• Korean Journal of Environment and Ecology
• /
• v.26 no.2
• /
• pp.186-191
• /
• 2012

The Chinese Sparrowhawk($Accipiter$ $soloensis$) is the most common breeding raptor in Korea, but its spatial use in the breeding season has been poorly documented. Therefore, to estimate the territory and home range sizes of breeding sparrowhawks, six territorial males(four in 2005 and two in 2006) were observed from June to July in Gyeonggi Province, the Republic of Korea. Main perches, which were used repeatedly(more than three times) or where apparent territorial behaviors were observed, were identified and the locations were analyzed by GIS software. According to the 100% Minimum Convex Polygons which were identified from $25.2{\pm}5.3$ perches, Chinese Sparrowhawks occupied $4.62{\pm}0.90$ ha for breeding territories and used $22.57{\pm}5.12$ ha for their home ranges. These estimates showed larger spatially occupied areas than those in one previous report, but this study suggests that Chinese Sparrowhawks intensively use small areas throughout the breeding season. This result also implies that the sparrowhawks have the potential to be significantly affected by any habitat changes and resource exploitation in the small areas(particularly in small rice paddies of 0.6-2.0 ha) which they largely rely on for food. Although this study was based on observations solely for territory size estimations, this study may be worthwhile as preliminary pilot research for Chinese Sparrowhawk conservation, management, and further studies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.10
• /
• pp.1196-1203
• /
• 2012

This paper presents a study on the calibration of a C-band HPS(Hongik Polarimetric Scatterometer) system using the DMMCT(Differential Mueller Matrix Calibration Technique). For calibration of the polarimetric scatterometer system, a fully-polarimetric antenna pattern(magnitudes and phase-differences) of the antenna main-beam is measured using a conducting sphere at anechoic chamber. The polarimetric scatterometer system could be accurately calibrated after retrieving its distortions using the DMMCT. Unlike a single-polarimetric system, in a fully-polarimetric system, not only backscattering coefficients but also phase differences are important parameters. This calibrated HPS system can be used to measure accurate Mueller matrices of bare soil surfaces, rice paddies, and vegetation fields. The phase-difference parameters as well as the backscattering coefficients for co- and cross-polarizations can then be obtained. The accuracy of calibration was verified by comparing the measured backscattering coefficients with a scattering model. The measured polarization response of a plowed bare field was also compared with the polarization response which was synthesized using a polarimetric scattering model for verifying the calibration technique.

• Journal of the Korean association of regional geographers
• /
• v.8 no.4
• /
• pp.430-450
• /
• 2002

This study empirically analyses the spatial features of land use and transportation, and residential characteristics of the cases of the Sangin and Siji newly developed districts in Taegu. Before the development, the areas consisted mainly of rice paddies and fields; these areas are now filled with high-density residential complexes, with a proliferation of commerce and service functions. In Sangin, restaurants, retail services, bars and bakeries are the main developments, but Siji developed retail services, restaurants, private institutions for students, and facilities for convenience goods. While the public transportation system is oriented to CBD, the inter-districts transportation network is lacking. The residents are mainly in their 40s to 50s, with white collar jobs. They have a relatively high level of education with high income. They have migrated a relatively short distance to the district. The locational(pull) factors influencing the decision to migrate, for Sangin are transportation, the physical environment and access to the working place, but for Siji it has been the physical environment, the school group, and access to the working place. The main dissatisfaction factors for Sangin are the management fee, the school group and for Siji they are commuting, the management fee and transportation.

• Journal of Korea Water Resources Association
• /
• v.44 no.3
• /
• pp.169-177
• /
• 2011

The impacts of climate change on paddy irrigation water demands in Korea have been analyzed. High-resolution ($27{\times}27\;km$) climate data for the SRES A2 scenario produced by the Korean Meteorological Research Institute (METRI) and the observed baseline climatology dataset were used. The outputs from the ECHO-G GCM model were dynamically downscaled using the MM5 regional model by the METRI. The Geographic information system (GIS) was used to produce maps showing the spatial changes in irrigation water requirements for rice paddies. The results showed that the growing season mean temperature for future scenarios was projected to increase by $1.5^{\circ}C$ (2020s), $3.3^{\circ}C$ (2050s) and $5.3^{\circ}C$ (2080s) as compared with the baseline value (1971~2000). The growing season rainfall for future scenarios was projected to increase by 0.1% (2020s), 4.9% (2050s) and 19.3% (2080s). Assuming cropping area and farming practices remain unchanged, the total volumetric irrigation demand was projected to increase by 2.8% (2020s), 4.9% (2050s) and 4.5% (2080s). These projections are contrary to the previous study that used HadCM3 outputs and projected decreasing irrigation demand. The main reason for this discrepancy is the difference with the projected climate of the GCMs used. The temporal and spatial variations were large and should be considered in the irrigation water resource planning and management in the future.

• Journal of Korean Society of Rural Planning
• /
• v.26 no.2
• /
• pp.107-116
• /
• 2020

Up to date, the majority research on the major landscape elements in organic farming has been mainly focused on the practice of seeking efficiency. The problem is that this type of study contributes to polluting the agricultural environment and damaging the ecological circulation system. As an alternative, there is a growing body of research on organic farming, but it is not widely applied that research on how to manage the landscape considering the scenic characteristics of farming villages practicing organic farming. Therefore, this study was carried out in the conservative aspects of rural landscapes in order to effectively manage the landscape of organic agriculture and, intended to be used to maintain and preserve natural and ecologically harmonious landscapes by deriving management methods suitable for landscape elements targeting the major landscape elements of the organic farming complex. To carry out, this study performed the experts survey which is composed of 13 major landscape elements, including rice paddies and fields, monoculture and diverse crops, dirt roads, windbreak trees, accent planting, dum-bung(small pond), natural small river, natural waterways, plastic film houses, one-storied houses, and pavilion. As a result, Farm land was formed in a square shape, concentrated in an independent space, planted companion plants around the crop, and covered with plants to manage the borders. As for the surrounding environment, it was analyzed that the aspart road system circulating through the village, the evergreen broad-leaved windbreak forest around the cultivated land, and the accent plant located at the entrance of the village were suitable. The hydrological environment consists of Round small pond made of stone in an open space, natural rivers around the village, and natural channels around the farmland, and The Major facilities are suitable for greenhouses that are shielded by plants in independent regions, and wooden duck houses located inside the cultivation area are suitable and The settlement facilities were analyzed to be suitable for single-story brick houses located in independent residential areas, pavilion located with greenery in the center of the village, and educational spaces shielded with wood from arable land. If supplementary evaluation criteria suitable for the management of organic farming landscape are additionally supplemented based on the results derived from this study, It is expected to enhance the landscape value of ecologically superior organic farming.

• Journal of Convergence for Information Technology
• /
• v.10 no.12
• /
• pp.201-207
• /
• 2020

In this study, the practicality of unmanned aerial vehicle photography information was identified. Therefore, a total of four consecutive surveys were conducted on the field-level survey areas among the areas subject to photography using unmanned aerial vehicles, and the changes in crop conditions were analyzed using pictures of unmanned aerial vehicles taken during each survey. It is appropriate to collect and utilize photographic information by directly taking pictures of the survey area according to the time of the on-site survey using unmanned aerial vehicles in the field layer, which is an area where many changes in topography, crop vegetation, and crop types are expected. And it turned out that it was appropriate to utilize satellite images in consideration of economic and efficient aspects in relatively unchanged rice paddies and facilities. If the survey area is well equipped with systems for crop cultivation, deep learning can be utilized in real time by utilizing libraries after obtaining photographic data for a certain area using unmanned aircraft in the future. Through this process, it is believed that it can be used to analyze the overall crop and shipment volume by identifying the crop status and surveying the quantity per unit area.

• Journal of Korea Water Resources Association
• /
• v.54 no.6
• /
• pp.395-405
• /
• 2021

When issuing forecasts and alerts for agricultural drought, the relevant ministries only rely on the observation data from the reservoirs managed by the Korea Rural Community Corporation, which creates gaps between the drought analysis results at the local (si/gun) governments and the droughts actually experienced by local residents. Closing these gaps requires detailed local geoinformation on reservoirs, which in turn requires the information on reservoirs managed by local governments across Korea. However, installing water level and flow measurement equipment at all of the reservoirs would not be reasonable in terms of operation and cost effectiveness, and an alternate approach is required to efficiently generate information. In light of the above, this study validates and calibrates the parameters of the TANK model for reservoir basins, divided them into groups based on the characteristics of different basins, and applies the grouped parameters to unmeasured local government reservoirs to estimate and assess inflow. The findings show that the average determinant coefficient and the NSE of the group using rice paddies and inclinations are 0.63 and 0.62, respectively, indicating better results compared with the basin area and effective storage factors (determinant coefficient: 0.49, NSE: 0.47). The findings indicate the possibility of utilizing the information regarding unmeasured reservoirs managed by local governments.

• Journal of Life Science
• /
• v.32 no.8
• /
• pp.595-600
• /
• 2022

Water dropworts, Oenanthe javanica and O. javanica var. japonica are called "minari" in Korea and are eaten as a vegetable. Cicuta virosa is common European water hemlock and has toxic properties, such as cicutoxin. Molecular variations of water dropwort species in Korea were investigated using random amplified polymorphic DNA (RAPD). The six populations were studied with 10 primers (Operon, OPB) for RAPD analysis. The 72 DNA fragments (bands) were found among six populations. Among these 72 bands, 61 (84.7%) bands were polymorphic. The typical populations of Cicuta virosa in Korea were small, isolated, and patchily distributed for natural populations and they maintained a high level of genetic diversity. However, when cultivated populations of O. javanica var. japonica were large and widely grown in rice paddies as vegetables, they maintained a lower genetic diversity than those of C. virosa and wild populations of O. javanica. Although the diversity indices of wild populations were shown to be higher than those of cultivated populations, no significant difference for measures of genetic variability was shown. Total genetic diversity value (H_T) was 0.342. The interlocus variation in the within-population genetic diversity (H_S) was 0.201. The proportion of total genetic variation due to differences among populations (G_ST) range was 0.414, indicating that 41.4% of the total variation was among populations. In conclusion, the RAPD technique was a useful method for discrimination between C. virosa and O. javanica. In addition, RAPD-OPB markers could further distinguish the strains from different food sources.

• Journal of Wetlands Research
• /
• v.25 no.4
• /
• pp.315-325
• /
• 2023

This study analyzed the disturbance process of river wetlands based on modern and contemporary maps and aerial photographs, and analyzed land cover and NDVI changes in the hydro-ecological impact zone around the Wangjin District. A stable sandbar was formed near Wangjinnaru and was naturally connected to the agricultural land within inland, but after the sandbar and river wetland were destroyed due to heavy floods, embankment construction, land readjustment, and comprehensive river management, artificial replaced wetlands and ecological parks were created, and sandbars in the form of river island were restored again. The change in land cover in the hydro-ecological impact zone showed that rice paddies and fields in agricultural areas decreased from 36.3% in 2013 to 22.9% in 2022, with the largest change in area to 814,476m². It was confirmed that the land cover was undergoing vegetation over time. Since the vegetation condition is good, a healthy food chain is formed in the waterfront ecosystem, which can be expected to be biodiversity-positive. Summarizing seasonal changes in the vegetation index, the overall change in the vegetation index was the largest in spring (March), followed by summer (June), and the change in autumn (September) was the smallest except for water. By land use, the overall vegetation index (NDVI) increased, including 39.1% improvement in alternative wetlands, 38.2% improvement in load, 44.3% improvement in ecological parks, 35.6% improvement in agricultural areas, and -8.1% decrease in water.

• Journal of Environmental Impact Assessment
• /
• v.26 no.2
• /
• pp.127-139
• /
• 2017

Measurements of net ecosystem exchange (NEE) of $CO_2$ based on the eddy covariance technique provide reasonable carbon balance estimates in response to local environmental conditions. In South Korea, the forest ecosystems cover approximately 64% of the total area, thereby strongly affecting regional carbon balances. Cultivated croplands that cover about 17% of the total area should also be considered when calculating the carbon balance of the country. In this study, our objectives were (a) to quantify the range and seasonal variation of NEE at forest ecosystems, including deciduous, coniferous, and mixed forests, and agricultural ecosystems, including rice paddies and a potato field, in South Korea and (b) to compare NEE at ten Fluxnet sites that have the same or similar ecosystems as found in South Korea. The results showed that the forest and agricultural ecosystems were carbon sinks. In Korea, NEE at the forest ecosystems varied between -31 and $-362gC/m^2/yr$, and NEE at the croplands ranged from -210 to $-248gC/m^2/growing$ season. At the deciduous forest, NEE reached low values in late spring, early summer, and early autumn, while at the coniferous forest, it reached low values in spring, early summer, and mid autumn. The young mixed forest was a much stronger carbon sink than the old-growth deciduous and coniferous forests. During each crop growing season, beet had the lowest NEE value within six crops, followed by wither wheat, maize, rice, potato, and soybean. These results will be useful for designing and applying management strategies for the reduction of $CO_2$ emissions.