Keitarou Hara

Tokyo University of Information Sciences · Department of Informatics

To clarify the autonomous vegetation recovery and the extent of human impact after the severe disturbance caused by the Great East Japan Earthquake/Tsunami in March 2011, we investigated the vegetation, 10 growing seasons after the tsunami disturbance, along a coastal sand-dune ecotone of Sendai Bay, Japan. Vegetation surveys were carried out in Au...

Japan Aerospace Exploration Agency (JAXA) is going to launch Advanced Land Observing Satellite 3 (ALOS-3) after 2022. ALOS-3 satellite is capable of observing global land areas with wide swath (4000 km along-track direction and 70 km cross-track direction) at high spatial resolution (panchromatic: 0.8m, multispectral: 3.2m). Maintenance and updatin...

Classification and mapping of plant communities is an essential step for conservation and management of ecosystems and biodiversity. We adopt the Genus-Physiognomy-Ecosystem (GPE) system developed in the previous study for satellite-based classification of plant communities at a broad scale. This paper assesses the potential of multi-spectral and m...

This research introduces Genus-Physiognomy-Ecosystem (GPE) mapping at a prefecture level through machine learning of multi-spectral and multi-temporal satellite images at 10m spatial resolution, and later integration of prefecture wise maps into country scale for dealing with 88 GPE types to be classified from a large size of training data involved...

Advanced Land Observing Satellite 3 (ALOS-3) is capable of observing global land areas with wide swath (4000 km along-track direction and 70 km cross-track direction) at high spatial resolution (panchromatic: 0.8m, multispectral: 3.2m). Maintenance and updating of Land Cover and Vegetation (LCV) information at national level is one of the major goa...

Classification and mapping of plant communities is an essential step for conservation and management of ecosystems and biodiversity. We adopt the Genus-Physiognomy-Ecosystem (GPE) system developed in previous study for satellite-based classification of plant communities. This paper assesses the potential of multi-spectral and multi-temporal images...

Vegetation indices are commonly used techniques for the retrieval of biophysical and chemical attributes of vegetation. This paper presents the potential of an Autoencoders (AEs) and Convolutional Autoencoders (CAEs)-based self-supervised learning approach for the decorrelation and dimensionality reduction of high-dimensional vegetation indices der...

Rough sets and rule induction in an incomplete and continuous information table are investigated under possible world semantics. We show an approach using possible indiscernibility relations, whereas the traditional approaches use possible tables. This is because the number of possible indiscernibility relations is finite, although we have the infi...

ContextIn March of 2011 a huge tsunami devastated forest habitats along the coast of Sendai Bay in northeastern Japan. Evaluation and monitoring of the changes in habitat connectivity caused by this disaster are essential for managing the recovery of ecosystems and biodiversity.Objectives This research is designed to clarify changes in habitat conn...

Rough sets under incomplete information with continuous domains are examined based on possible world semantics. We focus on possible indiscernibility relations, although the traditional approaches are done under possible tables. This is because we only obtain a finite number of possible indiscernibility relations even if infinite number of possible...

Information tables having continuous domains are handled by neighborhood rough sets. Two approximations in complete information tables are extended to handle incomplete information. Consequently, four approximations are obtained: certain and possible lower ones and certain and possible upper ones without computational complexity. These extended app...

Recently, land cover maps created from high resolution satellite images have been used for landscape analysis, in order to understand the impact of natural disasters on biodiversity and ecosystems. Conventional land cover classification methods, however, suffer from problems with isolated pixels (salt and pepper effect). Filtering can remove the is...

Rough sets under incomplete information with continuous domains are examined on the basis of possible world semantics. We show an approach under possible indiscernibility relations, although the traditional approaches are done under possible tables. This is because the number of possible indiscernibility relations is finite, even if the number of p...

This paper presents an assessment of the bidirectional reflectance features for the classification and characterization of vegetation physiognomic types at a national scale. The bidirectional reflectance data at multiple illumination and viewing geometries were generated by simulating the Moderate Resolution Imaging Spectroradiometer (MODIS) Bidire...

In recent years, the spatial resolution of satellite data has improved with advancements in satellite technology, and acquisition of even more detailed information on the surface of the earth can be expected in the future. Various complications, however, are still associated with retrieval and classification of ground surface information from very-...

Mapping the distribution of forested areas and monitoring their spatio-temporal changes are necessary for the conservation and management of forests. This paper presents two new image composites for the visualization and extraction of forest cover. By exploiting the Landsat-8 satellite-based multi-temporal and multi-spectral reflectance datasets, t...

Rule induction based on indiscernible classes from neighborhood rough sets is described in information tables with continuous values. An indiscernible range that a value has in an attribute is determined by a threshold on that attribute. The indiscernible class of every object is derived from using the indiscernible range. First, lower and upper ap...

This paper presents an evaluation of the multi-source satellite datasets such as Sentinel-2, Landsat-8, and Moderate Resolution Imaging Spectroradiometer (MODIS) with different spatial and temporal resolutions for nationwide vegetation mapping. The random forests based machine learning and cross-validation approach was applied for evaluating the pe...

Rough sets and rule induction based on them are described in incomplete information tables where attribute values are ordered. We apply possible world semantics to an incomplete information table, as Lipski did in incomplete databases. The set of possible tables on a set of attributes is derived from the original incomplete information table. Rough...

This paper presents the performance and evaluation of a number of machine learning classifiers for the discrimination between the vegetation physiognomic classes using the satellite based time-series of the surface reflectance data. Discrimination of six vegetation physiognomic classes, Evergreen Coniferous Forest, Evergreen Broadleaf Forest, Decid...

Irrespective of several attempts to land use/cover mapping at local, regional, or global scales, mapping of vegetation physiognomic types is limited and challenging. The main objective of the research is to produce an accurate nationwide vegetation physiognomic map by using automated machine learning approach with the support of reference data. A t...

The damage of buildings and manmade structures, where most of human activities occur, is the major cause of casualties of from earthquakes. In this paper, an improved technique, Earthquake Damage Visualization (EDV) is presented for the rapid detection of earthquake damage using the Synthetic Aperture Radar (SAR) data. The EDV is based on the pre-s...

Normalized Difference Water Index (NDWI), Green-Red Vegetation Index (GRVI), and other indices of remotely detected spectrum combinations have been proposed in order to evaluate the vegetation changes and distributions. The training area of artificial Japanese larch forest and deciduous broad leaved forest (Japanese white birch and Japanese oak) in...

As the barren lands play a key role in the interaction between land cover dynamics and climate system, an efficient methodology for the global-scale extraction and mapping of the barren lands is important. The discriminative potential of the existing soil/bareness indexes was assessed by collecting globally distributed reference data belonging to m...

The Great East Japan Earthquake of 11th March 2011 and subsequent huge tsunami caused widespread damage along the Pacific Ocean coast of eastern Honshu, Japan. This research utilizes field surveys and analyses of multi-resolution remote sensing images to clarify the impact on landscapes caused by this disaster and also to monitor the subsequent sur...

Physiographic environments, species composition, and population structure of coastal forests in Sendai City, Miyagi Prefecture, northeastern Japan, were investigated to clarify types of damage to trees and other impacts to the forests 3 months after the Great East Japan Earthquake and Tsunami of 2011. The coast at the study site was originally prot...

The distribution of vegetation is expected to change under the influence of climate change. This study utilizes vegetation maps derived from Terra/MODIS data to generate a model of current climate conditions suitable to beech-dominated deciduous forests, which are the typical vegetation of Japan’s cool temperate zone. This model will then be coordi...

The distribution of vegetation is expected to change under the influence of climate change. This study utilizes vegetation maps derived from Terra/MODIS data to generate a model of current climate conditions suitable to beech-dominated deciduous forests, which are the typical vegetation of Japan’s cool temperate zone. This model will then be coordi...

An up-to-date spatio-temporal change analysis of global snow cover is essential for better understanding of climate–hydrological interactions. The normalized difference snow index (NDSI) is a widely used algorithm for the detection and estimation of snow cover. However, NDSI cannot discriminate between snow cover and water bodies without use of an...

Achieving more timely, accurate and transparent information on the distribution and dynamics of the world’s land cover is essential to understanding the fundamental characteristics, processes and threats associated with human-nature-climate interactions. Higher resolution (~30–50 m) land cover mapping is expected to advance the understanding of the...

An improved methodology for the extraction and mapping of urban built-up areas at a global scale is presented in this study. The Moderate Resolution Imaging Spectroradiometer (MODIS)-based multispectral data were combined with the Visible Infrared Imager Radiometer Suite (VIIRS)-based nighttime light (NTL) data for robust extraction and mapping of...

Monitoring of water cover and shorelines at a global scale is essential for better understanding climate change consequences and modern human disturbances. The level and turbidity of the surface water, and the background objects in which they interact with, vary significantly at a global scale. The existing water indices applicable to detection and...

Vegetation and land cover in Japan are rapidly changing. Abandoned farmland in 2010, for example, was 396,000 ha, or triple that of 1985. Efficient monitoring of changes in land cover is vital to both conservation of biodiversity and sustainable regional development. The Ministry of Environment is currently producing 1/25,000 scale vegetation maps...

The Great East Japan Earthquake (magnitude 9.0; occurred on 11th March 2011) and subsequent huge tsunami caused widespread damage along the Pacific Ocean coast of eastern Honshu, Japan. This research utilizes multi-resolution remote sensing images to clarify the impact on landscapes caused by this disaster, and also to monitor the subsequent surviv...

Japan, with over 75% forest cover, is one of the most heavily forested countries in the world. Various types of climax forest are distributed according to latitude and altitude. At the same time, human intervention in Japan has historically been intensive, and many forest habitats show the influence of various levels of disturbance. Furthermore, Ja...

Sharpness of the satellite composite image is degraded by the period composite process associated with clouds and sensor zenith angles. In order to evaluate the image quality degradation by the period composite process, the period composites of band 1 of the corrected reflectance (CREFL) were created for the period of 1, 5, 10, and 30 days and for...

Paddy fields surrounded by forests are characteristic of the rural landscapes in East Asia. These characteristic landscapes are maintained by agricultural activities; recently, however, local and regional changes in economic and social systems have resulted in their deterioration. In order to conserve these landscapes, the diversity of land-use sys...

We investigated the population structure of trees in the coastal forests 3 months after the Great East Japan Earthquake to understand the impact of tsunamis. To clarify the impact on types of damage to trees, a belt transect (540 × 40 m) was set perpendicular to the shore line, transecting both the sand dune and back marsh. Species name and diamete...

Much of the coastal forest along Sendai Bay was severely disturbed by the huge tsunami resulting from the Great East Japan Earthquake (March 11, 2011). To evaluate changes in coastal forest vegetation after the tsunami, we implemented a phytosociological survey in four different microhabitats-remnant-forest, disturbed-forest, bare-soil, and moist-s...

The spatial patterns of plant diversity and environmental heterogeneity were analysed in a coastal forest, 2 years after the severe tsunami caused by the 2011 Great East Japan Earthquake in Japan, to gain basic knowledge for managing coastal forest after a severe disturbance. The ∼60.5-ha study site was divided into four patch types: 1) tall forest...

The Great East Japan Earthquake disturbed coastal regions facing the Pacific Ocean. Subsequent infrastructure reconstruction in the coastal region of southern Sendai Bay has now become a major threat to biodiversity. The recovering coastal forest zone has been artificially filled and re-planted with pine trees. Seawalls are being reconstructed by s...

The legacies of land use (such as plantations, pastures and coppices) in the Shilin karst area of central Yunnan, SW China have strongly influenced the plant communities' structure, dynamics, species diversity, litter nutrients inputs, and soil chemical properties. To evaluate the effects of various restoration approaches on ecosystem recovery in t...

Chongqing Municipality, located on the upper reaches of the Yangtze River, is one of China’s four largest megacities, comparable with Shanghai, Beijing, and Tianjin. In recent years, Chongqing and its surroundings have been experiencing severe environmental problems, such as urbanization, pollution, and deforestation, due to the rapid economic deve...

This paper aims to understand the ecological effects of disturbance on broadleaved evergreen forest in East China. We used a manipulative field experiment approximating the common natural and artificial disturbance types in this area to investigate the community physiognomy, floristic composition, and 5-year recovery dynamics of the post-disturbanc...

This study used remote sensing data and field research to analyze the damage to vegetation caused by the Great East Japan Earthquake and subsequent huge tsunami that struck the coast of eastern Tohoku on March 11, 2011. The damage sustained by four basic types of vegetation: coastal cliff, sandy beach, coastal forest, and marsh, is analyzed and com...

Currently, there is no extant technology that is able to measure only the amount of methane emission without recourse to laboratory work. Also, although observation data from Gosan, Republic of Korea, which is part of the WDCGG, is vital for understanding not only the atmospheric background pollution on the Korean Peninsula, but also background pol...

For reducing the labor cost involved in vegetation mapping, we attempted to identify the forest types in forest areas by using high-resolution IKONOS satellite data. Thus we conducted a vegetation survey of 96 plots in Satoyama forest area and classified the plots into 8 forest types on the basis of the dominant tree species in the canopy layer. Cr...

A method enabling the object-oriented image analysis of landscape elements incorporating topographic data was designed and tested on a Japanese countryside target area. IKONOS data (four multispectral bands with a spatial resolution of 4 m and a panchromatic band with a spatial resolution of 1 m) acquired on 23 April 2001 were used. Definiens v.5 s...

We analyzed vegetation cover and the diversity of native and alien aquatic plants in the Lake Teganuma watershed (northeastern Chiba Prefecture). Using digital elevation model data, we established six third-order sub-watersheds, which were further divided into second- and first-order sub-watersheds. The easternmost third-order sub-watershed (Kamena...

This study aimed to estimate the methane emission from forest and cropland vegetation region by using WDCGG data, methane concentration, wind direction, wind speed, relative humidity and air temperature, from 1998 to 2007 on Minamitorishima, Yonagunijima and Ryori. We developed Greenhouse gas Emission Presumption Method (GEP Method) for presuming t...

Evergreen broad-leaved forests (EBLFs, lucidophyllous forests) are vegetation types characteristic of East Asia. The extent of EBLFs has decreased significantly due to long-term anthropogenic disturbance, and remnant EBLFs in urban area are rare and important landscape types contributing to biodiversity and sustainable development. This study focus...

In recent years, identifying the relationship between pattern and scale has emerged as a central issue in ecology and geography. Scale has been defined by grain or resolution but bias in results will occur if the scale is wrongly selected relevant to the landscape evaluation. In this research, satellite data of varying resolution, QuickBird (2.5m),...

Landscape structure and land use history were clarified based on the old maps in the Boso Peninsula, central Japan. Landscape map dated around the 1880s was created through modification of old maps and landscape map from the 1980s was made based on actual vegetation maps. Natural vegetation of this area was evergreen broad leaved forest. Around the...

This research aims to evaluate the suitability of object-based image analysis as a tool for vegetation mapping. The research was implemented in the Tanzawa Mountains of the western Kanto Region, in central Honshu Island, Japan. This site is a typical mountainous area usually subject to misinterpretation due to shadows, where even visual interpretat...

Monitoring changes in a paddy-field area is important since rice is a staple food and paddy agriculture is a major cropping system in Asia. For monitoring changes in land surface, various applications using different satellites have been researched in the field of remote sensing. However, monitoring a paddy-field area with remote sensing is difficu...

Terra and Aqua, 2 satellites launched by the NASA-centered international Earth Observing System project, house MODIS (Moderate Resolution Imaging Spectroradiometer) sensors. Moderate resolution remote sensing allows the quantifying of land surface type and extent, which can be used to monitor changes in land cover and land use for extended periods...

Monitoring changes in paddy field area is important in Asia. For monitoring change in land surface, various applications using different satellites were researched in the field of remote sensing. However monitoring paddy field area with remote sensing is difficult due to the temporal change in land surface, and difference of spatiotemporal characte...

Well-tended bamboo groves, once an integral element in the satoyama, Japan's traditional countryside mosaic, have over the past half century been abandoned. These abandoned groves are vigorous and are now expanding, causing various problems, including loss of diversity and damage to cropland. To control and manage these groves, an effective yet eff...

Terra and Aqua, two satellites launched by the NASA-centered International Earth Observing System project, house MODIS (moderate resolution imaging spectroradiometer) sensors. Moderate-resolution remote sensing allows the quantifying of land-surface type and extent, which can be used to monitor changes in land cover and land use for extended period...

Vegetation mapping using IKONOS data was implemented at a countryside study area in central Japan, where small patches of various plant communities are mixed together in a complicated mosaic pattern. Pixel-based and object-based classifications using only spectral features were implemented and their accuracies were compared. In addition, the object...

Chongqing, as the central city of inland China, has been subject to especially fast economical development. With increasing population and urban development, various impacts on the surrounding environment, such as deforestation, urbanization and pollution, must be taken into consideration. In particular, decrease in vegetated area and disruption of...

Vegetation mapping using IKONOS data was implemented at a countryside study area in central Japan, where small patches of various plant communities are mixed together in a complicated mosaic pattern. Pixel-based and object-based classifications using only spectral features were implemented and their accuracies were compared. In addition, the object...

A study was conducted in Chiba, Japan, to validate Moderate Resolution Imaging Spectroradiometer (MODIS) albedo products by taking the field measurements of shortwave band albedos in paddy fields. A large difference in spatial scale, from field-measured point data to 1-km resolution, complicates the validation process. To assess such effect of diff...

Terra and Aqua, 2 satellites launched by the NASA-centered international Earth Observing System project, house MODIS (Moderate Resolution Imaging Spectroradiometer) sensors. Moderate resolution remote sensing allows the quantifying of land surface type and extent, which can be used to monitor changes in land cover and land use for extended periods...

Vegetation maps and forest inventory maps contain spatial and attribute data that can be useful in analyzing forest landscapes and ecology. The value of these data would be enhanced if the two types of maps could be accurately combined into an integrated vegetation map. In this research, IKONOS high resolution satellite data was utilized to generat...

Continuous monitoring and updating of distribution maps is essential for conservation and management of plant communities, especially in regions where change and development are rapid. Traditional methods of vegetation mapping rely on interpretation of aerial photographs and follow-up field research, and are expensive, time-consuming and labor-inte...

This study focuses on the ‘yatsu’ landscape of the southern Kanto Region, in central Japan. This agricultural landscape consists of narrow, branching valleys where rice is cultivated in irrigated paddies, and surrounding slopes and uplands devoted to a variety of landscape types, such as dry vegetable field, orchard, bamboo grove and coppice woodla...

This study compares pixel-based and object-based classification of land cover using high resolution satellite data available for urban fringe regions. In the pixel-based analysis the maximum likelihood method and the ISODATA method were applied. The results showed that in both methods misclassification tended to increase due to shadows. The pixel-b...

The unsupervised land cover classification method was applied on the monthly composite data obtained by Terra/MODIS sensor from December 2002 to November 2003 over the Kanto district, Japan, and was examined on the combination in effective bands and observation periods for the landcover classification. First, the combination in effective bands was...

The effect of the bidirectional reflectance distribution function (BRDF) is one of the most important factors in correcting and validating the reflectance obtained from remotely sensed data. While the importance of BRDF has become widely recognized, bidirectional reflectance factor (BRF) data measured for correction and validation are insufficient...

The effect of the Bidirectional Reflectance Distribution Function (BRDF) is one of the most important factors in correcting the reflectance obtained from remotely sensed data. Estimation of BRDF model parameters can be deteriorated by various factors; contamination of the observations by undetected subresolution clouds or snow patches, inconsistent...

The bidirectional reflectance distribution function (BRDF) effect has been one of the most important factors in correcting the reflectance obtained from remotely sensed data, especially the data having wide swath, e.g. Moderate Resolution Imaging Spectroradiometer (MODIS) data. For the BRDF effect correction, it is one of the most effective approac...

The effect of Bidirectional Reflectance Distribution Function (BRDF) is one of the most important factors to calibrate reflectance obtained from remotely sensed data. Because the measured BRDF data involve noise caused by various factors, BRDF model parameter estimation tends to become unstable. We examined parameter estimation robustness by using...