• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.770-779
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• 2012

In order to verify the characteristics of vegetation structure in Jeolgu valley, Nakdongjeongmaek, we set up 29 plots(each plot area is $10m{\times}10m(100m^2)$. The survey site is located in around the valley and its range is about 3km section. The forest vegetation communities were analysed by TWINSPAN classification. The results of communities were classified 5 types such as Pinus densiflora community, deciduous broad-leaved tree community, Quercus variabilis community, Quercus mongolica community, Larix leptolepis community. The deciduous broad-leaved tree which prefer to moist environment and Quercus spp. has dominant in around the valley and the northern slope. In addition, Larix leptolepis community expect to maintain the present status for a while. However, the under story of Larix leptolepis community have expanded the influence of deciduous broad-leaved tree such as Fraxinus mandshurica, Morus bombycis, Acer mono and so on. Therefore, there will be developed next ecological succession by species of deciduous broad-leaved tree. The diversity index showed form 0.9665 to 1.2450. It were analyzed that diversity index of Jeolgu valley was higher than other places in Nakdongjeongmaek.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.4
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• pp.31-42
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• 2015

The objective of this study is to estimate the flood flow of inaccessible regions using satellite-derived rainfall and global geographic data. This study focuses on Dongsingun, an area located upstream of the Cheongcheon River in North Korea. The IFAS model was used to estimate flood flow. The model was calibrated in the Gap Stream watershed in South Korea and verified for the Byeongsung Stream watershed in the Nakdong River basin. Satellite-derived rainfalls for North Korea was revised using ground gauge data. Analysis results using CMORPH and GSMaP_NRT showed $4,886m^3/s$ and $5,718m^3/s$ respectively. In future studies, hydrological analysis in unmeasured and inaccessible regions will be carried out by applying more rainfall events.

• Journal of Korea Water Resources Association
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• v.43 no.1
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• pp.95-104
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• 2010

The tap water supply in Korea mainly depends on the surface water. However, the advanced water purification process becomes a necessity due to the deterioration of surface water quality and the risk of accidental spill. High cost of water treatment and public concerns make the decision makers turn to riverbank filtration as an alternative to the surface water. Riverbank filtration has been employed for water supply in many developed countries for more than 150 years. In Korea, riverbank filtration has drawn attention since 1990s as a supply source having potential to stably meet the ever-increasing water demand. Some cities located in the Nakdong River Basin are currently supplying water through riverbank filtration. This work studies the site suitability analysis for riverbank filtration using game theory. Theory of games, which is a branch of applied mathematics used in social sciences (most notably economics), biology, engineering and computer science, was applied to candidate locations for the selection of riverbank filtration site. We proposed a policy game model as a new method adopting a probabilistic approach. The model developed turned out to be an effective tool for site selection.

• Journal of Korea Water Resources Association
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• v.41 no.7
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• pp.737-746
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• 2008

The purpose of developing a rainfall-runoff and reservoir model is to provide an analysis tool for hydrological engineers in order to forecast discharge of rivers and to accomplish reservoir operations easily and accurately. In this study, based on the short-term rainfall-runoff storage function model which has gained popularity for real time flood forecast in practical water management affairs, a long-term runoff model was developed for the improvement of the calculation method of effective rainfall and percolation at the infiltration area. Annual discharge was simulated for three dam watersheds(Andong, Hapcheon, Milyang) in Nakdong River basin to analyze the accuracy of the developed model and compare it to SSARR model, which is used as the long-term runoff model in current practical water management affairs. As the result of the comparison of hydrographs, SSARR model showed relatively better results. However, it is possible for the developed model to simulate reliable long-term runoff using relatively little available data and is useful for hydrological engineers in practical affairs.

• Journal of Korea Water Resources Association
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• v.33 no.6
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• pp.671-679
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• 2000

Regionalization technique using flow duration curve and spatial interpolation algorithm is developed for the purpose of estimating daily flow time series at ungauged station. In this study, we assumed a part of 8 gauging stations of Nakdong River basin as ungauged stations. Then, we generated flow duration curves and daily flow hydrographs by regionalization technique at ungauged stations. And we compared generated and observed hydrographs. The simulation results showed that the observed flows were well simulated by the proposed method and that the general patterns of the observed flows were satisfactorily reproduced by the regionalization technique. From these results, it is possible that we obtain daily flow information without application of labour intensive and time consuming deterministic models, which require complicating quantification of model parameter values. And we compared the regionalization techniques with the specific discharge method which is the most general approach in hydrological practice in Korea. The results showed that the regionalization technique was superior to specific discharge method.method.

• Journal of Korea Water Resources Association
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• v.37 no.12
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• pp.1065-1074
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• 2004

This study aims at the introduction of new catchment shape descriptor, developed by Moussa(2003), based on equivalent ellipse and the assessment of its hydrologic applicability. Two descriptors a+b and a+b+${\varepsilon}OM$were correlated to the lag time and those were applied to the estimation of representative values of Nash model parameters. They are applied in order to examine the practicality to 3 catchments in Korea, catchments in Korea, respectively, i.e. Pyeongchanggang catchment in Han river, Bocheongcheon catchment in Geum river and Wicheon catchment in Nakdong river. As a result both of two descriptors show higher correlations to the lag lime than classical geomorphologic factors and hereby Moussa's suggestion(2003) is confirmed. For the sake of simplicity the former is recommended. Also representative IUHs derived from this study show consistent basin response characteristics. It is desirable to conduct further more case studies on many other basins.

• Journal of Korea Water Resources Association
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• v.33 no.2
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• pp.159-167
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• 2000

The purpose of this study is to estimate the stochastic monthly runoff model for the Kunwi south station of Wi-stream basin in Nakdong river system. This model was based on the theory of Box-Jenkins multiplicative ARlMA and the state-space model to simulate changes of monthly runoff. The forecasting monthly runoff from the pair of estimated effective rainfall and observed value of runoff in the uniform interval was given less standard error then the analysis only by runoff, so this study was more rational forecasting by the use of effective rainfall and runoff. This paper analyzed the records of monthly runoff and effective rainfall, and applied the multiplicative ARlMA model and state-space model. For the P value of V AR(P) model to establish state-space theory, it used Ale value by lag time and VARMA model were established that it was findings to the constituent unit of state-space model using canonical correction coefficients. Therefore this paper confirms that state space model is very significant related with optimization factors of VARMA model.

• Water for future
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• v.20 no.4
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• pp.257-266
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• 1987

The existing stochastic models for the data with hydrologic persistence can be classified into two categories; the short-term and long-term models.For the present study, the Hurst coefficients which are the dominant parameter in the Fast Fractional Gaussian Noise(FFGN)model, one of the long-term models. are estimated with historical annual and monthly streamflows. In order to verify the applicability of these estimators the statistical properties of the generated annual streamflows by FFGN model are compared with those of the historical annual streamflows. Then the generated annual streamflows by FFGN model are disaggregated into the monthly streamflows by disaggregation model at two sites, i.e. Waekman and Jindong, in the Nakdong River Basin. On the other hand, the monthly stream flows at the two sites were also generated by the two-site Matalas model which is one of the short-term models. To evaluate the applicability of the above models and to select the better model the statistical properties of the generated monthly streamflows by two models were compared with those of the historicals, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.523-534
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• 1994

The purpose of this study is to develop computer simulation model that produce precipitation patterns from stochastic model. In the paper(I) of this study, the alternate renewal process(ARP) is used for the daily precipitation series. In this paper(Il), stochastic simulation models for the daily precipitation series are developed by combining Markov chain for the precipitation occurrence process and continuous probability distribution for the precipitation amounts on the wet days. The precipitation occurrence is determined by first order Markov chain with two states(dry and wet). The amounts of precipitation, given that precipitation has occurred, are described by a Gamma, Pearson Type-III, Extremal Type-III, and 3 parameter Weibull distribution. Since the daily precipitation series shows seasonal variation, models are identified for each month of the year separately. To illustrate the application of the simulation models, daily precipitation data were taken from records at the seven locations of the Nakdong and Seomjin river basin. Simulated data were similar to actual data in terms of distribution for wet and dry spells, seasonal variability, and precipitation amounts.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.323-329
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• 2018

In Escherichia coli, the transcription of genes related to metal homeostasis is activated by the presence of target metals. The promoter regions of those genes can be fused with reporter genes to generate whole-cell bioreporters (WCBs); these organisms sense the presence of target metals through reporter gene expression. However, the limited number of available promoters for sensing domains restricts the number of WCB targets. In this study, we have demonstrated an alternative method to generate novel WCBs, based on the notion that since the sensing mechanisms of WCBs are related to metal transportation systems, their properties can be modulated by disrupting metal homeostasis. Mutant E. coli strains were generated by deleting the znt-operon genes zntA, which encodes a zinc-export protein, and zntR, which encodes a znt-operon regulatory protein, to investigate the effects on the metal-sensing properties of WCBs. Deletion of zntA increased the sensitivity but abolished the selectivity of cadmium-sensing WCBs, whereas arsenic-sensing WCBs gained sensitivity toward cadmium. When zntR was deleted, cadmium-sensing WCBs lost the ability to detect cadmium, and this was recovered by introducing exogenous zntR. In addition, the metal-binding site of ZntR was genetically engineered to modulate metal selectivity. This study provides a valuable platform for the development of novel E. coli-based WCBs.