• Title/Summary/Keyword: observational errors

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High Resolution Gyeonggi-do Agrometeorology Information Analysis System based on the Observational Data using Local Analysis and Prediction System (LAPS) (LAPS와 관측자료를 이용한 고해상도 경기도 농업기상정보 분석시스템)

  • Chun, Ji-Min;Kim, Kyu-Rang;Lee, Seon-Yong;Kang, Wee-Soo;Park, Jong-Sun;Yi, Chae-Yon;Choi, Young-Jean;Park, Eun-Woo;Hong, Sun-Sung
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.2
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    • pp.53-62
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    • 2012
  • Demand for high resolution weather data grows in the agriculture and forestry fields. Local Analysis and Prediction System (LAPS) can be used to analyze the local weather at high spatial and temporal resolution, utilizing the data from various sources including numerical weather prediction models, wind or temperature profilers, Automated Weather Station (AWS) networks, radars, and satellites. LAPS has been set to analyze weather elements such as air temperature, relative humidity, wind speed, and wind direction every hour at the spatial resolution of $100m{\times}100m$ for Gyeonggi-do on near real-time basis. The AWS data were revised by adding the agricultural field AWS data (33 stations) in addition to the KMA data. The analysis periods were from 1 to 31 August 2009 and from 15 to 21 February 2010. The comparison of the LAPS output showed the smaller errors when using the agricultural AWS observation data together with the KMA data as its input data than using only either the agricultural or KMA AWS data. The accuracy of the current system needs improvement by further optimization of analyzing options of the system. However, the system is highly applicable to various fields in agriculture and forestry because it can provide site specific data with reasonable time intervals.

Validation of Suitable Zooplankton Enumeration Method for Species Diversity Study Using Rarefaction Curve and Extrapolation (종 다양성 평가를 위한 호소 생태계 동물플랑크톤 조사 방법 연구: 희박화 분석(rarefaction analysis)을 이용한 적정 시료 농축 정도 및 부차 시료 추출량의 검증)

  • Hye-Ji Oh;Yerim Choi;Hyunjoon Kim;Geun-Hyeok Hong;Young-Seuk Park;Yong-Jae Kim;Kwang-Hyeon Chang
    • Korean Journal of Ecology and Environment
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    • v.55 no.4
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    • pp.274-284
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    • 2022
  • Through sample-size-based rarefaction analyses, we tried to suggest the appropriate degree of sample concentration and sub-sample extraction, as a way to estimate more accurate zooplankton species diversity when assessing biodiversity. When we collected zooplankton from three reservoirs with different environmental characteristics, the estimated species richness (S) and Shannon's H' values showed different changing patterns according to the amount of sub-sample extracted from the whole sample by reservoir. However, consequently, their zooplankton diversity indices were estimated the highest values when analyzed by extracting the largest amount of sub-sample. As a result of rarefaction analysis about sample coverage, in the case of deep eutrophic reservoir (Juam) with high zooplankton species and individual numbers, it was analyzed that 99.8% of the whole samples were represented by only 1 mL of sub-sample based on 100 mL of concentrated samples. On the other hand, in Soyang reservoir, which showed very small species and individual numbers, a relatively low representation at 97% when 10 mL of sub-sample was extracted from the same amount of concentrated sample. As such, the representation of sub-sample for the whole zooplankton sample varies depending on the individual density in the sample collected from the field. If the degree of concentration of samples and the amount of sub-sample extraction are adjusted according to the collected individual density, it is believed that errors that occur when comparing the number of species and diversity indices among different water bodies can be minimized.