Makoto Sasamoto

Determination of tylosin excretion from sheep to assess tylosin spread to agricultural fields by manure application

Antibiotics administered to livestock are partly excreted with urine and feces. As livestock excrement is used as manure on agricultural fields, soil may be contaminated by excreted antibiotics, potentially resulting in the development of antibiotic-resistant bacteria. Therefore, it is necessary to determine the amount of antibiotic administered to livestock that could spread to agricultural fields through manure application. This study reveals the excretion ratio of tylosin from sheep. After developing an analysis procedure for tylosin in urine and feces from sheep, a tylosin excretion study was performed with two sheep. Tylosin was excreted in urine and feces for four days, after which its concentrations dropped below the limits of quantification (urine: 0.5μg/kg, feces: 2.4μg/kg). The total excretion ratio was 11% on average. The results of our study can provide useful knowledge for treating excrement in order to prevent the spread of antibiotics to agricultural fields through manure application.

RESEARCH OF SEVERAL PARAMETERS AND BUILDING OF THE SNOW DEPTH AND SNOWMELT RATE FORECASTING MODEL

Forecasting a snow phenomenon in the cold districts is a very important countermeasure to realize the repression of the natural disaster and the altitude use of the water resources. On the other hand, there are few examples that all necessary weather data are observed with a superficial spread in every time in the applicable basin. Therefore, the strict forecasting model of a snow phenomenon has low practicality in the present condition of such weather data observation. The model can forecast a change of snow depth and snowmelt rate of the snow layer by using only temperature is developed based on such conditions, and it aims at contributing to building of the safe society economic base it can be relieved, and reported here.

STATISTIC ANALYSIS ON QUANTITIVE EVALUATION OF FISH HABITAT IN THE RIVER BASED ON “NATIONAL CENSES ON RIVER ENVIRONMENT”

In order to evaluate the habitat of the fish inhabiting the river, it is necessary to know the relation between the amount of habitations of a fish, and the physical characteristic of a habitat “National Censes on River Environment” contains information about plants and animals as well as the physical features of rivers in a certain format. In the present study, the dominant physical attributes forming a fish habitat in various rivers of the large area in Japan are discussed by using the above database.The population of fishes (for example Carassius gibelio langsdolfi) and physical characteristic in each river are approximated by a regression function which is derived from a multiple regression analysis. Contribution of the physical characteristic to the quantity of fishes in a different district is compared, and the feature for every area is described. And district feature is described by result from a principal component analysis. CPUE (Catch per Unit Effort) is proposed to standardize the amount of fishes capture and is used in analysis shown above.

STATISTIC ANALYSIS ON THE RELATIONS BETWEEN PHYSICAL ATTRIBUTES AND FISH HABITAT QUALITY IN THE RIVER BASED ON “NATIONAL CENSES ON RIVER ENVIRONMENT”

To conserve fishes in river, it is important to understand what and how physical attributes are forming the habitats for fishes.“National Censes on River Environment” contains information about plants and animals as well as the physical features of rivers in a certain format. In the present study, the dominant physical attributes forming a fish habitat in the Yoneshiro River and the Koyoshi River are discussed by using the above database.A discriminant analysis shows that the possibility to be a habitat for Oncorhynchus masou or Plecoglossus altivelis in the Yoneshioro River can be predicted by the physical attributes. The population of Plecoglossus altivelis in the Yoneshiro River is approximated by an regression function which is derived from a multi regression analysis. A comparisons of the regression function for the Yoneshiro River to that for the Koyoshi River which is the nearest river to the Yoneshiro River shows that the contributions of each physical attribute are different in two rivers while the dominant attributes are same.

Relationship between benthos habitat conditions and physical-chemical attributes in Yoneshiro River

Field investigations were carried out to study the habitat conditions of benthos in Yoneshiro River basin. At the same time, physical-chemical attributes were also measured. Family number of benthos was not so different in each station, but total population in branches was larger than that in main stream. The importance and effectiveness of using families was examined by field data, and some diversity indices were examined. To develop prediction models of benthos diversity indices, which are total population, family number, Shannons diversity index and Simpsons, multiple regression analysis was carried out. The accuracy of prediction is poor for the population in the case with each family, but good for the family diversity in the case with all families.

OBSERVATION OF SNOWFALL BY RADAR RAFNGAUGE

To utilize data of Radar rain gauge in prediction for snowfall disttibution a model was proposed In this model, a calculation of wind field on arbitrary terrain is included. The accuracy of the prediction model are examined by comparisons with field data of hourly measurements of snow fall at seven sites, maximum snow depth distribution in dam depth basin and dam inflow.

PREDICTION MODEL FOR HABITAT QUALITY BASED ON HELD DATA OF NATIONAL INVESTIGATION ON RIVER ENVIRONMENT

HQI model which was developed to predict trout standing crop in Wyoming streams was modified to be applied to rivers in northwest Japan, analyzing the general preference of river fish to habitat attribute based on data observed in a systematic field investigation which has been performed by Ministry of Construction. The modified model gives a poor explanation on fish population. To develop more accurate prediction model, a multiple regression analysis for each kind of fish was carried out. The accuracy of prediction is good for trout, fair for minnow and poor for ayu, and the amount of stocked fry affects on the accuracy of the present model.

EXPERIMENTAL STUDY ON DEFORMATION AND FRACTURE OF ICE SHEET BY PROPAGATING WATER WAVE

A study of alternatives including a shoreline evolution numerical modelization has been carried out in order to both diagnose the erosion problem at the beaches located between Cambrils Harbour and Pixerota delta (Tarragona, Spain) and select nourishment alternatives.

Study on Rainfall Runoff Prediction System for Radar Raingauge

Radar rainfall gauge gives a better information of rainfall distribution than the conventional Thiesen method. In the present study, a system for the prediction of rainfall-runoff is constructed. This system includes packages to obtain a channel network from the digital map, to combine the radar rainfall information with the channel network, and to calculate the runoff using the kinematic wave model.This paper described the each package of the system. And parameters of the kinematic wave model were obtained for 20 runoff events in 1990 and 91. Application of this rainfall runoff prediction system to dam reservoiurs is possible with several minor improvements of the system.

Use of digital map for a radar rainfall-runoff model

When a radar rainfall information is available, the distributed rainfall-runoff model should be used. However a construction of the model includes a tedious procedure to construct a channel network from many corresponding maps.In this study a method to obtain the channel network automatically from the digital map based on simple principles is proposed. Then a distribution of radar rainfall can be supperimposed on this channel network to calculate the run-off by the kinematic wave model.Thus a distributed radar rainfall-runoff model could be easily established in any river basins.