• Title/Summary/Keyword: land resources

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Monitoring Land Cover Changes in Nakdong River Basins Using Multi-temporal Landsat Imageries and LiDAR Data (다중시기에 촬영된 Landsat 영상과 LiDAR 자료를 활용한 낙동강 유역의 토지 피복 변화 모니터링)

  • Choung, Yun Jae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.242-242
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    • 2015
  • Monitoring the land cover changes in Nakdong River Basins using the multi-temporal remote sensing datasets is necessary for preserving properties in the river basins and monitoring the environmental changes in the river basins after the 4 major river restoration project. This research aims to monitor the land cover changes using the multi-temporal Landsat imageries and the airborne topographic LiDAR data. Firstly, the river basin boundaries are determined by using the LiDAR data, and the multiple river basin imageries are generated from the multi-temporal Landsat imageries by using the river basin boundaries. Next the classification method is employed to identify the multiple land covers in the generated river basin imageries. Finally, monitoring the land cover changes is implemented by comparing the differences of the same clusters in the multi-temporal river basin imageries.

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The Influence on the Runoff Charateristics by the Land Use in Small Watersheds (II) (소유역의 토지이용이 유출특성에 미치는 영향 (II))

  • Choi, Ye-Hwan;Choi, Joong-Dae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.178-182
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    • 2005
  • In the forthcoming 21C, the development of cultural lives depends on that the water demand will increase or not. On the opposite site of that circumstance, many factors of the small watersheds will influence directly on how to cover the surface of watersheds with land use, no planning developing watersheds, and the rearrangement of small rivers. Especially as the extraordinary climatic Phenomena, exhaust of $CO_2$ and destruction of 03 layer, water resource and water foresting content of the small watersheds will be decreased by confusing on the malting a plan of water resources. For example, those are Typhoon Rusa in 2002, Typhoon Maemi in 2003 and heavy storms in 2004. This study area has three group and one of them having three small watersheds, total five small watersheds. That is, Sabukmyeon small watersheds in Chuncheon, Three small watersheds in Wonju(Jeoncheon, Jupocheon and Hasunamcheon), and Suipcheon in Yanggu-Gun which are located far away each other three group and different precipitation data. According to the land use such as dry field(or farm), rice field, forest land. building site and others in small watersheds, the amount of runoff will be impacted by monthly precipitation. The comparison between the runoff was getting from Kajiyama Formula and calculated runoff from multi-linear regressed equations by land use Percentage was performed with different precipitation data and different small watersheds. Its correlations which are estimated by coefficient of correlation will be accepted or not, as approached 1.0000 values. As the monthly water resources amount is estimated by multi-linear regressed equations with different precipitation data and different small watersheds having no gauging station, we make a plan in order to demand and supply the water quantity from small river watersheds during return periods.

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Temporal variability of Evapotranspiration simulated by different models at the croplands

  • Choi, Min-Ha;Lee, Jin-Woo;Kim, Tae-Woong;Cho, Yong-Sik
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.535-539
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    • 2009
  • Evapotranspiration (ET) is one of the main factor to understand the hydrologic cycle on land surfaces of entire globe. It accounts for about 65% of precipitation returning to the atmosphere. Accurate estimation of the ET is essential to many applications of water resources management, hydrology, meteorology, climatology, and agriculture. Over the past few decades, there have been extensive efforts to develop and validate a number of ET models. Priestley-Taylor (P-T) and Food and Agriculture Organization Penman-Monteith (P-M) models are generally recognized as simple, but great operational approaches to estimate ET over different land cover types. In this study, we compare/validate different models of increasing complexity, P-T, P-M, and Common Land Model (CLM) in croplands, IA.

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Merging technique for evapotranspiration based on in-situ, satellite, and reanalysis data using modifed KGE fusion method (수정된 KGE 방법을 활용한 지점, 인공위성, 재분석 자료 기반 증발산 융합 기술)

  • Baik, Jongjin;Jeong, Jaehwan;Park, Jongmin;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.52 no.1
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    • pp.61-70
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    • 2019
  • The modified Kling-Gupta efficiency fusion method to merge actual evapotranspiration was proposed and compared with the simple Taylor skill's score method using Global Land Data Assimilation System (GLDAS), Global Land Evaporation Amsterdam Model (GLEAM), MODIS Global Evapotranspiration Project (MOD16), and the flux tower on three different land cover types over the Korean peninsula and China. In the results of the weights estimated from two actual evapotranspiration merging techniques (i.e., STS and KGF), the weights of reanalysis data (i.e, GLDAS and GLEAM) in cropland and grassland showed similar performance, while the results of weights are different according to the merging techniques in forest. Both two merging techniques showed better results than original dataset in grassland and forest. However, there were no improvement in cropland compared to the other land cover types. The results of the KGF method slightly improved compared to those of the STS in grassland and forest.

Streamflow sensitivity to land cover changes: Akaki River, Ethiopia

  • Mitiku, Dereje Birhanu;Kim, Hyeon Jun;Jang, Cheol Hee;Park, Sanghyun;Choi, Shin Woo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.49-49
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    • 2016
  • The impact of land cover changes on streamflow of the Akaki catchment will be assessed using Soil and Water Assessment Tool (SWAT) model. The study will analyze the historical land cover changes (1993 to 2016) that have taken place in the catchment and its effect on the streamflow of the study area. Arc GIS will be used to analysis the satellite images obtained from the United States Geological Survey (USGS). To investigate the impact of land cover change on streamflow the model set up will be done using readily available spatial and temporal data, and calibrated against measured discharge. Two third of the data will be used for model calibration (1993?2000) and the remaining one-third for model validation (2001?2004). Model performance will be evaluated by using Nash and Sutcliff efficiency (NS) and coefficient of determination (R2). The calibrated model will be used to assess two land cover change (2002 and 2016) scenarios and its likely impacts of land use changes on the runoff will be quantified. The evaluation of the model response to these changes on streamflow will be presented properly. The study will contribute a lot to understand land use and land cover change on streamflow. This enhances the ability of stakeholder to implement sound policies to minimize undesirable future impacts and management alternatives which have a significant role in future flood control of the study area.

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Critical Factors on Forest Land Management in Vietnam

  • TRAN, Thai Yen;PHAM, Phuong Nam
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.9
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    • pp.167-179
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    • 2022
  • The study aims to determine the influencing factors and their impact on the management of the forest land used for production allotted to peasant households and proposes solutions to improve its management. Secondary data was calculated until the end of 2019 at state agencies. The primary data was collected through 2 steps. To determine the factors influencing forest land management for production, step one involved a survey of 100 households that were given access to forest land. Step 2 involved a survey of 215 households to determine how factors impacted the Likert scale's five levels. The study also used a multivariate regression model and SPSS24.0 software to determine the impact rates of factor groups. The study indicated 43 factors that belong to 11-factor groups affecting the management of forest land for production. The policy and legal factors group is the most influential, with an impact rate of 12.72%, followed by 10 other factor groups with impact rates ranging from 4.08% to 11.74%. The solutions include improving policies and laws, strengthening the dissemination of policies and laws; encouraging investment, completing cadastral work, intensifying inspection, examination, and sanctioning of administrative violations of land, upgrading the infrastructure system, and ensuring enough human resources to manage forest land.

Analyzing the Future Land Use Change and its Effects for the Region of Yangpyeong-gun and Yeoju-gun in Korea with the Dyna-CLUE Model (Dyna-CLUE 모델을 이용한 양평·여주 지역의 토지이용 변화 예측 및 평가)

  • Lee, DongKun;Ryu, DaeHo;Kim, HoGul;Lee, SangHouck
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.6
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    • pp.119-130
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    • 2011
  • Land-use changes have made considerable impacts on humans and nature such as biodiversity and ecosystem services. It is recognized as important elements for land use planning and regional natural resources conservation to identify the major causes of land use changes and to predict a process of changes and effects. This study, by using a spatially explicit Dyna-CLUE model, analyzed correlations between driving factors, quantified location characteristics of different land use types using logistic regression analysis and examined future land use changes and its effects in Yangpyeong and Yeoju region. We expected land use changes based on the three scenarios with different future land demands and simulated future changes for spatial variations of land use for the 20 years. The outcomes shows that larger change was found in agricultural areas than forest areas, based on the change in built-up areas. The changes in forest areas, which were mainly occurred in edge area, were expected to affect a large impact on its ecotone. It was found to be the importance of the management of forest edge and the necessity of the environmentally sound and sustainable development in order to conserve natural resources of the region.

Farm Mechanization on Slope Lands (경사지(傾斜地) 농업(農業)의 기계화(機械化))

  • Kim, Kyeong Uk
    • Journal of Biosystems Engineering
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    • v.12 no.3
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    • pp.62-72
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    • 1987
  • The necessity of using land on slopes for agricultural production has been recognized all arable land resources in plains are decreased. Mechanization is one of the main factors determining the extent of cultivating slope lands and it must be considered as a means of increasing labor productivity. This article discussed some relevent aspects of farm mechanization on slopes. It includes the potential slope land resources which can be tilled for food and forage productions, design characteristics of agricultural machines for use in slope lands, and possible solutions of the problems to be encountered in the mechanization process.

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