• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.5
• /
• pp.944-958
• /
• 2011

Soil hydraulic properties such as hydraulic conductivity or water retention which are costly to measure can be indirectly generated by soil pedotransfer function (PTF) using easily obtainable soil data. The field soil structure description which is routinely recorded could also be used in PTF as an input to reduce the uncertainty. The purposes of this study were to use qualitative morphological soil structure descriptions and soil structural index into PTF and to evaluate their contribution in the prediction of soil hydraulic properties. We transformed categorical morphological descriptions of soil structure into quantitative values using categorical principal component analysis (CATPCA). This approach was tested with a large data set from the US National Pedon Characterization database with the aid of a categorical regression tree analysis. Six different PTFs were used to predict the saturated hydraulic conductivity and those results were averaged to quantify the uncertainty. Quantified morphological description was successively used in multiple linear regression approach to predict the averaged ensemble saturated conductivity. The selected stepwise regression model with only the transformed morphological variables and structural index as predictors predicted the $K_{sat}$ with $r^2$ = 0.48 (p = 0.018), indicating the feasibility of CATPCA approach. In a regression tree analysis, soil structure index and soil texture turned out to be important factors in the prediction of the hydraulic properties. Among structural descriptions size class turned out to be an important grouping parameter in the regression tree. Bulk density, clay content, W33 and structural index explained clusters selected by a two step clustering technique, implying the morphologically described soil structural features are closely related to soil physical as well as hydraulic properties. Although this study provided relatively new method which related soil structure description to soil structure index, the same approach should be tested using a datasets containing the actual measurement of hydraulic properties. More insight on the predictive power of soil structure index to estimate hydraulic properties would be achieved by considering measured the saturated hydraulic conductivity and the soil water retention.

• Journal of Korean Society of Rural Planning
• /
• v.29 no.3
• /
• pp.15-24
• /
• 2023

The sense of crisis regarding regional extinction due to low birth rates and an aging population is expanding. Generally, the local extinction index is used to analyze local extinction. However, it is challenging to diagnose the actual situation of village extinction risk in rural areas, even though the regional extinction index can be analyzed in units such as Si-Gun-Gu and Eup-Myeon-Dong. This difficulty arises because the regional extinction index solely relies on natural population growth indicators (elderly population and female population aged 20-39). Therefore, the purpose of this study is to develop a village extinction index that can identify the disappearance of rural villages. Additionally, the aim is to apply the developed indicators to the village (administrative ri) spatial unit. The existing regional extinction index used only mortality-related indicators as factors for natural population decline and fertility-related indicators as factors for natural population growth. However, the developed village extinction index included not only the factors of natural population change but also incorporated social population growth factors and factors related to the pace of village extinction. This is the key difference between the developed village extinction index and the existing regional extinction index. In this study, the indicators of "total population," "number of young women aged 20-44," "number of elderly population aged 70 or older," and "number of incoming population" were selected to develop a village extinction index. The village extinction index was developed by incorporating both natural population growth indicators and social population growth indicators. The developed village extinction index was applied to administrative villages. This research is expected to provide a more accurate understanding of the current state of rural villages facing extinction.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.23 no.4
• /
• pp.340-348
• /
• 2021

Continuous monitoring of RGB (Red, Green, Blue) vegetation indices is important to apply remote sensing technology for the estimation of crop growth. In this study, we evaluated the performance of eight vegetation indices derived from soybean RGB images with various agronomic parameters under drought stress condition. Drought stress influenced the behavior of various RGB vegetation indices related soybean canopy architecture and leaf color. In particular, reported vegetation indices such as ExGR (Excessive green index minus excess red index), Ipca (Principal Component Analysis Index), NGRDI (Normalized Green Red Difference Index), VARI (Visible Atmospherically Resistance Index), SAVI (Soil Adjusted Vegetation Index) were effective tools in obtaining canopy coverage and leaf chlorophyll content in soybean field. In addition, the RGB vegetation indices related to leaf color responded more sensitively to drought stress than those related to canopy coverage. The PLS-DA (Partial Squares-Discriminant Analysis) results showed that the separation of RGB vegetation indices was distinct by drought stress. The results, yet preliminary, display the potential of applying vegetation indices based on RGB images as a tool for monitoring crop environmental stress.

• Journal of Korean Society of Rural Planning
• /
• v.23 no.1
• /
• pp.65-83
• /
• 2017

This paper proposes a village level settlement environment diagnostic indices in rural areas which can apply to analyze various conditions at village level. A living space in rural areas has been changed with a diverse aspect according to living infrastructure, industrial structure, accessibility to neighbor city and so on. This indicators considered these mega-regionalization of economy and lifestyle in rural areas. The indicators consists of basic indices for all types villages and convenience service indices for center villages and the other neighbor ones classified by a functionality of their convenience facilities. As the results of delphi expert survey and a field validation, rural village settlement environment diagnostic indicators were selected 3 types, 15 domains, 24 subdomains and 61 items. And these indicators weight were determinted by AHP method. These developed indicators were used to diagnosis settlement conditions of 31 villages, located on county of Yeongdong. to validate a applicability and feasibility.

• Journal of Korean Society of Rural Planning
• /
• v.24 no.1
• /
• pp.1-10
• /
• 2018

This study is to evaluate the per capita accessibility to child care facilities using road map in rural village unit considering the supply and demand of child care facilities in municipal (Si-Gun) units. Using these estimated accessibility, the most accessible regions to child care facilities was identifies using Moran's index. Assuming establish a new child care facility in the most accessible region, the sensitivity of child care environment was analyzed. The number of regions are 71 si-gun-gu where supply of child care facilities is insufficient. The average accessibility per capita is 1.09 km to child care facilities and the average accessibility in Myeon unit is approximately 2.2 times higher than accessibility in Eup unit (Eup unit 0.54 km, Myeon unit 1.21 km). Approach tendency from village to child care facilities has positive relationship as 0.451 global Moran's index. The high-high (H-H) accessibility regions are wide as Gangwon-do, Gyeongsangbuk-do, Gyeongsangnam-do, Jeollanam-do and Chungcheongbuk-do. Assumed to be established the new child care facilities in Yangyang-gun (Ganwon-do), accessibility changes of child care environment are up to 2.7 times greater and the recipient population is 77% of Yangyang-gun.

• Journal of Korean Society of Rural Planning
• /
• v.10 no.2 s.23
• /
• pp.1-6
• /
• 2004

This study tried to construct a direction in regional planning concerning the structural relationship between the ratio of aged population and the industrial characteristics. We investigated this structural relationship incorporating the aged population index and the number of classified companies. We applied diverse statistical analyses to understand the relationship. We classified the number of companies to reflect regional industrial characteristics using the principal component analysis. We applied a multiple regression model to understand the relationship between these two indices. The aged population index represents the degree of being old divided by the ratio of juvenile population and aged population. We found that such industries as manufacturing, service, and conveyance increase the ratio of juvenile population. However, industries such as tourism, waterworks, forestry, agriculture and etc. have a positive effect on the aged population index. In addition to these findings, we believe that the efficacy of this study is the possibility that can be used as the basic data when central or local autonomous entities need to adopt rural development planning.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.62 no.5
• /
• pp.85-91
• /
• 2020

In order to calculate the Crop Water Stress Index (CWSI), it is necessary to collect weather data (air temperature, humidity, wind speed and solar radiation) and canopy temperature. However, it is not always available to have necessary data sets for CWSI calculation. Therefore, this study was aimed to develop an easy and simple CWSI equation (CWSI_EE) using only two data, air and canopy temperatures. Infrared sensors and weather sensors were installed on apple and peach trees and nearby a study area and every ten-minute data were collected from June to October in 2018 and 2019, respectively. A relationship between air-canopy temperature difference and CWSI was statistically analyzed and used to develop CWSI_EE using the three dimensional Gaussian model. The performance of CWSI_EE against original CWSI showed R² and NSE to 0.780 and 0.710 for apple trees and R² and NSE to 0.884 and 0.866 for peach trees. This study found that the level of crop water stress could be easily calculated using CWSI_EE with only air and canopy temperature data.

• Journal of Korean Society of Rural Planning
• /
• v.28 no.1
• /
• pp.37-47
• /
• 2022

The purpose of this study is to introduce the concept of community resilience to rural society and build an index suitable for the reality of rural areas. Furthermore, by calculating the importance of evaluation factors, it was attempted to present priorities and alternatives for each evaluation factor. By stratifying the derived indicators, a survey was conducted targeting 20 researchers, practitioners, and public officials, three groups of experts working in rural areas who were well aware of the realities and problems of rural areas. In the survey, a pairwise comparison was performed to compare factors 1:1 to calculate the importance, and for rational and consistent decision-making, decisions were made in the 9-grade section. Using the collected data, consistency analysis that can evaluate reliability in the decision-making process and the relative weight of evaluation factors were calculated through AHP analysis. As a result of the analysis, as a result of examining the priority of final importance by summarizing the importance of all evaluation factors, 'Income creation using resources' > 'Population Characteristics' > 'Tolerance' > 'External Support' > 'Social Accessibility' > 'Physical Accessibility' > 'Community Competence' > 'Infrastructure' > 'Leader Competence' > 'Natural Environment' was derived in the order. In the study dealing with urban community resilience indicators, social aspects such as citizen participation, public-private cooperation, and governance were presented as the most important requirements, but this study differs in that the 'income creation' factor is derived as the most important factor. This can be seen through the change in the income difference between rural and urban areas. The income structure of rural areas has changed rapidly, and it is now reaching a very poor level, so it is necessary to prepare alternatives to 'income creation' in the case of rural areas. Unlike urban indicators, 'population characteristics' and 'tolerance' were also derived as important indicators of rural society. However, there are currently no alternatives to supplement the vulnerability by strengthening the resilience of rural communities. Based on the priority indicators derived from the study, we tried to suggest alternatives necessary for rural continuity in the future so that they can be supplemented step by step.

• Korean Journal of Remote Sensing
• /
• v.28 no.6
• /
• pp.597-609
• /
• 2012

Leaf area index (LAI) is important in explaining the ability of the crop to intercept solar energy for biomass production and in understanding the impact of crop management practices. This paper describes a procedure for estimating LAI as a function of image-derived vegetation indices from temporal series of IKONOS, Landsat TM, and MODIS satellite images using empirical models and demonstrates its use with data collected at Missouri field sites. LAI data were obtained several times during the 2002 growing season at monitoring sites established in two central Missouri experimental fields, one planted to soybean (Glycine max L.) and the other planted to corn (Zea mays L.). Satellite images at varying spatial and spectral resolutions were acquired and the data were extracted to calculate normalized difference vegetation index (NDVI) after geometric and atmospheric correction. Linear, exponential, and expolinear models were developed to relate temporal NDVI to measured LAI data. Models using IKONOS NDVI estimated LAI of both soybean and corn better than those using Landsat TM or MODIS NDVI. Expolinear models provided more accurate results than linear or exponential models.

• Journal of Korean Society of Rural Planning
• /
• v.20 no.1
• /
• pp.1-12
• /
• 2014

Living environments in rural area have become deteriorated rapidly. Increase of aging population, decline in agricultural income, polarization of wealth in rural community due to rural returners have caused severe decline and imbalance of living environments in rural area. Responding to this circumstances, governments currently develop projects for improving living environments focusing on individual housing which were excluded from governmental supports because those had been regarded as private property. Nevertheless, there are still some gaps and problems in evaluating the quality of living environment and suggesting effective solutions. It would be because standards and guidelines of the projects have been based on urban housing system. In order to support the implementation of the projects, this research has developed an index for evaluating and monitoring the quality of living environments in rural area. By applying Delphi method, the index has been created in four categories of 'security', 'convenience', 'comfortability', and 'durability' 'Security' consists of structural safety, crime, disaster, accident prevention. 'Convenience' includes three divisions of living, traffic, farm working. 'Comfortability' is divided into sanitation, indoor environments, and aesthetic appreciation. Lastly, 'durability' has four divisions of energy conservation, environmental friendliness, efficiency, and economics. Each sub-division also has different items from three to twelves. In the case of an index for performance evaluation, items have been derived from energy conservation(6-items), and environmental friendliness(7-items). Items developed as an index for evaluating rural living environments in this research might be good background information for remodeling project in rural housing development.