In Higashimatsuura Peninsula basin, abrupt temperature rise often affects the occurrence time of the lowest temperature in the night. In this study, the local meteorological observations were conducted in the peninsula basin to find the process of the temperature rise at night. In the observations, vertical temperature profiles were measured by using tetherd meteorological balloons, temperature distributions along the south slope by fixed small thermometers at the meteorological stations, and thermo images by an infrared thermgraphy. The observed results showed that nocurnal temperature rise was casused by advective heat transfer due to warm air flow affected by sea climate. When wind with velocity of less than 1 m s^-1 temporarily blew in the upland and atmosphere was calm in the basin, the temperature only around the height of more than 30 m from the sea level was raised. However, while the continuously blowing wind of more than lm s^-1 wasmaintained in the upland, we also observed that warm wind from southwest blows down over the south slope of the basin and causes the temperatrue rise in the basin in both vertical and horizontal directions. In addition, the thermographic image analysis clearly demonstrated that warm wind topographically invaded to the basin.

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In order to investigate the effect of opening (d) between upper and lower shear box of the ordinary direct shear apparatus (6cm in diameter), we compared the experimental results using air-dried Toyoura sand with strain softening elasto-plastic finite element analysis. When d was closely fitted to the thickness of shear band, the experimental values obtained by that apparatus with lubricated inner side walls of the box by the rubber membrane which also restrained the loss of sand showed reliable results. The direct shear angles (φ_ds) with various values of d obtained by analysis including strength anisotropy, exhibited good agreement with the experimental results. Also, the value of shear stress obtained by analysis in constant volume was changed by the difference of displacement boundary condition of finite element modes at the opening between upper and lower shear box.

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The water purification by a natural lagoon is examined by surveying the change of inflow and outflow loads of the lagoon accompanied with rain. Regarding the amount of inflow loads of nitrogen and phosphorus, the increase in particular type is conspicuous compared with dissolved type. This shows that the loads of non-point sources and sediments in rivers are flowing into the lagoon in large quantities. There is little increase of outflow loads. The loads, which flow into the lagoon, are stored and purified by the sedimentation accompanied by a decrease of the flow velocity. Hysteresis is shown in the amount of inflow loads. The direction of the amount of inflow loads at the time of the increase in flux is more than the time of a flux fall. Therefore, it is important to secure the storage capability at the time of the increase in flux in order to raise purification ability.

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Certain crops were cultivated under the clear-color PVC roof to know the productivity under the drought-prone environment of Hokkaido, the northern island of Japan, where the annual precipitation is around 1, 000mm. Since the potential evapotranspiration rate, which was calculated based on air temperature and solar radiation, was mostly less than 3mm·d^-1, this amount of water was irrigated to a plot as control. Two other irrigation plots also prepared and their rates of water supply were 1mm·d^-1 and 2mm·d^-1. The yield of the 2mm·d^-1 plot was compared with that of control, and the rates in yield at the 2mm·d^-1 plot to control were as follows:(1) soy bean, carrot, almost 100%(2) potato, 95%(3) sugar beet, 80 to 90%(4) onion, 80%(5) cabbage, 70 to 80%(6) chinese cabbage, almost 0%. The yield from the 1mm·d^-1 plot was also compared with that from control, and the rates in yield of the 1mm·d^-1 plot to control were as follows:(1) soy bean, carrot, potato, sugar beet; 60 to 80%(2) onion, 50 to 60%(3) cabbage, chinese cabbage, almost 0%. These data clearly demonstrate that this experimental method is available to quantitatively evaluation of yield under a drought-prone environment in a relatively high precipitation area such as Japan.

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This study investigated the potential of biodegradation of leftover by thermophilic oxic process (TOP). The characteristics of the thermophilic oxic process are that, a minute of excess of sludge is formed, and organic matter is efficiently biodegraded, as well as water is evaporated by the heat generated in biodegradation process. In this study, three sorts of intermedia were investigated and different BOD volume load (BVL) and feeding interval of leftover were conducted to seek the suitable disposal condition. Moreover, the T-N value of intermedia was determined throughout the process of TOP. The following points were derived from this study: 1) The cedar chips is more suitable than rice husks and diatomaceous earth as intermedia of TOP in the disposal of leftover; 2) During 23 days of operation of TOP, by the management of temperature, the capacity of degradation can be raised to 22.77 kg/m³·day as 1.61 times of normal level; 3) The feeding interval of 24-36hours was better than that of 12 hours and 48 hours; 4) After the disposal of TOP, although carbon was scattered from intermedia at the form of CO₂, nitrogen was remained in intermedia at the form of NO₂-N and NO₃-N. 30 days later, the value of T-N of intermedia was 11 times of it in beginnings.

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Estimation of the unsaturated hydraulic conductivity function is essential to provide proper input parameters for water flow simulation and prediction. The instantaneous profile method, referred to as the internal drainage method, was applied to determine hydraulic conductivity as a function of volumetric water content in a sand dune field. An automated monitoring system for volumetric water content and soil water pressure head with a data-logger was developed using a profile probe and a dual type underground suction gauge respectively. Calibration curves of the profile probe for the dune sand were made in the laboratory. The geometrical time series data collection by the data-logger for better estimation of the hydraulic conductivity was proposed. The hydraulic conductivity of the dune sand was determined by the internal drainage method and the unit hydraulic gradient methods. The results agreed well with the previously obtained data by the steady state infiltration method and the steady state evaporation method. It was concluded that hydraulic conductivities determined by a simple method with unit gradient assumption and using experimental function of soil water storage with elapsed time gave reasonable results.

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The aim of this paper is to esitimate the environmental benefits of the policy for preserving agriculture and rural area using by contingent valuation method (CVM). We evaluate multifunctionarities of agriculture and rural area including preventing floods, underground water nourishment, preserving water environment, preventing soil erosion, managing organic wastes, creation of beautiful landscapes, health recreation and serenity, and preservation of biodiversity and wildlife habitats. Our scenario is keeping status quo against decresing 20% of farm land during 30 years. The participants in this survey are 2, 140 households from the whole country. The result indicate that economic value of environmental benefits from preserving agriculture and rural area is 4, 441 yen/household/year (0.95 confidence interval is between 2, 918 yen and 7, 254 yen).

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Cohesive red soil of high water content was compacted in a mold and change in pore water pressure was observed. The pore water pressure at the bottom of the specimen was at first very high just after compaction and then it decreased very rapidly. The pressure continued to decrease and finally approached a negative constant value. Several experiments were conducted to investigate the reason for suh a phenomenon. Increase in bulk volume of specimen and height of soil skeleton were observed after compaction. Water exudation which followed the expansion of soil volume was also observed. Soil was stored at high/low temperature before compaction and the change in pore water pressure after compaction was compared at room temperature. Soil was compacted in a chamber filled with different gases such as carbon dioxide and surfer hex fluoride whose solubility to water is different from air. It was revealed that expansion of entrapped air and soil skeleton coincides with the rapid reduction of pore water pressure and residual high pressure may be the cause of water exudation. The cause for long lasting reduction in pore water pressure was found to be solution of entrapped air to pore water which takes a long time.

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Farm road improvement projects promote recreation in rural areas by providing easier access from the urban area to the rural area. This paper evaluates the effects of Farm road improvement projects by Travel costs method, with a case study of Ibaraki prefecture flower park and Fruits line. The equation, that relates the travel costs to the number of visitors per thousand residents, is estimated by the analysis of the information collected at Ibaraki prefecture flower park. The effects of Fruits line, which is estimated as the difference of consumer's surplus under the with-project conditions and the without-project conditions, is calculated to 9.7 % of the actual consumer's surplus of the visitors to Ibaraki Prefecture Flower Park. These results indicate that not only the improvement of the recreational environment in the rural area but also easier access by Farm road improvement project is an effective measure to promote recreation in rural areas.

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A useful and effective in-situ measurement of hydraulic conductivity of soil is critically important in engineering and agricultural problems related to water movement in soil. In this study the Guelph well permeameter (GWP) method is effectively introduced into an in-situ permeability test, and its accuracy and effectiveness are successfully examined by a field test and by a numerical experiment in sand soil. The GWP provides a field-saturated hydraulic conductivity of soil based on measurement of a constant-head infiltration from a well into soil. The values of the field-saturated hydraulic conductivity are measured along soil depth by the in-situ permeability test using the GWP method, and compared well with those of soil cores as well as those computed by the numerical experiment which is designed to simulate the sand soil and the infiltration from the well into soil. From these comparisons it is concluded that the in-situ permeability test is now available to measure easily and effectively the soil permeability along the soil depth about one to two meters deep below the soil surface.

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A former pipeline system for pumping water conveyance has been designed on condition that include a flywheel and other facilities for suppressing the negative pressure to 7 m or lower to prevent the water column separation. Authors also measured the pressure of the pump discharge side at sudden failure of the pump power in pipeline for waterworks. As the result, the pressure fluctuation was confirmed to be caused possibly by generating the water column separation generation and its recombination. Authors examined the method for installing non-water hammer pressure check valve which is the improved swing check valve and used in the downstream in the place which is generating the negative pressure in order to suppress the water hammer pressure by sudden pump stop. The field measurement on water column separation in pump power failure and water hammer pressure caused by its recombination, and the effect of setting up the non-water hammer pressure check valve was carried out. As the result, the usefulness of the method for installing water hammer pressure protective valve was confirmed. Then, it was possible to reproduce these phenomena accurately at the practical level by the simulation using the simplified model of non-water hammer pressure check valve and discrete cavity model of the water column separation. Therefore, the place which water column separation and its recombination generates, and the size of water hammer pressure which arises simultaneously are estimated by the simulation in the sudden pump stop. In addition, it becomes possible that the more appropriate judgment on the necessity and scale of the facilities for negative pressure countermeasure is made by the simulation considering the various kinds of these facilities.

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