Tsuguki Kinoshita

Land Cover Classification and Change Analysis in the Horqin Sandy Land From 1975 to 2007

Observations over the last three decades show that desertification poses a serious threat to the livelihood and productivity of inhabitants of the Horqin Sandy Land region of China. We evaluated the dynamics and trends of changes of land cover in the Horqin Sandy Land by using Landsat archive images from 1975, 1987, 1999, and 2007. We applied two supervised classification methods, the self-organizing map neural network method and the subspace method. Our analyses revealed significant changes to land cover over the period 1975-2007. The area of cropland doubled over the last three decades. This expansion was accompanied by large increases in water consumption and considerable loss of areas of grassland and woodland. Many lakes and rivers shrank rapidly or disappeared in this region between 1975 and 2007. The sandy area expanded rapidly from 1975 to 1987 but gradually slowed thereafter.

Evaluation of spatially explicit emission scenario of land-use change and biomass burning using a process-based biogeochemical model

Using a socioeconomic scenario of representative concentration scenarios, terrestrial emissions from biomass burning and anthropogenic land-use change for the twenty-first century are evaluated in a spatially explicit manner using a biogeochemical model. The model is validated with the historical net land-use change CO2 emission and biomass-burning trace gas emission: net land-use change CO2 emission for 1990s to be from 1.03 to 1.53 Pg C year−1 and black carbon emission from biomass burning during 1997–2000 to be 3.1 Tg BC year−1. For future emissions, uncertainty due to CO2 concentration and land-use change scenario is examined using sensitivity experiments and reveals significant effect of CO2 on the biomass-burning emissions in terms of direct effect of vegetation mass and the indirect feedback through the fire ignition probability. It also reveals the importance of CO2 fertilization on net land-use change CO2 emission through the regrowing absorption in abandoned agricultural land.

Combination of AVNIR-2, PALSAR, and Polarimetric Parameters for Land Cover Classification

We evaluate the potential of combined Advanced Land Observing Satellite Advanced Visible and Near-Infrared (AVNIR-2) and fully polarimetric Phased-Array-type L-band Synthetic Aperture Radar (PALSAR) data for land cover classification. Optical AVNIR-2 and fully polarimetric PALSAR can provide both surface spectral information and scattering information of the ground surface. The fully polarimetric PALSAR is particularly important for land cover classification because quad-polarization PALSAR data and its polarimetric parameters contain additional surface information. As a consequence, by combining optical AVNIR-2, PALSAR, and polarimetric parameters into a single data set, land cover classification accuracy may be further improved. For efficient and convenient handling of the combined multisource data, we used a subspace method for the classification and estimated its classification capability for various combinations of optical, PALSAR, and polarimetric parameter data sets in the Lake Kasumigaura region of Japan. We also compared the results obtained using the subspace method with those obtained by the support vector machine (SVM) and maximum-likelihood classification (MLC) methods. The classification results confirm that, when the combined optical AVNIR-2, PALSAR, and polarimetric coherency matrix data were used, the classification accuracy of the subspace method was better than that when other data combinations were used. The subspace method also performed better than the SVM or MLC method in high-dimensional data set classification. Moreover, the experimental results demonstrated that the proposed subspace method is robust for data classification when there is data redundancy and thus allows optimal feature selection procedures to be avoided.

Spatial–Temporal Analyses of Surface Coal Mining Dominated Land Degradation in Holingol, Inner Mongolia

Surface coal mining and urbanization, as well as crop-based agriculture, have resulted in accelerated degradation and desertification of grasslands in the Holingol region, Inner Mongolia Autonomous Region, over the last three decades. The purpose of this study was to investigate the spatial-temporal changes of land cover due to the surface coal-mining activities in the Holingol region from 1978 to 2011. In this study, we used the subspace method to apply land-cover classification schemes to Landsat archival images from 1978, 1988, 1999, and 2011. We then used the grid square method to investigate spatial-temporal land-cover changes during the period of 1978-2011. The results show that both surface coal mining and urban areas have increased dramatically. This expansion was accompanied by considerable loss of grassland and wetland. Grid-cell-based spatial-temporal analysis showed that urban/bare expansion had a strong negative correlation with grassland change (-0.67), coal-mining area expansion had a negative correlation with grassland change (-0.29), and coal-mining area expansion was positively correlated with urban/bare expansion (0.21). Furthermore, the correlation coefficients of land-cover categories for three time intervals between 1978 and 2011 (1978-1988, 1988-1999, and 1999-2011) showed that there was almost no correlation between grassland and coal-mining area in 1978-1988 and 1988-1999, but the correlation coefficient became negative (-0.21) in 1999-2011.

Creation of New Global Land Cover Map with Map Integration

We present here a new approach to the development of a global land cover map. We combined three existing global land cover maps (MOD12, GLC2000, and UMD) based on the principle that the majority view prevails and validated the resulting map by using information collected as part of the Degree Confluence Project (DCP). We used field survey information gathered by DCP volunteers from 4211 worldwide locations to validate the new land cover map, as well as the three existing land cover maps that were combined to create it. Agreement between the DCP-derived information and the land cover maps was 61.3% for our new land cover map, 60.3% for MOD12, 58.9% for GLC2000, and 55.2% for UMD. Although some of the improvements we achieved were not statistically significant, this project has shown that an improved land cover map can be developed and well-validated globally using our method.

Numerical Simulation of Tidal Current in the Coastal Region With an Artificial Seabed Mound for Upwelling

The technology of generating an artificial upwelling by constructing a seabed mound to increase the primary production is being examined off Ikitsuki Island, Nagasaki, Japan. A numerical simulation model is being developed in order to evaluate the effects and environmental influence of the artificial seabed mound. At the first stage of the modeling, tidal current is calculated for the coastal region including the artificial upwelling area. Since most of the boundaries of the computational domain are open to the ocean, it is necessary to give incoming tidal wave all over them, which is not easy because of complicate topography. A newly developed inverse method using the observation data at tidal stations along the coastline was applied to determine the boundary conditions of tide. The calculated tide by the method agreed fairly well with the observation data. Currents near the seabed mound was also investigated, whose result is indicated that internal wave induced by the mound makes the mixing larger.Copyright

Expression of the BTB/POZ domain-containing protein At1g63850-like gene CsFDI1 is enhanced by sugar starvation in cucumber fruit

The cDNA of Cucumis sativusFruit Defoliation Induced 1 (CsFDI1) was newly cloned using the subtraction method from a fruit of a defoliated cucumber (Cucumis sativus L. cv. Tokiwa) plant. An expression analysis of CsFDI1 in fruits and leaves was conducted along with those of the asparagine synthetase 1-like gene (AS) and Cucumis sativusSomatic Embryogenesis Zinc Finger 1 (CsSEF1), previously reported as control marker genes for sugar starvation. The transcript level of CsFDI1 and AS was relatively high, whereas that of CsSEF1 was very low under normal fruit development. The time course of the transcript levels of the three genes under prolonged darkness was compared with that of the fruit respiration rate and leaf starch concentration. The fruit respiration rate suggested that photoassimilate translocation to fruit ceased abruptly under prolonged darkness. The transcript level of CsFDI1, AS, and CsSEF1 increased in fruits, but the time course of the change was quite different in fruits and leaves under the condition of sugar starvation. The response of AS in leaves and CsSEF1 in fruits was close to all-or-none.

Creation of a global land cover and a probability map through a new map integration method

Abstract Global land cover maps are widely used for assessment and in research of various kinds, and in recent years have also come to be used for socio-economic forecasting. However, existing maps are not very accurate, and differences between maps also contribute to their unreliability. Improving the accuracy of global land cover maps would benefit a number of research fields. In this paper, we propose a methodology for using ground truth data to integrate existing global land cover maps. We checked the accuracy of a map created using this methodology and found that the accuracy of the new map is 74.6%, which is 3% higher than for existing maps. We then created a 0.5-min latitude by 0.5-min longitude probability map. This map indicates the probability of agreement between the category class of the new map and truth data. Using the map, we found that the probabilities of cropland and grassland are relatively low compared with other land cover types. This appears to be because the definitions of cropland differ between maps, so the accuracy may be improved by including pasture and idle plot categories.

Fundamental Study on the Behaviour of Submarine Groundwater Discharged into the Coastal Sea

In order to investigate the behaviour of submarine groundwater flowing into the ocean, field observation, hydraulic tank experiments, and numerical simulations were carried out. As the results, the early-stage behaviour of the discharged submarine groundwater as density plume could be categorized into three types due to the ratio of discharge velocity to the background horizontal current velocity. When the ratio is relatively large, the behaviour of the discharged water can be predicted by the conventional theoretical model for the density plume. When the velocity ratio is relatively small, the inclination of the plume path gets smaller than the predicted values by the conventional model. It is because the effect of background diffusion becomes larger. If the velocity ratio is very small, the discharged water is transported almost along the sea bottom, which is the situation of the field observation. This result suggests that the submarine groundwater discharge in Toyama Bay supplies the nutrients for the benthic producer such as seagrass, rather than for the pelagic phytoplankton.

Downscaling Global Emissions and Its Implications Derived from Climate Model Experiments

In climate change research, future scenarios of greenhouse gas and air pollutant emissions generated by integrated assessment models (IAMs) are used in climate models (CMs) and earth system models to analyze future interactions and feedback between human activities and climate. However, the spatial resolutions of IAMs and CMs differ. IAMs usually disaggregate the world into 10–30 aggregated regions, whereas CMs require a grid-based spatial resolution. Therefore, downscaling emissions data from IAMs into a finer scale is necessary to input the emissions into CMs. In this study, we examined whether differences in downscaling methods significantly affect climate variables such as temperature and precipitation. We tested two downscaling methods using the same regionally aggregated sulfur emissions scenario obtained from the Asian-Pacific Integrated Model/Computable General Equilibrium (AIM/CGE) model. The downscaled emissions were fed into the Model for Interdisciplinary Research on Climate (MIROC). One of the methods assumed a strong convergence of national emissions intensity (e.g., emissions per gross domestic product), while the other was based on inertia (i.e., the base-year remained unchanged). The emissions intensities in the downscaled spatial emissions generated from the two methods markedly differed, whereas the emissions densities (emissions per area) were similar. We investigated whether the climate change projections of temperature and precipitation would significantly differ between the two methods by applying a field significance test, and found little evidence of a significant difference between the two methods. Moreover, there was no clear evidence of a difference between the climate simulations based on these two downscaling methods.