This article attempts to examine the time and space use patterns of the fishing grounds for hand-line fishing in Mukuna, a village on the 4chi Islands of Ehime Prefecture from the ecological point of view. Using the results of a field survey, applicability of ecological researches on the fishing ground use the geography of fisheries is also investigated. Data were collected by direct observation of fishing activities on the sea, as well as by interviewing the fishermen.
The results of the field survey are summarized as follows:
1. It is nagashi-ipponzuri or the drifting hand-line fishing technique that is adopted by M ukuna fishermen. Motorboats operated by one fisherman are put to use for hand-line fishing.
2. The hand-line fishing takes place all year round. The fishing season is, however, divided into two periods in accordance with the seasonality of the catch: from April to January the fishing of madai (Chrysophrys major) and suzuki (Lateolabrax Japonicus) is practiced, while the fishing of kasago (Sebastiscus marmoratus) and mebaru (Sebastes inermis) is complementarily carried out in February and March.
3. Several sorts of bait are employed according to the seasonal variation in availability,
4. There are about thirty boats for hand-line fishing in Mukuna. This number is seasonally reduced according to shifts in the local climate. Merely ten are in use when the water temperature reaches its peak in the hottest months of August and September and when the water becomes cold and rough in winter with the northwest monsoon.
5. Mukuna waters provide twenty-two fishing spots, which can be classified into three categories in terms of the tidal current conditions.
a) fishing spots used at ebb current (ten)
b) fishing spots used at flood current (ten)
c) fishing spots used at both ebb and flood current (two)
6. Considering the tidal current conditions, a fisherman decides the type of fishing spot which is suitable and then chooses by turns some of the fishing spots within the same category.
7. The hand-line fishing is conducted from early morning to evening.
8. It is not possible to do hand-line fishing when the tidal flow is fast. Fishermen cannot avoid stopping their work at sea until the tidal current conditions turn favourable. Some fishermen go back to the land to take a rest when the tidal current conditions are bad.
9. Mukuna fishermen can perceive clearly enough where they are at sea through yamasate, a location-finding technique by visual triangulation which is based on the observation of counter movements of two or more mountains or islands seen from the sea. An application of yamatate enables the fishermen to grasp the speed and direction of the currents. When their location at sea is once confirmed, the fishermen understand such attributes of the fishing ground as range, water depth, morphology of the sea bed, and so on, because they are well equipped with a large amount of empirical knowledge of each fishing spot.
The author analyzed the use of the fishing ground in Mukuna from the viewpoints of the time-use pattern and the space-use pattern. In terms of the time-use pattern, data on daily, m onthly, seasonal, and annual cycles must be collected according to the fishing activity: In terms of the space-use pattern, three-dimensional space.……the surface, the water, and the sea bottom …… has' to be grasped as a whole.
The author is intended to carry on this ecological study on the fishing ground use by accumulating more data on the time and space use of the fishing grounds and to integrate the data for a comprehensive ecological analysis of the fishing villages using these fishing, grounds.

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In this paper, a method of evaluating a transportation condition in a given area is proposed from the viewpoint that a transportation system as one of the conditions of industrial location should be relatively evaluated. In other words a given small area should be treated not as an independent entity but as a relative part of the whole area. When the local transportation system is improved more slowly than the average of the whole area, its relative condition degrades in the whole area in spite of a certain amount of actual improvement.
Employing the graph theory and the MDS technique, we obtain both the gain and loss ratio of accessibility and the time-space configuration of the respective cities of the Chugoku and Shikoku District. This district constitutes the whole area in this study. With the aid of these ratio and configuration, we evaluate the expected change of the transportation condition caused by the realization of some important projects in this area. The results are as follows.
1. The gain and loss ratio of accessibility.
When a region is treated as a relative part of the whole area, the gain and loss ratio of accessibility is an useful index to evaluate the change of its transportation condition. According to the gain and loss ratio of accessibility the construction of the Honshu-Shikoku Bridge (this level of transportation system being termed stage II) gives only four percent of gain to the region near the approach to the bridge in Shikoku. In contrast with this stage the construction of the Chugoku Jukan Expressway (stage III) greatly expand the accessibility in the surrounding areas, the highest gain ratio reaching more than 20 percent. Provided that both of the Honshu-Shikoku Bridge and Chugoku Jukan Expressway are built (stage IV), the entire Shikoku district shows a loss ratio of accessibility in spite of the construction of the bridge. The building of the Shikoku Jukan-Odan Expressways, the Chugoku Odan Expressway, and the Sanyo Jidosha Expressway together with the construction of the bridge and the Chugoku Jukan Expressway (stage V) still brings a loss ratio in the entire Shikoku district except for the small area adjacent to the approach to the bridge.
2. The time-space configuration.
The time-space configuration of cities by the MDS method is an useful geographical device because the area with a gain ratio of accessibility is reduced and the area with a loss ratio enlarged on the same map. The results obtained from the maps drawn by this method are as follows.
The time-space configuration of stage I, representing the state of the area before the construction of the expressways and the bridge, bears a striking resemblance to the real geographi cal map. This shows a similarity between the physical and the time space in the Chugoku and Shikoku district before their construction. The bridge construction hardly changes the time-space configuration of stage I in spite of the big project. There are two reasons for this. One is that the well-developed ferry boat network has been already organized in the Inland Sea of Seto and the other is that the bridge construction is geographically a mere local improvement in the whole transportation system. On the other hand, the construction of the Chugoku Jukan Expressway extremely reduces the time-space configuration in the Chugoku district in the east and west directions, while relatively speaking this turns out to enlarge the time-space configuration in the Shikoku district. The time-space configuration of stage IV bears another striking resemblance to that of stage III. The construction of the bridge together with the Chugoku Jukan Expressway scarcely changes the time-space configuration of stage III.

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The left bank of the River Kokai was collapsed by the flood water of the River Tone caused by a storm of Typhoon 8115 at Ryugasaki City, Ibaraki Prefecture, at about 02:12 a. m. on August 24, 1981. The collapsed point was the place about 4.5 km upper from the junction to the River Tone, where a meandering segment was shortly cut in 1925.
Typhoon 8115 produced a heavy storm over 300 mm in the mountainous region of the uppermost basins of the River Tone for 3 days from August 21 to 23 (Fig. 1). More thai one days after the peak of precipitation, the collapse of the bank of the River Kokai occur-r ed. The inundation area was about 3, 300 ha as shown in Fig. 2.
The authors measured a maximum depth of the inundation water at 165 elevation spots in the inundation area (Fig. 5). Judging from its result and aerial photos taken about 7 hours after the collapse of the bank, the authors found the following facts on the behavior of the inundation water.
1. The inundation water had three main flows as seen in Figs. 3 and 4. Among them, the strongest one flowed southward.
2. The inundation water advanced straightforwardly under little control of a relief of ground surface when the inundation water flowed strongly. As leaving from the center of the main flow or weakening of the strength of the flow, the inundation water was controlled by a relief of ground surface (Figs. 6 and 7).
3. The Ronsho Drainage drained much inundation water, but it was not a main route forr the inundation water flow.
4. The spread of the inundation area was significantly influenced by the existence of the inner bank constructed in the Edo era.
5. It is very. important for our present society to digest and apply a traditional land use and counterplan for disaster prevention from all kinds of materials such as archives.

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Various patterns of sand ripples found on sandy shallow sea bottom are classified into planar parallel, lunate, diagonal, nearshore irregular parallel and regular parallel ripples. They generally appear in this order with increasing water depth. Relations between ripple types and intensities of wave-induced oscillatory water flow have been studied by severall researchers. In these studies, however, flow intensities are computed from wave data on the basis of wave theories.
In order to consider the relation between ripple types and sand movement, more detailed characteristics of oscillatory water flow over each ripple type is necessary. Tatado Beach, Izu Peninsula, Japan (Fig. 1) was selected as a study site. The flow measurement was conducted using an ultrasonic current meter installed at heights of 26 to 80cm above the sea bottom. The characteristics of oscillatory water flow, such as the flow intensity, the directional variation and the velocity asymmetry, were examined for the flows over regular parallel, nearshore irregular parallel, diagonal and lunate ripples, and also over a flat bed.
As shown in Fig. 2, the horizontal flow velocity is lowest for the flows over regular parallel ripples and is highest for those over a flat bed. The relation between ripple types and flow intensity represented by Manohar's (1955) non-dimensional function Ψ₁' is examined (Fig. 3): Ψ₁' is calculated using actually measured velocity. Fig. 4 shows the similar relation, in which the maximum horizontal velocity, U_m, is calculated from wave data using wave theories. As compared with Fig. 4, Fig. 3 shows: a smaller variation in the value of Ψ₁' for each ripple type and gives more clear boundaries for the ripple-type demarcation. This suggests that the calculated value of U_m in the nearshore zone involves considerable error.
The directional variation of flow oscillation is examined in relation to the flows over each ripple type using a rose diagram with 16 directions (Fig. 6). This figure indicates that little difference in the directional variation exists among different ripple types. Especially, the range of directional variation in the oscillatory flows is too narrow to explain the directional angle between main and sub-crests of diagonal ripples, which intersect nearly at right angles to each other (Photo. 1). This result does not support the opinion that diagonal ripples are generated by waves advancing from two different directions. The relation between ripple types and velocity asymmetry of the oscillatory flows is shown in Fig. 7, which indicates no general tendency.

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