• 제목/요약/키워드: paddy field area

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여름철 논에서의 기온저감 효과 (The cooling effect of a paddy field area during summer)

  • 송철민;김진수;박종화;정구영
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2006년도 학술발표회 논문집
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    • pp.1497-1500
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    • 2006
  • The cooling effect of paddy fields was compared with those of other land-use areas (upland, urban park, and urban residential area) during midsummer. The temperature were monitored using data logger at one hour intervals in study sites. Diurnal temperature range of study areas in clear days was larger than in cloudy days. Also, diurnal temperature ranges in paddy field, upland, and park areas were larger than those in the urban residential area during clear days. The paddy field or upland area has shown more remarkable cooling effect compared to urban residential areas: Mean duration of temperature below $25^{\circ}C$ in the paddy field area is longer(7 to 8 hours) than in the residential area; The time to fall to below $25^{\circ}C$ in the paddy field area is sooner than in the residential area; Mean daily minimum temperature in the paddy field area is much lower than in the residential area.

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유역배율이 작은 저수지의 이수관리방법 (Operation Rule Curve for Reservoir with Low Areal Ratio of Watershed to Downstream Paddy Field)

  • 노재경
    • 한국관개배수논문집
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    • 제18권1호
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    • pp.68-80
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    • 2011
  • To provide a operation rule curve for reservoir with low ratio of watershed area to paddy field area, Duckyong reservoir with watershed area of $15.8km^2$ and paddy field area of 1,071ha was selected, in which 4 meters are being heightened and full water levels will be increased from EL.26.0m to EL.30.0m, total water storages from 365.6M $m^3$ to 708.0M $m^3$. There was no operation rule curve that satisfied over 90% reliability of water supply in reservoir with watershed area of 1.48 times of paddy field area. The differences between observed and simulated reservoir daily water storages were minimized to determine parameters for simulating reservoir inflow in case of paddy field area of 550ha from 1991 to 2010. A operation rule curve was drawn to have a maximum storage with total water storage, which was in paddy field area of 700ha with ratio of 2.3 between watershed area and paddy field area. This case showed that annual irrigation water supply was 668M $m^3$ and instream flow of 57M $m^3$, water supply reliability of 55.6% in normal operation, and annual irrigation water supply was 605M $m^3$ and instream flow of 38M $m^3$, water supply reliability of 95.6% in withdrawal limited operation. Water supply reliabilities showed 35.6% without flood regulation and 17.8% with flood regulation in existing reservoir before heightening.

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여름철 토지피복별 기온변화 특성 (Characteristics of Air Temperature Variations under Different Land Covers during Summer)

  • 김진수;박종화;정구영;오광영
    • 한국농공학회논문집
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    • 제49권1호
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    • pp.79-88
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    • 2007
  • We investigated the characteristics of temperature variations under different land covers (paddy field, upland, urban park, and urban residential area) during hot summer (July 15 to August 19, 2005). The temperatures were monitored using data loggers at one hour intervals in study sites. The mean temperature generally increased with the distance from edge of paddy fields, being $1.5^{\circ}C$ higher at a site 170-m far from paddy fields than at a paddy field area at 22 h. The mean daily temperatures in the study period followed the ordo. of paddy field $(26.6^{\circ}C)$ < upland $(27.0^{\circ}C)$ < park $(27.5^{\circ}C)$ < residential area $(28.0^{\circ}C)$. The paddy field area has shown remarkable cooling effects compared to the residential area: Mean duration of temperature below $25^{\circ}C$ in the paddy field area was longer (8.6 hrs) than in the residential area; The time to fall to below $25^{\circ}C$ in the paddy field area was sooner (22.4 hr) than in the residential area; Mean daily minimum temperature in the paddy field area was much lower $(2.4^{\circ}C)$ than in the residential area. More research is needed to better clarify the mechanism of cooling effect of a paddy field area by investigating heat balance of a paddy field.

농업용수 개발을 위한 보의 실태조사와 그 분석 (강원도를 중심으로) (A Study on the Research of Actual Condition and the Analysis for the Weir to Develope the Agricnltural Irrigation Water (around Gangwon-Do))

  • 최예환;황은
    • 한국농공학회지
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    • 제20권1호
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    • pp.4614-4625
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    • 1978
  • The construction of the equipment of water utilization has been developed since the ancient Korea period, 1906 in order to develope and modernize the agriculture. As the results, 83% of total paddy field area, 1,268,949.8 ha has developed into the irrigated paddy field, and the rest of area, 17% has remained nonirrigated paddy field (due to the data of the statistics of 1975). The ratio of the irrigated paddy field area among the total weir was marked 13.14% (area, 137,926.3 ha) and the third grade of total irrigated paddy field in accordance with the facilities of water utilization. In case of Gangwon-Do, the 44.18 percentage of the total irrigated paddy field, 51,057.2ha has been and pointed out first grade. As the results, we found out the following articles : 1. The total weir, 1,641 that sumed concrete weir 647 and conventional weir 967 has been constructed and has irrigated the 44.l8% of total irrigated paddy field of Gangwon-Do. 2. These weirs have been public possession of those villages to be 96.1 percentage of total weir and was controled by them. 3. Those weirs that were constructed across tributary (first, secondary and third tributary) at vallies (elevation 100∼1,000m) have marked that 45 percentage of total number of catchment area has 100∼1,000 ha, and 70 percentage of total number of basin area has been below 10 ha and has constructed about 5 of step-shape. 4. The construction of most weirs has became generally about 50m length, about 1m height. 5. The 80 percentage of newly constructed concrete weir has aged below 10 years. It seemed that 79 percentage of conventional weir has aged over 20 years and 41% of contructed weir has needed to be improved quickly. 6. If privious weirs, 296 will constructed newly, they can irrigate 3,600.8 ha of paddy field and 45.8% of total irrigated paddy field will have been and will contribute to the production of much rice.

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변화할당효과를 고려한 논 면적 예측 모형의 개발 (Development of a Paddy Field Estimation Model Considering Shift-share Effects)

  • 장우석;정남수;박기욱
    • 한국농공학회논문집
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    • 제50권3호
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    • pp.83-89
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    • 2008
  • Estimations of paddy field area are important for agricultural water supply planning. Especially these estimations have to be excused by drainage basin. In this research, we developed a paddy field estimation model considering shift-share effects such as national growing, structural, local effects. National growing effects are estimated by adopting the result of KREI-ASMO model which predict farm land area in national level. Paddy field structural effects are estimated using statistical data about farmhouse numbers and cultivation areas. Local allocation effects are calculated by differences of estimations and real data. The results using data from 1998 to 2003 show that developed model estimates 2006 paddy field areas in each province in 5% error and is applicable to predict future change of paddy field.

RapidEye 위성영상의 시계열 NDVI 및 객체기반 분류를 이용한 북한 재령군의 논벼 재배지역 추출 기법 연구 (Extraction of paddy field in Jaeryeong, North Korea by object-oriented classification with RapidEye NDVI imagery)

  • 이상현;오윤경;박나영;이성학;최진용
    • 한국농공학회논문집
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    • 제56권3호
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    • pp.55-64
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    • 2014
  • While utilizing high resolution satellite image for land use classification has been popularized, object-oriented classification has been adapted as an affordable classification method rather than conventional statistical classification. The aim of this study is to extract the paddy field area using object-oriented classification with time series NDVI from high-resolution satellite images, and the RapidEye satellite images of Jaeryung-gun in North Korea were used. For the implementation of object-oriented classification, creating objects by setting of scale and color factors was conducted, then 3 different land use categories including paddy field, forest and water bodies were extracted from the objects applying the variation of time-series NDVI. The unclassified objects which were not involved into the previous extraction classified into 6 categories using unsupervised classification by clustering analysis. Finally, the unsuitable paddy field area were assorted from the topographic factors such as elevation and slope. As the results, about 33.6 % of the total area (32313.1 ha) were classified to the paddy field (10847.9 ha) and 851.0 ha was classified to the unsuitable paddy field based on the topographic factors. The user accuracy of paddy field classification was calculated to 83.3 %, and among those, about 60.0 % of total paddy fields were classified from the time-series NDVI before the unsupervised classification. Other land covers were classified as to upland(5255.2 ha), forest (10961.0 ha), residential area and bare land (3309.6 ha), and lake and river (1784.4 ha) from this object-oriented classification.

The analysis of the cultivation status of the upland crops in the paddy field using unmanned aerial vehicle

  • Park, Jin-Ki;Kwak, Kang-Su;Park, Jong-Hwa
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.352-352
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    • 2017
  • Recently, the South Korean government encourages the cultivation of upland crops in the paddy field to maintain an adequate level of rice production and then to balance the demand and supply of rice. This is mainly because the rice consumption per capita per year has continued to decline from 135 kg in 1979 to 61.9 kg in 2016, although the rice production was relatively stable. As a result, the rice overproduction became a big social problem. As a part of that, various upland crops such as soybean, maize, minor cereals and forage crops are planted in the paddy field 10 years ago. The cultivation of these crops may settle the problem of short supply and mass import of the crops to some extent. However, a systematic remote observation of upland crops in the paddy field is very scarce. This study investigated the cultivation status of upland crops and any changes of crop harvesting in the paddy field by using an unmanned aerial vehicle (UAV). Also, we analyzed the kind of upland crops and cultivation area in the paddy field by utilizing time series observation images. A fixed wing UAV is used for the investigation. This is because it is easy to use the flight operation and to control flight management software, and it can automatically cope with various emergency states such as a strong wind and battery discharge. The material of UAV is expanded polypropylene, which has an advantage of less equipment damage and risk during takeoff and landing. We acquired observed images in Buljeong-myeon, Goesan-gun, Chungcheongbuk-do, South Korea by using fixed wing UAV in 2015 and 2016. The total investigated area reaches 6,045 ha, and among them the agricultural area was 1,377 ha. For the next step, we created an orthoimage from all images taken using Pix 4D mapper program. According to the results of image analyses in 2015, the paddy field covered total 577 ha (75.9%) with crop plant. The cultivation area of beans, ginseng, maize, tobacco and peach was 256 ha (36.6%), 63 ha (9.2%), 37 ha (5.4%), 31 ha (4.5%) and 27 ha (3.8), respectively. And in 2016, the total covered area was 586 ha (77.1%), and it was comprised of 253 ha (35.5%), 88 ha (12.3%), 29 ha (4.1%), 22 ha (3.1%) and 32 ha (4.5%) in the same order. In this study, we focused on identifying the paddy field which was converted to the cultivation of upland crops by using UAV. And, it has been indicated that the cultivation area of rice decreased from 141 ha in 2015 to 127 ha in 2016, although that of ginseng increased by 25 ha. As a result, it is expected that a lot of paddy field could be replaced by high-income crops such as ginseng and fruit tree (peach) instead of relative low-income rice. More specific and widespread research on the remote sensing in the paddy field needs to be done.

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Revised Soil Survey of Yangju City in Gyunggido

  • Hyun, Byung-Keun;Sonn, Yeon-Kyu;Kim, Keun-Tae;Cho, Hyun-Jun;Jung, Sug-Jae;Choi, Jung-Won
    • 한국토양비료학회지
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    • 제50권2호
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    • pp.81-92
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    • 2017
  • Recently, agricultural lands have decreased sharply, which was caused by huge housing site, urbanization, land consolidation, and road construction etc. In particular, Yangju city near Seoul city has the most severe land use change in Korea. Therefore, we analyzed changes of land use, soil properties, and soil information in order to provide the basic soil information and soil management practices in this city. The area of crop cultivated land in Korea (2015) reduced by 12,090 ha compared to ones from the previous year (2014). The paddy field decreased by 25,421 ha but, upland field increased by 13,331 ha. One of the reasons for the reduction of the paddy field was converting paddy field to upland (20,916 ha) > others (3,056) > building (2,571) > public facilities (847) > idle land (217). But, reasons for increase of upland field were switching paddy to upland (20,916 ha) > land developed (634). The main reason of converting paddy field to upland was changing from rice to more profitable speciality crops or pulses. The cropland area (paddy fields, upland, orchard) of Yangju city reduced by 1,412 ha (2015/2014). The ratio of cropland area in each city reduced by 22.9% dramatically compared 2015 to 1999. The paddy fields located in alluvial plains in Yangju city were changed into upland or green house. The drainage classes of soil have been deteriorated because the flows of water were intercepted by road construction and other disturbance to water flows. In particular, paddy fields have been changed to not only upland, orchard, greenhouse cultivation but also to fallow and soil dressing on paddy in Yangju city. To analyze result of soil survey of Yangju city, 858 soil codes (soil phases) were used and the area was 105.17ha. The number of soil series increased from 60 to 65, and that of soil phase increased from 105 to 124. The largest increased area was Noegog soil series. 125.7ha of Neogog soil series was incorporated from the existing Sachon, Yecheon and Eungog soil series. The soil suitability class of paddy field in Ogjung huge housing site of Yangju city was the 4th grade for 32.6% of the area. The soil suitability classes of upland were 2nd and 3rd grade for 72.4% of the area. Farm land with high quality should be conserved by related law.

논관개 양수량의 관개면적과 강수량과의 관계 (Correlations between Pumping Rate to Irrigated Area and Rainfall Amount in a Paddy Field)

  • 이성희;김태철
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2001년도 학술발표회 발표논문집
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    • pp.89-92
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    • 2001
  • This study was to analyse the correlations between pumping rate to irrigated area and rainfall amount in the Geum river basins. A total of 84 pumping stations and field data from the paddy of 28,772 ha were introduced to the analysis. The results showed that the pumping volume was highly correlated to the rainfall during the irrigation period and irrigated area. But, it was difficult to determine the exact correlation factors, because of the lack of data like the efficiency of water in the paddy field.

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위성영상기반 증발스트레스지수를 활용한 필지단위 논 가뭄 모니터링 (Drought Monitoring for Paddy Fields Using Satellite-derived Evaporative Stress Index)

  • 이희진;남원호;윤동현;김하영;우승범;김대의
    • 한국농공학회논문집
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    • 제63권3호
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    • pp.47-57
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    • 2021
  • Drought monitoring over paddy field area is an important role as the frequency and intensity of drought due to climate change increases. This study analyzed the applicability of drought monitoring on paddy crops using MODIS-based field surveys. As a satellite-based drought index using evapotranspiration for quantitative drought determination, ESI (Evaporative Stress Index), was applied and calculated through the ratio of MODIS- based actual and potential evapotranspiration. For the irrigated areas of Idong, Gosam, Geumgwang, and Madun reservoirs the availability of irrigation water supply, ponding depth, precipitation, paddy growth were investigated for the paddy field within one grid of MODIS. In addition, the percentile-based ESI drought severity was calculated to compare the growth process of paddy and changes in the drought category of ESI. The Idong area was irrigated about a week later than other reservoirs for the period of water supply, transplanting, and water drainage and the ESI drought category tended to be different. The Gosam, Geumgwang, and Madun area expressed moderate drought prior to the farming season, and indicated normal as the water was supplied. During the water drainage, the drought category intensified, indicating that the water available on land was decreasing. These results demonstrated that the MODIS-based ESI could be an effective tool for agricultural drought monitoring over paddy field area.