Statistical Analysis of Land-use Change and Driving Forces in the Kansai District, Japan

The current state of land use is the result of a variety of factors, caused by both biophysical and socio-economic conditions, and their interactions. Land-use features prominently in many disciplines such as geography, economics, civil engineering, architecture, city and rural planning, soil science, forest management, and so on. But the study of land-use is often limited to only one discipline. There are only a few studies where the influence of both natural and socio-economic factors on land-use is simultaneously investigated. The purpose of this study is to demonstrate the relations among land use, socio-economic variables and geophysical factors in the case study area of Kansai district, Japan. This region contains the second largest urbanized area in Japan (after the Tokyo metropolitan area), while maintaining significant paddy rice cultivation in the suburban surroundings. Here we seek to extract the crucial relationships between land use in the Kansai district and the associated factors with statistical techniques. In general, land-use change can be separated into two levels. "Minor land-use change" is land-use change within the same economic sector. "Major land-use change" means land-use conversion from one major industry to another [Black, 1931; Wada, 1980]. For example, according to this classification, a crop change in agriculture is a minor land-use change, and land-use conversion from farmland to residential land is a major land-use change. In this study, we focus mainly on major land-use change. A first reason is that land-use conversion usually brings about permanent change. Conversion to residential land from any other land-use, and even conversion from farmland to forest land are actually irreversible processes. The second reason is a practical one, since it is difficult to obtain the detailed land-use data that are prerequisites for within category land-use analysis. In this paper, we first present some basic information on the case study area, describe the characteristics of the local agriculture and briefly discuss the statistical data used in the case study. The subsequent analysis consists of two parts: an analysis of the distribution of land uses and an analysis of the driving forces of land-use change. The distribution of land use is represented by percentage of total area. We calculate the static relationships between the distribution of land uses and socio-economic and geophysical factors. We then try to elucidate whether the static relations are temporally stable, i.e. how these relationships have changed during the study period from 1970 to 1990. For farmland and residential land we investigate what kind of socio-economic factors as well as natural conditions explain the temporal changes of these major land-use categories during the study period. Through these analyses, we extract some driving forces of land-use change in the study area. The data set for this study was originally developed in the project "Land-use and Global Environment Change" (LU/GEC, 1995) sponsored by the National Institute for Environmental Studies, Japan

Three Dimensional Evolution of a Relativistic Current Sheet : Triggering of Magnetic Reconnection by the Guide Field

The linear and non-linear evolution of a relativistic current sheet of pair ($e^{\pm}$) plasmas is investigated by three-dimensional particle-in-cell simulations. In a Harris configuration, it is obtained that the magnetic energy is fast dissipated by the relativistic drift kink instability (RDKI). However, when a current-aligned magnetic field (the so-called "guide field") is introduced, the RDKI is stabilized by the magnetic tension force and it separates into two obliquely-propagating modes, which we call the relativistic drift-kink-tearing instability (RDKTI). These two waves deform the current sheet so that they trigger relativistic magnetic reconnection at a crossover thinning point. Since relativistic reconnection produces a lot of non-thermal particles, the guide field is of critical importance to study the energetics of a relativistic current sheet.Comment: 12 pages, 4 figures; fixed typos and added a footnote [24

Relativistic Particle Acceleration in a Folded Current Sheet

Two-dimensional particle simulations of a relativistic Harris current sheet of pair plasmashave demonstrated that the system is unstable to the relativistic drift kink instability (RDKI) and that a new kind of acceleration process takes place in the deformed current sheet. This process contributes to the generation of non-thermal particles and contributes to the fast magnetic dissipation in the current sheet structure. The acceleration mechanism and a brief comparison with relativistic magnetic reconnection are presented.Comment: 11 preprint pages, including 3 .eps figure

Electronic Orders Induced by Kondo Effect in Non-Kramers f-Electron Systems

This paper clarifies the microscopic nature of the staggered scalar order, which is specific to even number of f electrons per site. In such systems, crystalline electric field (CEF) can make a singlet ground state. As exchange interaction with conduction electrons increases, the CEF singlet at each site gives way to Kondo singlets. The collective Kondo singlets are identified with itinerant states that form energy bands. Near the boundary of itinerant and localized states, a new type of electronic order appears with staggered Kondo and CEF singlets. We present a phenomenological three-state model that qualitatively reproduces the characteristic phase diagram, which have been obtained numerically with use of the continuous-time quantum Monte Carlo combined with the dynamical mean-field theory. The scalar order observed in PrFe_4P_{12} is ascribed to this staggered order accompanying charge density wave (CDW) of conduction electrons. Accurate photoemission and tunneling spectroscopy should be able to probe sharp peaks below and above the Fermi level in the ordered phase.Comment: 7 pages, 8 figure

Relativistic particle acceleration in developing Alfv\'{e}n turbulence

A new particle acceleration process in a developing Alfv\'{e}n turbulence in the course of successive parametric instabilities of a relativistic pair plasma is investigated by utilyzing one-dimensional electromagnetic full particle code. Coherent wave-particle interactions result in efficient particle acceleration leading to a power-law like energy distribution function. In the simulation high energy particles having large relativistic masses are preferentially accelerated as the turbulence spectrum evolves in time. Main acceleration mechanism is simultaneous relativistic resonance between a particle and two different waves. An analytical expression of maximum attainable energy in such wave-particle interactions is derived.Comment: 15 pages, 9 figures, 1 tabl