Heavy Rainfall Areas Research Articles

Heavy rainfall areas in Peninsular India

By incorporating data from unofficial, non-reporting raingauge stations a list of 17 locations with an average annual rainfall exceeding 5000 mm can be compiled for Peninsular India. All stations are located along the westward exposed escarpment of the Western Ghats at a distance of not more than 100 km from the Arabian Sea. Here the superimposition of large-scale dynamic and static, location “controls” during the Southwest Monsoon period (June–September) results in annual, monthly and daily rainfall amounts that are only surpassed at a few stations outside the peninsula in Northeast India. Potentials and problems of water resources development in the heavy rainfall areas are briefly discussed.

Benefit‐Cost Analysis of Surfaced Roads in the Eastern Rice Region of India

In a recent study, Easter, Abel, and Norton attempted to measure the contribution of various inputs to total output in the eastern rice region (ERR) of India.1 They included both the traditional inputs such as land, labor, and fertilizer as well as nontraditional inputs such as irrigation, technology, environmental factors, and infrastructure. They estimated production functions in log form using district level data and found that the production elasticity on surfaced roads was highly significant and very stable under alternative equation specifications. The present research note uses their estimated production elasticity on surfaced roads (0.208) in estimating a benefit-cost measure of public investment in surfaced roads in the ERR. In this paper, a model is set up to estimate the benefits, then costs are estimated, and, finally, the estimated benefits and costs are joined together in a benefitcost ratio. According to the Easter-Abel-Norton (EAN) study: Surfaced roads appear to be important in explaining productivity differences among districts. . . The absence of roads in a heavy rainfall area such as the rice region has the effect of raising input prices paid by farmers and lowering output prices received by them due to higher transportation costs. Following this, the benefits of public investment in surfaced roads may be assessed as follows. Consider figure 1, which depicts the basic economic interrelationships between the rural producing and consuming sector, the marketing sector, and the nonrural consuming sector. Figure 1(a) describes the supply (S) and demand (D) curves for the rural or food surplus area. Figure 1(b) describes the excess supply (ES) curve from this area and a demand (DU) curve for the urban or food deficit area. Figure 1(c) describes the supply (SM) and demand (DM) curves for marketing services, where the supply of marketing services are assumed to be perfectly elastic over the observed range of services supplied. This is thought to be reasonable, in the absence of congestion costs, following some earlier research (for example, Ruttan).2 Using a perfectly competitive model, the last mentioned curve is a vertical subtraction of the ES from the DU curve.

Meteorological Analysis for the Las Vegas, Nevada, Flood of 3 July 1975

Meteorological data are analysed to determine the location and intensity of the rainstorms that led to flash flooding in the Las Vegas Valley and resulted in approximately $4.5 million in damages on 3 July 1975. The effective precipitation contributing to the flood was found to cover an area of 550 km2. Within this area two centers of heavy rainfall were found, one situated approximately 14 km southwest of the central business district and the other about 13 km north-northwest. Maximum rainfall amounts are estimated to be of the order of 3.0 inch. A maximum rainfall rate of 1.0 inch per hour was detected in a weighing-bucket raingage. Hail and surface wind gusts of about 50 kt were observed in the northwestern portion of the city. Furthermore, the area of heavy rainfall is shown to have developed over the Las Vegas Valley and not over the surrounding mountains. Integration of an isohyetal analysis shows that, at least, 2.3×107 m3 (1.9×104 acre ft) of water was available before infiltration. This amount of detail in the documentation of southwestern desert rainstorms is rarely available.

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

訂正 24巻1号 山下論文

Haemaphysalis (Alloceraea) aponommoides Warburton (Ixodoidea: Ixodidae), Description of Immature Stages, Hosts, Distribution, and Ecology in India, Nepal, Sikkim, and China

Haemaphysalis (Alloceraea) aponommoides Warburton has been reported from only 8 collections of adults. The larva and nymph are described and compared with those of H. (A.) inermis Birula (S Europe, SW USSR, N Iran) and H. (A.) kitaokai Hoogstraal (Japan). Data and observations are presented for 102 collections (2,075 specimens) of aponommoides from Nepal and for others from India, Sikkim, and China. Immature stages are recorded from a pheasant and 2 shrew and 4 rodent spe- cies between 8,000 and 11,500 ft altitude in Nepal. Hosts of adults are chiefly artiodactyl mammals, the barking deer and serow, and the domestic cow, yak, cow/yak hybrid, buffalo, horse, goat, and sheep, but also include humans, a domestic dog, a flying squirrel, two wildcats, and a black bear. Adults occur be- tween 7,000 and 16,000 ft altitude in Nepal but as low as 2,975 ft altitude in dense forests in heavy rainfall areas of Sikkim. Larvae and nymphs quest for hosts from low vegetation beside small-mammal runways before, during, and after the monsoon season. Adults are active most of the year. Biotopes in- clude pastures and clearings, bamboo thickets, original forest with moss and fern but little underbrush, dense sal forest, various coniferous forests, oak-rhododendron forest, and alpine meadow.

The Synoptic-Climatological Characteristics of Heavy Rainfalls in the Region of Pacific Ocean of Tohoku District

The appearance-distribution of heavy rainfalls (above 50 mm per day) in the region of Pacific Ocean side of Tohoku district is analysed synoptic-climatologically. The main results obtained are as follows;1) The heavy rainfalls in warm season tend to appear in the eastern (coastal) region of Tohoku district. This tendency is more obvious as the maximum amount in rainfall-area is larger.2) The heavy rainfalls in the western and central regions are mianly due to the front, thunderstorm and northwesterly monsoon. On the other hand, those in the eastern (coastal) region are mainly due to the typhoons and subtropical cyclones. Regarding the latter, almost every case (80-90%) having the maximum rainfall-amount more than 100 mm per day is due to the typhoon or subtropical cyclone.3) The larger the daily mean sea-level pressure difference (Δp) between Nemuro and Choshi, the more frequently thd heavy rainfalls (above 100 mm per day) appear in the eastern region.4) The fact mentioned in 2) is more obvious in the eastern (coastal) region when positive Δp is larger, and in the western and central regions when negative Δp is larger.5) The annual variation of frequency of heavy rainfalls in an area with the size of a prefecture corresponds to that of precipitable water. This relation, however, is not obvious in smaller regions covering a half or one third of a prefecture, because the heavy rainfall areas are dislocated according to synoptic condition specially in summer and in winter.

The Iranian Village before and after land reform

Agriculture in Iran, as in most of the Middle East, has traditionally produced a surplus that has gone to support city dwellers with only the barest minimum of investment returned to the countryside. The 'city feudalism' of the Middle East and much of Asia, where the major landlords dwelt in, and often dominated, the cities, has been seen as one of the reasons why modern capitalism did not develop indigenously in these areas. In the discussion of this question, stress has usually been put on the lack of independent municipal communes in Asia and on the stifling economic effects of landlord domination of the cities. Whatever the merits of this argument, recent research would indicate that the agricultural part of the pattern was perhaps even more important. The manorial system of western Europe and Japan, and the increasing productivity of agriculture in these areas of heavy soils and rainfall, seem to have produced an expanding agricultural surplus. In both Europe and Japan men with agricultural origins played a key role in the development of modern capitalism. In the arid Middle East, however, agricultural production seems to have shown a general decline over many centuries, due in part to deforestation, soil erosion, and the salinization of irrigated lands. There appear to have been no major agricultural improvements in the area for many centuries before the recent imports from the West. Perhaps improvement was more difficult in the Middle East than in the West such an important European innovation as the heavy wheeled plough is useless on most of the soils of the Middle East. One may also suspect that the residence of landlords in the cities and the vulnerability of the villages to nomadic and other pillaging were positive obstacles to the building up of a surplus or of heavy investment in the countryside. Investment was confined to such things as the traditional irrigation networks, which were essential

THE EXTREME VALUES OF DAILY PRECIPITATION IN JAPAN (2 ND REPORT)

In the previous study (Geographical Review of Japan. Vol. 31, No. 2, pp. 86_??_94, 1958), the author estimated the annual and seasonal maximum daily precipitations for 5, 10, 25, 50, and 100-year return periods by applying the Gumbel's theory. Using the estimated data, distribution maps of extreme values were constructed. But it was pointed out that the Gumbel's theory contained some questions. One of them is the fitness to actual distribution of extreme values. According to the works by Brooks, C. F. P. and N. Carruthers (1953), the extreme values of air temperature are liable to be overestimated and those of precipition understimated, if the Gumbel's theory is used. Jenkinson, A. F. (1955) presented an improved theory for the estimation of extreme values. This shows better fitness and the process of estimation is not so difficult. Hence the author reestimated the extreme values according to this theory for several return periods in Japan. The results at a number of stations were added to the previous works. Regional distribution of the extreme values generally shows similar patterns to the previous maps (Fig. 2). Details of distribution, however, have some different features from the previous maps. The following facts were made clear in this paper:1) The June-July season: heavy rainfall areas appear in western Kyushu, southeaster part of Kii and entire part of the Izu peninsula.2) The August-November season: heavy rainfall areas appear in the eastern Kyushu, southeastern Kii peninsula, and northern and western Kanto.3) The December-May season: an area with scanty rainfall appears in the coastal regions of Seto Inland Sea.4) Year: heavy rainfall areas appear in southeastern and western Kyushu and western Kanto, and an area with scanty rainfall inn the coastal regions of Seto Inland Sea.The author compared the estimated extreme values of the June-July season with those of the August November season. Heavy rainfalls in the June-July season are mainly caused frontal activities (Bai-u), and those in the August-November season are by typhoons. At stations where the estimated values in the June-July season are larger than those in the August-November season, fronal rainfall is distinctly heavier than typhoon rainfall. On the contrary, at stations where the estimated values in the August-November season are larger than those in June-July, typhoon rainfall is heavier than frontal rainfall. The author calculated the ratio of the extreme values in the June-July season to those in the August-November season for each station. At the stations with the ratio exceeding 1. 0, frontal rainfall is predominant, whereas typhoon rainfall is abundant at the stations with the ratio below 1.0. Areas with the ratio exceeding 1.0 are concentrated in the following districts (Bai-u areas): 1) Northern and western Kyushu, 2) Chugoku (except eastern San'in), 3) Western Shikoku, 4) Middle Kinki, 5) Hokuriku. Areas where the stations with the ratio less than 1.0 are concentrated are the following districts (typhoon areas): 1) Eastern Kyukhu, 2) Eastern Shikoku, 3) Northern and southwestern Kinki, 4) Western Kanto and Izu islands, 5) Eastern Ou, 6) Northeartern Hokkaido.Based on these facts, Bai-u and Typhoon areas can be distinguished in Japan. Lastly, the author made clear the regionalities that a found in the secular changes of maximum . daily precipitation in each season. He divided the trends of secular change into the following three types: increasing (type 1), decreasing (type 2), and indefinite trend (type 3). Thg results are as follows:1. The June-July season. 1) Type 1 is distributed all over the country, except a few districts. 2) Type 2 is concentrated in the inland areas of Chubu and in Hokuriku.2. The August-November season.

DISTRIBUTION OF RAINFALL RELATED TO THE ACTIVITIES OF BAIU FRONTS

In this article, the author studied on regional characteristics of rainfall related to Baiu fronts. Heavy rainfall concentrate in tonal area in some restricted regions, such as the middle Kinki, west Chugoku and north and west Kyusyu. These areas are freely exposed to southwest airflow working as a trigger of heavy rainfall with large amount of vapour. So the author considered that the rainfall zones may correspond to the areas freely exposed to southwest airflow. In order to confirm this idea, several examples of heavy rainfall are taken and some phenomena that seemed to supporte this idea are investigated. For example, the diurnal variations of water vapour in the lower troposphere, the upper wind conditions, and airflow trajectories are analized. By these analyses, the idea is confirmed and it becomes clear that the heavy rainfall areas are pref ectly related to the topographic conditions.

Rainfall around monsoon depressions over India

Rainfall that occurrs for 2 to 3 days within a radius of 350 miles from the centre of a depression along its track has been combined using the data of all raingauge stations within that area. Such 'composite' charts of rainfall were prepared for a sample of three mid-monsoon depressions in the year 1944. Falls of heavy rain of 3 and above in 24 hours are confined to an area lying to the left hand side of the track. On any particular morning, the heavy rainfall area extends to about 300 miles ahead and to about 300 miles behind the centre of the depression on that morning, measured respectively along the expected and past track of the depression. The width of the area is about 250 miles and extends to the left of the track. It is further noticed that out of this belt, about 30 per cent of the area is almost the maximum over which there may be rainfall of 3" or more in 24 hour's. The results are discussed from a forecaster's point of view.

HIGH COUNTRY GRASSLANDS IN NEW ZEALAND: Their Characteristics and Problems

From the farming point of view the high country of the South Island of New Zealand is generally taken to mean all the high native grassland devoted to the growing of wool and store stock and subject to risk of Slidui. This covers some 12 million acres of country with a great variety of topography, climate, and soils, Rainfalls range from 1%. in the arid regions of Otago to over 100in. in the heavy rainfall areas close to the main ranges, and soils and vegetation vary accordingly. The winter is long and the growing season short, a maximum of 6 months in most districts.