• 한국농공학회논문집
• /
• 제46권1호
• /
• pp.107-117
• /
• 2004

Hourly monitoring data from Saemangeum estuary, which is expected to become freshwater, was analyzed to evaluate the water quality characteristics. Higher algal growth at spring season than winter influenced the high ratio of organic nitrogen to total nitrogen and concentration of chemical oxygen demand (COD). About 87.9％ and 59.7％ of organic nitrogen was observed at winter season and spring season, respectively. Daily salinity analysis at the mouth of two main rivers demonstrated that the Dongjin in river was more influenced by tidal effect and showed higher variation than the Mankyung river. The ratio of nitrogen to phosphorus (N/P ratio) was different with site (estuary versus sea area) and season (winter versus spring) remarkably. The N/P ratio was highest (32.74 ∼ 43.93) at estuary in winter and was lowest (1.78 ∼ 3.06) at sea in spring. The high N/P ratio at estuary area implies that phosphorus can be the limiting nutrient factor for algal growth as in general freshwater river, therefore, water quality management practice considering river characteristics rather might be needed in the Saemangeum estuary. The Saemangeum project is nationally recognized for its environmental issues, and especially water quality concern is a critical factor to make policy decision and further assessment with continued monitoring is strongly recommended.

• Advances in environmental research
• /
• 제7권3호
• /
• pp.161-175
• /
• 2018

Krishna River is significantly affected due to Srisailam dam from past 30 years. The impact of this hydraulic structure drastically reduced the minimum flow regime on the downstream, which made the river nearing to decaying stage. In the present paper, Environmental Flow called minimum flow values released for the dam are estimated with the help of three hydrological methods viz., Range of variability Approach (RVA), Desktop Reserve Model (DRM), and Global Environmental Flow Calculator (GEFC). DRM method suggested considering the intermediate values obtained from among the three methods to preserve the ecosystem on the downstream of the river, which amounts to an average annual allocation of 9378 Million Cubic Meter (MCM) which is equal to 23.11% of mean annual flow (MAF). In this regard GEFC and RVA methods accounted for 22% and 31.04% of MAF respectively. The results indicate that current reservoir operation policy is causing a severe hydrological alteration in the high flow season especially in the month of July. The study concluded that in the case of non-availability of environmental information, hydrological indicators can be used to provide the basic assessment of environmental flow requirements. It is inferred from the results obtained from the study, that the new reservoir operations can fulfil human water needs without disturbing Environmental Flow Requirements.

• The Journal of Asian Finance, Economics and Business
• /
• 제9권5호
• /
• pp.389-396
• /
• 2022

Tourism has always played an important role in socio-economic development in Vietnam and in many countries around the world. Tourism is also an industry that has attracted a large number of workers in the past two decades in Vietnam in general and territories in particular. Over the past two decades, tourism in the southern Red River sub-region has created thousands of jobs for local workers and neighboring provinces. The study aims to examine the factors affecting the employment decision of workers in the tourism industry in the South Red River sub-region. Using a pilot study surveying 10 workers in three provinces to adjust the questionnaire and a sample data of 193 observations were performed. The experimental results prove that the independent variables explain 64% of the variation of the dependent variable, and other reasons can explain the rest (36%). Research results show that four factors, namely, welfare (WE), working conditions (IN), the potential for tourism development (POT), and development policy (POL) have a positive impact on the employment decision of workers. Meanwhile, the two factors that are tourism cooperation (CO)and Education (EDU), have an insignificant impact on the employment decision of workers in the southern Red River sub-region.

• 한국환경과학회지
• /
• 제32권12호
• /
• pp.943-953
• /
• 2023

This study analyzed the ecological characteristics of the wetland protection area at tthe Nakdong River through vegetation and biota surveys, which showed that brackish water meets fresh water, a unique ecological environment has been created, biodiversity is high, and diverse habitats are distributed. Eleven plant communities, including four woody communities and seven grass communities, are distributed along the coast, and a total of 514 species, including 11 endangered wildlife species, were identified in terms of species diversity. Among them, the species diversity of the Eulsuk-do area was found to be relatively higher than that of other Barreir Islands areas. The presence of a population of Sterna albifrons on Sinja-do and a population of Eremias argus on Jinwo-do, an area outside the boundaries of the wetland protection area, confirmed the conservation value of the wetlands and the need to expand the boundaries of the wetland protection area. It is judged that this information can be used as basic information for a systematic conservation and management plan for the wetland protection area at the Nakdong River Estuary and as basic data to support the establishment of a policy.

• 한국환경생태학회:학술대회논문집
• /
• 한국환경생태학회 2003년도 추계학술논문발표회 논문집
• /
• pp.23-29
• /
• 2003

It has been declared in 1992 at Rio about the management of united water control and method of the management of the water resources at the water basin. And it was also mentioned about the protection of fresh water's quality and it's supply under chapter the 18th of the agenda 21. It has been 10years passed after Rio declaration, and water crisis Is getting more serious than before. Fairly, right for using water resources was given to every life as the public resources. But at the last world water forum, water was commercialized, and regulated as the basic requirement not basic right. Therefore, we could use the water according to the logic of supply and demand at the market, and with money. Furthermore, construction of the big dam which was build to solve the problem of the lack of water became one of problems for water control. Korea is keeping consistent policy such as providing water by the building of dam. Control of the water demand is the most basic and effective policy for the preservation of water resources. If we change the policy such as the construction of the dam, we should put the management of the water demand in the center with the reliable philosophy. United management of the river basin has to be made with the security of water, improvement of water quality, and protection of the ecological side each other. Management of water basin also has to be completed to solve the trouble caused by using water conflict people who live up and down stream. To maintain the good quality of water, management of water basin is necessary. Also, bottom line of the united management of water basin is voluntary involvement of every citizens and local community. We suggest to preserve the origin of river and the upper at the ecological side. It is worth it to preserve.

• 한국환경생태학회지
• /
• 제28권1호
• /
• pp.71-79
• /
• 2014

본 연구는 최근 홍천강의 생태적 기능을 되살리기 위해 계획 중인 생태하천 복원사업의 경제적 편익을 정량적으로 추정하는 것을 목적으로 하고 있다. 생태하천 복원사업의 결과물은 시장에서 거래되는 재화가 아니기 때문에 가격을 이용한 가치 측정에 어려움이 있으므로, 사용가치 및 비사용가치에 대한 지불의사액을 분석하는 조건부 가치측정법을 적용하였다. 또한 지불의사액이 0인 응답자들을 고려한 스파이크 모형을 추가적으로 이용하였다. 분석 결과 사업지 인근에서는 가구당 연간 3,300원~4,628원, 비사업지에서는 가구당 연간 1,308원~2,929원의 지불의사가 있었다. 이를 우리나라 전체로 확대할 경우, 홍천강 생태하천 복원사업의 경제적 편익은 현재가치로 약 976억 원~2,163억 원에 이를 것으로 판단된다.

• 한국수자원학회논문집
• /
• 제44권8호
• /
• pp.629-637
• /
• 2011

본 연구는 수질악화 등으로 사회적 논란이 되고 있는 영산강 하구를 대상으로 하구의 환경가치를 추정하였다. 본 연구는 (1) 동식물 산란지 및 서식지 기능, (2) 오염정화 기능, (3) 여가 및 심미적 기능, (4) 교육/과학/연구 기능 등 하구의 세부 기능별 가치를 평가하기 위하여 MAUT에 근거한 CVM을 적용하였다. 또한 하구 인근 지역만 대상으로 하거나 하구에서 떨어진 지역만 대상으로 해서는 결과의 일반화가 보장될 수 없으므로 하구 인근 지역과 인근 지역을 제외한 전국으로 표본을 분리하여 설문조사를 시행하였다. 분석결과 영산강 하구역인 전남 목포시, 나주시, 강진군, 해남군, 영암군, 무안군, 함평군에연간 약 10.6억원의 환경가치를 창출하고 있으며, 영산강 하구역을 제외한 전국에서연간 약 273.9억원의 환경가치를 창출하는 것으로 나타났다. 두 지역을 합칠 경우 연간 약 284.5억원에 해당한다. 본 연구의 결과는 하구 관리 정책을 위한 적정 투자수준 결정 및 하구관리정책과 관련하여 중요한 정량적 자료를 제공할 뿐만 아니라 후속 연구를 위한 방법론적 지침을 제시 할 것으로 기대된다.

• Journal of Forest and Environmental Science
• /
• 제34권1호
• /
• pp.31-45
• /
• 2018

At present the biodiversity of the riparian forest is under threat due to various anthropogenic pressures. Hence study was conducted along the three unprotected zones of riparian forest in Dikhu river, Nagaland, north-east India in order to compared the diversity, distribution and population structure of riparian trees. In each zone $100{\times}100m^2$ plot were marked and subdivided into 20 plots of $10{\times}10m^2$. 10 plots on each side of the river were taken randomly covering 0.02 ha. Only tree with dbh ${\geq}10cm$ and dbh above 1.5 m above ground level were recorded as individual species. A total of 29 tree species belonging to 18 families were recorded from the three zones of the river. Tree species richness was highest at the middle zone (19) followed by upper (14) and lower zone (7). The most abundant species and family recorded at upper, middle and lower zones were Melia azaderach of Euphorbiaceae ($380\;stems\;ha^{-1}$), Terminalia chebula of Euphorbiaceae ($432.5\;stems\;ha^{-1}$) and Duabanga grandiflora of Lythraceae ($365\;stems\;ha^{-1}$) respectively. The ranges of diversity indices observed in the three zones were: Shannon-Wiener index (1.25-0.73), Simpson diversity index (0.42-0.93), Evenness index (0.47-0.37) and Index of co-dominance (0.75-0.94). Rest of other indices were also estimated and compared. Distribution of trees shows the contagious pattern common in the upper and middle zones and regular in the lower zone. The girth size class analysis demonstrated that the riparian forest is in less mature succession stage. This study emphasize the need for management and conservation of riparian forest by developing policy to declare the riparian zone as protected area to prevent further degradation and loss of biodiversity from these unregulated zones along the river.

• 한국환경복원기술학회지
• /
• 제3권4호
• /
• pp.84-90
• /
• 2000

The objective of this study was to introduce the current status and development strategy for an environmental restoration of stream side in Japan, and to consider a methodology which could be effectively applied for the environmental restoration of stream side in Korea. 1. In order to change the recent direction of the forest conservation and erosion control projects which are focused on the restoration of stream side ecology, we have to quit the past erosion control policy such as water control purpose, and establish new plans regarding on the forest conservation and erosion control which is considered the regional environmental restoration of watershed. 2. When we restore stream side and river side ecosystem, we should establish restoration plans which can keep the original nature of stream and river. 3. The forest conservation and erosion control construction projects for the restoration of stream and river ecosystem should be planned for the perfect restoration of their ecosystem by way of sustainable maintenance and management. 4. The restoration direction of stream and river ecosystem needs to be planned to restore the diversity of small geographies such as waterway, shoal and puddles rather than flattening of stream bed. 5. The main principle in the restoration of stream and river ecosystem is to accomplish forest conservation and erosion control construction projects which can conserve the existing stream and river ecosystem.

• 한국농공학회논문집
• /
• 제60권1호
• /
• pp.111-120
• /
• 2018

The purpose of this study was to develop a ridge regression (RR) model to estimate BOD and TP load using runoff weighted value. The concept of runoff weighted value, based on distributed curve-number (CN), was introduced to reflect the impact of land covers on runoff. The estimated runoff depths by distributed CN were closer to the observed values than those by area weighted mean CN. The RR is a technique used when the data suffers from multicollinearity. The RR model was developed for five flow duration intervals with the independent variables of daily runoff discharge of seven land covers and dependent variables of daily pollutant load. The RR model was applied to Heuk river watershed, a subwatershed of the Han river watershed. The variance inflation factors of the RR model decreased to the value less than 10. The RR model showed a good performance with Nash-Sutcliffe efficiency (NSE) of 0.73 and 0.87, and Pearson correlation coefficient of 0.88 and 0.93 for BOD and TP, respectively. The results suggest that the methods used in the study can be applied to estimate pollutant load of different land cover watersheds using limited data.