地学雑誌117巻1号（2008）掲載「戦後日本の地学（昭和20年～昭和40年）〈その1〉―『日本地学史』稿抄―」のp.270脚注において，日本地学史編纂委員2名（委員，矢島道子委員）のお名前が抜けていましたので訂正いたします。
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^＊委員長：石山　洋
 委員：藤井陽一郎
 黒田　和男
 高村　弘毅（日本地学史編纂委員会担当理事；立正大学）
 谷本　勉（法政大学）
 矢島　道子（東京医科歯科大学教養部）
 山田　俊弘（県立千葉高校）
 八耳　俊文（青山学院女子短期大学）
^＊Hiroshi ISHIYAMA
 Yoichiro FUJII
 Kazuo KURODA
 Hiroki TAKAMURA (Rissho University)
 Tsutomu TANIMOTO (Hosei University)
 Michiko YAJIMA (College of Liberal Arts and Sciences, Tokyo Medical and Dental University)
 Toshihiro YAMADA (Chiba High School)
 Toshifumi YATSUMIMI (Aoyama Gakuin Women's Junior College)

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Recently many kinds of water quality data have been collected by the Environmental Agency, the Ministry of Construction and so on, but these data are not necessarily systematic. As the first step, authors rearrange these water quality data, especially BOD and COD data collected by the Environmental Agency, for the analysis and mapping. Through this process, the characteristics of the water quality data, the structure of the data, and difficulties of the standardization of the data were discussed. A necessity of water quality maps was mentioned for a rational design of the countermeasures against water pollution. An importance of compilation of related data such as river discharge, geomorphological factors and pollutant sources besides water quality data was also pointed out.
As an example of a hydrological map of water quality, authors tried to draw up two distribution maps: BOD concentration over the rivers of Kanto District as shown in Fig. 2 and temporal changes of BOD and COD at the major water bodies over Japan in Fig. 3. Figure 2 shows annual mean concentrations of BOD given by the arithmatic mean of measuring points where more than 9 daily mean values were recorded in 1978. This figure shows that the large rivers such as the Ara, the Tama, and the Sagami Rivers in the metropolitan area have BOD concentration of 3_??_8ppm, which indicates recent improvement of water quality. However, at the midium and small rivers in the area BOD concentration shows terrible conditions with values of above 10ppm. On the other hand, the upper parts of the Tone and the Naka Rivers are still keeping a good water quality of about 1_??_2 ppm. These facts reflect the history of water pollution control policy in Japan and also imply what kinds of measures or controls are needed. However, in order to clearly understand circumstances of water quality or water pollution, more information such as water use, hydrological conditions and geomorphological factors should be included in the map.
In Figure 3, the annual mean concentrations of BOD and COD of rivers, lakes and coastal seas in Japan during 1971 and 1974 are compared with those during 1975 and 1978. Water quality of most rivers where high concentrations were recorded during the first period was improved very well at the second period. However, improvements at lakes and coastal seas could not seen. These regional characteristics and differences among different water bodies of water pollution and its control suggest the necessity of a new policy and countermeasures against water pollution.
As a concluding remark, systematic arrangements of water quality data collected by many different organizations and their expression as hydrological maps give a great help to water quality control.

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Desertification occurs in various parts of the world including humid region as well as arid and semi-arid regions. It is reported that more than one-fourth of land area on the earth is involved in this phenomenon. In some areas, land and vegetation degradation has caused such a serious problem as abandonment of farmlands. This phenomenon has been a universal issue since it was discussed at UNCOD (United Nations Conference on Desertification) in 1977. In Japan a research group of arid lands was organized in 1983 as one of the commissions of the Association of Japanese Geographers to proceed to research activities on regional problems of those areas and on desertification in the world. Then in 1985 the group was replaced by a working group. In the period of 1984 to 1986 the regular meeting for research was held 8 times, and the following studies were presented
OHMORI, H. (The Univ. of Tokyo): Natural Environment of Semi-Arid Regions in the Southern Part of Australia
TAKEUCHI, K. (The Univ. of Tokyo): Vegetation of Australia-Zonal Structure and its Anthropogenic Modification
NISHIZAWA, T. (Univ. of Tsukuba): Natural Environment of the Brazilian Northeast and Symptom of Desertification
KADOMURA, H. (Hokkaido Univ.): Savannization in Africa
TAMURA, T. (Tohoku Univ.): Grassfields-Forest Disappearance due to Human Activities in the Western Highlands of Cameroon
WASSON, R. J. (Australia Research Organization of Science and Technology): Geomorphology and Quaternary History of the Australian Desert Dunefields
HAGIWARA, H. (Graduate Student of Rissho Univ.): Problems of Sewerage System in Mexico
OJANY, F. F. (Univ. of Nairobi): Desertification in East Africa
KADOMURA, H. (Hokkaido Univ.): Drought in the Sahel-Sudan Zone (1)
TAKAMURA, H. (Rissho Univ.): Fire-burned fields and Symptom of Desertification in Zambia
MATSUMOTO, S. (.The Univ. of Tokyo): Some Problems Caused by the Development of Agriculture in Arid Zone of Middle and Near East
TAKAMURA, H. (Rissho Univ.): Salt Injury Caused by Groundwater Rising in the Costal Area of Persian Gulf
Moreover the symposium on “Geographical Aspects of ‘Desertification’” was held in September, 1986, in which the following subjects were set up, and 16 studies were presented:
1. Climatic variation and desertification
2. Water use and salinization
3. Agro-pastoral land use and degradation of land
4. Natural environment and change in land use
5. Control of desertification and suggestions for environmental management
Abstructs of paper submitted at the symposium were shown in the Geographical Review of Japan (Ser. A), Vol. 60, No. 2.
The present edition was planned to get those activities, especially at the symposium, into shape. If desertification is brought about not only by natural agency but also by human activities, then it must be examined from both physical and human points of view. Accordingly this edition aims at analyzing the present situation of desertification in the various fields of geography and studying out proper measures against this phenomenon.

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A great number of hydrological studies have recently been done and presented in various fields. If these achievements can be represented in the form of maps, their use will be of a remarkably wide range. The research group of hydrological map was organized in October, 1976 (replaced by the working group in April, 1979) as one of the commissions in the Association of Japanese Geographers to discuss how to map the hydrological environment. The summary of the commission activities is as follows.
The regular meeting for research was held 23 times; the annual report, Researches on Hydrological Map was published twice (No. 1, 1977 and No. 2, 1978). Seven papers were presented for IGU-IHP Commission Symposium, 1980 IGC. The group also set up such subjects for study as “The definition of the map of hydrological environment and methods of mapping hydrological elements”, “Mapping of hydrological environment on a middle scale”, and “Mapping of hydrological environment on a large scale” and has been making researches in concrete work. The results of the study were presented in Studies on Mapping Hydrological Environment (Grant-in-aid for co-operative research (A), The Ministry of Education, Science and Culture, Japan 1980).
The purpose of the present study is to attempt to decide methods of mapping hydrological environment. Before entering into the main subject, the author refers to the definition of the map of hydrological environment: the map reflects all kinds of hydrological phenomena around earth's surface presented by complex actions of natural factors and human impacts in relation to the earth's hydrological cycle.
It is the most important work in mapping to select carefully proper factors for representing on a map from a large amount of information and to develop a method of representation as rational as possible. In other words, the legible representation of carefully selected elements of hydrological phenomena is the key to mapping hydrological environment.
Hydrological phenomena are classified into three groups according to the situation in which the phenomena occur: one in the atmosphere, the second on the earth's surface and the last in the underground. The principal hydrological elements in the first group are precipitation, probable precipitation, rainfall intensity, evapotranspiration, potential evapotrans iration temperature, etc.; in the second, topography, river, lake, soil, vegetation, land use, etc.; in the last, hydro-geology, groundwater, etc. As it is impossible both in quality and in quantity to map the hydrological environment embracing all those phenomena. The description of the elements should be confined to the irreducible minimum and the most proper method of representation should be decided according to the object of the map. However, there still remain some problems such as, which scale to use in drawing base map, how to represent the distribution of groundwater use, and how many ranks to use in showing the different elements on the same map.

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地下水位の変動は地域の帯水層の物理的性質を反映する.とくに,沿岸部では,地下水位の正弦波形変動が潮汐に応呼して起こる.地表水体が単純な調和関数的運動をもって変化すれば岸の方から内陸に一連の波形が伝播するであろう.従って,潮汐の影響下にある自噴井の湧出量はそれに対応して変動する.故に筆者は,利根川の河岸からいろいろの距離にある自噴井を用いて同地域の地下水の変動特性を定量化することを試みた.自噴井の湧出量の変動に関するデータは岸から内陸に向かって一直線上にある三つの自噴井から得た.定量化に用いた筆者の方法は次のとおりである.自噴井の日湧出量の変動特性は振幅変動係数Q_rを用い,年間の単位時間の湧出量Qの頻度分布の特性値は湧出量の頻度の最多値Pdと分散度Qd(累加曲線から求めた)を用いた.一年間の湧出状況は,自噴井の湧出量状況曲線を作り,これから豊水期湧出量QH・平水期湧出量QM・渇水期湧出量QLの三つの値で示した.地下水の挙動を支配する帯水層の透水性は,各観測井におけるQの経時変化曲線からその振幅値Δhを求めて透水係数に相当するk値を計算して得た.以上の解析から,本地域の地下水位は潮汐型周期変化をもつ利根川水位R_rと降雨Pとが密接な関係にありその特性が各指標値に現われていることが判明した.

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On the Arakawa Alluvial fan, northwestern part of the Kanto Plain, late Quaternary fluvial terraces are widely distributed along the Arakawa river and a part of them are deformed by the Fukaya fault. The ages of the terraces have rarely been reported in this area, due to the scarcity of outcrops and lack of visible tephras. In this paper, we carried out a drilling survey on terraces to obtain samples of the overlying loamy soil and upper part of terrace deposits. From these samples, we extracted some well-known widespread volcanic ash, from which we were able to estimate the approximate age of the terraces and the vertical slip rate of the active faults. Late Quaternary fluvial terraces in the Arakawa fan are divided into 5 levels: from the Osato terrace to the Hanazono terrace in descending order. Widespread tephras such as the Hr-Hp (50ka) is contained in the lowest part of the loamy soil in the Kushibiki terrace and the As-BP (20-25ka) is present in the lower part of the loamy soil in the Miizugahara 1 terrace. From the ages and the vertical displacements of the fluvial terraces, the late Quaternary average vertical slip rates of the Fakaya fault are estimated to be 0.25-0.30 m/kyr (Kushibiki terrace, the minimum value), and 0.36-0.45 m/kyr (Miizugahara 1 terrace), respectively.

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 It is important to understand the history of water development and the water environment to solve problems related to water and plan its effective future use. First, surface water and groundwater from shallow areas where groundwater flow was controlled by geomorphology provided sources of water in Tokyo. Following the Edo period, the development of water resources accelerated, and groundwater controlled by geology was used by industries. The expansion of water use in Tokyo led to major problems such as land subsidence in the 1970s. Many studies have been undertaken on water use, which extend to the fields of pollution, land subsidence, and flow systems, etc. Development and management of the total groundwater environment in the near future requires an understanding of issues including water level, water quality, and water temperature.

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本会では, 本誌第26巻1号より「講座」を開設し, 第1回目のテーマとして「蒸発散」を取り上げた.5人の執筆者による講座「蒸発散」は, 現時点における最新の研究動向を踏まえ, 広範な角度から蒸発散についての基礎的な内容を伝えることができたものと思われる.第一線の研究者によるかなり高度な内容にもかかわらず, 好評のうちに第1回目のテーマを終了することができた.

本巻より始まる第2回目のテ-マは「降雨浸透」である.降雨浸透も古くて新しいテ-マであるが, 本講座では土壌の保水性や透水性といった水文土壌物理特性, クラストやマクロポアなどの土壌の間隙特性, 斜面の成層性や不均一性などの場の条件との関連において, 林地, 畑地, 都市, 傾斜地のそれぞれにおける降雨浸透過程についての基礎知識をとりまとめることを意図している.執筆者の皆様には最新の研究成果を取り入れていただき, 本講座によって降雨浸透現象についてのより一層の理解が増すことを願っている.

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