeling is to capture and describe the dynamic time-space evolution of the rainfall during rainstorm events. In this study, radar data with a high spatial (1 km2) and temporal (6 min) resolution of four rainstorm events in Hong Kong are analyzed. A geostatistical approach based on indicator variograms of rain-fields is used. The spatial structure of a rain-field is found to be highly anisotropic and should be adequately considered in the model. Variability of the spatial structure of a rain-field was described well by the main features of the variograms. Moreover, it is possible to identify whether multiple rainstorm centers exist by comparing the mean length and range. In order to establish reliable statistics on the spatial and temporal structure of rain-fields in Hong Kong, this approach could be applied to a large set of rainstorm events in this same region in the future.
Effect of saltwater intrusion due to over-exploitation and earthquakes on mineralization processes ...
The study focuses on the monitoring of physicochemical parameters and major chemical elements of six springs and wells during two seasons. Waters from the coastal karst aquifer Massif Bokkoya Al-Hoceima were analyzed for their chemical quality, and their state of anthropogenic and/or natural contamination was quantified. The waters are highly mineralized and marked by a chloride-sodium or sodium-sulfate facies mainly linked to a process of marine intrusion and dissolution of evaporitic minerals included in the...
Prediction of groundwater levels using evidence of chaos and support vector machine
Many nonlinear models have been proposed to forecast groundwater level. However, the evidence of chaos in groundwater levels in landslide has not been explored. In addition, linear correlation analyses are used to determine the input and output variables for the nonlinear models. Linear correlation analyses are unable to capture the nonlinear relationships between the input and output variables. This paper proposes to use chaos theory to select the input and output variables for nonlinear models. The nonlinear...
Stevens HydraProbe Helps in Landslide Research
Each year during the wet season we hear news reports about landslides in America and abroad. Sometimes these events happen in unpopulated areas but unfortunately they also occur in areas where people live, causing property damage and taking lives. But what causes these events and what can be done about them? That’s what Dr. Burns, a geology professor at Portland State University is trying to answer Dr. Burns, whose fields of expertise cover geomorphology, engineering and environmental geology, and soils...
Landslide Investigation in Turkey - Case Study
After a landslide, how do you know it’s safe to build again? In 2011, after a record-setting month of rainfall, a landslide devastated the infrastructure and roads near Cankiri in Northern Turkey, effectively cutting the highway from two cities. Fortunately, the landslide occurred in the evening, and there were no casualties. Our client, the Geophysical Modeling Group from Ankara University, Turkey, used AGI tools to investigate the landslide’s bedrock and weak zone. The goal of this study was to...
Case study - South Pool Creek, Devon
Part of the works to repair an essentials road recently damaged by a landslide required hydroseeding to it`s slopes and to help retain the soil an erosion control blanket was fitted by the client prior to seeding. Additional tackifier was added to the mix to help bind the sprayed on material to the steep slopes until germination and the establishment of the new grasses.Project Size: 1,000m2Location: South Pool, DorsetClient: South Hams CouncilCompletion: March 2011