• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.325-328
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• 2007

We discuss the Normalized Difference Vegetation Index (NDVI) of the forest canopy and floor separately based on airborne spectral reflectance measurements and simultaneous airborne land surface images acquired around Yakutsk, Siberia in 2000. The aerial land surface images were visually classified into four forest types: no-green canopy and snow floor (Type-1), green canopy and snow floor (Type-2), no-green canopy and no-snow floor (Type-3), and green canopy and no-snow floor (Type-4). The mean NDVI was calculated for these four types. Although Type-2 had green canopy, the NDVI was rather small (0.17) because of high reflection from the snow cover on the floor. Type-3, which had no green canopy, indicated considerably large NDVI (0.45) due to the greenness of the floor. Type-4 had the largest NDVI (0.75) because of the greenness of both the canopy and floor. These results reveal that the NDVI depends considerably on forest floor greenness and snow cover in addition to canopy greenness.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.2
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• pp.97-107
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• 2020

To analyze temporal and spatial changes in vegetation, it is necessary to determine the associated continuous distribution and conduct growth observations using time series data. For this purpose, the normalized difference vegetation index, which is calculated from optical images, is employed. However, acquiring images under cloud cover and rainfall conditions is challenging; therefore, time series data may often be unavailable. To address this issue, La et al. (2015) developed a multilinear simulation method to generate missing images on the target date using the obtained images. This method was applied to a small simulation area, and it employed a simple analysis of variables with lower constraints on the simulation conditions (where the environmental characteristics at the moment of image capture are considered as the variables). In contrast, the present study employs variables that reflect the growth characteristics of vegetation in a greater simulation area, and the results are compared with those of the existing simulation method. By applying the accumulated temperature, the average coefficient of determination (R²) and RMSE (Root Mean-Squared Error) increased and decreased by 0.0850 and 0.0249, respectively. Moreover, when data were unavailable for the same season, R² and RMSE increased and decreased by 0.2421 and 0.1289, respectively.

• Journal of the Korea Construction Safety Engineering Association
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• s.55
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• pp.37-51
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• 2012

There is a shround of mystery surronnding Gaudi. In all probability, the first mist preventing us from gaining acess to his work is the intrinstic mysteriousness of all genius and, at the end of the day, of all human spirit. The situation is complicated by the well-known fact that Gaudi wished to creat an aura of silence around his persona, while, at the same time as maintaining this secretiveneness - in other words, the annihiliation of his fundamental values-gave expression and symbolisation to his moods and incerdible mental power. On a piece of land on the Muntanya Pelada, in the Barcelona district of La Salut, Eusebi G$\ddot{u}$ell Wanted to build an urbanisation inspired by the concepe of the garden city. in this he sought to return to nature, health and an escape from the insalubrous industrial city. Gaudi worked on the construction of this park between 1900 and 1914, and even moved his home there in 1906. An outstanding feature of park G$\ddot{u}$ell is the integration of architecture with nature. In other to save the natural slopes, Gaudi built viaducts from brick pillars, which he covered with stone obtained from the excavation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.2
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• pp.121-132
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• 2016

This study proposes an approach for simulating high spatial resolution satellite images acquired under arbitrary sun-sensor geometry using existing images and 3D (three-dimensional) data. First, satellite images, having significant differences in spectral regions compared with those in the simulated image were transformed to the same spectral regions as those in simulated image by using the UPDM (Universal Pattern Decomposition Method). Simultaneously, shadows cast by buildings or high features under the new sun position were modeled. Then, pixels that changed from shadow into non-shadow areas and vice versa were simulated on the basis of existing images. Finally, buildings that were viewed under the new sensor position were modeled on the basis of open library-based 3D reconstruction program. An experiment was conducted to simulate WV-3 (WorldView-3) images acquired under two different sun-sensor geometries based on a Pleiades 1A image, an additional WV-3 image, a Landsat image, and 3D building models. The results show that the shapes of the buildings were modeled effectively, although some problems were noted in the simulation of pixels changing from shadows cast by buildings into non-shadow. Additionally, the mean reflectance of the simulated image was quite similar to that of actual images in vegetation and water areas. However, significant gaps between the mean reflectance of simulated and actual images in soil and road areas were noted, which could be attributed to differences in the moisture content.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.143-154
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• 2012

As demand of water resources and attentions to changes in climate (e.g., due to ENSO) increase, long/short term prediction of precipitation is getting necessary in water planning. This research evaluated the ability of MM5 to predict precipitation in the Tampa Bay region over 23 year period from 1986 to 2008. Additionally MM5 results were statistically bias-corrected using observation data at 33 stations over the study area using CDF-mapping approach and evaluated comparing to raw results for each ENSO phase (i.e., El Ni$\tilde{n}$o and La Ni$\tilde{n}$a). The bias-corrected model results accurately reproduced the monthly mean point precipitation values. Areal average daily/monthly precipitation predictions estimated using block-kriging algorithm showed fairly high accuracy with mean error of daily precipitation, 0.8 mm and mean error of monthly precipitation, 7.1 mm. The results evaluated according to ENSO phase showed that the accuracy in model output varies with the seasons and ENSO phases. Reasons for low predictions skills and alternatives for simulation improvement are discussed. A comprehensive evaluation including sensitivity to physics schemes, boundary conditions reanalysis products and updating land use maps is suggested to enhance model performance. We believe that the outcome of this research guides to a better implementation of regional climate modeling tools in water management at regional/seasonal scale.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_2
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• pp.529-538
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• 2013

Coastline is the most dynamic part of seascape since its shape is affected by various factors. Coastal zone is an area with immense geological, geomorphological and ecological interest. Monitoring coastal change is very important for safe navigation, coastal resource management. This paper shows a result of monitoring coastal morphological changes using Remote Sensing and GIS. Study was carried out to obtain intensity of erosion, deposition and sand bar movement in the Red River Delta. Satellite images of ALOS/AVNIR-2 and Landsat were used for the monitoring of coastal morphological changes over the period of 1975 to 2009. Band rationing and threshold technique was used for the coastline extraction. Tidal levels at the time of image acquisition varied from -0.89m to 2.87m. Therefore, coastline from another image at a different tidal level in the same year was considered to get the corrected coastline by interpolation technique. A series of points were generated along the coastal line from 1975 image and were established as reference points to see the change in later periods. The changes were measured in Euclidean distances from these reference points. Positive values represented deposition to the sea and negative values are erosion. The result showed that the Red river delta area expanded to the sea 3500m in Red river mouth, and 2873m in Thai Binh river mouth from 1975 to 2009. The erosion process occurred continuously from 1975 up to now with the average magnitude 23.77m/year from 1975 to 1989 and 7.85m/year from 2001 to 2009 in Giao Thuy area. From 1975 to 2009, total 1095.2ha of settlement area was eroded by sea. On the other hand, land expanded to the sea in 4786.24ha of mangrove and 1673.98ha of aquaculture.

• Journal of Korea Water Resources Association
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• v.41 no.10
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• pp.1067-1077
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• 2008

An understanding of temporal trends of stream flows can help in the river management and the water resources planning for natural circumstances and human communities. Changes in temperature, precipitation, flow, and land use (agriculture, flood prevention activities, reservoir operation, interbasin diversion, etc.) are all eventually reflected in the flow pattern of the river. An assumption that the stationarity of the hydrologic series implying time-invariant characteristics of the time series accepted in water structure designs can no longer be valid if the flow changes as a result of the climate change or the stream flow use. Therefore, the identification and description of the characteristics of changes in hydrologic time series is a very important task in the river basin management. In this study, the statistical tests on the flow change forced by excess water diversions in the Sumjin River basin were performed by ways of single variable and time series variable comparisons. The tests showed that currently the Sumjin River basin statistically keeps its homogeneity in annual streamflow series, but the changed situation has been appeared in dry season streamflow series.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.255-263
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• 2021

Background: Ecosystem service mapping is an important tool for decision-making in landscape planning and natural resource management. Today, pollination service mapping is based on the Lonsdorf model (InVEST software) that determines the availability of nesting and floral resources for each land cover and estimates pollination according to the foraging range of the desired species. However, it is argued that the Lonsdorf model has significant limitations in estimating pollination in a landscape that can affect the results of this model. Results: This paper presents a free software, named PollMap, that does not have the limitations of the Lonsdorf model. PollMap estimates the pollination service according to a modified version of the Lonsdorf model and assumes that only cells within the flight range of bees are important in the pollination mapping. This software is produced for estimating and mapping crop pollination in agricultural landscapes. The main assumption of this software is that in the agricultural landscapes, which are dominated by forest and agriculture ecosystems, forest patches serve only as a nesting habitat for wild bees and the surrounding fields provide floral resources. Conclusion: The present study provided new software for mapping crop pollination in agricultural landscapes that does not have the limitations of the Lonsdorf model. We showed that the use of the Lonsdorf model for pollination mapping requires attention to the limitations of this model, and by removing these limitations, we will need new software to obtain a reliable mapping of pollination in agricultural landscapes.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.903-916
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• 2023

This study aims to establish basic data for efficient management of rural water by analyzing regional irrigation facilities and benefitted areas in the statistical yearbook of land and water development for agriculture at the watershed level. For 511 domestic rural water use areas, water storage facilities (reservoirs, pumping & drainage stations, intake weirs, infiltration galleries, and tube wells) are spatially distributed, and the benefitted areas provided at the city/county level are divided by water use area to provide agricultural water supply facilities. The characteristics of rural water district areas such as benefitted area, were analyzed by basin. The average area of Korea's 511 rural water districts is 19,638 ha. The average benefitted area by rural water district is 1,270 ha, with the Geum River basin at 2,220 ha and the Yeongsan River basin at 1,868 ha, which is larger than the overall average. The Han River basin at 807 ha, the Nakdong River basin at 1,121 ha, and the Seomjing River basin at 938 ha are smaller than the overall average. The results of this basic analysis are expected to be used to set the direction of various supply and demand management projects that take into account the rational and scientific use and distribution of rural water and the characteristics of water use areas by presenting a quantitative definition of Korea's agricultural water districts.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.267-276
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• 2018

Volcanic ash from volcanic eruptions spreads to vast areas hundreds of kilometers away, and when volcanic ash flows into surface waters, it will be damaged by water supply. In case of water supply facilities, it provides to people drinking water and domestic water, be consumed by the people cause social disorder when water supply is cut off due to damage such as water pollution caused by harmful materials of volcanic ash. However, when we looked at the disaster management manual, the establishment of a water supply facility manual to deal with the damage of volcanic ash was found to be insufficient. Therefore, in this study, the existing volcanic and water pollution related manuals were analyzed and problems were derived. In order to make quick situation judgment and response activities, we have suggested the scope of the water supply facility manual, disaster type, major missions and system of related organizations, and scenario of crisis situation by disaster type.