• Ecology and Resilient Infrastructure
• /
• v.3 no.4
• /
• pp.322-326
• /
• 2016

The distribution of floodplain vegetation is mainly affected by hydrological and hydraulic processes. In this study, we investigated changes in the vegetation distribution due to flood discharge alteration, and the relationship between the vegetation types and the flood frequency during the last ten-year period in the Cheongmi-cheon Stream. Flood discharge of the Cheongmi-cheon Stream tended to decrease from 2006 to 2016. It has greatly decreased to less than $160m^3/s$ since 2013. This resulted in the settlement of Phragmites japonica to the wide sand bar at the Cheongmi-cheon Stream, even though it had sparse vegetation before 2013. The sand bar was fully covered with P. japonica in 2016. Vegetation communities in the floodplain were classified by dominant species, i.e. the annual-hygrophytic, the perennial hygrophytic and the mesophytic communities. Analysis of the relationship between the vegetation communities and the flood frequency shows the annual hygrophytes, perennial hygrophytes and the mesophytes communities distributed in the range of under 1 year, 1-10 year and over 7 year flood inundation area, respectively. In conclusion, distribution of the floodplain vegetation is closely related with the flood discharge and frequency in the Cheongmi-cheon Stream.

• Korean Journal of Remote Sensing
• /
• v.38 no.6_1
• /
• pp.1207-1217
• /
• 2022

Vegetation indices using the reflectance of selected wavelength, associating with the monitoring purpose such as identifying the progress of crop growth, on the vegetation canopy surface is widely used in the digital agriculture technology. However, the surface reflectance anisotropy can distort the true value of vegetation index related to the condition of surface, even though the surface property be unchanged. That causes difficulty to observe accurately crop growth on the monitoring system. In this study, a simple type goniometer was designed to measure the reflectance from the anisotropic surface according to various zeniths and azimuths of sun and viewing sensor in the field. On the tarp like as Lambertian surface, the reflectance of Blue, Green, Red, Near-Infrared band was similar to the tarps' reflectance properties. However, the reflectance was slightly overestimated in the cloudy day. The relative difference values of vegetation indices on grass were overestimated for the forward viewing and underestimated for the backward viewing. In addition, enhanced vegetation index (EVI) showed less sensitive according to the positions of sun and sensor viewing. Field observation with a goniometer will be helpful to understand the anisotropy characteristics on the vegetation surface.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.14 no.3
• /
• pp.21-31
• /
• 1987

The overuse in the outdoor recreation lands has been deteriorating the natural resources and landscapes. So this study was executed to measure the users'impacts on vegetation and soil at Hwaum Temple District Campsite in the Mt. Jiri National Park, the southern part of Korea. Five sites were sampled in the study area according to the extent of impact observed. Then the users'densities and impacts on vegetation and soil were measured at each site. According to the result of this study, the numbers of species and individuals and the coverage of lower-layer vegetation showed outstanding changes by only light use. The numbers of species and individuals of middle-layer vegetation, species diversity indices, change rate in species composition of lower and middle-layer vegetation, damage rate of forces, contents of clay, soil moisture and organic matters, exchangeable base ions, soil hardness, organic matter depth and bare area of the campsite showed conspicuous changes from the site 4(19.6men / 1,000㎡). Especially, the self-repair of vegetation was impossible as the result of analysis of soil hardness and the formation of natural vegetation was expected to be difficult as the result of vegetation sturcture analysis over the users'average density of 19.6men /1,000㎡. The campsite management of this area shall be proposed as follows to prevent serious deterioration of natrual environment. A limitation of the present use and a conservation on soil and vegetation should be required at the site 4 and 5. Specially, prevention of camping recreation and artificial rehabilitation are necessary at the site 5(24. 3 men/1000㎡)

• Journal of the Korean Society of Hazard Mitigation
• /
• v.5 no.3 s.18
• /
• pp.47-55
• /
• 2005

In order to design and manage the urban streams, the change of hydraulic characteristics by vegetation must be analyzed clearly. Planting criteria of vegetation in a urban stream were investigated and the design method of vegetation permission map was analyzed in this study. In addition, variations of water level due to vegetation are calculated by quasi two dimensional numerical model, HEC-RAS model and FESWMS model. Joongrang stream(Gunja bridge${\sim}$Jangan bridge reach) was selected as the case study stream. According to the criteria of vegetation, it is decided that vegetation density was $0.5{\sim}1.0$ tree/ha for selected tall tree in right floodplain and shrubs can be planted in the right and left floodplain area except the important hydraulic structures site. The selected shrubs planting simulations with three models show that water level in selected floodplain area increase approximately 12cm for the 100 year return period flood. The applicability of vegetation permission map in Korean urban stream was analyzed in this paper.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.10 no.3
• /
• pp.58-69
• /
• 2007

The vegetation area that occupies 76% in land surface of the earth can give a considerable impact on water resources, environment and ecological system by future climate change. The purpose of this study is to predict future vegetation cover information from NDVI (Normalized Difference Vegetation Index) extracted from satellite images. Current vegetation information was prepared from monthly NDVI (March to November) extracted from NOAA AVHRR (1994 - 2004) and Terra MODIS (2000 - 2004) satellite images. The NDVI values of MODIS for 5 years were 20% higher than those of NOAA. The interrelation between NDVIs and monthly averaged climate factors (daily mean, maximum and minimum temperature, rainfall, sunshine hour, wind velocity, and relative humidity) for 5 river basins of South Korea showed that the monthly NDVIs had high relationship with monthly averaged temperature. By linear regression, the future NDVIs were estimated using the future mean temperature of CCCma CGCM2 A2 and B2 climate change scenario. The future vegetation information by NOAA NDVI showed little difference in peak value of NDVI, but the peak time was shifted from July to August and maintained high NDVIs to October while the present NDVI decrease from September. The future MODIS NDVIs showed about 5% increase comparing with the present NDVIs from July to August.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.725-730
• /
• 2005

In case of the national roads which is opened in the past, there are carried out the expansion and improvement for enlargement of the traffic demand by industrial development and safety road operation to narrow of road width and serious change of the road alignment with effect of topography and graphical features of a mountain. A protection method using vegetation in the cut-slope has been constructed for harmony of ambient environment after cutting the slope recently. But it requires a study because the surface lose and the failure have been occurred in the large cut-slope which is covered by vegetation. In this study it was presented a countermeasure and examined a stability of contained uncertainty in the cut-slope according to the failure example of the cut-slope which is covered by vegetation. The additional research will be necessary against the development of the investigation technique which executes the stability investigation of the cut-slope which is covered by vegetation.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.957-960
• /
• 2004

From a water-environmental point of view, with a change of understanding and concern about vegetation, it changes that vegetation acts as stability of channel and bed, providing habitats and feed for fauna, and means improving those with appreciation of the beautiful but resistant factor to the flow So, it becomes important concern and study subjects that turbulent structure by vegetation, shear stress and transport as well as roughness and average velocity by vegetation. But from a hydraulic point of view, vegetation causes resistance to the flow and can increase the risk of flooding, Therefore, this thesis concern the flow characteristics in vegetated open channels. According to the experimental results, $z_0$ was on an average $0.4h_p$ in a vegetated open channel. So, the elevation corresponding to zero velocity in a vegetated channel was the middle of roughness element. The limit for logarithmically distributed profile over the roughness element was from $z_0$ to $0.80h_{over}$ for a vegetated channel. Among the existing theory, the method of Kouwen et al.(1969), Haber(1982), and El-Hakim and Salama(1992) except Stephan(2001) gave a very good value compared to the measured velocity profile.

• Journal of Korean Society of Forest Science
• /
• v.109 no.2
• /
• pp.145-156
• /
• 2020

In 2000 and 2018, phytosociological surveys were carried out in the forest vegetation of Mt. Yeompo, a representative isolated urban forest in Ulsan city. The trends of change in forest structure, composition, and spatial distribution were compared between years. Total percent coverage per 100 squaremeters of forest vegetation was similar, but natural vegetation showed a 9% increase. The importance of constituent species changed slightly. Specifically, Lindera erythrocarpa and Styrax japonicus showed very high growth rates of 835% and 269%, respectively. Species richness (S) and diversity (H') decreased by about 22% and 8%, respectively. Both S and H' showed slightly higher rates of decrease in artificial compared with natural vegetation. The constituent species life form spectrums were the same in 2000 and 2018 as 'MM-R5-D4-e'. The similarity (Jaccard coefficient) in the species composition of the forest vegetation was almost homogeneous at approximately 75%. The number of indicator species decreased from 16 species in 2000 to 7 species in 2018. This decrease was mostly due to a decline in herbaceous plants, such as Hemicryptophytes, Geophytes, and Therophytes, which are sensitive to disturbances. The spatial distribution of forest vegetation did not change significantly. The number of forest landscape elements (patches) increased by approximately 25% from 537 in 2000 to 721 in 2018, while the average size decreased by about 20% from 1.28 ha in 2000 to 1.03 ha in 2018.

• Journal of Environmental Impact Assessment
• /
• v.27 no.5
• /
• pp.475-488
• /
• 2018

Surveying urban tributary vegetation is based mainly on field sampling at present. The tributary vegetation survey integrating UAV NIR(Unmanned Aerial Vehicle Near Infrared Radiance) imagery and in-situ point photo has received only limited attentions from the field ecologist. The reason for this could be the largely undemonstrated applicability of UAV NIR imagery by the field ecologist as a monitoring tool for urban tributary vegetation. The principal advantage of UAV NIR imagery as a remote sensor is to provide, in a cost-effective manner, information required for a very narrow swath target such as urban tributary (10m width or so), utilizing very low altitude flight, real-time geo-referencing and stereo imaging. An exhaustive and realistic comparison of the two techniques was conducted, based on operational customer requirement of urban tributary vegetation survey: synoptic information, ground detail and quantitative data collection. UAV NIR imagery made it possible to identify area-wide patterns of the major plant communities subject to many different influences (e.g. artificial land use pattern), which cannot be acquired by traditional field sampling. Although field survey has already gained worldwide recognition by plant ecologists as a typical method of urban tributary vegetation monitoring, this approach did not provide a level of information that is either scientifically reliable or economically feasible in terms of urban tributary vegetation (e.g. remedial field works). It is anticipated that this research output could be used as a valuable reference for area-wide information obtained by UAV NIR imagery in urban tributary vegetation survey.

• Journal of Korean Society of Forest Science
• /
• v.110 no.4
• /
• pp.516-529
• /
• 2021

Coniferous forests in the Baekdudaegan protected area are gradually losing their landscape diversity and uniqueness along with their ecological stability due to changes in vegetation composition and structures caused by various disturbance factors, such as climate change, vegetation succession, and human interference. This study provides basic data for establishing a comprehensive conservation plan for coniferous forests in the Baekdudaegan protected area. We classified the vegetation unit types using the Zurich-Montpellier School of Phytosociology and two-way indicator species analysis methods and analyzed the species diversity and structural characteristics based on the vegetation information of 755 stands collected in the natural resources change survey of the Baekdudaegan mountains (2016 to 2020) by the Korea Forest Service. Therefore, the vegetation of the coniferous forests of theBaekdudaegan protected area was classified into 15 types under the vegetation unit hierarchy of two community groups, four communities, seven sub-communities, and 14 variants. Furthermore, we compared the total coverage among vegetation types, importance values, constancy classes, life-forms, and diversity indices. Additionally, the average total coverage and number of species per 100 m² of all coniferous forests were 232% and 21 species, respectively, with the species diversity and dominance indices averaging 1.907 and 0.222, respectively.