In this paper, a comparison of experimental and numerical analyses is made regarding the problem of the simultaneous transfer of heat and moisture of a sandy soil for an airtight cylindrical container.
Befor calculation and discussion the following items are made clear: a few physical properties of the soil, thermal conductivity and hydraulic diffusion coefficient versus soil moisture content and order of correction factor of vapor flux in the soil (the authors reported before that the order would be kept almost constant in capillary potential of the soil water).
Consequently, in the soil moisture distribution measurements clearly exist processes of both sorption and desorption. It is found in all domains of the measured distribution that the calculated distribution with hydraulic diffusion coefficient of the sorption process is in good agreement with the measured distribution in the domain of the sorption process only, but not with that in the domain of the desorption process. This fact gives a good evidence to the recent report that the hydraulic diffusion coefficient in the desorption process tends to become smaller at the same moisture content than that in the sorption process.
Calculated temperature distribution is in good agreement with measured one.
In the last section of this paper, the correction factor of vapor flux by thermal gradientis obtained from the steady state data about the measured distributions of soil moisture and temperature.

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Freeze-thaw action has a large effect on [soil-water] system and the following interesting points were observed in liquid limit, shrinkage and swelling.
1. A tendency of decrease in liquid limit by the freeze-thaw action was indicated.(Figs. 1, 2)
2. The apparent shrinking coefficient of soil mass by drying decreased by the freeze-thaw action.(Figs. 3, 4)
3. Under the same condition, the shrinking behavior of prefrozen soil is completed quicker than unfrozen soil. Also the dehydration rate of prefrozen soil is higher and this tendency is enhanced the lower the freezing temperature.(Figs. 5, 6)
4. Shrinkage of undisturbed soil by drying is much less than that of disturbed soil. Also undisturbed soil does not receive the effect of freeze-thaw action to such an extent.(Figs. 7, 8)
5. When rehydrated after shrinkage has been completed, the swelling amount and water-absorption amount of prefrozen soil are larger than those of unfrozen soil and these tendencies are more marked the lower the freezing temperature. In case of undisturbed soil, however, swelling is not indicated in both unfrozen soil and prefrozen soil.(Table)
6. Observation of the surface of specimens after swelling indicated formation of numerous cracks in prefrozen soil.(Photo.)

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[in Japanese]

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Three components of the unit hydrograph are the time of concentration, the time ofrecession and the recession constant, and these three are treated as peculiar to each river basin. The.: refore it is said that the runoff is a linear function and simple proportional to the rainfall intensity.
On the other hand, the usual unit hydrograph is said not to express exactly the actual runoff, because it is a non-linear function.
The writer analized possibe relation between the rainfall intencity and the components of the unit hydrograph, and made several formulas by measured data of 19 rivers, within the scope of the standard of farmland drainage.
These are formula 7, 12 and 14 to be applied also for unmeasured basins.

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The group method of data handling (GMDH) based on the heuristic self-organization, which has been proposed by A. G. Ivakhnenko was applied to the water quality data (electrical conductance, turbidity, dissolved oxygen and chemical oxygen demand) observed at Inuyama in Kiso River located in the middle of Japan. The GMDH is an identification method, advantageous to the systems characterized by many variables and parameters, complex structure and limited data. It is a main object of this paper to analyse the variation with time of the water quality in Kiso River due to the change of flow rate and discuss the algorithm for the successful application of the GMDH to the water quality prediction or forecasting problems.
The est!mation models for each water quality index, which resemble linear multiple regression equation, as shown in eqs.(9-1)-(23-3), were found out with the polynomial algorithms of the GMDH. Comparison of the estimated values using the models with those observed are shown in Figs. 3-6 and Fig. 8.
The variational characteristics with time of the water quality are as follows electrical conductance (EC) decreases in accordance with increasing rate of flow. It's variational pattern can be described with the 1 day antecedent EC and daily mean discharge. Turbidity varies in almost the same pattern as hydrograph, with a time lag of nearly 3 hours. The variation of concentration of DO seems to be related to water temperature. As time interval for analysis or unit time of this analysis was adopted 1 day, no more useful information could be obtained. However, more results will be obtained with the analysis in a shorter unit time. The variation of concentration of COD is different according to the runoff level. When the level is low, the variation of concentration of COD is temporal. On the other hand, when the level is high (above 2, 000 m³ /s/day), the concentration of COD increases rapidly in a short time and varies gradually there after.
To make more effective use of the GMDH, it is necessary to select a unit time appropriate for the purpose and to give consideration to the physical meaning of the detected models. Finally the GMDH is recomended for the identification or the construction of prediction model of complex systems such as environmental or ecological systems.

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On water resources management and planning, it is required to quantify discharges from a watershed. Runoff analysis provides a scientific basis for that. Essence of runoff analysis is to express the features of watershed by determining the relationship between rainfall and runoff. There are two methods ; one is based on clarifying the runoff mechanism, another, on determining the response function.
The concept of GMDH, proposed by A. G. Ivakhnenko, was for constructing a polynomial of optimal complexity with most essential features selected from numerous input variables, as an effective means in determination of the response function without reference to linear or nonlinear systems.
Authors applied this GMDH to the rainfall-runoff data observed at Kizu river basin in Ueno, Mie, illustrating three cases supplying different sets of input variables. The response function is identified using the data obtained in a period of April-October, 1969, and the runoff predictions are made for the same season in years, 1970, 1971 and 1972. The estimation is quite agreeable in the identification period and satisfactory results are obtained for the prediction periods with correlation coefficients in the range 0.688-0.965.Furthermore, by decomposing complete polynomials into subsystems, the contribution of each subsystem to the total output becomes clear and prediction is expected to become more accurate by understanding the role of each subsystem.

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The water pollution of the Yamada River is mainly caused by the inflow of household wastewater. The rate of the effluent discharge changes with time, and generally two peaks appear in a day. Both the discharge and water quality of the Yamada River therefore change with time, due mainly to the effect of the inflow of household wastewater.
Considering the points mentioned above, the authors developed a water quality model which has both a time and a spatial dimension. According to this model, using equation (5) which is the same type as the Streeter-Phelps' equation, the load at any time and any point along a stream can be calculated from the effluent loads from sources in the upper part of the basin.
As a result of applying the model to the Yamada River basin, the calculated values were found to approximate the variation of the observed values with an accuracy of better than 10%. The parameters estimated by the computer simulation are given.

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Identification of system parameters such as transmissivity and the storage coefficient has been one of the major difficulties preventing the utilization of a simulation model of regional groundwater flow. The accuracy of the mathematical model mainly depends on that of the estimated system parameters. Nevertheless, little research has been done on the identification of widely distributed system parameters. As a substitution for empirical trial and error procedures, an inverse method to identify system parameters using spatially distributed values of hydraulic heads is presented in this paper. In this method, Galerkin-finite element techniques coupled with the least square method were applied to the inverse problem. Using this method, the system parameters of the groundwater flow system in the Yamashina basin, Kyoto City, were identified. A comparison of the simulation result using the inversely identified system parameters with the observed result showed good agreement.

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In a continuation of a previous paper, a waterhammer theory is developed from the viewpoint of the vibration model, in which waterhammer phenomena are treated as a phase of waterpressure vibration in pipeline systems. In this paper, the following equation is introduced in order to evaluate maximum pressure rise with vibration energy and periodic time.
_??_
Where X_max is maximum pressure rise, V is initial mean velocity, g is gravity accelaration, ΔH ismean head loss from friction, and a_m is equivalent elastic wave velocity.
a_m of the composite pipeline system is represented by the following equation.
_??_
or
a_m=4L/T
Where a_m is physical mean velocity, (f·f') is coefficient, L is pipeline length, and T is periodic time.
It is confirmed with numerical simulation that this equation is a better approximation than the, traditional theory based on elastic wave propagation.
In particular this relationship is very useful when we want to evaluate the maximum pressure rise in situ.

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In the present study, the mechanism of the penetration of a cone into the ground was investigated analytically and experimentally. The dimensions of the slip line fields around the cone and the values of the contact pressures on the cone surface were calculated by the slip-line method, assuming that the ground is a plastic-rigid body. The values of the bearing capacity factor of the cone (N_cra) were calculated using the mean values of the contact pressures and were compared with the ratios (I_c/c_u) of the cone index (I_c) to the undrained shear strength of the clay (c_u), which were obtained by experiments. As a result, it was established that this method of analysis is applicable to cone penetration into pure cohesive soils (φ=0). The results obtained by this investigation are summarized as follows:
1) The slip line field for a cone with rough surface (a rough cone) is larger than that of a cone with smooth surface (smooth cone). The value of the intermediate principal stress (σ₂) does not affect the shape of a slip line field.
2) The distribution pattern of the contact pressure changes greatly with the value of σ₂ The contact pressure increases rapidly toward the central axis of the cone when (σ₂=σ₃, and it increases slowly when σ₂=σ_m.
3) The value of Ncra varies greatly not only with the apex angle of the cone.(2α) and the roughness of the cone surface, but also with the value of σ₂. It has a peak value (minimum) at 2α =30°-40° for a smooth cone, while the value for a rough cone decreases hyperbolically with the value of 2α.In general, the value is larger for a rough cone than that for a smooth cone, and larger when σ₂=σ₃than when σ₂=σ_m.
4) The cone penetration resistance (P) is in proportion to the square of the depth of cone penetration (h), which is measured from the tip of the cone, and expressed as, P= (π·tan²α·I_c) h², within the range when the penetration depth is smaller than the height of the cone.
5) The speed of cone penetration (ν) does not affect the value of I_c/c_u within the range of the experiments (speed range is 1.0 cm/sec.(commonly used speed in situ)-1/2, 000 cm/sec.).
6) The surface of commonly used cones can be considered rough in a considerable range of shearstrength for clays having plastic indices larger than 30 (I_P≥30). The values of c_u for these clays are therefore easily obtained using the values of I_c and N_cra for a rough cone.
7) The surface of commonly used cones can not be considered rough for clays having plastic indices smaller than 30 (I_p<30). In this case, it is necessary to take the adhesive characteristics of the clay into account.

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The analysis of slope stability under complex conditions occurring in practical problems such as inhomogeneity of soils, degeneration of composing materials, and changes in loading conditions must be carried out based on the realistic stress distribution in slopes. In addition, the analysis of slope stability seen from the viewpoint of the design process must be performed in the following two procedural phases
1. Determine the minimum F. S at the section in question.
2. Search and confirm a value of the design variable to make the minimum F. S optimal.
It is shown in this research that the use of sensitivity derived by FEM analysis as a linear extrapolated predictor of possible variation of the safety factor represents a useful and consistent method of stability analysis of slopes containing the above two phases.
The safety of the slope against slip is expressed here as
_??_
The sensitivity of F. S S_f =∂F_s/∂x_e is also derived.
The handling of the first of the above phases is discussed in part 1.

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During the triaxial compression test, the frictional force applied to the end surfaces causes the test specimen to take on a barrel shape with the central portion expanded. Noting this deformation characteristic, the author conceived of treating the assumed lateral stress in equattion 7, figure 3 as one of the boundary conditions in place of the frictional force applied to the end surfaces and thus derived the equation for the various components of stress (equation 15) and displacement (equation 16). In view of the nonlinear stress-strain relationship of soils, the author then suggested a method of calculating the Δφ_s constant (equation 21), the secant modulus ΔE (equation 22), and Poisson's ratio Δν(equation 20) by expressing equation 16 by the incremental procedure and substituting the measured values for the stress difference, axial displacement, and lateral displacement in the resulting equation (equation 17). When the Δφ_s constant, the secant modulus, and Poisson's ratid are known, the various stress increments can be calculated from equation 23.
Using methods such as those described above, the author investigated the deformation behavior of test specimens in triaxial compression and stress distribution (Fig. 6-9) and calculated the secant modulus and Poisson's ratio as constants of the mechanical properties of soils (Fig. 10-11).

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Sufficient studies have not been made as yet on the system of hydroponics flooding and circulating solution in growing vats. In the present study, the author developed a simple aerator of superior function, designed a supply pipe of equal delivery, (the solution-delivery to multiple growing vats in the existing system is unequal), and improved the existing supply risers.
The results obtained are summerized as follows:
(1) The aerater (No.5 in Fig. 4), which is attached to a portion of the supply riser, was developed. In general, the greater the solution flow and the smaller the cross sectional area in the throat portion, the more air is mixed, and this air mixing apparatus is not stopped up structurally.
(2) The mixing ability of aerater No.5 is superior to the existing aeraters provided the flow rate is greater than 15 l/min (Fig. 5 & 7). If it drains off at 2 cm below the solution surface, the surrounding fruit vegetables are protected from the effect of spray and their roots are completely shaded.
(3) The ratio of the flow at the first and the distal outlet of the 31 mm supply pipe (total length 40m) was 2. 65 (Table 1) in the existing system, and the quality of the tomatoes in the distal growing vat was inferior to the first.
(4) For new supply pipes, the pipe size can be determined from. Eq.(17) by selecting a value for the solution-delivery variable k.
(5) For existing supply pipes the method of supplying the solution equally by varying the height lof the supply riser has been devised (Eq.(3) & Fig. 10 & 12). Good results were obtained in real-life experiments in which two samples were grown varying the riser height only in one case and both the riser height and the supply pipe diameter in the other (Table 4 & 6).

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