A Fuudo of Bali, Indonesia is discussed through aspects of water and agriculture in Bali. The concept of Fuudo used here, which may be translated into Western words as clima, oikos, or milieu, is the same as that defined by Teturo Watsuji or Tokuji Chiba. Discussed in details are the difference in Hindu gods between India and Bali, the concept of direction in Bali, and the triad principle in Bali. Importance of the triad principle which is fundamentally different from the dualism in the Western world is stressed.
Bali, a small and active volcanic island in the humid tropics, is close to the east of Java, Republic of Indonesia, with an area of about 5, 600km2 and a total population of about 2.8 millions. Subak system, a traditional irrigation system of Bali island, is considered to be an example of skillful and developed irrigation system at the foot of volcanic mountains. A large number of studies about the subak system have already been made, but there is no attempt to make clear the relationship between actual condition of subak system and its physical conditions. In the present paper, a comparative description of the subak system in several rivers is conducted, based on field observation with special reference to physical condition. The subak system taking river water via long channel including tunnel has been developed under the following hydrological condition : 1) high precipitation without severe drought, 2) geology composed of tephra deposits with high permeability, 3) stable base flow from groundwater, and 4) soft rocks composed of pyroclastic flow deposits for excavating tunnel. There exists a wide regional difference in water intake and distribution system of the subak, and it would be strongly affected by the different physical conditions. Major findings of the present investigation of subak irrigation systems are summarized as follows : 1) Improvement works of subak system have been actively done under government assistance. A large number of small-sized traditional dam (empelan) made of local materials such as stones and coconut trees, have been changed to large-sized permanent dam (bendung) made of concrete. 2) The permanent dam improved by Public Works of Bali Province, has an average area of about 400ha and primary channel length of 3 km including water tunnel (aungan) of 1 km. The length of tunnel accounts for approximately 30% of primary channel in average. 3) In the south-central region of Bali, there exists the long tunnel with average of 2 km in Gianyar, constituting about 60% of primary channel. In Tabanan it constitutes only 10% of primary channel. 4) In the Pati river basin at the foot of Mt. Agung, which consists of lava and debris flow slope with shallow valley, there exist many small-sized subak systems having no long tunnel. 5) In the Batur pyroclastic flow region, many parallel rivers run in the deepest and narrow valleys and the large sized sawahs are widely distributed on the slope area. Long water tunnels have been constructed as a part of primary channel, with the maximum length of about 5 km in the Bendung Bedulu area. 6) In the Buyan-Bratan pyroclastic flow region, parallel river system is formed in valley. Most of dams have very long primary channels including short tunnel. 7) In the Mt. Batukau volcanic region consisted of lava flow hills and shallow valleys, rice terraces are widely distributed, and subak system has usually long primary channel with out water tunnel.
Environmental tracer method was applied to investigate groundwater flow regime in the pyroclastic flow slope of Mt. Batur, Bali, Indonesia. Tracers analysed were tritium (3H) concentrations and stable isotopic compositions (δ18O) of groundwater sampled from springs and wells. Tritium concentration in groundwater depend on residence time. On the other hand, comparison of the stable isotopic compositions between groundwater and precipitation informs of recharge area of groundwater flow systems. Combined analysis of these environmental tracers and chemical quality suggested that there were two types of groundwater in the pyroclastic flow slope of Mt. Batur. One was groundwater recharged by local rainfall, and it's residence time was relatively short. The other type of groundwater indicated heavier isotopic composition than local precipitation and relatively longer residence time. Whereas, sodium and sulphate concentrations of several springs couldn't be explained by mixture of the two types of groundwater, suggesting the contribution of the leakage water from L. Batur in Batur caldera.
The purpose of this paper is to clarify the relation of development of the Tertiary inner arc basins in north Kyushu with the plate tectonics. Sedimentary bodies of inner arc basins must afford better foundation for basin analysis than those of the accretion zone bacause of weaker tectonic disturbance. The Tertiary basins in north Kyushu are chosen for an example. The basins are chronologically analysed for two particular items, i.e. migration of basins and changes of subsidence-velocity, which respectively reveal one feature of tectonics and must serve for regional correlation of tectonic phases. On the basis of the correlation of the strata, chronologically spanning from the early Eocene to the late Middle Miocene (55-10 Ma), dates of onset, termination and migration of sedimentary basisns are first checked. Secondly mean subsidence-velocities for one stage or substage are calculated for each basin employing hitherto published thickness-data. The Tertiary basin in north Kyushu first appeared in and around Amakusa and thereafter migrated north-and northeastward accompanied by termination of subsidence of old basins and birth of new ones. Dates of onset of notable migration are referred to 55 Ma, 49 Ma, 43 Ma and 37 Ma. Comparison of mean subsidence-velocities clarified two facts. While mean subsidence-velocity for any stage or substage remarkably differs from basin to basin, patterns of velocity-changes in chronologic series are quite harmonious among the basins. The latter fact suggests that the subsidence of basins is controlled by regional tectonics beyond the extent of each basin. The general pattern of serial velocity-changes is cyclic repeatition of the early phase of higher velocity and the succeeding phase of lower velocity and of longer duration. Four cycles are recognized separated by marked increase of subsidence-velocity (velocity jump). Dates of the four velocity jumps are referred to 55 Ma, 37 Ma, 39 Ma and 17 Ma, of which the former two dates chronologically coincide with two of the migration events. Synchronism of different kinds of events suggests tectonic importance of 55 Ma and 37 Ma. Rea et al. (1990), Aubry et al. (1988), Caress et al. (1988) etc. claim that the most distinct global environmental change throughout the Tertiary caused by reorganization of plates occurred at and around 55 Ma. 37 Ma is also regarded by several researchers (Scotese et al., 1988 ; Hag et al., 1987 ; Shackleton, 1986 etc.) as another phase of a global environmental change involved reorganization of plates. It must be noted that velocity jumps of basin subsidence are also documented at 55 Ma and 37 Ma in the marginal basins of the South China Sea (Ru and Pigott, 1986). The third velocity jump (30 Ma) is synchronous with the beginning of the spreading of the Shikoku basin (Uyeda and Kanamori, 1979). The fourth velocity jump (17 Ma) chronologically corresponds with the crockwise rotation of Southwest Japan (Otofuji and Matsuda, 1983, 1984) just after the termination of spreading of the Tsushima basin (Chough and Barg, 1987) and the Shikoku basin (Uyeda and Kanamori, 1979). Overview of the above noted facts shows a clear tendency that the older velocity jumps correspond with global tectonic events and younger ones do with more provincial or local events. Considering the present accuracy level of chronology of the tectonic events both of the inner arc basins and ocean plates, the above mentioned obvious coincidence among major events of both sides strongly suggests that the coincidence is not accidental, but the correponding events are linked together by causal relation. If this is the case, confirmed date of any basin event, whose counter event has hitherto unknown for the ocean plates, may forecast the latter.
Extensive field survey on natural radiation was conducted from 1967 to 1991 over Japan Islands. The average level of the islands was found to be 79.7 nGy/h. In general, Southwest Japan has higher level compared with the Northeast one. From the data obtained at 1304 sites of the survey, a contour map of natural radiation level in the islands was made by simple interpolations, and a geological interpretation on the distribution of the level was done by comparing the contour map with geological information. The islands were divided into four areas according to whether the level is higher or lower than the average level. The boundaries between these areas were found almost exactly coincide with major geo-tectonic lines. This feature suggests that natural radiation level is controlled mainly by distribution of granitic and volcanic rocks.