Estimation of Rice Yield by Province in South Korea based on Meteorological Variables

Abstract. Together with emissions of air pollutants and precursors, meteorological conditions play important roles in local air quality through accumulation or ventilation, regional transport, and atmospheric chemistry. In this study, we extensively investigated multi-timescale meteorological effects on the urban air pollution using the long-term measurements data of PM10, SO2, NO2, CO, and O3 and meteorological variables over the period of 1999–2016 in Seoul, South Korea. The long-term air quality data were decomposed into trend-free short-term components and long-term trends by the Kolmogorov–Zurbenko filter, and the effects of meteorology and emissions were quantitatively isolated using a multiple linear regression with meteorological variables. In terms of short-term variability, intercorrelations among the pollutants and meteorological variables and composite analysis of synoptic meteorological fields exhibited that the warm and stagnant conditions in the migratory high-pressure system are related to the high PM10 and primary pollutant, while the strong irradiance and low NO2 by high winds at the rear of a cyclone are related to the high O3. In terms of long-term trends, decrease in PM10 (−1.75 µg m−3 yr−1) and increase in O3 (+0.88 ppb yr−1) in Seoul were largely contributed by the meteorology-related trends (−0.94 µg m−3 yr−1 for PM10 and +0.47 ppb yr−1 for O3), which were attributable to the subregional-scale wind speed increase. Comparisons with estimated local emissions and socioeconomic indices like gross domestic product (GDP) growth and fuel consumptions indicate probable influences of the 2008 global economic recession as well as the enforced regulations from the mid-2000s on the emission-related trends of PM10 and other primary pollutants. Change rates of local emissions and the transport term of long-term components calculated by the tracer continuity equation revealed a decrease in contributions of local emissions to the primary pollutants including PM10 and an increase in contributions of local secondary productions to O3. The present results not only reveal an important role of synoptic meteorological conditions on the episodic air pollution events but also give insights into the practical effects of environmental policies and regulations on the long-term air pollution trends. As a complementary approach to the chemical transport modeling, this study will provide a scientific background for developing and improving effective air quality management strategy in Seoul and its metropolitan area.

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Sensitivity analysis of drought indices under substantially different agricultural systems in North and South Koreas

10.5194/egusphere-egu2020-8491 ◽

2020 ◽

Author(s):

Seonyoung Park ◽

Jongmin Yeom ◽

Jeongho Lee ◽

Jaese Lee ◽

Jungho Im ◽

...

Keyword(s):

Soil Moisture ◽

South Korea ◽

Soil Water ◽

Correlation Coefficient ◽

Drought Index ◽

Rice Yield ◽

Rice Production ◽

Drought Indices ◽

Irrigation Canals ◽

North And South

<p>Rice is a staple food in the North and South Koreas. Rice yield is closely related to water supply including irrigation, precipitation, and soil water. Drought typically occurs due to the lack of precipitation, and prolonged drought leads to the decrease of soil water, which results in plant water stress. Drought monitoring is crucial for agricultural mitigation because it enables us to estimate rice production in a timely manner. The purpose of this study is to suggest an optimal drought index for monitoring agricultural drought over North and South Koreas. Although North and South Koreas have similar climate conditions, they have different levels of infrastructure for agriculture such as irrigation facilities. In this study, nine satellite-based drought indices were used and evaluated based on in situ measurements at weather stations including Standardized Precipitation Index (SPI) and rice yield. Drought indices were calculated using the Global Land Data Assimilation System (GLDAS) soil moisture, Tropical Rainfall Measuring Mission (TRMM) precipitation, Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI). Since various drought indices have been developed with their own purpose, considering the characteristics of the study area under investigation, their applications for other regions are relatively limited. Thus, comparison of various drought indices is needed to identify an optimal drought index for a certain area. The measurable objectives of this research were to 1) compare the characteristics of drought depending on the properties of drought indices such as temperature, vegetation, precipitation, and soil moisture and 2) evaluate various drought indices using SPIs and rice yield data. The performance of the drought indices was evaluated using correlation coefficient values (R) for reference data (i.e., SPI and rice yield). As expected, drought indices including NDVI showed positive relationships with rice yield in both regions (averaged R=0.37). Meanwhile, temperature based drought indices showed negative relationships with rice yield in both regions because high temperature means high solar radiation, which is essential to rice production. While the correlation coefficient between precipitation based indices and rice yield was positive in North Korea (averaged R=0.34), it was negative in South Korea (averaged R=-0.26). The opposite pattern by area is because South Korea (117,457 irrigation Canals) has more artificial controls over agricultural land such as irrigation facilities and reservoirs than North Korea (51,400 irrigation Canals).</p>

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A meta analysis of the climate change impact on rice yield in South Korea

Journal of the Korean Data and Information Science Society ◽

10.7465/jkdi.2015.26.2.355 ◽

2015 ◽

Vol 26 (2) ◽

pp. 355-365 ◽

Cited By ~ 3

Author(s):

Deok Ha Shin ◽

Mun Su Lee ◽

Ju-Hyun Park ◽

Yung-Seop Lee

Keyword(s):

Climate Change ◽

South Korea ◽

Climate Change Impact ◽

Rice Yield ◽

Meta Analysis ◽

Change Impact

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Some Meteorological Anomalies and their Relationships with Rice Yield for El Niño Years in South Korea

Korean Journal of Agricultural and Forest Meteorology ◽

10.5532/kjafm.2016.18.3.143 ◽

2016 ◽

Vol 18 (3) ◽

pp. 143-150

Author(s):

Kyo-Moon Shim ◽

Myung-Pyo Jung ◽

Yong-Seok Kim ◽

In-Tae Choi ◽

Ho-Jung Kim ◽

...

Keyword(s):

South Korea ◽

El Niño ◽

Rice Yield ◽

El Nino

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Extensive spatiotemporal analyses of surface ozone and related meteorological variables in South Korea for the period 1999–2010

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-6395-2014 ◽

2014 ◽

Vol 14 (12) ◽

pp. 6395-6415 ◽

Cited By ~ 23

Author(s):

J. Seo ◽

D. Youn ◽

J. Y. Kim ◽

H. Lee

Keyword(s):

South Korea ◽

Surface Ozone ◽

Measurement Data ◽

Coastal Region ◽

Control Policy ◽

Meteorological Variables ◽

Short Term ◽

Kz Filter ◽

Term Variation

Abstract. Spatiotemporal characteristics of surface ozone (O3) variations over South Korea are investigated with consideration of meteorological factors and timescales based on the Kolmogorov–Zurbenko filter (KZ filter), using measurement data at 124 air quality monitoring sites and 72 weather stations for the 12 yr period of 1999–2010. In general, O3 levels at coastal cities are high due to dynamic effects of the sea breeze while those at the inland and Seoul Metropolitan Area (SMA) cities are low due to the NOx titration by local precursor emissions. We examine the meteorological influences on O3 using a combined analysis of the KZ filter and linear regressions between O3 and meteorological variables. We decomposed O3 time series at each site into short-term, seasonal, and long-term components by the KZ filter and regressed on meteorological variables. Impact of temperature on the O3 levels is significantly high in the highly populated SMA and inland region, but low in the coastal region. In particular, the probability of high O3 occurrence doubles with 4 °C of temperature increase in the SMA during high O3 months (May–October). This implies that those regions will experience frequent high O3 events in a future warming climate. In terms of short-term variation, the distribution of high O3 probability classified by wind direction shows the effect of both local precursor emissions and long-range transport from China. In terms of long-term variation, the O3 concentrations have increased by +0.26 ppbv yr−1 (parts per billion by volume) on nationwide average, but their trends show large spatial variability. Singular value decomposition analyses further reveal that the long-term temporal evolution of O3 is similar to that of nitrogen dioxide, although the spatial distribution of their trends is different. This study will be helpful as a reference for diagnostics and evaluation of regional- and local-scale O3 and climate simulations, and as a guide to appropriate O3 control policy in South Korea.

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