• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1087-1091
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• 2008

Evapotranspiration (ET) is an important factor while simulating daily streamflow in hydrological models. The LAI (Leaf Area Index) value reflecting the conditions of vegetation generally affects considerably in the estimation of ET, for example, when using FAO Penman Monteith equation. Recently in evaluating the vegetation condition as a fixed quantity, the remotely sensed LAIs from MODIS satellite data are avaliable, and the time series values of spatial LAI coupled with land use classes are utilized for ET evaluation. The 4 years (2001-2004) MODIS LAI data were prepared for the evaluation of continuous hydrological model, SLURP (Semi-distributed Land Use-based Runoff Processes). The model was applied for simulating the dam inflow of Chungjudam watershed ($6661.58\;km^2$) located in the upstream of Han river basin of South Korea. From the model results, the FAO Penman Monteith ET was affected by the MODIS LAIs. Especially for the ET of deciduous forest, the Total ET was 33.9 % lager than coniferous forest for the 3.8 % lager of LAI. The watershed average LAI caused a 7.0 % decrease in average soil moisture of the watershed and 14.3 % decrease of ground water recharge.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.369-374
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• 1987

Relationships among root yield, planting density (PD), missing plant rate (MR), leaf area index (LAI) , leaf area per plant(LAP), root weight(RW), number of harvested root(RN) and leaf fall plant rate (LFP) were investigated by survey of white ginseng plantations in Pungi and Geumsan area. In Geumsan PD was about twice than in Pungi but yield was low with high rates of MR and LFP. Yield depended on RN in high PD cultivation while on RW in low PD. The effect of MR on yield was prominent in high PD cultivation. PD showed insignificant negative correlation with yield and no clear relation with MR. RN depended on PD and was especially limited by MR, Yield depended on LAI at harvest time and especially at maximum growth time. LAI was not different between high and low PD area but depended only on RN in high PD and only on LAP in low PD area, and limited by MR in both PD. LAP depended highly on RW and this fact seems to be the very reason that LAI could not increase with the increase of PD. All fields showed the suboptimum LAI.

• Korean Journal of Remote Sensing
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• v.19 no.1
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• pp.1-9
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• 2003

MODIS LAI product has been one of key variable for analyzing the quantitative aspects of terrestrial ecology at global scale. This study was designed to validate MODIS global LAI product for regional application. To examine the quality of MODIS LAI data, we developed a reference LAI surface that was derived by relating the ground LAI measurements to Landsat ETM+ reflectance. The study area, the Kwangneung Experiment Forest in Korea, covers mixed deciduous and coniferous species of temperate forest. Ground measurements of LAI were conducted at 30 sample plots by using a photo-optical instrument during the growing season of 2002. Ground measured LAI data were then related to the ETM+ reflectance to produce a continuous map of LAI surface over the study area. From the comparison between the MODIS LAI and the reference LAI, it was found that the MODIS LAI values were slightly higher at the forestland. Considering the limitations of producing the reference LAI surface and the uncertainty of the input variable for the MODIS LAI algorithm, such small discrepancy mal not be significant.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.3
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• pp.51-59
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• 2004

Focusing on WBGT(Wet Bulb Globe Thermometer Index) according to the LAI(Leaf Area Index) variation of trees, this study verifies the effects of urban shade trees on the outdoor thermal environment. As for methodology, air$.$globe temperature, air humidity and WBGT were measured under three shade trees whose LAIs were 2.1, 4.0 and 8.2 respectively at midday(12:00-13:00) of 14 sunny days from the 4th through the 29th day of September 2003. Those factors were also measured at the unshaded areas and compared with the values of shaded areas. The measured site was paved with interlocking concrete bricks. The measurements were analyzed through the ANCOV A(Analysis of Covariance) and the regression routines of SPSS11 for windows (SPSS Inc., 2001). The major findings were as follows. 1. The direct correlation between WBGT and LAI was very low. On the contrary, the WBGT showed close correlation with air$.$globe temperature and air humidity, and the LAI also showed very close correlation with globe temperature. These results tell that dominant shading effect by the tree is on the screening of direct solar radiation which lower the globe temperature and WBGT consequently. 2. While the average globe temperatures and WBGT at unshadowed area were 40.4$^{\circ}C$ and 26.2$^{\circ}C$ respectively, the former under the shade tree with LAI 2.1, 4.0 and 8.2 were 34.5$^{\circ}C$, 32.6$^{\circ}C$ and 30.2$^{\circ}C$, and the latter were 24.6$^{\circ}C$, 24$^{\circ}C$ and 23.4$^{\circ}C$ respectively. 3. The relationship between LAI(x) and WBGT(y) can be presented with the following equation: y = 24.23+1.53 $e^{-x}$+0.36x $e^{-x}$+0.46 $x^2$ $e^{-x}$ ($R^2$ =.98) =.98)

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.25-28
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• 2002

The aim of the present study was the evaluation of methods for estimating the vegetation information in the field on the basis of spectral reflectance measured farm field, in particular the estimation of Leaf Area Index(LAI). Variability in tissue optical properties was wavelength-dependent. For rice and bean, the lowest variation was in the visible spectral region and the highest in the near-infrared. The structural attributes of ecosystems determine the relative contribution of tissue and canopy factors that drive variation in a reflectance signal.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.1
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• pp.94-98
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• 1982

To understand the growth pattern of ginseng plant under shading, the vertical distribution of leaf area, leaf area index (LAI) and specific leaf weight (SLW) and changes in light intensity as affected by planting position were investigated in 3 to 5 years old ginseng plant populations. Light intensity was vertically lowest at about 10cm above the ground and became low at the rear planting position in 3-year-old population. When culturing bed (96cm in width) were divided into three parts at intervals of 32cm from front to rear, the leaf area in 3-year-old population was largest in middle 1/3 part of planting bed. Light intensity affected the SLW positively, but LAI showed no distinct difference among planting positions. The light environment of 4-year-old population was worse than that of 3-year-old population and leaf area and LAI differed greatly among planting positions. In 5-year-old population, leaf dry weight and leaf area of furrow part (that is, the amount of leaves protruded from the plants which were planted in 1st, 2nd or 3rd lines into the furrow) increased. The dry weights of leaves and stem increased considerably as plant became aged, and were distributed mainly in upper layer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.815-820
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• 2015

For the establishment of effective water resources management platform for Jeju-Island, the characteristics, including surface runoff, evapotranspiration, groundwater recharge and discharge are to be properly quantified. Among these hydrologic components, interception due to vegetation is very important factor but it is hard to be quantified. After Von Hoyningen-Huene (1981) found the relationship between LAI (Leaf Area Index) and interception storage, LAI has been used for key factor to estimate interception and transpiration. In this study the equation suggested by Kozak et al. (2007) is implemented in SWAT-K (Soil and Water Assessment Tool - Korea) model and is tested at the Cheonmicheon watershed in Jeju-Island. The evaporation due to interception was estimated as 85~104mm, 8~11% of whole evaporation. Therefore it is necessary to consider the evaporation due to interception as a controlling factor to water budget of this watershed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.1
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• pp.1-15
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• 2016

Annual litterfall production and leaf area index (LAI, $m^2/m^2$) were estimated using litter traps in Gwangneung, Mt. Taewha and Mt. Gariwang. Annual total litter fall production including branch, bark, others was the highest in Gwangneung($7497.3{\pm}326.5kg/ha/yr$), which had the highest basal area at late successional stage, and followed by Mt. Taewha($5929.1{\pm}225.8kg/ha/yr$) and Mt. Gariwang($3,210.1{\pm}220.1kg/ha/yr$). Mt. Gariwang had the lowest litterfall production due to high elevation and short growing season even with the higher stand density and basal area than Mt. Taewha. Similarly, LAI, which was calculated by multiplying the mass of leaf litter with specific leaf area, was the highest in Gwangneung($5.99{\pm}0.69$) and followed by Mt. Taewha($5.20{\pm}0.24$) and Mt. Gariwang($4.06{\pm}0.42$) and the upper canopy species had the highest leaf area index in every sites (Gwangneung : 4.72, Mt. Taewha : 3.08, Mt. Gariwang : 2.19). However, species specific LAI estimation based on the relationship between basal area and leaf area was limited due to upper canopy species non-proportionality of basal area with LAI. In addition, the comparison between direct and indirect LAI measurement showed the importance of canopy clumping, especially at high density. Our study emphasized the necessity of direct LAI measurement using litter fall traps especially at temperate deciduous forest with diverse species.

• Korean Journal of Remote Sensing
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• v.31 no.1
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• pp.11-20
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• 2015

This study aimed to investigate the canopy growth conditions and the accuracy of phenological stages of paddy rice using ground-based remote sensing data. Plant growth variables including Leaf Area Index (LAI) and canopy reflectance of paddy rice were measured at the experimental fields of Chonnam National University, Gwangju, Republic of Korea during the crop seasons of 2011, 2012, and 2013. LAI values were also determined based on correlations with Vegetation Indices (VIs) obtained from the canopy reflectance. Three phenological stages (tillering, booting, and grain filling) of paddy rice could be identified using VIs and a spatial index (NIR versus red). We found that exponential relationships could be applied between LAI and the VIs of interest. This information, as well as the relationships between LAI and VIs obtained in the present study, could be used to estimate and monitor the relative growth and development of rice canopies during the growing season.

• KCID journal
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• v.10 no.2
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• pp.43-54
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• 2003

This study investigated the spectral reflectance and leaf area index (LAI) of field crops and determined vegetation indices when intermixed with field crops and soil. Ground-level spectral reflectance and leaf area index (LAJ) were collected for eight cro