• Journal of the Korean Geographical Society
• /
• v.28 no.3
• /
• pp.193-199
• /
• 1993

The interannual fluctuation, trends and perio-dicties in summer rainfall of South Korea were analyzed primarily by using Mann-Kendall rank method and Power Spectrum analysis for the period from 1920 to 1985. Their relations to Indian summer monsoon rainfall have also been examined. Increasing or decreasing rainfall tendencies are not found in South Korea. In Power Spectrum alalysis, 2.5 years periods are predominent at the 95 per cent confidence level in south Korea as a whole and Pusan. Also the period of 11.0 years is found in Seou. There are another prominent spectral peaks at 2.4, 3.1, 6.2 and 7.3 years period, which are significant at 90 per cent confidence level.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.31 no.4
• /
• pp.81-89
• /
• 1989

This study is to determine seasonal consumptive use of water of a design year during growing period (June-September) for paddy rice in Suwon. To obtain Dry flay Index which is defined as the number of probable dry days occurring at a design year, Slade Partly Un- symmetrical Distribution Function was adopted. Dry Day Index was analysed with 5, 10 and 30 day-term. And each of them was evaluated with recurrence intervals of 1, 3, 5, 10 and 20 year using 49 years daily rainfall data('35-'83). Their singnificance were tested at 1% level by X$^2$ test. On the basis of these values, Probable Evapotranspiration (ET) which is the daily average ET for the sum of both ET on dry days and ET on rainy days were esti- mated using 5 years daily actual ET data(' 82-' 86). Their Crop Coefficients were also de- termined by the modified Penman equation(1977) proposed by Doorenbos & Pruitt.

• Journal of Korean Society of Forest Science
• /
• v.89 no.2
• /
• pp.223-231
• /
• 2000

This study aims to clarify the effect of forest management practices(thinning and pruning) on water quality to get the fundamental information on the facility of cleansing water quality after forest operation. Rainfall, throughfall and stemflow were sampled at the study sites which consist of Abies holophylla and Pinus koraiensis in Kwangnung Experimental Forest for 6 months from May 4, to November 1, 1999. Average tree height in the management sites increased by 0.5m more than that in the non-management sites in Abies holophylla and Pinus koraiensis, respectively. Increment of average D.B.H. at the management sites grew 3.5cm and 2.6cm more in Abies holophylla and Pinus koraiensis compared with that at non-management sites. Average pH of the total amount for the event in throughfall and stemflow was higher than that of throughfall and stemflow of the beginning of the event at the management and non-management sites. Average electrical conductivity of throughfall and stemflow at the beginning of the event was higher than that of the total amount for the event at management and non-management sites. Water qualities of throughfall and stemflow were buffered more by the management practice in both. The forest management may affect purification of water quality of throughfall and stemflow in Abies holophylla and Pinus koraiensis.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.35 no.2
• /
• pp.65-72
• /
• 1993

When a drought occurs in an area irrigated by multi-reservoirs, onerating a single reservoir separately to control the reservoir' storage is not a desirable solution. In order to reduce damages effectively for the areal drought, the storage of the reservoirs within the areal boundary should be managed as a group. Storage management procedures are as follows : 1. Collecting and checking the present storages of all reservoirs 2. Computing the drought frequency and depth; and finally, establishing a suitable storage saving strategy based on the estimated drought depth. For the purpose of this storage management, the RESTOMS(Reservoirs Storage Management System) was developed and the system was composed of the PRIME computer and the ORACLE as a distributed database management system, which was the host computer of Rural Development Corporation and would be on-lined with the regional offices throughout the country. Reservoirs operated by Farm Land Improvment Association were comprised in the DB system. Using the RESTOMS, the drought frequencies and drought depths were calculated with respect to the reservoir storage records(1967 to 1992). It was obvious that the results were closely corresponding to the real drought records.

• Journal of Korean Society of Forest Science
• /
• v.75 no.1
• /
• pp.55-66
• /
• 1986

A complete diallel cross using ten varieties of Corylus avellana was made to select the best general combiners and the best specific combiners for each characteristic of each variety. The variety "Barcelona" showed the best general combining ability in kernel yield per hectare and the combinations, between Kara and Badem, between Badem and Barcelona, between Sivri and Barcelona, between Sirri and Barcelona, between Palaz and Barcelona, between Tombul and Kara, between Barcelona and Sivri, between Fiukuken2 and Hukuken3, and between Hukuken3 and Hukuken2, showed the best specific combining abilities in kernel yield. The other characteristics such as fruiting rate, pericarp thickness, weight/nut, kernel weight/nut, kernel ratio, and kernel yield per tree or hectare were also compared between the combinations.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2017.05a
• /
• pp.87-87
• /
• 2017

최근 이상기후로 인해 국내 가뭄피해가 증가하고 있는 추세이며, 미래 가뭄의 심도 및 지속시간은 증가할 것으로 예측되고 있다. 특히 우리나라는 용수공급의 56.5%를 댐에 의존하여 댐 유역의 가뭄은 생 공 농업용수 공급제한 등의 광범위한 피해를 발생시킬 수 있다. 다만 가뭄은 홍수와 달리 진행속도가 비교적 느리기 때문에 사전에 정확한 댐 유입량 예측이 가능하다면, 용수공급량 조정을 통해 피해를 최소화할 수 있다. 국내에서는 댐 유입량 예측에 ESP (Ensemble Streamflow Prediction) 기법을 활용하고 있으며, ESP 기법은 과거 기상자료를 기반으로 미래를 예측하기 때문에 기상자료, 초기수문조건, 매개변수 등에 불확실성을 가지고 있다. 본 연구에서는 베이지안 이론을 이용하여 댐 예측유입량의 정확도 향상기법을 개발하고 예측성을 평가하고자 하며, 강우유출모델은 ABCD를 활용하였다. 대상유역은 국내의 대표 다목적댐인 충주댐 유역을 선정하였으며, 기상자료는 기상청, 국토교통부 및 한국수자원공사의 지점자료를 수집하였다. 예측성 평가기법으로는 도시적 분석방법인 시계열 분석, 통계적 분석방법인 Skill Score (SS)를 활용하였다. 시계열 분석 결과 ESP 댐 예측유입량(ESP)은 매년 월별 전망값의 큰 차이가 없었으며, 다우년 및 과우년의 예측성이 떨어지는 것으로 나타났다. 베이지안 기반의 댐 예측유입량(BAYES-ESP)는 ESP의 과소모의하는 경향을 보정하였으며, 다우년에 예측성이 향상되었다. 월별 평균 댐 관측유입량과 ESP, BAYES-ESP의 SS 비교분석 결과 ESP는 유입량 값이 적은 1, 2, 3월에 SS가 양의 값을 가졌으며, 이외의 월에는 음의 값으로 나타났다. BAYES-ESP는 ESP와 관측값이 비교적 선형관계를 나타내는 1, 2, 3월에 ESP의 예측성을 개선시키는 것으로 나타났다. ESP 기법은 강수량의 월별, 계절별 변동성이 큰 우리나라에 적용하기에는 예측성의 한계가 있었으며, 이를 개선한 BAYES-ESP 기법은 댐 유입량 예측 연구에 가치가 있는 것으로 판단된다.

• Journal of Korea Water Resources Association
• /
• v.50 no.7
• /
• pp.489-502
• /
• 2017

The objective of this study is to propose and evaluate the BAYES-ESP, which is a dam inflow prediction method based on Ensemble Streamflow Prediction method (ESP) and Bayesian theory. ABCD rainfall-runoff model was used to predict monthly dam inflow. Monthly meteorological data collected from KMA, MOLIT and K-water and dam inflow data collected from K-water were used for the model calibration and verification. To estimate the performance of ABCD model, ESP and BAYES-ESP method, time series analysis and skill score (SS) during 1986~2015 were used. In time series analysis monthly ESP dam inflow prediction values were nearly similar for every years, particularly less accurate in wet and dry years. The proposed BAYES-ESP improved the performance of ESP, especially in wet year. The SS was used for quantitative analysis of monthly mean of observed dam inflows, predicted values from ESP and BAYES-ESP. The results indicated that the SS values of ESP were relatively high in January, February and March but negative values in the other months. It also showed that the BAYES-ESP improved ESP when the values from ESP and observation have a relatively apparent linear relationship. We concluded that the existing ESP method has a limitation to predict dam inflow in Korea due to the seasonality of precipitation pattern and the proposed BAYES-ESP is meaningful for improving dam inflow prediction accuracy of ESP.

• Parasites, Hosts and Diseases
• /
• v.22 no.1
• /
• pp.21-29
• /
• 1984

A scanning eletron microscopic study was performed to observe the tegumental surface of adult Fibricola seoulensis. The adult worms were collected from the small intestine of mice 5 days to 3 weeks after experimental infection with the metacercariae. The metacercariae were obtained from the viscera of the snakes, Matrix tigrina lateralis, by artificial digestion technique. The results were as follows: 1. The tegument of anterior body was covered with cobblestone-like cytoplasmic processes and that of posterior body showed finger-like processes. The posterior body had 4-5 large transverse wrinklings which formed many discontinued shallow rugae. 2. The entire surface of anterior body was regularly arranged with the spines of which tips diverged into 3 to 4 points. They were densely packed in anterior mid-median portion of dorsal surface where appeared a few spines indented upto 5 points. Farther laterally and posteriorly from this portion, the pointed spines were more sparse and became single tipped and extended to anterior one-third of posterior body, 3. The posterior surface of oral sucker was armed with 50-60 spines having 2-3 tips and ventral sucker also covered with such spines. On anteriormost dorsal surface arranged 60-70 spade-shaped spines. The tribocytic organ was armed with many stout recurved pile-like spines arranged radially. 4. There were 3 types of sensory papillae. The ciliated knob-like (Type I) papillae were almost bilaterally symmetrical in ventral and dorsal surfaces of anterior body, and abundant especially aroundbases of oral and ventral suckers, tribocytic organ, and in lateral margins of anterior body. About 24 non-ciliated round swellings (Type II) were observed around each lip of oral and ventral suckers. The plate-like elevated papilla without cilium (Type III) was found to distribute only in posterior body. These 3 types of papillae seem to be tangoreceptive and/or rheoreceptive in function when their morphology and distributions are considered.

• The Korean Journal of Ecology
• /
• v.26 no.1
• /
• pp.23-28
• /
• 2003

In order to identify plant species and communities characteristic of lithospheric condition, forest vegetations of igneous(mainly granite) and sedimentary(mainly sandstone) areas in Kyungpook province were compared. We collected 108 phytosociological releves from the older forests over 20 years old. 444 vascular plant species and 25 plant communities were identified. Results of Principal Coordinates Analysis (PCA) indicated that lithospheric conditions and human impacts were the most important factors related to the plant community diversity and species richness. In the igneous rock areas net contribution degree (rNCD) of 139 species including Quercus serrata, Q. mongolica, Lindera obtusiloba and Fraxinus sieboldiana increased and those of Carpinus laxiflora and Styrax japonica decreased. In the sedimentary rock areas, to a lesser extent, 96 species including Q. aliena, Zanthoxylum schinifolium, Potentilla fragarioides var. major, Rhus javanica, and Plectranthus japonicus increased, whereas character species of Lindero-Quercion mongolicae such as Q. mongolica, Q. serrata, Rhododendron schlippenbachii, Acer mono and Styrax obassia decreased, and particularily the species Sasa borealis, the Alangium-Zelkova serrata community and the Philadelphus-Fraxinus mandshurica community were absent. The vegetation of sedimentary rock area is characterized as a regional type shaping dwarf pine forests and sparse and light broad-leaved forests.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.2
• /
• pp.127-136
• /
• 2011

In this study, annual maximum storm events are proposed to determined by the return periods considering total rainfall and rainfall intensity together. The rainfall series at Seoul since 1961 are examined and the results are as follows. First, the bivariate exponential distribution is used to determine annual maximum storm events. The parameter estimated annually provides more suitable results than the parameter estimated by whole periods. The chosen annual maximum storm events show these properties. The events with the biggest total rainfall tend to be selected in the wet years and the events with the biggest rainfall intensity in the wet years. These results satisfy the concept of critical storm events which produces the most severe runoff according to soil wetness. The average characteristics of the annual maximum storm events said average rainfall intensity 32.7 mm/hr in 1 hr storm duration(total rainfall 32.7 mm), average rainfall intensity 9.7 mm/hr in 24 hr storm duration(total rainfall 231.6 mm) and average rainfall intensity 7.4 mm/hr in 48 hr storm duration(total rainfall 355.0 mm).