Where no records are available at a site, a preliminary estimate may be made from relations between floods and catchment characteristics. A number of these characteristics were chosen for testing and were measured for those catchments where mean annual flood estimates were available.
Although the improvement using extended data in regression of flood estimates on catchment characteristics was small, this may be due to the limitations of the regression model. When an individual short term record is to be extended, more detailed attention can be given; an example is presented of the technique which should be adopted in practice, particularly when a short term record covers a period which is known to be biassed.
A method of extending the peaks over a threshold series is presented with a numerical example. The extension of records directly from rainfall by means of a conceptual model is discussed, although the application of such methods is likely to be limited by lack of recording raingauge information.
Methods of combining information from various sources are discussed in terms of information from catchment characteristics supplemented by records. but are generally applicable to different sources of information.
The application of this technique to estimating the probable maximum flood requires more conservative assumptions about the antecedent condition, storm profile and unit hydrograph. It is suggested that the profile and catchment wetness index at the start of the design duration should be based on the assumption that the estimated maximum rainfall occurs in all durations centered on the storm peak.
Dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 6 sampling sites in Pusan area from March, 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP.
The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal distribution. Dustfall amount of regional variations were found in order of coastal zone, industrial zone, commercial zone, agricultural zone and residential zone, and seasonal total dustfall had higher concentrations during spring for 6.741 ton/㎢/season, lower concentrations during summer for 1.989 ton/㎢/season, and annual total concentration was 17.742 ton/㎢/year.
The regional distributions of enrichment factor show well-defined anthropogenic metals (Cd, Cu, Pb, and Zn) at industrial and agricultural zone, and contribution rate of soil particles were found in order of summer, fall, winter and spring. Factor loading effects of chemical composition of dustfall were found in order of road traffic emission source and combustion processed source, industrial activity source, soil source and marine source.
To investigate the physio-chemical components and properties of aerosol particles in urban area sampling of aerosol particles was carried out in the campus of Hokkaido University, Sapporo, Japan, during snowfall. Aerosol particles were collected on millipore filter papers using a low volume air sampler. Their shapes, sizes and chemical components were analyzed by a SEM (Scanning Electron Microscope) and an EDX (Energy Dispersive X-ray).
As a results, ice crystals of dendrite and column types were predominantly shown at mature and developing stage of snowfall intensity. The denerite and sector plate types of ice crystals were mainly originated from the sea but column types were come from soil. Scavenging effect by snowfall was greatly also shown at dendrite type ice crystals that embryo was fully developd. Al, Si elements were shown at high frequencies as compared with others. Na, Cl components were especially shown at high frequencies under the sea-breeze wind during snowfall. Anthropogenic aerosol particles had shown with irregular shapes and sizes, relatively. Mainly 3-7㎛ aerosol particles were abundant and coarse particles also could be seen during snowfall. Ca, Zn, Fe components mainly caused by spike tires from vehicles in winter season were dominant before snowfall, however the element S mainly caused by human activity was rich after snowfall. The pH values of snow in Sapporo city were higher than those at coastal area. The concentration of chemical components in aerosol particles was also affected by surface winds.
Aerosol particles in urban area, Sapporo were mainly affected by human activities like vehicles and combustion with wind system. And their types were related with snowfall intensity.
It was supposed that CSA could be one of the best way to promote the movement of organic agriculture since there is little reliability on the organically grown food by consumer. In the replies submitted to a questionnaire to farmer and consumer, both group responded that the need of development of cultivation technique for organic farming and the permitted substances for organic farming and production. Both of them also replied that it is necessary to establish the lectures or division/department for organic agriculture in the agricultural education program of University.1)
Their response to CSA was so much positive that they are willing to participate the CSA farm as a active CSA farmers or consumers. Based on the evaluation of questionnaire survey, it was suggested to do the utmost efforts that farmer preferentially practice an organic farming, and consumer consciously buy an organic food to protect an ecosystem and environment pollution.
According to the research of the cultivation result on the spot farmers for 5 years in order to investigate its cultivation conditions and problems of Lycium chinetrse Mill, the development of the variety with early mature, pest tolerance, and high yielding is urgent and it is call for the development of rooted cutting cultivation by testing of bed soil, growth regulator and cutting times. The development of cultivation method with planting year, planting density, supplementary period and amounts of supplementary of Lycium chinense Mill planted in growing field are required and for the disease and the effective control of disease and insect pest resistance is needed by auxotrophic fertilizing and organic agricultural method, met by agricultural chemicals.
We studied the appearance and proliferation of red tide organisms from March, 1998, to February, 1999, in the Jindong Bay. There were two red tide events during investigation, and we found that the dominant species Ceratium furca in May and Gymnodinium sanguineum in September, 1998.
At surface, temperature and salinity showed 18.3∼19.7℃ and 30.6∼30.9 psu in May and 25.6∼27.0℃, 28.0∼28.5 psu in September, respectively. When the red tide occurred, the water mass was stable.
Dissolved inorganic nitrogen(DIN) and dissolved inorganic phosphate(DIP) in Jindong Bay showed seasonal variability. In May, the nitrogen was a limited nutrient in which the ratio of DIN versus DIP was less than 16 (Redfield ratio), while in September phosphate. During June to September, 1998, phosphate acted as a limited nutrient due to the increased river run-off from land.
In May, chlorophyll-a, dissolved oxygen(DO) and chemical oxygen demand(COD) showed higher than 20㎍/ℓ, l0㎎/ℓ and 5.0㎎/ℓ, respectively. In September, they showed in turns 100㎍/ℓ, 10㎎/ℓ and 10㎎/ℓ, respectively.
In order to investigate horizontal wind field in the boundary layer around Pusan area, wind speed and wind direction measured at 14 AWS(Automatic Weather Station), 1997, was used. The wind direction at PRMO(Pusan Regional Meterological Office) was showed that southwest and northeast wind dominated for spring and summer, northeast wind for fall and northwest for winter. Anticline flow was showed at 'Gaekumm' which is located between Mt. Backyang(641 m) and Mt. Yumkwang(503 m) and affected on wind field at 'Pusanjin'. The low wind speed and various wind direction was represented at the basin topography, 'Buckgu', 'Jeasong', 'Ilkwang' and 'Kijang'. The annual mean wind speed at 14 sites, 2.5 ms-1, was lower than that measured at PRMO, 3.9 ms-1. The wind direction analysis showed that the case of same direction in compare with that measured at PRMO is about 54% and case of opposite direction is about 12%. Annual and seasonal mean windrose showed wind direction is affected by not only synoptic weather state but also topography.
본 연구에서는 한강유역의 1일, 2일, 3일 연최대강우자료를 대상으로 L-모멘트법을 이용한 지점 빈도해석과 지역 빈도해석을 실시하여 그 결과를 비교하였다. 지역빈도해석을 실시하기 위하여 한강유역을 남한강, 북한강, 한강하류부 유역의 3개 소유역으로 분할하고, 각 유역에 대한 자료의 이산도 및 동질성을 검토하였으며, 각 소유역에 대하여 여러 분포형을 적용한 결과, 남한강유역과 한강하류부 유역은 lognormal 분포형, 북한강 유역은 gamma-3 분포형
The Cretaceous granite, andesite and sedimentary rocks are widely distributed in the northern Pusan area. The present study investigates mineralogical and geochemical charateristics of residual and cultivated soils derived from these rocks. The soils of granite area contain a large amount of quartz relative to clay minerals, whereas the soils of the andesite area contain more clay minerals than quartz. Clay minerals consist mainly of kaolin minerals illite hydroxy interlayered vermiculite interstratified mica/vermiculite and chlorite. Kaolin minerals are abundant in paddy soils while illite is abundant in less weathered soils. Si and K are major elements in the soils of granite area while Fe and Al in the soils of andesite area. In all the soils Ca, Mg and Na were generally depleted in comparison to those in parent rocks. Analysis data of trace element show that the enrichment pattern in soils depends on parent rock type with high oncentration of some elements over 100 ppm: Ba and Rb in granite area Zn, Bn, and V in andesite area, and Ba and V in sedimentary rock. In granite area, Rb and Th were greatly enriched in soil than in parent rocks. However, Cr, Ni and Sr commonly decrease, whereas Pb increases in all the soils. Exchangeable cation capacity(CEC) is relatively high in the soils of andesite are including abundant clay minerals. Collective evidences prove that the mineralogical and chemical compositions of soils are strongly dependent on the parent rock type. The mineralogy and chemistry of long cultivated soils are not significantly different from those of residual soils.
공주군 유구면 일대의 화강암질 편마암의 풍화작용에 따른 원소의 거동과 pH와 이차광물과의 관계를 XRF, ICP-AES, ICP-MS를 이용한 원소분석결과를 통하여 검토하였다. 이 지역의 암석은 pH6 내외의 산성환경, 침철석, 아나타제와 같은 다양한 이차광물을 생성하면서 심각한 화학조성의 변화를 초래했다. 주원소의 화학조성을 이용한 풍화지수는 토양층에서 79~88로 모암 중의 사장석이 용해되고 흑운모가 변질되어 캐올리광물의 생성이 활발한 방향으로 풍화작용이 진행되었다. 지표층으로 가면서 Al에 대한 주 원소의 거동은 Si, Ca, Na, K, P가 감소하고 Fe, Ti, Mn이 증가하는 경향을 보이며 pH가 낮은 풍화단면에서 주 원소의 변화량이 더 크다. 이 풍화대에서 Mg은 거의 일정하다. Li, As 모든 전이원소는 pH가 감소함에 따라 증가하며 특히 이들 원소는 Fe의 함량과 비례해서 증가해 침철석과 공침하였거나 표면에 흡착되어 있는 것으로 보인다. Ga은 Fe와 비례하기는 하지만 변화량은 전 풍화단면에서 일정하다. Zr, Mo, Sn, Cd은 pH에 변화에 상관없이 일정한 반면에 Rb, Sr, Ba, Y, Pb, Th, U 등은 감소하는 경향을 보인다. 특히 Rb 과 Sr은 Ca에 비례해서 감소한다. 희토류원소는 전 풍화단면에서 감소하는 경향을 보이는데 Al2O3에 대한 상대적인 변화량을 보면 경희토류원소는 사프롤라이트(saprolite)하부와 상부에서 부화되어 있고 중부 사프롤라이트와 토양층에서 감소하는 반면에 중희토류원소는 사프롤라이트 하부와 상부에서 감소하고 중부사프롤라이트 및 토양층에서 부화되는 경향을 보인다. 전반적으로 희토류원소의 원자번호가 클수록 손실율이 커진다. 이 풍화단면에서 원소의 거동은 각 풍화층의 pH와 생성된 이차광물의 조성에 지배를 받았다.
본 조사는 우리나라 율무 주산지역인 연천지역의 율무재배 농가의 일반사항, 경종개요, 생육 특성 및 조곡 수량, 수확후 토양 성분 등을 조사하여 율무 재배법 개선을 위한 기초자료로 활용하기 위해 수행되었다. 율무 재배 농가의 연령은 51세 이상으로 고령화되어 있었고 재배 면적은 작았다. 대부분의 농가는 자가 노동력에 의한 영세농이었으며 종자는 자가 채종하여 사용하고 있었다. 파종방법은 발뒤굼치를 사용하는 점파가 주종을 이루었고, 재식밀도는 10a 당 2000-3500 주가 64%이었고, 시비량은 농가별로 차이가 많았다. 병해충 방제 횟수는 적은 편이었다. 조사 농가의 평균 초장, 주간절수, 주간직경, 개체당 분얼경수, 천립중, 종피경도 및 조곡 수량은 각각 184 cm, 10, 10 mm, 14.4, 108 g, 3.22 g/cm3, 및 341 kg/10a 이었다. 조사농가의 수확직후 토양의 pH, 유기물 함량, 유효인산 함량, 칼리 및 전기전도도는 평균적으로 각각 5.8, 0.11 g/kg, 385 mg/kg, 0.48 cmol+kg 및 0.21 dS/m이었다. 종피경도와 조곡수량은 P=0.01 수준에서 (-0.7442) 높은 부의 상관관계를 나타냈다.
우리나라 황칠나무 주요 자생지인 남부도서지역의 완도지방에서 황칠나무의 적정 파종기를 구명하여 자생지 보호와 농가의 재배면적 확대 그리고 관상가치가 높은 실생 파종묘의 재배법을 체계적으로 확립 하고자 본시험을 실시한 결과는 다음과 같다. 1. 비닐하우스를 이용하여 황칠나무의 종자를 포트에 파종할 경우 3월 중순 파종이 출현율이 높고, 초기생육이 양호하여 알맞은 파종기로 판단된다. 2. 노지에 황칠나무 종자를 직파할 경우 4월 상순 파종이 종자의 출현율이 높고, 생육이 양호하여 알맞은 파종기로 생각된다. 3. 황칠나무의 적정 파종방법으로는 포트파종이 노지 파종보다 발아율이 높고, 묘목의 수고와 경직경이 커서 초기생육이 양호하여 알맞은 파종방법으로 생각된다.
According to the results of the groundwater quality investigation about 230 holes all over the country, the groundwater which was in excess of standard grows larger every year and closed holes increased to 23,457 holes in 1997 from 15,724 holes in 1996. This is the major reasons that water quality contamination, shortage of water quantity, increasing of salinity and so on.
There are 7 groundwater salinization sources which are considered as most important on a regional level. And among theses the Cheju Island groundwater salinization sources are (1) halite solution, (2) natural saline groundwater, (3) sea-water intrusion.
The method of taking an isotopes is one of research methods of the origin of groundwater salinization and is used in so many studies because it has very high confidence. 18O, 2H, 3H, 14C and so on in an isotopes are frequently used in the method of them.
Consequently on this study we analyzed major ions and 3H in groundwater, sea-water and rain of the eastern part of cheju island known as contaminated site from long time ago to examine the origin of groundwater salinization.
Relation ratios of the major ions versus chloride ion shows similar tendency to sea-water. This indicates that sea-water entered the groundwater layer.
And amount of 3H in holes of the land side is higher than that of the sea side. Relation of chloride ion versus 3H indicates negative character. Therefore we can think that the reason of groundwater salinization of this part is natural saline groundwater and halite solution by relation.