A mobile observation of pressure was performed to confirm the formation of meso-low under the Kiyokawa-dashi winds which are strong local easterlies in the Shonai coastal plain. The pressure observation was made by means of the American Paulin System Altimeter. Temperature and altimetric height were measured at bench marks where their elevations are shown on the 1/25, 000 topographic map. The barometric pressure and therefore sea-level pressure were obtained by the hypsometric formula. By the procedure geographical precise pressure distribution can be obtained.
The observation was made between 11000 and 15:00 on July 11, 1987. Temperature and winds were also measured through the mobile observation by using the Assmann ventilated psychrometer and a Nakaasa-type portable wind vane and anemometer, respectively. At the base station, pressure and winds were recorded by a barograph and by a portable wind vane and anemograph, respectively, during the mobile observation. In addition to the observation, the vertical distribution of upper wind and static stability were analyzed by using the serological observation data obtained at Akita and Sendai Meteorological Observatories. During the observation, an extratropical low was passing over the Sea of Japan(Fig. 3)and pressure distribuution was typical “east high/west low” situation(Fig. 4).
The results of the present investigation are summarized as follows:
1. The mobile observation of meso-low by using the altimeter was found to be very useful to examine mesoscale distribution of the barometric pressure.
2. Surface easterlies prevail over the plain under the condition of southerlies at about summit level of surrounding mountains. Wind speed is the highest at the valley mouth where the Mogami River comes out on the plain, and the speed is low in the valley and southern part of the plain (Fig. 6).
3. A meso-low develops over the plain and pressure difference between the center of the meso-low and inner part of the valley reaches above 4mb (Fig. 7). In particular, pressure gradient becomes largest in the vicinity of the valley mouth.

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最上川流域は,朝日山地,飯豊山地,奥羽山脈などの山並みに囲まれており,これらの山間部に,降り積もった雪が3月中旬より融けだし,約2ヶ月間続く雪融け出水をもたらす.この期間の流出量は年間流出量の約40%を占め,この地方における主要な水資源となっている.同時に,この出水は中にさまざまな物質を懸濁あるいは溶融し,流域から河口へと輸送している.本研究は,この中の懸濁物質に着目し,輸送量の把握,濃度の時空間的な特性を調べることを目的として,観測・資料収集・解析を行った. 観測は,筆者らが開発した簡易採水器を用いて, 1996年5月2日に最上川中流部の須川合流地点から,下流の鮭川合流地点までの主要5合流地点で行った.また,筆者らの観測データの他に, NOAAの衛星データ,建設省の流量・濁度の連続観測データなどを集め,雪域や時系列の特性を解析した. 本川の流下方向の濃度分布と流量分布を調べた結果,朝日山地や飯豊山地が含まれる,長崎の集水域で生産される濁質が支配的であることがわかった.この地域では, 4月の下旬においても雪域が広く残っていることが衛星データより確認されている.また流量・濃度の連続観測記録を検討した結果,両者には相関があり,濃度は流量の1.44乗に比例することがわかった.その比例係数は時期が遅くなるに従って小さくなり,流域に存在する細粒分が洗い流されたために濃度が小さくなったものと解釈される.これを物質収支を考えてモデル化し,流量の時系列データだけから濃度を予測する方法を提案した.

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The large-scale landslide landforms, wish source areas wider than 1 km were mapped by air-photograph interpretation in the Tohoku district between latitude 38°N and latitude 42°N. On the basis of the mapping, characteristics of the distribution of those large-scale landslide landforms are discussed from geomorphological and geological points of view.
Six regions are recognized as those of concentration in the central part of the Ou Mountains, the Shirakami Mountains, the Hinotodake-Kamura Mountains and the northern part of the Asahi Mountains. Those regions mostly coincide with the areas of the maximum uplift during the Quaternary time in the Tohoku district. Those are also underlain by the zones of the Lower and Middle Miocene sedimentary rocks and submarine volcanic rocks, commonly called “Green Tuff”, and the Quaternary volcanic rocks. The topography in those zones are characterized by cap rock structures.
The large-scale landslide landforms of the Quaternary volcanic areas are dominantly found in the old and/or dormant volcanoes, and are roughly divided into three types from the main contributing factors of landsliding, the volume in source area, morphology and so on.
(1) Type 1 is a catastrophic landslide or collapse of a volcanic cone associated with volcanic activity. Its tophographic and structural feature is composed of the so-called the collapse caldera of the source area and hummocky relief of the deposition area. The latter is a typical topographic feature of volcanic dry avala nche deposits composed of megablocks and interstitial fine material. The volume of the source area is the largest of the three types. Examples can be seen in Iwate volcano, Iwaki volcano, Gassan volcano, Cheikai volcano, Zao volcano and Shirataka volcano.
(2) Type 2 shows a typical landslide landform associated with a gentle arc-shaped main scarp and a moving mass. Main scarp of this type is found on the slope of a thick lava flow near the top of the volcano.
The activity of the volcanoes, where the landslides of this type occurred, ceased in the late Pleistocene and seems to be almost dormant at present.
The contributing factor to the landsliding may be a large quantity of water supply related to the late Quaternary climatic change.
Water are prepared in the form of the perennial snow patches and are supplied by the rapid melting of the perennial snow patches with the rising air temperature. The formative age of the perennial snow patches ranges from the late Pleistocene to the eariest Holocene (period about 18, 000y. B. P. to 8, 000y. B. P.).
Because the sea level of this period is lower than that of the present, mountains were vigorously dissected. Then the stability of the mountain slopes rapidly deteriorated and a number of large-scale landslides occured.
Those landslides are found in Hachimantai volcano, Yakeishi volcano, Kurikoma volcano, Funakata volcano, Gassan volcano and Zao volcano.
(3) Type 3 is recognized along the dissected vally wall in the pyroclastic deposits and pumice fall deposits. Type of movement is mostly rotational. The volume in source area is smaller than that of the type 2. However, the same contributing factor may be important for the landslides of type 3 as the type 2.

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岩手県は太平洋側にあって東北6県中牛の頭数が最多で公共草地も青森県と共に桁違いに多い。大規模火砕流の溶岩台地と北上山地の準平原に集中造成された。日本海側の秋田県にも広い台地が分布するが,不透水質海底堆積層からなり草地に適さず,数少ない公共草地が県内に散在する。県の大半が粘質上に被われていることで畑適地に乏しく,酪農への発展もなかったが,適地適作の原理に従い銘柄米の栽培に重点を置く。こうした傾向は青森県津軽から山形,新潟県の日本海側に共通している。

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東北地方およびその南方地域に設置されている一等三角点は1893〜1904年の測量開始以来,第2回(1960〜1964年),第3回(1973〜1985年)の改測が行われ,一等水準点の測量は1892年以来今日まで逐次改測が行われてきた.これらの資料を基に当地域について,観測期間を前期(1898〜1962年),後期(1962〜1979年)に分け,変動解析を行った.その変動様式から,当地域は仙台平野-山形盆地-新庄盆地-横手盆地-酒田周辺の帯状地域の境界,それより北方の北半部,南方の南半部の3地域に区分される.面積歪み(膨張/収縮)は垂直変位(隆起/沈降)と正の相関をもつ.すなわち北半部においては,前期の収縮域は後期には膨張域に変わり,その変動に符合するように垂直変動は,沈降域から上昇域に転ずる.他方南半部においては,前期の膨張域は後期の収縮域に移行し,垂直変動は上昇域から沈降域に変わる.こうした変動地塊の規模は数10kmから200kmである.これら各地塊は膨張・隆起運動と収縮・沈降運動が交互に進行し,脈動する.そしてその境界地域はほぼ一定しており変動の要因は地下深部にあることを示唆する.一方,各水準路線の変動様式の不連続点は継続的に現れており,変動地塊の構造を示唆している.この地塊の単元は数kmから20km程度である.1.0×10_-5を超える最大せん断歪みは,膨張域,収縮域のコンターが密な地域,すなわち変化率の大きい地域に分布する.また10×10_-5を超える最大せん断歪みは分布していない.この値が歪みの集積値の上限を示唆している可能性がある.M6.0以上の被害地震は1.0×10_-5以上のせん断歪みの分布域に発生している.被害地震が頻発する領域はそのようなせん断歪みの分布域である.

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本研究では，希少猛禽類クマタカの保全・保護対策のために，クマタカの生息適地推定モデルを構築し山形県内における生息適地分布図を作成した．本モデルでは対象地域をグリッドで分割し，個々のグリッドに対して周辺の地形・植生状況を表現する各種指標値を与えて生息地としての適否を推定した．従来の研究では，約5 km×5 kmのグリッド内の，平均標高・平均傾斜・最低標高等の地形指標が主に用いられていた．しかし本研究では，クマタカの生息環境をより的確に表現するため，クマタカの生息に重要とされる谷地形の分布状況を表現する指標等，全部で13種類の地形・植生指標を対象とした．また，詳細な生息適地分布図を作成するためグリッドサイズを50 mとした．なお，各指標が集計対象とする周辺範囲の広さによって指標の環境説明力が変化するため，既往の研究を参考に，集計対象範囲を各グリッドから半径0.5 km，1 km，1.5 km，3 kmの円内の4通りに設定した．各指標値の算出には国土地理院の数値地図50 mメッシュ（標高）および環境省の現存植生図（1/50,000）を用いた．最適モデルの選択においては，ロジスティック回帰分析を用いて各地形・植生指標を組み合わせたモデル式を作成し，各々の適合度や推定精度等を比較した．その結果，周辺半径1 kmの谷地形の分布状況を表す指標と周辺半径3 kmの樹林地の面積割合を表す指標を組み合わせたモデルが最適モデルとして選択された（Overall accuracy 91.8％）．さらに，最適モデルにもとづいて作成した生息適地分布図を5 kmグリッド化したものとクマタカ確認情報分布図を比較すると，概ね高い精度（Overall accuracy 89.0％）で一致し，推定された生息適地の大部分においてクマタカの確認情報が存在していることが判明した．以上より，本研究で作成したモデルは高い精度で生息適地を推定できており，クマタカの生息適地推定には谷地形の分布と樹林面積に着目することが重要であるといえる．

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後氷期に異なった植生変遷をたどったと考えられている。ヒノキアスナロとスギの寒冷環境に対する性質を, 現在の天然分布と気候環境を比較することによって検討した。東北地方において, ヒノキアスナロとスギは, 同じ地域に成育することもあるが, ヒノキアスナロは北上山地などのより乾燥した太平洋側に, スギは日本海側のより湿潤な地域に分布している。特にヒノキアスナロの高度限界は, このような水文環境に関連して, 乾燥側で上昇し, 匍匐形で森林限界を越えるという性質を持っている。すなわち, ヒノキアスナロは年水過剰量700mm, 冬3ヶ月の降水量200～300mmで, 暖かさの指数25℃・month の気候環境で成育することができる。
最終氷期の温度低下を7℃程度とすると, スギは東北地方が北限地域となって北海道では成育不可能であるが, ヒノキアスナロは降水量が減少した条件下で, 渡島半島で標高約200m, 東北地方で標高約500mまで成育可能で, レフユジアを形成し得たと考えられる。

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In the summer of 1965,the alpine vegetations of herbaceous and dwarf shrub communities were investigated phytosociologically near the summits of the lide mountains, which are situated only about 40km distant from and facing with no obstacle the Sea of Japan. From the results obtained, the following associations are recognized in the region. 1. Association Primulo-Faurietum crista-galli nov .(Table 1) Ia. Subass, typicum Ib. Subass. veratretosum Ic. Subass. vaccinetosum 2. Association Leontopodio-Arcterietum prov. (Table 3) 2a. Subass. empetretosum 2b. Subass. potentilletosum The two new associations proposed here are obvious to be included in the alliances occurring in the alpine zone, in spite of their having several subalpine components cited in the tables. The occurrence of the alpine communities near the summits of these mountains could be due mostly to the following environmental factor : The area for the associations are covered by deep snow every year. The alpine communities discussed here might have possibly been substitutional vegetations for the coniferous forests. Considering these, the vegetational zone called"pseudo-alpine zone", might be discussed more in the future, because the communities proposed here are considered to be one of the compensational vegetations.

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The purpose of this paper is to analyze the regional structure of Japanese agriculture in terms of part-time farming. For this purpose, the writer made up a matrix of the characteristcis of part-time farming by 3, 199 unit areas (shi, cho, son) in Japan. Factor analysis was then applied to this matrix. The mapping of the factor scores suggests the regional structure of part-time farming.
Consequently, four regional distribution patterns were distinguished with regard to the regional structure of part-time farming in 1960 (Figs. 1-4), and four regional distribution patterns were distinguished with regard to the regional structure of part-time farming in 1980 (Figs. 5-8).
Next, the relationships among these spatial patterns were examined by canonical analysis. Four statistically significant relationships were recognized between the regional structure of part-time farming in 1960 and that in 1980. The results are summarized as follows;
1) Those regions with a larger percentage of full-time farmers in 1960, had become by 1980 regions with a larger percentage of full-time farmers and side-business types of farming (where income is mainly earned from farming), or with farmers continuously employed in non-agricultural jobs. And those regions with a larger percentage of side-business types of farming in 1940 (where income is mainly earned from other activities) had become regions with a larger percentage of the farmers engaged in part-time fishing, or farmers going to other regions to work (whose earnings come mainly from non-agricultural jobs).
2) Those regions with a larger percentage of the farmers engaged in part-time forestry or as day-laborers (receiving earnings mainly from non-agricultural jobs) in 1960, had become in 1980 regions with a larger percentage of full-time farmers, farmers engaged in part-time forestry or as day laborers, and farmers going to other regions to work (mainly at non-agricultural jobs). These regions with a larger percentage of farmers continuously employed in non-agricultural jobs became regions with a larger percentage of farmers having their own enterprises and farmers continuously employed in non-agricultural jobs (as the principal source of their income).
3) Those regions with a larger percentage of the farmers engaged in part-time fishing, going to other regions to work, or self-employed (and receiving their main income from such work) had become regions with a larger percentage of the farmers engaged in part-time fishing and going to other regions to work.
4) Those regions with a larger percentage of the farmers engaged in part-time fishing or self-employed, had become regions with a larger percentage of the farmers self-employed in their own enterprises.

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東北日本に分布する構造性盆地には,広い沖積面が分布するものと,盆地床の大部分が開析の進んだ丘陵地となっているものの2つのタイプがある.本研究では,両タイプの盆地が隣接する,新庄盆地から山形盆地にかけての地域を取り上げ,活構造の分布および変位の様式を明らかにし,盆地床の形態に相違が生ずる原因とメカニズムを考察した.
新庄盆地は,鮮新世にすでに沈降域であったため,盆地内堆積物は非常に厚い.そのため,低角逆断層が山地寄りから盆地内へ次々に移動発生し,それらの上盤側は隆起域へと転じ丘陵地化した。それに対し,山形盆地では第四紀後半に初めて盆地域となったため,盆地内堆積物は未だ低角逆断層の移動発生にとって充分な厚さを有していない.そのため,断層運動は盆地の縁辺部に集中し,広い沖積面を形成している. 両盆地における断層運動様式の相違とその変遷から,低角逆断層の移動発生と共に盆地床の形態が変化していく盆地発達過程のモデルが提示された.

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