In order to make clear the local climatological characteristics of bora winds, the observations were carried out in two famous bora regions in Yugoslavia. The main re-sults obtained in the Senj region are as follows: (i) In the case of relatively weak bora, the bora wind begins gradually from the Vratnik Pass to the coast. on the other hand, in the case of strong bora, the bora begins abruptly on the whole lee side slope. (ii) The temperature decreases lesser on the foot of the slope than at the pass in the clear begin-ning of bora. (iii) When the wind velocity at the pass reaches 11-14 m/s, the wind velocity on the foot of the slope increases sharply. The wind on the foot becomes not so strong in the cases that the wind at the pass blows stronger than these wind ranges. (iv) If the vertical structure of the atmosphere is unstable, the wind is relatively weak. (v) The strongest bora region is located on the slope north of Senj. Along the coast, the bora is strong between Senj and Klenovica.
The results obtained in the Ajdovscina region are: (i) The axis with strong wind runs parallel to the ridge in the case of relatively weak bora. The horizontal distance between the axis and the mountain ridge is 3-4 km. (ii) If the bora wind becomes more and more strong, a closed region with strong wind west of the Ajdovscina city experiences higher wind velocity than the axis region. (iii) In the case of the strongest bora, the axis moves leewards and accordingly, the strongest wind appears in the center of the basin. (iv) It is considered that the distribution pattern revealed by the wind-shaped trees, reported by Yoshino et al. (1973) in Climatological Notes No. 14, corresponds to the condition of the long year average, which contains the whole cases with wide ranges of wind velocity.

View full abstract

The wind-shaped trees were observed in order to make clear the distribution of bores on the Adriatic coast from Istria Peninsula to Dubrovnik and on the five islands, Krk, Cres, Lošinj, Rab and Pag. The observation was carried out at 380 points. The main species of trees observed were Ostrya, Fraxinus, Quercus in the northern part and Pinus in the south. The results can be summarized as follows : (1) The strongest bora region is located near Senj. The ENE wind flows out from the Vratnik pass. It turns gradually as NE flow on the sea and reaches to Cres and Lošinj islands as NE-NNE flows. (2) The strongest bora reaches as far as 50-60 km from the coast. On the north and south of this region, the bora is strong as far as 20 km from the coast. (3) The strong NE wind appears only in restricted areas south of Zadar. On the contrary, E-SE winds, Jugo, become to prevail. (4) On the slopes of the Dinar Alps facing the Adriatic Sea, the NE winds are strong up to 800 m above sea level and become weak suddenly at a height of 1, 000 m. At the pass topography with a height of 700-800 m, the wind is very strong locally. (5) On the islands, a contrast between the windward slopes and the leeward slopes is extraordinally sharp. At the col situation, the wind is very strong. (6) There is a high correlation between the mean wind velocity (m/s), W_w, in January, and the grade, G_w, of the wind-shaped trees. It is expressed by a linear equation by
W_w=3.231+1.64 G_w

View full abstract

The vegetation distribution on the Adrratic coast from Rijeka to Dubrovnik and on the five islands, Krk, Cres, Losinj, Rab and Pag, was studied in relation to the climatic conditions, especially to the local wind, bora. The climax vegetation in this region is the Mediterranean evergreen hard wood forests and deciduous broad leaved forests. The vegetation shows the Mediterranean type on the Adriatic slopes of the Velebit Mts., but, in contrast, the continental type on the inland-facing slopes. The deterioration of vegetation is the most serious on the slopes up to 500 m above the sea level on the coastal region. It looks like a land almost without vegetation. The evergreen oak forests re-main in restricted areas on the Rab island and their degradation types, maquis and garrigue, were found along the coast and on the islands south of Zadar. The poor-vegetation landscape prevails on the windward slopes, but, on the contrary, the forests or the ever-green vegetations on the lee side slopes on the islands.
The degree of density of the vegetation was studied for determining quantitatively the effect of the winds in this region. The rough density is found in the coastal and island regions from the north of Senj to the north of Zadar. This region coincides perfectly with the strong bora regions, which was revealed through an intensive investi-gation on the wind-shaped trees. The effect of wind, however, might be in a following way : (i) the original vegetation was destroyed first by human activity, (ii) the strong bora winds hindered the vegetation from restoration, and (iii) overgrazing of goat and sheep and felling of trees for fire-wood intensified the effect of hinderance by the winds.

View full abstract

Central Kyushu, which is located in the westernmost part of the Median Tectonic Line, has been investigated because of its geological and geomorphological importance in regional structures. Oita coastal plain is situated in the eastern part of Central Kyushu and terrace morphology is well developed in the area.
The present writer tried to clarify the mode of recent crustal movement in relation to the geological structure, after careful consideration of geomorphic history of the area.
Terrace surfaces distributing in Oita coastal plain are either marine or fluvial in origin. They are classified into seven levels, namely I, II, Ill, IV, V, VI and VI terrace surfaces in descending order. These surfaces were formed after Ozai sub-stage which is contemporaneous with Pyobugaura stage in southern Kanto.
Among these terrace surfaces, the V surface is most widely developed and its conti-nuity is very well. This surface consists of marine silt, and sand and pebble overlying the Oita Group with unconformity. The silt member filling the preceding dissected valley is called oka Formation and a bay environment is indicated from the molluscan fossils included in the member. Therefore, the V surface is considered to have been formed during the last major interglacial stage of Pleistocene age.
The I and II surfaces are distributed along the rivers, and these surfaces are of fluvial origin. The III surface was constructed during the ecstatic rise of sea-level in Pleistocene, preceding the V surface, judging from its distribution, altitude and deposit facies. Hereafter, the slow lowering and staying of sea-level followed and the IV surface was formed. The VI surface is a erosional river terrace surface with narrow area. The VII surface was formed during the last glacial stage, since the inclination of its longitudinal profile is the steepest among all terraces in this area, and the surface is buried by alluvium.
In Oita coastal plain, fault systems in two directions are observed. They are Median Tectonic Line direction (NE-SW) and N-S direction diagonal to the former. The former system is mainly recognized at the northern part of Saganoseki peninsula, but its recent activity is not conspicuous.
On the other hand, the latter system is presumed to be active in recent years from the displacements of terrace surfaces. In the area to the east of the Ono river, the most continuous V surface (17 m-41 m) increases its altitude westward, but the surface continuity is interrupted at the Ono River by a fault (Ono-gawa Fault) belonging to the latter system. The surface also increases again its altitude westward in the area to the west of the Ono River. There are double tiltings in both sides of the fault. The Ill, IV and VI surfaces are deformed in the same mode as the V surface. This west-ward tilting is clearly recognized on the surfaces below the II, and it is considered to be resulted from the recent activity of the Ono-gawa Fault.
The IV surface in Tsurusaki-daichi has been displaced by the Yokoo Fault, named by the present writer, being nearly parallel to the Ono-gawa Fault, with the same mode of deformation as by the Ono-gawa Fault. It seems that the activity of the Yokoo Fault associates with the recent activity of the Ono-gawa Fault.
Fault system of the Median Tectonic Line direction is recognized in the southern part of the study area where the Mesozoic Ono-gawa Group is distributed, and dextral displacements along some faults of the system can be deduced from the stream anomaly.

View full abstract

The Mediterranean red soil on the Adriatic coast was studied by making chemical analysis. The results were examined in relation to the climatic factors.
The red degree of soil color increases in the area south of Zadar, where the content of Free Fe is large and that of C is small. There found no relation between the annual precipitation, annual temperature, accumulated temperature over than 10°C or Lang's rain factor R=P/T. But the degree of soil color shows clear relation to the moisture index (Im), and water deficiency (d) defined by Thornthwaite (1948). Under the same condition of d, Free Fe increases with decreasing Im. In the case of the same Im values, a reverse relationship between Free Fe and d was found. As the region has the Mediter-ranean climate, water deficit concentrates in summer. So that, if Im has the same value, Free Fe contents becomes larger in the case of smaller water deficit in summer, which means increasing chemical action of red soil in warmer season. However, Free Fe contents are conditioned not by Im, but probably by the other factors, when the d value is zero.
Ca and Mg contents have no clear relation to the annual precipitation, but have to the Im and d values.

View full abstract

Local names of the winds from various directions such as sjeverac, oštro, levante and burg (widely known as bora) and their characteristics are mentioned here. The description of this article is based on neither the meteorological nor the climatological measurement, but on the summarization and induction of the local people's experiences, which have a close connection to their occupations—agriculture and fishery. The followings are the major results obtained :(1) The main signs of bores wind are : i) Mountain clouds called “brv”, which look like a form of foehn wall, are formed at the cols at first, then gradually covers all over the ridges of Dinar Alps forming kapa clouds. ii) In the case that the whole sky is covered by low clouds, the relatively high and bright clouds are to be seen in the northwest direction and the dark clouds in the south. (2) The bora wind blows with striking gustiness (na mahove) with a cycle of 3-4 minutes. The bora wind falls down on the coast as if “hard things were thrown on the ground”. The tops of the sea waves turn to sprays by the strong wind, causing a thick, hazy visibility over the sea. This phenomenon is called fumaria at Trieste. (3) Calm after the bora wind, called bonaca in this region, generally continues 2 or 3 days. Then the southerly wind, jugo, begins to blow. (4) There are two types of bora wind recognized widely by native fishermen because of their distinct characteristics. One is jasna bura (literally, bright bora) which means an anticyclonic bora, and the other is mra_??_na bura (dark bora), a cyclonic bora, respectively. The former prevails in the whole region of Adriatic Coast in the Croatian territory, but the latter limits itself to the northern part of the region. The border line may be located between Šibenik and Split.
Some shelters from the bora wind are used among the fishermen, who have a good knowledge of the local peculiarities of land and sea, and also of the sequential phenomena by their long experiences.

View full abstract