• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.1-9
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• 2015

The development of drought index that provides detailed-spatial-resolution drought information is essential for improving drought planning and preparedness. The objective of this study was to develop the concept of using satellite-based hybrid drought index called the Vegetation Drought Response Index in South Korea (VegDRI-SKorea) that could improve spatial resolution for monitoring local and regional drought. The VegDRI-SKorea was developed using the Classification And Regression Trees (CART) algorithm based on remote sensing data such as Normalized Difference Vegetation Index (NDVI) from MODIS satellite images, climate drought indices such as Self Calibrating Palmer Drought Severity Index (SC-PDSI) and Standardized Precipitation Index (SPI), and the biophysical data such as land cover, eco region, and soil available water capacity. A case study has been done for the 2012 drought to evaluate the VegDRI-SKorea model for South Korea. The VegDRI-SKorea represented the drought areas from the end of May and to the severe drought at the end of June. Results show that the integration of satellite imageries and various associated data allows us to get improved both spatially and temporally drought information using a data mining technique and get better understanding of drought condition. In addition, VegDRI-SKorea is expected to contribute to monitor the current drought condition for evaluating local and regional drought risk assessment and assisting drought-related decision making.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.235-243
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• 2013

In Korea, where the plain land is greatly deficient as a mountainous nation, most of riparian zones were transformed into agricultural fields and urban areas. Excessive use of the land, which is close to river, makes the rivers enduring severe pollution stresses. Disappearance of riparian buffer, which plays a function of filter in the riverside, appears as a main factor aggravating water pollution of rivers. In this respect, it is imperative to restore the lost riparian vegetation. This study found out restoration models of riparian vegetation from the Bongseonsa stream, which has remnant riparian vegetation patches as a conservation reserve. Feasible reference information applicable for restoration of riparian vegetation was shown in the species level in the order of herb, shrub, and tree and sub-tree zones as far away from the waterway. Those information could contribute to restoring integrate and healthy rivers and streams beyond simple landscaping differently from the other restoration projects when they will be applied to the restoration project to be carried out in the future. In addition, the spatial range of river and stream, background that riparian zone disappeared in Korea, and application plan of the obtained reference information were discussed.

• Korean Journal of Remote Sensing
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• v.29 no.4
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• pp.351-360
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• 2013

Harmonic analysis enables to characterize patterns of variation in MODIS NDVI time series data and track changes in ground vegetation cover. In harmonic analysis, a periodic phenomenon of time series data is decomposed into the sum of a series of sinusoidal waves and an additive term. Each wave is defined by an amplitude and a phase angle and accounts for the portion of variance of complex curve. In this study, harmonic analysis was explored to tract ground vegetation variation through time for land-cover vegetation change detection. The process also enables to reconstruct observed time series data including various noise components. Harmonic model was tested with simulation data to validate its performance. Then, the suggested change detection method was applied to MODIS NDVI time series data over the study period (2006-2012) for a selected test area located in the northern plateau of Korean peninsula. The results show that the proposed approach is potentially an effective way to understand the pattern of NDVI variation and detect the change for long-term monitoring of land cover.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.356-364
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• 2012

This study was to estimate the biomass of Mt. Changbai mountain area using the IKONOS imagery and field survey data. Then, we prepared the regression function using the vegetation index derived from the IKONOS and biomass estimated from field measured data of previous studies, respectively. The five vegetation index which used in the regression model was SAVI, NDVI, SR, ARVI, and EVI. As a result, the rank of the R-square from coefficient of correlation was as follow, SAVI(0.84), NDVI(0.73), SR(0.59), ARVI(0.0036), EVI(0.0026). Finally, we estimated the biomass of non-measured area using the Soil Adjusted Vegetation Index (SAVI). This study can be used as reference methodology for the estimation of carbon sinks of primary forest.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.71-81
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• 2007

One of the most important hydrologic components is evapotranspiration. It is a process by which water is evaporated from moist land surfaces and transpired into atmosphere by plants. There are many methods of estimating evapotranspiration rate and its potential such as the methods of soil-moisture sampling, lysimeter measurements, water balance, energy balance, groundwater fluctuations and evapotranspiration. But it is very difficult to estimate evapotranspiration in terms of regional discrete characteristics of topography and/or vegetation. The evapotranspiration is strongly affected by ground covering vegetation, and the degree of vegetation growth. In order to grasp vegetation condition over a vast study area, NDVI (Normalized Difference Vegetation Indices) calculated from the data obtained from NOAA/AVHRR were utilized. Through multi-regression analysis, we developed a model equation to estimate the evapotranspiration using NDVIs and temperature data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.107-120
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• 2010

The effect of potential future climate change on the inflow of agricultural reservoir and its impact to downstream streamflow by reservoir operation for paddy irrigation water was assessed using the SLURP (semi-distributed land use-based runoff process), a physically based hydrological model. The fundamental input data (elevation, meteorological data, land use, soil, vegetation) was collected to calibrate and validate of the SLURP model for a 366.5 $km^2$ watershed including two agricultural reservoirs (Geumgwang and Gosam) located in Anseongcheon watershed. Then, the CCCma CGCM2 data by SRES (special report on emissions scenarios) A2 and B2 scenarios of the IPCC (intergovernmental panel on climate change) was used to assess the future potential climate change. The future weather data for the year, m ms, m5ms and 2amms was downscaled by Change Factor method through bias-correction using 3m years (1977-2006) weather data of 3 meteorological stations of the watershed. In addition, the future land uses were predicted by modified CA (cellular automata)-Markov technique using the time series land use data fromFactosat images. Also the future vegetation cover information was predicted and considered by the linear regression between monthly NDVI (normalized difference vegetation index) from NOAA AVHRR images and monthly mean temperature using eight years (1998-2006) data.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.1
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• pp.11-22
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• 2003

This landscape design proposal was presented to a design competition for the Incheon-city Southern Region Integrated Disposal Treatment Facility. The site is located in Dongchun-dong, Yeonsu-gu, Incheon. The main design concepts are as follows: First, considering connection of the site with surrounding water, inner sea is designed as an environmentally friendly place and as a leisure-sports theme park in which several sports facilities and relaxing places are arranged. It is also designed for everyone: people of all ages, disabled, workers, visitors and local residents. The design was processed on the basis of survey, analysis of surrounding competing facilities and SWOT analysis. Second, the ecological planting model was developed by analyzing the natural vegetation map in the surrounding area and planted vegetation types in the seaside reclamation area. The model was then applied to the ecological community, park area and roadside trees, so as to harmonize with the local habitat. Third, the project is intended to launch private capital for managing the sports park and golf course. This will enable a entrepreneur to make flexible plans for golf training field that is expected to yield a good financial return. It is expected that this design would serve the local residents as a symbolic, environmentally friendly leisure-sports theme park.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.361-371
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• 2020

Since the implementation of the sunset law in 2020, concerns have been raised over the reckless development of long-term non-executed urban parks. In this study, the FSDAF method and CASA-NPP model were used to evaluate the annual average NPP of long-term non-executed urban parks in Seoul. Based on this, the carbon loss and economic value were assessed under five development scenarios. The total NPP value of long-term non-executed urban parks, except for the greenbelt area in Seoul, was 4,892.18 t C. In the first scenario, the NPP and cost were 4,892.18 t C of vegetation carbon and 1.18 billion won, 2,548.55 t C of vegetation carbon and 615 million won in the second scenario, 238.94 t C of vegetation carbon and 58 million won in the third scenario, 848.38 t C of vegetation carbon and 205 million won in the fourth scenario, and 1,596.00 t C of vegetation carbon and 385 million won in the fifth scenario. These results are meaningful for evaluating vegetation carbon and economic value loss according to five different development scenarios. The results of this study are expected to be useful for the preparation of measures to minimize the impact of the development of long-term non-executed urban parks.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1427-1435
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• 2023

Vegetation indices based on selected wavelength reflectance measurements are used to represent crop growth and physiological conditions. However, the anisotropic properties of the crop canopy surface can govern spectral reflectance and vegetation indices. In this study, we applied an ensemble of bidirectional reflectance distribution function (BRDF) models to high-resolution Sentinel-2 satellite imagery and compared the differences between correction results before and after reflectance. In the red and near-infrared (NIR) band reflectance images, BRDF-corrected outlier values appeared in certain urban and paddy fields of farmland areas and forest shadow areas. These effects were equally observed when calculating the normalized difference vegetation index (NDVI) and 2-band enhanced vegetation index (EVI2). Furthermore, the outlier values in corrected NIR band were shown in pixels shadowed by mountain terrain. These results are expected to contribute to the development and improvement of BRDF models in high-resolution satellite images.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.470-483
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• 2017

Changes in land cover or land use, such as changes in forest area, can cause changes in water and energy circulation, ultimately affecting overall hydrological cycle including stream flow, evapotranspiration, soil moisture, and base flow. In this study, the changes of the hydrological processes over the past long period were simulated by using large-scale surface hydrologic model along with various soil, land use, vegetation, and meteorological data. For this purpose, this study simulated and evaluated the changes in the hydrological cycle for the past 50 years (1955-2010) in East Asia including China, Japan and South Korea. In particular, this study used the land cover maps which can properly reflect the vegetation condition for each simulation period. As results, the mean runoff ratio of China was estimated to be 47.0% over the entiree period, 62.7% in Japan and 49.4% in South Korea. The mean soil moisture of China was estimated to be 22.2%, 35.6% in Japan and 23.9% in South Korea. Finally, the mean evapotranspiration rate was estimated to be 52.7% in China, 37.3% in Japan and 50.4% in South Korea. Especially, in China, the hydrological cycle was found to be changed very much for the entire simulation period. However, in Japan, the hydrological cycle was found to be very stable for the entire simulation period. The hydrological cycle was also found to become stable mainly due to the stabilization of the vegetation.