Keinosuke Gotoh

Geological prognosis ahead of a tunnel face

Abstract The locations of a specific geological boundary and aquifer were predicted, prior to reaching them, by a reflection method and the measurement of geothermic temperature. The determination was performed during tunnelling work which passed through the Median Tectonic Line in central Japan. The reflection method procedure was as follows. A P-wave was produced on the tunnel face by a small blasting. The location of the velocity layer boundary was predicted by the travel time of the direct wave and the reflected wave. The geothermic temperature was measured by a thermocouple which was set in the borehole at the face. The location of the aquifer was predicted by the thermal deviation between the measured value and the theoretical value that was determined from a mean geothermal gradient. Also, a water quality survey is performed, discussing the quality of the fissure water. In addition, we were able to confirm, using the Seismic Tomography method, that the sheared zone found, was the layer including lens-shaped low-velocity zone. The methods considered proved to be simple and effective for geological prognosis from within the tunnel.

Impact of banning polythene bags on floods of Dhaka City by applying CVM and remote sensing

Through the last decade Dhaka, the capital city of Bangladesh got flooded even in moderate rainfall. Free flowing of polythene shopping bags jamming the city drainage system is considered as one of the main reasons for this problem. Accordingly, the use of polythene bags was banned in Dhaka City since January 2002. On this background, this study aimed at analyzing the impact of banning polythene bags in reducing flood disasters of Dhaka City by using contingent valuation method (CVM) and remote sensing. The results of the study indicated that, the decision to prohibit polythene bag use was positive in reducing flood disaster intensity in Dhaka City as a whole and suggested the need for more detailed study.

Analysis of ground surface temperature before occurrence of earthquake by satellite thermal infrared data

The damage caused by strong earthquakes is usually enormous and requires huge amount of money and labor to return back to the usual life again. This study aimed to monitor the change in land surface temperature by considering the Niigataken Chuetsu Earthquake 2004 as a case and analyzed the land surface temperature of the surrounding area before the occurrence of the earthquake. As a result of the study, we have detected a rise in the land surface temperature of around 6 C in Kawaguchi Town, where a quake of magnitude 7 was recorded, indicating the trend of variation in the temperature before the occurrence of the earthquake. The results of the study are expected to participate towards the research of predicting potential earthquake in future.

Selecting location of urban parks in hillside city nagasaki by using gis and remote sensing

Although urban parks provide various benefits, the area and number of such parks in Nagasaki City is below the national standard. This study aimed at identification of areas lacking urban parks and selection of their location in Nagasaki City by using GIS (Geographic Information Systems) and Satellite Remote Sensing and incorporated slope considerations into the analysis. As a result of the study, we were able to find the areas with insufficient urban parks and provide guidelines for their selection of optimum location.

Seasonal sea surface temperature of the Omura Bay, Japan estimated from multi-date Landsat-5 TM thermal infrared band

Seasonal sea surface (SST) of the Omura Bay was estimated using 13 digital data of Landsat-5 TM thermal infrared (TIR) band. These data consisted of 5 data collected in autumn, 3 in winter, 3 in spring and 2 in summer. The simple regression model between TIR and SST truth data of each season showed that each model is good for estimating the SST with high correlation coefficient and low root mean square (RMS) error. The RMS error are 0.35/spl deg/C for autumns SST ranges of 18-25/spl deg/C, 0.33/spl deg/C for winters SST ranges of 8-14/spl deg/C, 0.55/spl deg/C for springs SST ranges of 12-23/spl deg/C and 0.37/spl deg/C for summers SST ranges of 25-31/spl deg/C. The potential utility of TIR band in Landsat TM for mapping SST is discussed.<<ETX>>

Influence of phytoplankton pigments and bottom features for water quality and depth estimation

In the field of coastal studies, water quality and water depth estimates are very important. However, an estimation of the pollution in the sea using point sampling techniques is very difficult. Further, bathymetric surveying of shallow water areas by conventional ship-board sounding is slow and dangerous and needs expensive devices such as a sonar and a ship with very shallow draught. As a result, optical remote sensing is considered.<<ETX>>

Appearance characteristic analysis of Heat Island phenomenon by using satellite remote sensing and GIS

Recently, the heat island phenomenon in which the temperature of a city part rises from the circumference ground has developed into a big problem. In this study, we have analyzed the impact of vegetation, altitude and inclination of the city in reducing heat island phenomenon of Fukuoka City by using satellite remote sensing and GIS (Geographic Information systems). As result of the study, we have found that, vegetation and degree of inclination of the city influences the heat island phenomenon of Fukuoka City. Finally, this study suggested the need for more detailed study by including more factors in future.

A comparative study of thermal-infrared camera monitored data and theoretical data regarding roof surface temperature of buildings

Abstract-Recently, the heat island phenomenon developed into one of the biggest environmental problems. Extraction of heat from the building structures is considered as one of the main reasons behind this phenomenon. In order to solve this problem, reducing heat by vegetation planting is advocated and in various cities in Japan such as Tokyo, Hyogo and Sendai, laws are formulated to enforce vegetation in the city area. On this background, this study initiated a comparative analysis of Thermal-infrared Camera monitored data and theoretical data relating to roof surface temperature of buildings. As a result of this study, we have found that the Heat Budget’s Theory of land uses are also effective in estimating surface temperature of the roof of the buildings.

A VERIFICATION FOR TIDAL FLOW SIMULATION OF CLOSED BAY BY USING SATELLITE REMOTE SENSING

Omura Bay in Nagasaki Prefecture, which is called a double-closed bay, is connected with Sasebo Bay through very narrow channels. The authors had applied satellite remote sensing technique to confirm the exchange condition of seawater between these bays. This method is capable of investigating only the surface current. In this paper, the numerical simulation system was improved in order to simulate actual tides by using three-element control function. The results of satellite remote sensing were compared with the outcome of the simulation system. It follows that the results of satellite remote sensing and the outcome of the system corresponded well when the axis of coordinates which is rotated 34 degrees from circles of latitude and longitude and eddy viscosity in the 40m2/s to 60m2/s range were used for the numerical simulation.

The urban environmental significance of the Tokiwa-Dejima water front park project in Nagasaki Harbor

The purpose of this paper is to descrive the process how we planned and preserved the environment of Tokiwa-Dejima water front area in Nagasaki Harbor. According to the remote sensing survey, the green zone in Nagasaki urban area is reducing, especially along the water front. The amount of green area allocated in urban space planning may be limited but connecting this green area with the existing vegetation, the total bio-activity area (“biotope”) will be enlarged. When we design waterfront area, we have to create a wholesame evironment for the bio-activity in beach, tidal and sub marine area. And also we should not use up all the spaces for human beings but we should save the space for bufferings and relieving the human pressure against the bio-activity.