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다목적 댐 저수지의 비점오염실태 및 친환경적 관리방안 연구
최지용,민준식,고은주 한국환경연구원 2006 수시연구보고서 Vol.2006 No.-
Multipurpose dam has developed Korean economy by satisfying various water uses of industrial and residential areas. However, nonpoint source pollutants discharging to upper watersheds degraded water quality, increasing turbidity and algal bloom. We may face problems including unpleasant smell and taste, malfunctioning equipment and changing landscape. Dam watersheds are mainly agricultural lands or mountains. Thus, these areas are characterized as distributed pollution sources while urban areas contain specific and concentrated pollution sources. Besides, it is hard to control nonpoint source once it outflows. Therefore, advanced countries are focusing on resource management system based on public education in managing agricultural nonpoint source pollution. Generally, main pollution sources in dam watersheds in Korea are highlands, cultivated streambanks, stock farms, roads, and construction sites. To manage these main sources efficiently, following principles should be considered commonly: (1) to mitigate pollution through controlling sources; (2) to take advantages of surroundings as much as possible; (3) to prioritize water quality problems. Specifically, highland cultivation should be controlled depending on its grade and altitude. Excessive organic chemicals such as fertilizer and pesticide can be exuded from the land, and the area is likely to be eroded by heavy rain. In the case of slope in 15% degree or more, prohibiting cultivation and restoring the surface is preferred to improving cultivation method in order to protect topsoil. Fallow, conservative cultivation, and covering can be alternatives for soil protection and reinforcement. In addition to these, construction of detour waterways and improvement of irrigation method can minimize the impact of runoff. For streambanks, it is the best way to prohibit cultivation. However, if the prohibition is not possible, potential pollution should be reduced with improved farming technique. In the case of livestock farms, highly concentrated runoff can be generated. Management practices like roofing and waterway diversion are required to decrease total discharging volume and to prevent potential pollutants from entering rainwater. Following practices can be also considered to reduce the impact; to balance a whole farm, to treat livestock wastes, and to fence the area. In forest, logging areas and roads are the major nonpoint sources. Especially, the roads should be managed continuously because those are easily disturbed. The surface can be conserved by covering with riprap and woodchip. However, if the roads are badly damaged or aged, pavement or reconstruction should be considered. Seeding, mulching, and vegetative covering can be also applied to protect fill and cut sides of the roads. In construction activity, advanced permit system and management plan should be established to mitigate damage to waterbodies because a great amount of sediment are generated from the site. After pollutants are discharged, decreasing or depositing them can contribute to delaying pollution expansion. Ponds, wetlands, vegetative waterways, and buffer strips will function to reduce and treat pollutant loads with other best management practices. Simultaneously, direct treatment can be implemented to control turbidity and algae in dam reservoir. To manage nonpoint source pollution successfully, public involvement and education are fundamentals. The involvement can be achieved voluntarily or mandatorily and education will be helpful to achieve the goal economically when the knowledge is coherent with the economical drivers and regulations. Same programs will generate different results depending on socio-economic condition and natural properties of the region. Therefore, many trials and pre and post assessment of projects will result in better management measures.
Cyanate를 처치한 흰쥐에서 승압제에 대한 심맥관계 반응
최지용,양은경,서준형,박재식,안동국 慶北大學校 醫科大學 1995 慶北醫大誌 Vol.36 No.4
목적 : 숫컷 흰쥐에 cyanate를 섭취케 하여 나타나는 산소-혈색소 결합력의 증가가 동맥압, 심박수, 압감수성 반사 및 동맥압 증가율에 미치는 영향을 관찰하며, 또한 승압제인 angiotensin Ⅱ (AngⅡ) 및 norepinephrine (Norepi) 그리고 칼슘 통로 차단제인 nifidipine(Nif)이 산소-혈색소 결합력이 증가된 상태에서 심맥관계에 미치는 영향을 평가 하고자 하였다. 대상 및 방법 : Wistar 숫쥐를 3주간 cyanate를 섭취하도록 한 실험군과 물을 먹도록 한 대조군으로 나누었다. 먼저 채혈하여 pH와 산소 및 탄산가스 분압을 측정하였다. 이어서 승압제인 Ang Ⅱ와 Norepi을 정맥 주입하여 심맥관계에 변화를 조사하였다. 또한 Nif를 전처치한 후 역시 Ang Ⅱ와 Norepi의 승압 반응을 관찰하였다. 결과 : 동정맥 산소분압은 유의하게 낮았으며 pH는 알칼리증을 나타내었다. 평균동맥압은 유의한 차이는 아니지만 높은 경향을 보였다. 심박수 변화는 일관성은 발견할 수 없었지만 동맥압의 변화에 대한 심박수의 변화 비로 계산한 압감수성 반사는 더욱 둔화되는 경향을 보였다. 승압제를 주입하면 농도 증가에 따라 동맥압 증가 현상을 볼 수 있었고, 동량의 Ang Ⅱ나 Norepi에 대해 대조군보다 동맥압 증가가 더 컸다. Nif를 전처치한 후 승압제를 주입한 경우 승압작용을 더 많이 차단하였다. 동맥압 상승률은 동맥압의 변화와 반대로 상승률이 적었다. 결론 : cyanate는 산소-혈색소 결합력을 증가시켜 동정맥 산소 분압을 감소시켜서 알칼리가 되게 하며, 승압제에 의해 심장 부하가 커지면 동맥압 상승률을 감소시켰다. 산소-혈색소 결합력 증가에 의한 조직의 산소 부족 현상을 극복하기 위하여 압감수성 반사 둔화를 포함한 몇가지 기전으로 동맥압이 더 증가하는 것으로 생각이 된다. This study was aimed to elucidate the cardiovascular responses to angiotensin Ⅱ (Ang Ⅱ) and norepinephrine (Norepi) together with blood gas profiles during elevated oxygen-hemoglobin binding affinity caused by ingestion of cyanate in rats. Male Wistar rats were divided into an experimental group that were fed cyanate in drinking water and a control group that were supplied with tap water for 3 weeks. On the experimental day, arterial and venous blood was sampled for measurement of pH, PO_2 and PCO_2. After 6.25, 12.5 and 25 ng/100g of Ang Ⅱ, or 0.1, 0.25 and 0.5 g/100g of Norepi was administered intravenously cardiovascular responses were recorded. The cardiovascular responses to pressor agents were also monitored in pretreatment with nifedipine. Arterial and venous blood had significantly low PO_2 and alkaline pH values in the cyanate group. Mean arterial pressure tended to be higher, though not significant. Arterial pressure was increased by pressor agents dose-dependently, and the magnitude of increase at given doses of Ang Ⅱ or Norepi was higher in the cyanate group than in the control group. The pressor effects blocked by pretreatment with nifedipine in the cyanate group was greater than in the control. No consistent change was observed in heart rate, but the baroreceptor sensitivity tended to be more compromised. The rate of increase in arterial pressure was lower in contrast to its absolute level. These results indicate that, during elevated oxygen-hemoglobin binding affinity caused by cyanate, arterial and venous blood becomes alkaline with lowered PO_2, and the rate of increase in arterial pressure is diminished under a condition when cardiac afterload is elevated by pressor agents. It seems that the arterial pressure is increased to a higher level by several mechanisms including lowered baroreceptor sensitivity to compensate for the relative tissue hypoxia induced by elevated oxygen-hemoglobin binding affinity.
최지용,장수환 한국환경정책평가연구원 2003 한국환경정책평가연구원 연구보고서 Vol.2003/re-11 No.-
유역의 도시화로 인해 하천은 수순환, 하천형태, 수질 측면 등에서 악영향을 받고 있으며, 이로 인해 도시하천은 홍수, 건천화, 수질악화 문제를 겪고 있다. 특히 대도시에 인접하여 개발 수요가 많은 하천유역은 최근의 난개발로 도시 수순환에 심각한영향을 경험하였으나 이를 관리할 정책수단은 미흡한 실정이다. 최근 들어 우리나라에서 수질관리 등 환경문제 해결을 위해 유역관리 차원에서 접근하려는 시도가 시작되었으나 어떠한 수단을 통해 유역관리를 접근할 수 있는가에 대한 연구는 아직 부족한 실정이다. 따라서 유역 내 물의 순환 및 하천의 상태에 영향을 미치는 요소를 규명하고 이를 유역관리차원에서 관리지표로 활용하는 연구가 필요하다. 유역관리 지표로는 불투수면, 인구밀도, 주택밀도, 도시적 토지이용 등이 있으며, 이 중에서 유역관리 방법으로써 활용하기 가장 적합한 것은 불투수면 지표이다. 불투수면은 유역관리지표로서의 효율성뿐만 아니라 불투수면의 감소 외에 투수율을 높이는 등 다양한 유역관리기법의 도입을 통해 관리가 가능하다는 측면에서 유역관리에 있어 가장 좋은 지표가 될 수 있다. 불투수면은 두 개의 주요 요소로 구성되어 있는데, 이는 우리가 살아가고, 일하고, 쇼핑하는 공간인 지붕(rooftops)과 이 지붕들을 연결해주는 교통체계(transportsystem)이다. 대부분의 도시에서는 교통체계에 의한 불투수 면적이 지붕(주택, 건물)으로 인한 불투수면 면적을 초과하고 있다. 예를 들면, 실제 한강유역에서 측정된 단독, 아파트, 상업지역의 부지에서의 교통관련 불투수면은 전체 블투수면 면적의 63~70%를 구성하고 있다. 불투수면은 하천으로의 유출량, 수온, 수질, 하천형태, 생물적 다양성에 영향을 미친다는 것은 많은 연구에서 입증되었다. 불투수면이 많을수록 이와 비례하여 유출이 증가한다. 이러한 증가된 유출량으로 인해 지하침투량이 감소됨으로써 결과적으로 더 낮은 기저유량을 초래하고 이는 하천의 건천화로 이어지게 된다. 토질 및 경사 요소가 큰 영향을 주는 평지를 제외하고는, 유출계수는 불투수면과 밀접한 관계가 있어500m²주차장(유출계수: Rv=0.95)에서 생성된 총유출량은 개발되지 않은 초지(Rv=0.06)에서 생성된 유출량의 약 16배정도 된다. 또한 하천은 유량이 증가하면 이를 수용하기 위하여 하천의 단면적을 증가시키는 방향으로 반응하는 것이 자연적인 현상이다. 이와 같은 현상은 하천 둑이나 바닥을 침식하는 두 가지 현상을 병행하면서이루어진다. 이처럼 하천의 하상이 불안정한 단계에서는 하천 둑의 침식 및 서식지교란이 발생하게 된다. 불투수면이 증가하면 수질에도 영향을 주는데, 대기로부터의 침적, 차량으로부터의 유출, 기타 발생원에 의한 오염물질이 이에 축적되어 있고, 강우시에는 이것이유출수에 의해 운반되어 흘러간다. 불투수면과 수온의 관계를 살펴보면, 하천의 수온은 국부적인 대기 온도에 의해 영향을 받으며, 여름철 동안 도시유역에서 하천 수온의 상승은 초지나 산림지 유역보다 상승 폭이 크며, 수온이 유역의 불투수면 비율과 직접적인 관련이 있음이 밝혀졌다. 불투수면이 증가함에 따라 수생태계에도 부정적인 영향을 미치는 것으로 나타났다. 불투수면의 증가는 수서 곤충군과 어류의 다양성에 부정적인 영향을 주고 종 구성에 변화를 초래하는 것으로 나타났다. 불투수면을 산정하는 방법은 유역내 총 Urbanization of watershed exerts bad influence on circulation of water, shapes of rivers, or water quality, etc for which urban rivers suffer from flood, dry stream phenomenon, or deterioration of water quality. Especially, watersheds adjacent to the cities receiving constant development pressure are badly affected by disordered development. Nevertheless, policies to cope with these problems are rather insufficient. Although approaches are emerging recently in Korea to deal with these problems in the aspect of watershed management, practical methodological studies still run short. So it is deemed desirable to clarify the factors affecting the water circulations or conditions of rivers m the cities, and utilize them as management indexes in the course of watershed management. Watershed management indexes include impervious surface, population density, and urban land utilization, etc., among which impervious surface index is the most adequate to be used as a method of watershed management. Impervious surface index could be the most useful index for watershed management not only because it is efficient in managing watershed, but also because management is possible through the introduction of various watershed management techniques such as reduction of impervious surface or increase of permeability ratio Impervious surface consists of two major factors, the rooftops under which we live, work, and shop, and the transportation system connecting the rooftops In most cases impervious area related to the transportation system exceeds those related to the rooftops(house, building, etc.) For example, impervious area related to the transportation in the independent house complex, apartment complex or commercial area along the watershed of Han River occupies 63-70% of total impervious area. As it has been proven by lots of researches, impervious surface exerts influence on the scale of debouchment into the river, water temperature, water quality, shape of rivers, and biological diversity, etc. Debouchment is increased in proportion to the increase of impervious surface. Increased debouchment causes decrease of underground water percolation which again causes less base flux, which after all accelerates dry stream phenomenon. Except the land easily affected by soil quality or degree of slope, debouchment coefficient is closely related with impervious surface. Amount of total runoff generated in the parking lot of 500m² (runoff coefficient Rv=0.95) is as good as approximately 16 times the amount of those generated in the wild grassy place (Rv=O.06). Further, when the runoff increases, it is natural that a river reacts to increase its cross-sectional dimensions in order to accommodate it. This reaction is proceed either by widening the banks or by shaving the riverbed, or both of them. In the stage where the riverbed is unstable, the banks are eroded or the habitats are disturbed. The increase of impervious surface also affects the quality of water. In the impervious surface, contaminated materials are piled up which are floating in the air, discharged by vehicles, or generated by other sources. These are carried by surface runoff, then are washed off when it rains. As to the relation between impervious surface and water temperature, it is turned out that the water temperature of a river is affected by the temperature of local atmosphere. During the summer season, the level of increase of water temperature in the urban watershed is greater than in the rural watershed. It is discovered that water temperature is directly related to the ratio of impervious surface, and increase of impervious surface exerts negative impact on aquatic ecosystem, damaging the diversity of aquatic insects and fishes, and causing change in the constitution of species. There are two methods of calculating impervious surface, the one to calculate total impervious area (TIA) along the watershed, and the other to calculate effective impervious area (EIA) w