• 한국농림기상학회지
• /
• 제3권3호
• /
• pp.156-162
• /
• 2001

In order to monitor local climatic information, twelve automated weather stations (AWS) were installed in alpine area by the Alpine Agricultural Experiment Station, Rural Development Administration (RDA), at the field of major crop located in around highland area, and collected data from 1993 to 2000. Hourly measurements of air and soil temperature (underground 10 cm,20 cm), relative humidity, wind speed and direction, precipitation, solar radiation and leaf wetness were automatically performed and the data could be collected through a public phone line. Datalogger was selected as CR10X (Campbell scientific, LTD, USA) out of consideration for sensers' compatibility, economics, endurance and conveniences. All AWS in alpine area were combined for net work and daily climatic data were analyzed in text and graphic file by program (Chumsungdae, LTD) on 1 km $\times$ 1 km grid tell basis. In this analysis system, important multi-functionalities, monitoring and analysis of local climatic information in alpine area was emphasized. The first objective was to obtain the output of a real time data from AWS. Secondly, daily climatic normals for each grid tell were calculated from geo-statistical relationships based on the climatic records of existing weather stations as well as their topographical informations. On 1 km $\times$ 1 km grid cell basis, real time climatic data from the automated weather stations and daily climatic normals were analyzed and graphed. In the future, if several simulation models were developed and connected with this system it would be possible to precisely forecast crop growth and yield or plant disease and pest by using climatic information in alpine area.

• 한국농공학회논문집
• /
• 제51권6호
• /
• pp.1-9
• /
• 2009

Watershed topographical data is essential for the management for water resources and watershed management in terms of hydrology analysis. Collecting watershed topographical and meteorological data is the first step for simulating hydrological models and calculating hydrological components. This study describes a specialized Web-based Geographic Information Systems, Soil Water Assessment Tool model data generation system, which was developed to support SWAT model operation using Web-GIS capability for map browsing, online watershed delineation and topographical and meteorological data extraction. This system tested its operability extracting watershed topographical and meteorological data in real time and the extracted spatial and weather data were seamlessly imported to ArcSWAT system demonstrating its usability. The Web-GIS would be useful to users who are willing to operate SWAT models for the various watershed management purposes in terms of spatial and weather preparing.

• The Korean Journal of Ecology
• /
• 제23권2호
• /
• pp.117-123
• /
• 2000

Changing patterns and the possibility of climate change in the area of Cheiudo island, the southernmost Island in Korea, were analyzed using daily temperature and Precipitation data observed at the Cheiu Regional Meteorological Office from May 1923 to December 1998. A hydrologic simulation model "BROOK" was used to simulate and analyze the dynamics of daily soil moisture content and soil moisture deficit by applying the daily weather data. During the period, significantly increasing pattern was observed in temperature data of both annual and monthly basis, while no significantly changing pattern was observed in precipitation data. During the last 76 years. mean annual temperature was observed to have risen about 1.4$^{\circ}C$, which may show the Possibility of the initiation of climate change on the island whose validity should be tested in future studies after long-term studies on temperature. Based on the simulation, due to increased temperature, significant increase was predicted in evapotranspiration. while no significant decrease was detected in simulated soil moisture content during the period. Changing pattern of annual soil moisture content was markedly different from those of precipitation. In some dominant trees, negative effects of the drought of the late season for the previous year were shown to be statistically significant to radial growth of the tree for the current year. As annual variation of radial growth of trees is mainly affected by the soil moisture content. the information on the dynamics of soil moisture deficit possibly provides us with useful information for the interpretation of tree growth decline on the mountain. mountain.

• 대한원격탐사학회지
• /
• 제19권3호
• /
• pp.223-231
• /
• 2003

With the negative influences and damage from Asian dust increasing, it's getting important to investigate the climate and soil condition of the source region of Asian dust. There is a high possibility that the desertification and the drastic decrease of plants in China and Mongolia make worse the situation (bad effects of Asian Dust). To detect the movement of Asian dust caused by air circulation, we need to watch the state of the source region to get useful information for the prevention of the dust pollution, and to predict what part of China will become the source region. Therefore, using TOMS aerosol index data, NCEP reanalysis data that is Remote Sensing data from 1981 to 2000 (except 1993~1996, 4 years), for 16 years, examined the relation between the dust occurrence and weather elements. Dust occurrence appeared much in spring season from March to May in study areas. It had a dry climate during that season as follows : relative humidity about 20~40%, temperature about -5~5$^{\circ}C$, precipitation about 33-180 mm, wind speed about 4-10 ms-1. Dust occurrence and weather element annual change in study areas decreased gradually till 1990, but in Gobi desert the incidence of dust occurrence increased since 1997. As a result, found out that the more the precipitation, the less dust occurrence, because the precipitation and surface wind speed had a direct influence on the soil of the source region of dust.

• Journal of Multimedia Information System
• /
• 제5권4호
• /
• pp.235-244
• /
• 2018

Potential maximum soil moisture retention (S) is a dominant parameter in the Soil Conservation Service (SCS; now called the USDA Natural Resources Conservation Service (NRCS)) runoff Curve Number (CN) method commonly used in hydrologic modeling for event-based flood forecasting (SCS, 1985). Physically, S represents the depth [L] soil could store water through infiltration. The depth of soil moisture retention will vary depending on infiltration from previous rainfall events; an adjustment is usually made using a factor for Antecedent Moisture Conditions (AMCs). Application of the method for continuous simulation of multiple storms has typically involved updating the AMC and S. However, these studies have focused on a time step where S is allowed to vary at daily or longer time scales. While useful for hydrologic events that span multiple days, this temporal resolution is too coarse for short-term applications such as flash flood events. In this study, an approach for deriving a time-variable potential maximum soil moisture retention curve (S-curve) at hourly time-scales is presented. The methodology is applied to the Napa River basin, California. Rainfall events from 2011 to 2012 are used for estimating the event-based S. As a result, we derive an S-curve which is classified into three sections depending on the recovery rate of S for soil moisture conditions ranging from 1) dry, 2) transitional from dry to wet, and 3) wet. The first section is described as gradually increasing recovering S (0.97 mm/hr or 23.28 mm/day), the second section is described as steeply recovering S (2.11 mm/hr or 50.64 mm/day) and the third section is described as gradually decreasing recovery (0.34 mm/hr or 8.16 mm/day). Using the S-curve, we can estimate the hourly change of soil moisture content according to the time duration after rainfall cessation, which is then used to estimate direct runoff for a continuous simulation for flood forecasting.

• 대기
• /
• 제22권3호
• /
• pp.357-365
• /
• 2012

High spatio-temporal resolution hydrologic components can give important information to monitor natural disaster. The objective of this study is to create high spatial-temporal resolution gridded hydrologic components using TOPLATS distributed land surface model and evaluate their accuracy. For this, Andong dam basin is selected as study area and TOPLATS model is constructed to create hourly simulated values in every $1{\times}1km^2$ cell size. The observed inflow at Andong dam and soil moisture at Andong AWS site are collected to directly evaluate the simulated one. RMSEs of monthly simulated flow for calibration (2003~2006) and verification (2007~2009) periods show 36.87 mm and 32.41 mm, respectively. The hourly simulated soil moisture in the cell located Andong observation site for 2009 is well fitted with observed one at -50 cm. From this results, the cell based hydrologic components using TOPLATS distributed land surface model show to reasonably represent the real hydrologic condition in the field. Therefore the model driven hydrologic information can be used to analyze local water balance and monitor natural disaster caused by the severe weather.

• 드라이브 ㆍ 컨트롤
• /
• 제21권3호
• /
• pp.46-55
• /
• 2024

In the agricultural machinery field, load analysis is mostly done through field tests. However, field tests are time-consuming and costly. There are also limitations in test conditions due to weather conditions. To overcome these environmental limitations, research on load analysis through simulation in a virtual environment is actively being conducted. This study aimed to select the most appropriate soil particle size for modeling by analyzing the effect of soil particle size on the prediction of draft force of the implement using simulation and soil particle modeling in a virtual environment with the discrete element method (DEM) software. The accuracy was verified by simulating the draft force for the same moving speed by soil particle size. For soil particle modeling, DEM soil modeling was performed by designing soil property measurement procedure. Soil particle correction was performed with a virtual vane shear test. Average DEM simulation results showed an error of 27.39% (19.43~40.66%) compared to actual measured data. The possibility of improvement was confirmed through additional research. Results of this study provide useful information for selecting soil particle size in soil modeling using DEM from the perspective of agricultural machinery research.

• 한국농림기상학회지
• /
• 제19권4호
• /
• pp.246-251
• /
• 2017

벼의 생육에 있어서 중요한 역할을 하는 출수기를 예측하기 위해 작물모델이 사용될 수 있다. 벼의 생육을 모의하는 모델 중 널리 사용되던 ORYZA2000 모델이 개선되어 ORYZA (v3)가 최근에 보고되었다. 그러나, 최근까지 ORYZA (v3)의 국내 적용 가능성에 대해서는 연구가 이루어지지 않았다. 본 연구에서는 ORYZA (v3)를 이용하여 예측된 출수기의 신뢰성을 검토하였다. 또한, 새로운 모델에 요구되는 입력자료를 생성하는데 있어서의 편의성을 평가하였다. 국립농업과학원의 실험포장에서 2015년과 2016년에 걸쳐 중만생종인 신동진벼를 이용하여 화학비료 표준시비 조건에서 실험을 수행하였다. 입력자료는 실험에 사용한 재배관리자료, 기상청으로부터 수집한 기상자료, 흙토람으로부터 수집한 토양자료 및 Lee et al.(2015)에서 사용한 품종모수 자료를 사용하였다. 또한, 벼우량계통 지역적응시험에서 얻어진 출수기 관측자료와 예측자료를 비교하였다. 예측된 출수기는 인근 기상관측소에서 얻어진 기상입력 자료가 사용되었을 경우, 실제 출수기와 비교적 유사한 결과를 보였다. 예를 들어, 전주, 대구, 영남, 논산, 계화에서 예측된 출수기는 1일 이내의 상당히 작은 오차는 가졌다. 그러나, 기상자료가 비교적 멀리 떨어져 있거나 해안가 인근지역에 위치하여 출수기 관측지의 국지적 기상조건을 충분히 반영하지 못할 경우 상당한 오차가 발생하였다. ORYZA (v3)의 입력자료 생성과 관련한 편의성 측면에서는 기존의 자료 처리도구를 활용할 수 있는 기상 자료 확보는 비교적 용이할 것으로 판단되나, 토양자료에 대해서는 ORYZA 2000 모델의 입력자료에 추가적인 자료가 요구되어 토양자료 처리도구의 개발이 필요할 것으로 보였다.

• 대한원격탐사학회지
• /
• 제38권6_3호
• /
• pp.1847-1859
• /
• 2022

북한에서 발생한 산불은 비무장지대 등으로 남하하는 경우 우리나라에 직·간접적인 영향을 줄 수 있다. 이에 본 연구는 정보 접근불능 지역인 북한의 산불위험정보를 획득하기 위하여 Local Data Assimilation and Prediction System (LDAPS) 기상자료 기반의 지역 최적화된 산불위험지수 Forest Fire Danger Index (FFDI)를 산출하고, 2022년 4월 북한 고성군과 철원군의 산불 사례에 적용하였다. 그 결과 발화일 당시 FFDI가 각각 위험등급 Extreme과 Severe 구간에 해당하여 적합성을 확인하였다. 또한 산불 발생 전후의 위험도지도와 토양수분지도를 정성적으로 비교한 결과 상호 관계성을 파악하였으며, 향후 토양수분, 표준화강수지수(Standardized Precipitation Index, SPI), 식생수분지수(Normalized Difference Water Index, NDWI) 등을 결합하는 방식으로 산불발생위험지수의 개선이 필요하다.

• 한국농림기상학회지
• /
• 제3권1호
• /
• pp.37-43
• /
• 2001

Crop status monitoring and yield prediction at higher spatial resolution is a valuable tool in various decision making processes including agricultural policy making by the national and local governments. A prototype crop forecasting system was developed to project the size of rice crop across geographic areas nationwide, based on daily weather pattern. The system consists of crop models and the input data for 1,455 cultivation zone units (the smallest administrative unit of local government in South Korea called "Myun") making up the coterminous South Korea. CERES-rice, a rice crop growth simulation model, was tuned to have genetic characteristics pertinent to domestic cultivars. Daily maximum/minimum temperature, solar radiation, and precipitation surface on 1km by 1km grid spacing were prepared by a spatial interpolation of 63 point observations from the Korea Meteorological Administration network. Spatial mean weather data were derived for each Myun and transformed to the model input format. Soil characteristics and management information at each Myun were available from the Rural Development Administration. The system was applied to the forecasting of national rice production for the recent 3 years (1997 to 1999). The model was run with the past weather data as of September 15 each year, which is about a month earlier than the actual harvest date. Simulated yields of 1,455 Myuns were grouped into 162 counties by acreage-weighted summation to enable the validation, since the official production statistics from the Ministry of Agriculture and Forestry is on the county basis. Forecast yields were less sensitive to the changes in annual climate than the reported yields and there was a relatively weak correlation between the forecast and the reported yields. However, the projected size of rice crop at each county, which was obtained by multiplication of the mean yield with the acreage, was close to the reported production with the $r^2$ values higher than 0.97 in all three years.