This paper presents a method of estimating spatial distributions of the aquifer transmissivity and the groundwater head which are disturbed by random noises.
The Kalman filtering theory is applied to an equation of motion of the two-dimensional groundwater flow and to the autoregressive model that describes the spatial structure of the transmissivity. These two system equations are coupled to account for an influence of the groundwater movement in the estimation of the transmissivity.
The observed values of the groundwater head and the transmissivity, which include measuring errors, can be effectively used in the Kalman filtering algorithm.
In order to confirm the validity of the present method, an experiment is carried out for a one-dimensional aquifer model.

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流動している地下水中における熱や物質の輸送問題に出てくる非定常分散・移流方程式を特性曲線法を併用した有限要素法により数値的に解く手法を開発した.本法は固定有限素網固定影響要素及び多数の移動点から構成され,移動点はそれぞれの位置及び温度や濃度などの惰報を持ち,特性曲線上を移動する.通常の差分法や有限要素法で分散・移流方程式を解くと,自然現象としての分散を越える数値的な分散が生じたり,また解が振動するため実際にはありえない負の濃度あるいは最大濃度を越える濃度が計算上現われる等,計算法自体に由来する数値誤差を生じ,実際の問題への適用は非常に困難である.しかし本法では移流項は特牲曲線法で,分検討す散項は有限要素法で解ぐため,このような数値誤差を解消することが出来る.また本法の精度をるため,正確な解が得られている問題を本法で解き,正確解と比較したところ非常によい一致が得られた.

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The Hashirimizu spring had been utilized for the city water supply of Yokosuka City, since one hundred years ago.
“ Where the spring water come from ?” was a mysterious question for a long time.
From 1976 to 1978, we could chtllenge to elucidate the semieternal puzzle by means of thermal-infrared imagery method (on air), measurement of temperature of sea-water (by sea), gammaray survey (carborn), geological test boring, pumping water well test and others.
It was presumed that the origin of the spring water would be came up from plural brecciated rock zones in Neogene formation.
The brecciated zones are extending from the western coast to the eastern coast of Miura peninsula and accordingly the spring has distinct characteristics in constant flowing quantity and water quality all the year round, in spite of its too-small catchment-area compared with yielding amounts from the spring.
Next, we could understand that, the yield of the spring had only 300 cubic meters a day or a little more as a surplus, beyond the daily yield of 2,700 cubic meters a day. This matters was actually certified by installation of a horizontal water collector with radially installed strainers at a suitable site to get superfluous ground-water.

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