• 제목/요약/키워드: southwestern region

검색결과 150건 처리시간 0.029초

The Role of the Spatial Externalities of Irrigation on the Ricardian Model of Climate Change: Application to the Southwestern U.S. Counties

  • Bae, Jinwon;Dall'erba, Sandy
    • Asian Journal of Innovation and Policy
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    • 제10권2호
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    • pp.212-235
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    • 2021
  • In spite of the increasing popularity of the Ricardian model for the study of the impact of climate change on agriculture, there has been few attempts to examine the role of interregional spillovers in this framework and all of them rely on geographical proximity-based weighting schemes. We remedy to this gap by focusing on the spatial externalities of surface water flow used for irrigation purposes and demonstrate that farmland value, the usual dependent variable used in the Ricardian framework, is a function of the climate variables experienced locally and in the upstream locations. This novel approach is tested empirically on a spatial panel model estimated across the counties of the Southwest USA over 1997-2012. This region is one of the driest in the country, hence its agriculture relies heavily on irrigated surface water. The results highlight how the weather conditions in upstream counties significantly affect downstream agriculture, thus the actual impact of climate change on agriculture and subsequent adaptation policies cannot overlook the streamflow network anymore.

하계 서해안 새만금 연안역 주변 저염수와 순환 (Low-salinity Water and Circulation in Summer around Saemangeum Area in the West Coast of Korea)

  • 이상호;최현용;손영태;권효근;김영곤;양재삼;정해진;김종구
    • 한국해양학회지:바다
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    • 제8권2호
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    • pp.138-150
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    • 2003
  • 만경강과 동진강이 담수를 유출하는 서해중부 연안에서 41,000 ha의 하구 천해역을 간척하기 위해 33 km의 새만금 방조제가 건설되고 있다. 이 연안역에 담수의 주 공급원은 방조제 북쪽에 위치하는 금강이다 현재 고군산군도 와 연결되고 있는 방조제는 이 해역을 세 지역으로 나누는데 방조제의 북서, 남서 그리고 동부(새만금) 지역이고, 새만금 지역 해수는 북방조제에 한 곳과 남방조제에 두 곳인 미축조 구간을 통해 교환된다. 이 연안역에서 저염수와 관련된 하계순환을 진단하기 위해 1998년과 1999년에 수온과 염분의 분포와 구조를 관측하였다. 북방조제 외측지역의 표층에서는 저염수의 혀모양 분포가 관측되었는데, 금강하구 입구에서 북서쪽으로 60 km까지 확장하고 외해수와 경계지어지는 강한 풀룸전선을 형성한다. 새만금 방조제 내측에서 염분분포는 두 강물이 병합되고 있으며 저염수가 북방조제 미축조 구간쪽으로 편향되었음을 보여준다. 남방조제 외측지역 표층에서는 곰소만으로부터 북쪽으로 확장하는 다른 저염수의 작은 혀모양 분포가 관측되었다. 이러한 저염수 분포와 전선구조 분석을 바탕으로 새만금 방조제 주변에 반시계방향의 연안수 순환을 제시할 수 있는데, 이는 방조제 내측에서 북방조제 미축조 구간으로 유출되는 하구 수와 남쪽 방조제 미축조 구간을 통하여 외해에서 유입하는 해수로 구성된다. 하지만 방조제 축조가 완성된 후에는 만경강과 동진강 담수 유출이 인위적이고 직접적으로 남방조제 외측으로 변경되기 때문에 방조제 주변 연안역 순환형태는 변화될 것이다.

지표수-지하수 연계를 고려한 국내 내륙산간지역 시공간적 지하수자원 관리 취약성 평가 기법 개발 (Development of the spatiotemporal vulnerability assessment method for groundwater resources management at mountainous regions in Korea considering surface water-groundwater interactions)

  • 이재범;아거쑤아모스;김건;양정석
    • 한국수자원학회논문집
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    • 제54권10호
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    • pp.807-817
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    • 2021
  • 본 연구에서는 국내 내륙산간지역의 행정구역을 대상으로 지표수-지하수연계를 고려한 시공간적 지하수자원 관리 취약성 평가를 수행하였다. 내륙산간지역을 4개 산지권역으로 구분하고 지표수-지하수 연계를 고려할 수 있는 공간적 지하수자원 관리 취약성 평가 지표를 선정하였다. 지하수 자원 관리 취약지역 선정 결과 중부산야권역의 파주시, 산악권역의 가평군, 남서산야권역의 구례군, 남동산야권역의 양산시가 선정되었다. 선정된 지역에 대하여 지하수위 및 침투량의 변동에 따른 월 단위 지하수자원 관리 취약 시기 평가를 수행하였다. 월 단위 지하수자원 관리 취약시기 평가결과 12 ~ 2월이 지하수자원 관리에 취약한 시기로 평가되었다. 본 연구의 결과는 지하수자원 관리 취약 지역과 취약 시기 평가 기법 및 결과를 제공함으로써 행정구역 별 보다 효율적인 지하수자원 관리 방안 도출에 기여할 것으로 기대된다.

목초 및 사료작물 정부장려품종의 지역적응성 평가 I. 연맥품종의 사초수량 및 사료가치 (Evaluaton of the Government Recommended Forage Cultivars in Korea I. Forage performance and quality of oat cultivars)

  • 김동암;전우복;신정남;권찬호;한건준;금종성;임상훈
    • 한국초지조사료학회지
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    • 제17권2호
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    • pp.101-109
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    • 1997
  • Nine oat(Avena sativa L.) cultivars have been recommended as the govemment recommended forage cultivars since 1984, however, their forage performance and quality have mostly been tested at two locations, such as Suweon in the Middle Northwestem Coast Region and Sunghwan in the Middle Southwestern Coast Region. Therefore, the objective of this experiment was to retest the forage performance and quality of six government recommended oat cultivars at five scattered locations, such as Icheon, Suweon, Sunghwan, Keongsan and Kwangju fom 1992 to 1994 with the intention of improving recommendations to dairy farmers. Among the oat cultivars tested, "West" was the highest yielding cultivar at all locations in 1992-94, but the lowest yielding cultivars varied by location and year. At both Icheon and Suweon, "Cayuse", "Magnum" and "Foothill", at Sunghwan, "Cayuse" , "Ensiler" and "Foothill", at Keongsan, "Magnum", "Cayuse" and "Swan", and at Kwangju, "Cayuse", "Magnum" and "Cayuse", were the lowest yielding cultivars in 1993, 1994 and 1995, respectively. At all locations in 1992-94, "West" and "Swan" were the most advanced in growth stage, but "Cayuse", "Foothill", "Magnum" and "Ensiler" were the latest developing cultivars among the oats. Differences among the oat cultivars for the three-year mean NDF, ADF and IVDMD were small and inconsistent, but forage quality of the oats was generally lowest in the early developing cultivars and highest in the late developing cultivars. The govemment recommended oat cultivars tested were generally well adapted across the country, however, in forage production situations in the fall where high yield is more important, early maturing oat cultivars might be preferable to late cultivars because they have higher forage yield earlier in the fall.ction situations in the fall where high yield is more important, early maturing oat cultivars might be preferable to late cultivars because they have higher forage yield earlier in the fall.

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영동대설 사례와 관련된 동해상의 현열속과 잠열속 분포 특성 (Characteristics of Sensible Heat and Latent Heat Fluxes over the East Sea Related with Yeongdong Heavy Snowfall Events)

  • 김지언;권태영;이방용
    • Ocean and Polar Research
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    • 제27권3호
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    • pp.237-250
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    • 2005
  • To investigate the air mass modification related with Yeongdong Heavy snowfall events, we examined sensible and latent heat fluxes on the East Sea, the energy exchange between atmosphere and ocean in this study. Sensible and latent heats were calculated by a bulk aerodynamic method, in which NCEP/NCAR reanalysis data and NOAA/AVHRR weekly SST data with high resolution were used. Among winter precipitation events in the Yeongdong region, 19 heavy precipitation events $(1995{\sim}2001)$ were selected and classified into three types (mountain, cold-coastal, and warm types). Mountain-type precipitation shows highly positive anomalies of sensible and latent heats over the southwestern part of the East Set When separating them into the two components due to variability of wind and temperature/ specific Humidity, it is shown that the wind components are dominant. Cold-coastal-type precipitation also shows strong positive anomalies of sensible and latent heats over the northern part and over the central-northern part of the East Sea, respectively. It is shown that the sensible heat anomalies are caused mostly by the decrease of surface air temperature. So it can be explained that cold-coastal-type precipitation is closely related with the air mass modification due to cold air advection over warm ocean surface. But in warm-type precipitation, negative anomalies are found in the sensible and latent heat distributions. From this result, it may be postulated that warm-type precipitation is affected by the internal process of the atmosphere rather than the atmosphere-ocean interaction.

조석-해일 비선형성과 관련된 태풍-해일 특성 (Typhoon-surge Characteristics in Relation with the Tide-surge Interaction)

  • 강주환
    • 한국해안·해양공학회논문집
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    • 제27권1호
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    • pp.25-37
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    • 2015
  • 태풍발생시기의 조석-해일 비선형 특성을 분석하였다. Chi-square test를 통한 정량적 해석결과 목포를 비롯한 서남해안 지역에서 비선형성이 가장 우세하였고 서해안과 남동해안에서는 뚜렷하게 나타나지는 않고 있다. 태풍-해일 발생패턴을 첨두형과 지속형으로 구분하여 해석하였는데 조석-해일 비선형성은 지속형에서 다소 높게 나타나는 것으로 확인되고 있다. 서해안의 경우 저조시 해일발생빈도가 높지 않게 나타나는 이유는 남해안경로 태풍에 의한 음해일 발생이 많은 것과 무관치 않은 것으로 보인다. 그러나 서해안경로 태풍에 대해서는 태풍통과 이후 저조시에 최대해일고가 발생하는 조석-해일 비선형효과가 두드러지게 나타나고 있다. 남동해안의 경우에는 첨두형 태풍이 잦아 비선형효과에 의한 저조시 해일발생빈도가 낮은 것으로 분석되고 있다. 이에 따라 남해안경로 태풍의 경우 통과인근지역에서는 고조시에도 대규모 해일발생이 가능하므로 태풍-해일에 의한 범람 위험도가 매우 높은 것으로 판단된다.

동해지역 NOAA/AVHRR 고해상도 주평균 해수면 온도의 통계적 분석 : 지역적 변동성과 엘니뇨/남방진동과의 관계성 (Statistical Analysis of NOAA/AVHRR High Resolution Weekly SST in the East Sea: Regional Variability and Relationships with ENSO)

  • 권태영;이방용;이정순
    • Ocean and Polar Research
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    • 제23권4호
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    • pp.361-376
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    • 2001
  • The characteristics of SST variability in the East Sea are analyzed using NOAA/AVHRR weekly SST data with about $0.18^{\circ}{\times}0.18^{\circ}$ resolution ($1981{\sim}2000$) and reconstructed historical monthly SST data with $2^{\circ}{\times}2^{\circ}$ resolution $(1950{\sim}1998)$. The distinct feature of wintertime SST is high variability in the western and eastern parts of $38^{\circ}{\sim}40^{\circ}$ latitudinal band, which are the northern boundary of warm current in the East Sea during winter. However, summertime SST exhibits variability with similar magnitude in the entire region of the East Sea. The analysis of remote correlation also shows that SST in the East Sea is closely correlated with that in the region of Kuroshio in winter, but in summer is related with that in the western and eastern regions of the same latitudes. From these results it is postulated that the SST variability in the East Sea may be related with the variations of East Korean Warm Current and Tsushima Warm Current in winter, but in summer probably with the variations of atmospheric components. In the analysis of ENSO related SST anomaly, a significant negative correlation between SST anomalies in the East Sea and SST anomalies in the tropical Pacific is found in the months of August-October (ASO). The SST in the ASO period shows more significant cooling in E1 $Ni\~{n}o$ events than warming in La $Ni\~{n}a$ events. Also, the regional analysis shows by the Student's t-test that the negative SST anomalies in the E1 $Ni\~{n}o$ events are more significant in the southwestern part of the East Sea.

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목포-해남 연안 조간대 퇴적물중 유기물 및 미량금속 분포 특성 (Distributions of Organic Matter and Trace Metals in Intertidal Surface Sediment from the Mokpo-Haenam Coast)

  • 황동운;김평중;정래홍;윤상필
    • 한국수산과학회지
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    • 제46권4호
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    • pp.454-466
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    • 2013
  • To evaluate the organic matter and trace metal pollution in intertidal sediment of the coastal zone, various geochemical parameters (grain size, ignition loss [IL], chemical oxygen demand [COD], acid volatile sulfide [AVS], and metals [Al, Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As]) were measured for the intertidal surface sediment of the mainland and islands between Mokpo and Haenam in the southwestern coast of Korea. The surface sediments consist mainly of finer sediments, such as mud and silt. The concentrations of IL, COD, and trace metals in intertidal sediment were relatively high in the shoreline of the mainland than in that of islands and those in some stations exceeded the sediment quality guidelines (SQGs). Moreover, the concentrations of IL, COD, and trace metals (except As) in sediment showed relatively good positive correlations with mean grain size, indicating that the concentrations of organic matter and trace metals in intertidal sediment of the study region are dependent on grain size of sediment. Pollution evaluation for trace metals using geochemical assessment techniques, such as enrichment factor, geoaccumulation index, and SQGs, suggested that the intertidal sediments in the study region show light pollution with Cr and moderate pollution with As. More extensive interdisciplinary studies are required to determine the potential causes of As pollution in intertidal sediment.

주성분분석에 의한 거금수도의 수질환경 및 식물플랑크톤 변동 요인 해석 (The analysis of variational characteristics on water quality and phytoplankton by principal component analysis(PCA) in Kogum-sudo, Southwestern part of Korea)

  • 윤양호;박종식
    • 한국환경과학회지
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    • 제9권1호
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    • pp.1-11
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    • 2000
  • A study on the variational characteristics of water quality and phytoplankton biomass by principal component analysis(PCA) was carried out in Kogum-sudo from February to October in 1993. We analyzed PCA on biological factors such as chlorophyll a and phytoplankton cell numbers for centric and pennate diatoms, phytoflagellates, and total phytoplankton as well as physico-chemical factors as water temperature, salinity, transparency, dissolved oxygen(DO), saturation of DO, apparent oxygen utilization (AOU), chemical oxygen demand(COD), nutrient (ammonia, nitrite, nitrate, phosphate and silicate), N/P ratio and suspended solid(SS). The source of nutrients supply depended on the mineralization of organic matters and inputs of seawater from outside rather than runoff of freshwater. The phytoplankton biomass was changed within short interval period by nutrients change. And it was controlled by the combination of several environmental factors, especially of light intensity, ammonia and phosphate. The marine environmental characteristics were determined by the mineralization of organic matters in winter, by runoff of freshwater including high nutrients concentration in spring, by ammonia uptake and high phytoplankton productivity in summer, and phosphate supplied input seawater from outside of Kogeum-sudo in autumn. And Kogum-sudo was separated with 2 regions by score distributions of PCA. That is to say, one region was middle parts of straits which was characterized by the mixing seawater and the accumulated organic matters, other one region was Pungnam Bay and the water around Kogum Island which was done by high phytoplankyon biomass and productivity year-round.

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한국 장수도(長壽度) 변화의 공간적 특성 (Spatial Characteristics of Longevity Degree in Korea)

  • 박삼옥;정은진;송경언
    • 한국지역지리학회지
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    • 제11권2호
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    • pp.187-210
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    • 2005
  • 본 연구의 목적은 빠른 속도로 고령화과정을 겪고 있는 한국의 장수 현상 및 장수지역의 공간적 특성을 파악하는 것이다. 이를 위해 1966년부터 2000년까지의 인구 자료를 이용하여 각 지역의 고령화 현상과 장수도 변화를 파악하였다. 또한 장수의 지역요인을 알아보기 위해 자연환경 및 대도시에 이르는 거리와의 관련성을 분석하였다. 연구 결과 첫째, 호남권 농어촌지역이 전국에서 가장 높은 고령화 수준을 나타내고 있었다. 둘째, 70년대 남부지역 섬과 해안을 중심으로 높은 장수도를 나타내던 것이 최근 내륙의 소백산맥 산간지역으로 이동 확장되어 장수지역의 공간적 확산이 이루어졌다. 셋째, 지역환경요인 분석 결과 기온보다는 강수량과 평균표고가 장수도와 관련성이 높은 것으로 나타났다. 넷째, 대도시의 경우 자연환경요인이 아닌 다른 사회 경제적 요인들 중에서 장수도 인자를 찾아야 함을 시사하는 결과를 얻었다.

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