Landform Units Research Articles

A Study on a Landform Design in Lanbscape Architecture

Prudent landscape design distinguishes landform. design in landscape architecture from landform planning in civil engineering. While the criteria of landform construction has been well known, there is. no standard for landform design, yet it is an important element of landscape. This study attempts tosearch them out. The process of the study is basically divided into three steps: (1) lStudies on “TSUKI-YAMA” in famous historic Japanese gardens.(“TSUKI-YAMA” is a mound in a Japanese garden. and also considered a standard unit of landform.); (2) Examination of the facts found throughout former research efforts, and; (3) Overall conclusion.The criteria for the study consisted of three basic elements. They are as follows:1) The relation between the dimension of a mound and the distance from the view points to it;2) The form of a mound; and, 3) The optimum dimension of a space for such a mound.The indicators corresponding to the elements are below:1) ' The ratio “D/W”; “D”, the horizontal distance from a view point to the highest point of a mound divided by “W”, the width of a mound.(See Figure 1)2) ' “θ” (d°); the grade of a mound, and “H/h×100” (%); the percentage of “H”, the height of a mound divided by “h”, the height of the fundamental triangle of the mound.3) ' The limits of “D” (m).The overall conclusion throughout this study is as follows; the standards for “D/W” are shown in Table 2 (D/W=3 is suggested for the optimum standard). The standards for “θ” are shown in Table 5 (θ=23° or 24° is suggested for the prudent standard). The optimum percentage of “H/h×100” should be above 85% or 90%.(See Figure 4) The optimum space for a mound is limited to between. 23m. and 165m. All of these criteria should be considered in this landform design.

Arrangement of Swamp Forests and Landforms of the Alluvial Plain in the Lower Nakama River, Iriomote Island, Ryukyu Archipelago, Japan

The alluvial plain along the lower Nakama River on Iriomote Island can be divided from the shore landward into the following four sections: 1) a section consisting of the estuary, the coast of which is occupied by mangrove forests with Avicennia marina and Sonneratia alba constituting the seaward fringe; 2) a section of the delta covered with mangrove forests, dominated by Bruguiera gymnorhiza and/or Rhizophora stylosa, but also with some Kandelia candel but not including Avicennia marina or Sonneratia alba; 3) a section consisting of low, flat mounds composed of estuarine deposits formed during the Holocene transgression and covered with Pandanus tectorius thickets; 4) a section of a floodplain on which Barringtonia racemosa forests are prominently distributed.This paper, as the second part of a study on vegetation-landform relationships on this alluvial plain, deals mainly with detailed descriptions of the relationships in the third and the fourth sections mentioned above. In those sections, natural levees have developed along the Nakama River and its branches, and mixed forests of Machilus thunbergii and Mallotus paniculatus are found there. They are distinguishable from Barringtonia racemosa forests which compose a swamp forest in the back swamps and the Pandanus tectorius thickets on the flat mounds of the estuarine deposits. Colluvial slopes are occupied by other Barringtonia racemosa forests including Cyclobalanopsis miyagii.Close correspondence between the areal extent of landform units and plant communities is found both in small-scale and in micro-scale. The landforms of the area were outlined in the course of deposition during the Holocene transgression and have been differentiated by the processes that followed. The arrangement of the plant communities on this alluvial plain can be interpreted in terms of both present and historical land-forming process types.

Use oe aerial photograph for study of soil salinity and landscape relationship in parts of Haryana

In order to know the development of soil salinity and alkalinity in relation to landform, a systematic approach has been adopted by using aerial photo-interpretation techniques followed by field checks. The major land form units identified in the area are (i) alluvial upland (ii) low land (iii) back-swamp areas (iv) remanent horstland (v) interfiuve (vi) abandoned channel (vii) plain undifferentiated and (viii) plain with aeolian activity. salt accumulation is pronounced in landform units (i), (ii), (iii) and (iv) due to configurating slopes and basement ridge control, whereas in landform units (v) and (vi), a patchy distribution of salinity has been found. Landform units (vii) and (viii) are free from this hazard The elements of landscape have controlled the distriburion of salts within each landscape.

Sub-surface water regime related to landform studies through satellite images

Based on the visual interpretation of satellite (Landsat) false colour composite imagery, the entire Haryana State is divided into eleven landform units. Seven major landform units are studied in details with respect to water table fluctuation, ground water quantum and draft. The studies reveal that usable recharge and draft per unit area are maximum in case of area of water seepage and periodic flooding followed by Yamuna and Ghaggar flood plain and upper alluvial plains with occasional sand dunes. The minimum recharge and draft are observed in case of dune areas.

Land Classification and Development of the Sendai Coastal Plain

The Sendai Coastal Plain is located in the northeastern part of Honshu Island. The studied area in this paper is the southern part of this coastal plain and is about 30km long from north to south and 8km wide from east to west. Natural levees, beach ridges and other micro-landform units are commonly recognized in this area, but in place exist some landform units with slight elevation which can not be classified into either natural levee or beach ridge according to their similar topographic forms. The present author attempted to discriminate these uncertain landform units into natural levee or beach ridge from statistical parameters which depend on the shape of grain size frequency curves.For this purpose the author first of all clarified from the grain size distributions of sediment on typical natural levees and beach ridges, that standard deviation versus skewness and standard deviation versus mean grain size are effective in distinguishing the sediment of natural levee from that of beach ridge (Figs. 3, 4). The beach ridge sand and the natural levee sand are mainly separated by standard deviation, that is to say, beach ridge sand is more sorted than natural levee sand. And these sands are much more distinguishable by an analysis of the relation between standard deviation and other parameters of skewness and mean grain size.As the result of land classification, with consideration of sedimentary structures of alluvium and distribution of historical remains, the geomorphological development of this coastal plain was considered as follows (Figs. 8, 9).i) About 7, 500yrs. B. P. this area was under shallow maritime environment and the shore line was indented into the hilly area.ii) And by the beginning of the Yayoi period (about 2, 000yrs. B. P.), the 1st (innermost) beach ridge in this area was formed along the foot of hill-land, which resulted in shallowing of sea bottom by deposition of the terrestrial sediment, according to the reduced rate of sea level rise.iii) The 2nd beach ridge range appeared on the shallow off-shore bottom, before the middle Kohun period (about 1, 500yrs. B. P.), following to accmulation of terrestrial sediments on sea bottom. The marsh between 1st and 2nd beach ridges was gradually filled by fluvial sediment and peaty sediment, and the later period of this stage, the natural levee, to the north of Abukuma river, was formed on the marsh.iv) The 3rd beach ridge range was formed near the present shore line in the last stage. The marsh formed between 2nd and 3rd beach ridges was gradually accumulated and modified by natural levees while the Abukuma river changed its course due to repeated floodings and cut the 2nd beach ridge, then the natural levee, to the south of the river, was formed.

42. Classification of volcanic landform units and availabilities of air photographs.(Abstracts of Papers Submitted for the Meeting of Society)

42. Classification of volcanic landform units and availabilities of air photographs.(Abstracts of Papers Submitted for the Meeting of Society)

Method of Making Population Density Map by Landform Division and Accumulated Result

Intending to make a population density map based on the natural regional unit instead of the administrative one of Shi (city) and Machi (town) and Mura (village), we divide the territory of Japan into landform divisions and calculate the population density by each landform division. As for the elements which will be useful for establishing the natural regional units, we have to consider climate, soil, vegetation etc.. However, in case of Japan which belongs to the Circurn Pacific Orogenic Zone and whose lands are divided into many pieces of block mountains and small planes, landform should be considered having the first priority as the base of population distribution and suitable to represent the detailed regional differences of population distribution. Establishment of landform division The whole land is classified as following landform areas based on its morphology and developmental mechanism. mountain : mountain, volcano, hill land flat land : piedmont gentle slope, volcanic flank, upland, lowland When one kind of landform area is too large, we divide it into minor landform units according to the difference of form and construction material such as fan, delta, peat-bog or sand dune in lowland area, and maturely dissected mountain or elevated peneplain in mountain area. The areas of each landform unit is measured by using planimeter on the map of 1:200, 000 and decided by giving the necessary corrections. Calculation of population of landform unit Population of each landform unit is readjusted from the population of Shi, Machi and Mura illustrated in the population census. When the administrative unit is completely included in one landform unit, its population is simply tabulated, but when it extends over two or more landform units, its population is divided into each landform unit basing upon the number of dots found on the population map 1. Urban population The urban podulation living in the urban agglomerations with area of 0.25km2 or more is excluded in the tabulation of population of landform unit, because it spreads over the boundary of urban agglomeration and makes the population density of the whole unit up too high. The population of urban agglomeration is estimated by multiplying the definite coefficient as following classification getting from sampling to the total population of Shi, Ku (ward) and Machi. 1) Five major Shi 2) Shi with inhabitants of more than 100, 000 or established before 1940 except the five major Shi 3) Other Shi 4) Machi 2) and 3) are subdivided into two according to the area of urban agglomeration and population growth caused by amalgamation of Shi, Machi and Mura from 1950 to 1955. Map and appendix (See Fig. 1 and Table 1) The scale of the map is 1:800, 000 and the map covers the whole of Japan. There are three sheets in one set with 7 colors including boundaries of landform divisions, symbols of the kinds of landf orms and index number of landform units. Population density is presented in the map in grades from yellow, tan to dark brown tone by shading method. The situation and size of urban agglomeration are presented according to its size in its physical shape or definite round shape in brownish red. The base map which includes contour lines, limits of water body, administrative boundaries, settlements and place names are doubly printed in grey color. The appendix includes index number of landform divisions, place names, areas, number of inhabitants and population density, These were published as population census of Japan 1955, population maps of Japan 3. Population density by landform devision in JapanPopulation density by landform division of whole Japan and each district are shown in Table 2 and Table 3. Mountains and Volcanoes which occupy 61% of the whole land are almost low density areas, especially in a volcanic area.