Hideki Hashiba

Analysis of landuse change in periphery of Tokyo during last twenty years using the same seasonal landsat data

Abstract Urbanized areas are growing rapidly with the concentration of city functions and the increment of population, and the natural environment has been deteriorating. This paper reports the increasing urbanization occurring through changes in landuse, population, and land price in Japans national capital city, Tokyo, during the past twenty years. Selecting the capital city and the periphery of Tokyo as the test region, the areas within this region were classified according to the distance from the center of Tokyo and the access to the capital city by train. The landuse change for each area can be characterized according to the classification of artificially developed areas, areas of vegetation cover and others. The process of urbanization in the capital city of Tokyo is further discussed.

Landuse change analysis of Tama river basin with different spatial resolution sensor data by Landsat/MSS and TM

Abstract A lot of engineering problems which cannot be solved occur if the change process of the land use in the object basin is not understood over a long term when the land use in river basin is planned and social base is maintained. It is necessary to use the images observed with Landsat MSS and TM sensor for the time series to investigate the land use over a long term from the first half of 1970s. In this study, the classification method for the area of mixed land cover influenced easily by the difference of the TM and MSS was examined. It was verified how there was the classification difference between TM and MSS in the whole of actual basin. The investigation possibility for a long term of the land use change in river basin was verified by using both TM and MSS. In addition, the land use change in the Tama basin was able to be shown for the past 25 years.

Digital roof model (DRM)using high resolution satellite image and its application for 3D mapping of city region

In urban area artificial structures are built over crowdedly and show their complex three-dimensional (3D) characteristics. The authors create a concept of digital roof model (DRM) for giving a series of height of buildings roofs in urban area retrieved from a pair of high resolution images from satellites as IKONOS or QUICKBIRD. They develop consequently an automatic method to generate a DRM. Three-dimensional data of topography of the ground has been expressed mainly with the contour lines or the digital elevation model (DEM) obtained from aerial photographs so far. The contour lines or the DEM show the elevation of ground surface. In order to express correctly the detail of urban space structure, however, single data of ground elevation cannot be said enough. Thus the authors tried making an algorithm to obtain the roof elevation of buildings from high resolution satellite data. Two DRMs were generated for two urbanized areas concentrated with lower buildings and with taller buildings. The accuracy of the DRM was compared with the truth data. Differences between both heights of buildings by the truth and the DRM value became 5.2m rms. Fusing IKONOS spectral data and DRM product, a 3D birds-eye view of the city region is presented. Though it shows a certain quality of reproducibility of the 3D structure, more improvement of DRM is required. Key word - Digital Roof Model (DRM), Birds-eye view, High resolution9y Urban environment

An application of digital roof model (DRM) for height measurement of trees

Three dimensional data of forest structure provided by measurement of tree height fulfils an important role to nurture the forest and to conserve its environment. The authors have advanced the investigation of three-dimensional information of a city area by using high resolution satellite images. This image succeeds in providing three-dimensional descriptions of building roofs in the city area by the digital roof model (DRM). DRM is the half side of twin data expressing the ground surface and the tree canopy surface. The ground data are expressed by the digital terrain model (DTM). Measuring the coordinates of corresponding same points on a pair of the high resolution satellite image observed from different orbits, the DRM of forest, i.e. the canopy surface height can be made. Choosing trees in a city park experimentally, a DRM was generated. The shape of the canopy surface accords with the height of the trees obtained by ground surveying.

Evaluation of small-scale vegetation in city region from high-resolution satellite images with different ground resolution

The authors have verified the possibility of an investigation of vegetation using images by the IKONOS satellite, which ground resolution as high as 4 m times 4 m for the multi spectral image and 1 m times 1 m for the panchromatic one. As a result, the images have a capability to extract small-scale vegetation covering as an area of about 1 m times 1 m. However, there is still a lot of small-scale vegetation in the city area not falling within this level of ground resolution. The Quickbird satellite has a higher ground resolution of 2.4 m times 2.4 m for multi-spectral images, and 0.6 m times 0.6 m for panchromatic one than the IKONOS satellite. Using Quickbird image, an attempt to extract the distribution of small scale vegetation was carried out. The extracted vegetation distribution was compared with that from IKONOS image. Small-scale vegetation was extracted from Quickbird image more in detail in proportional to the spatial resolution. These results were discussed with detailed ground truth as how large flower pot with miniature vegetation can be recognized. A class of spatial resolution as IKONOS or Quickbird enables us to evaluate distribution of small scale vegetation in city area effectively

Time series evaluation of re-urbanization in disaster area of large-scale tsunami in Japan by high-resolution satellite remote sensing

The 2011 tsunami caused by the Tohoku Region Pacific Offshore Earthquake caused severe damage. In particular, the city of Rikuzentakata, Iwate Prefecture, a coastal city in the Tohoku district, sustained enormous damage, and long-term revitalization process is in progress. For this disaster, several satellite observations and remote disaster investigations by aerial photography were conducted, and various damage situations were reported. Although there are many interpretations of images, few continuously evaluate the recovery process after the disaster. Here, land cover was investigated using image information observed time-sequentially by high-resolution satellite remote sensing. In addition, the re-urbanization process of the disaster area was evaluated from evaluation index values obtained from several types of filtering analysis. The distribution of debris caused by the tsunami, the change in the characteristics of the bare ground due to debris removal, and the characteristics of the land cover shape were quantitatively evaluated from the regularity and identity of the land cover distribution. In addition, the early stages of re-urbanization, which is still in progress, were effectively evaluated.

Continuous evaluation of land cover restoration of tsunami struck plains in Japan by using several kinds of optical satellite image in time series

The Mw 9.0 earthquake that struck Japan in 2011 was followed by a large-scale tsunami in the Tohoku region. The damage in the coastal plane was extensively displayed through many satellite images. Furthermore, satellite imaging is requested for the ongoing evaluation of the restoration process. The reconstruction of the urban structure, farmlands, grassland, and coastal forest that collapsed under the large tsunami requires effective long-term monitoring. Moreover, the post-tsunami land cover dynamics can be effectively modeled using time-constrained satellite data to establish a prognosis method for the mitigation of future tsunami impact. However, the remote satellite capture of a long-term restoration process is compromised by accumulating spatial resolution effects and seasonal influences. Therefore, it is necessary to devise a method for data selection and dataset structure. In the present study, the restoration processes were investigated in four years following the disaster in a part of the Sendai plain, northeast Japan, from same-season satellite images acquired by different optical sensors. Coastal plains struck by the tsunami are evaluated through land-cover classification processing using the clustering method. The changes in land cover are analyzed from time-series optical images acquired by Landsat-5/TM, 7/ETM+, 8/OLI, EO-1/ALI, and ALOS-1/AVNIR-2. The study reveals several characteristics of the change in the inundation area and signs of artificial and natural restoration.

Analysis of land cover changing in coastal plain by the 2011 off the pacific coast of Tohoku Earthquake and Tsunami with ALOS satellite images

Extensive damage occurred as a consequence of the earthquake in a large area of East Japan on March 11, 2011, which generated a huge tsunami. Every municipal district town and village in the coastal regions received catastrophic damage due to this tsunami. It is necessary to investigate specially the struck situation in the coastal plain from the viewpoint of the analysis of land cover to clarify the struck characteristics by the tsunami and supporting revival planning for the future. The influences of the tsunami, a time series of changing land cover condition were investigated by using ALOS/AVNIR2 images observed before and after the disaster by the tsunami with land cover classification processing. From these results, the relationship between the land cover and the process of running up the tsunami were considered.

Research of Haiti earthquake disaster by using time series ALOS satellite image

An earthquake with a presumed magnitude of 7.0 occurred on January 12, 2010 in Port au Prince/Haiti. The disaster area has been extracted using an overlay technique of multi spectral data from the ALOS satellite and the maximum likelihood classification technique to compare images before the earthquake strike and after it struck. In addition, the situation of reconstruction was interpreted by using the images taken immediately after and six months after the quake in detail.

A relationship between tsunami disaster along west coast of Sumatra and land elevation analyzed with Landsat/ETM+ and SRTM data

Among the tsunami disaster area in December 26, 2005, the northwest coast of Sumatra was suffered with heavy damage along 250 km length. Though the degree of damage depends upon various reasons, this work focuses on clarifying the relationship between disaster and elevation. Landsat/ETM+ data are available in handicapped condition with SLC problem. Nevertheless, it serves to investigation of the affected area. SRTM data of the NASAs Space Shuttle Endeavor in February 2000 offers us a reliable data of land elevation at an interval of 90 meters. Affected area is interpreted on Landsat-5/TM also with the SRTM elevation data. Affected area can be seen in brown and coincides with the elevation less than 9 meters on the true color composite of Landsat/TM or on the RGB:543 composite. In addition to this, tsunami run-up height and intrusion distance, land subsidence, and land uplift are measured.