월단위 토양유실가능성 추정을 위한 ArcGIS 기반의 모형 개발

유나영,이동준,한정호,임경재,김종건,김기형,김소연,김은석,박윤식,Yu, Na Young,Lee, Dong June,Han, Jeong Ho,Lim, Kyoung Jae,Kim, Jonggun,Kim, Ki Hyoung,Kim, Soyeon,Kim, Eun Seok,Park, Youn Shik 한국농공학회 2017 한국농공학회논문집 Vol.59 No.1

Soil erosion has been issued in many countries since it causes negative impacts on ecosystem at the receiving water bodies. Therefore best management practices to resolve the problem in a watershed have been developed and implemented. As a prior process, there is a need to define soil erosion level and to identify the area of concern regarding soil erosion so that the practices are effective as they are designed. Universal Soil Loss Equation (USLE) were developed to estimate potential soil erosion and many Geographic Information System (GIS) models employ USLE to estimate soil erosion. Sediment Assessment Tool for Effective Erosion Control (SATEEC) is one of the models, the model provided several opportunities to consider various watershed peculiarities such as breaking of slope length, monthly variation of rainfall, crop growth at agricultural fields, etc. SATEEC is useful to estimate soil erosion, however the model can be implemented with ArcView software that is no longer used or hard to use currently. Therefore SATEEC based on ArcView was rebuild for the ArcGIS software with all modules provided at the previous version. The rebuilt SATEEC, ArcSATEEC, was programmed in ArcPy and works as ArcGIS Toolset and allows considering monthly variations of rainfall and crop growth at any watershed in South-Korea. ArcSATEEC was applied in Daecheong-dam watershed in this study, monthly soil erosion was estimated with monthly rainfall and crop growth variation. Annual soil erosion was computed by summing monthly soil erosion and was compared to the conventional approach to estimate annual soil erosion. The annual soil erosion estimated by the conventional approach and by summing monthly approach did not display much differences, however, ArcSATEEC was capable to provide monthly variation of soil erosion.

A Study on Efficient Management Strategy for Soil Erosion

황정배,김남찬,임창인,강윤민 한국토양비료학회 2018 한국토양비료학회지 Vol.51 No.4

Soil value was estimated 26 trillion Korean won and recent climate change due to global warming is highly affecting soil erosion. Especially, about 10% of surface soil was annually eroded because of massive construction in Korea. Main purpose of this research was i) to investigate occurrence, mechanism, affecting parameters of soil erosion especially focused on wind erosion and ii) to conduct wind tunnel experiment for evaluating feasibility of dry fog system in stabilizing wind erosion. Result of wind tunnel experiment showed that wind erosion could be reduced about 22-38% after applying dry fog system. Two parameters, soil particle size and spreaded water drop size, are main parameters to affect efficiency of wind erosion stabilization and smaller water drop size is more effective to prevent wind erosion than soil particle size. In terms of wind erosion management, evaluation of soil erosion should be conducted for environmental impact assessment (EIA) when land usage is changed or massive construction was conducted. Since there is no evaluation form of soil erosion in EIA, not only soil erosion but also wind erosion evaluation should be included in the EIA. In addition, transaction of soil and rock open portal recycle system (TOCYCLE) could be utilized to recycle surface soil and consequently, prevent wind erosion and conserve value of soil. Overall, dry fog system is an effective technique for wind erosion preventing system and it could be combined with natural and/or artificial soil conservation system to enhance wind erosion prevention. Furthermore, policy and management system for preventing soil erosion should be thoroughly reviewed to make better soil conservation.

SATEEC 시스템을 이용한 객토 토양의 토성고려에 따른 도암댐 유역의 토양유실 및 유사량 분석

유동선 ( Dongsun Yoo ),안재훈 ( Jaehun Ahn ),윤정숙 ( Jongsuk Yoon ),허성구 ( Sunggu Heo ),박윤식 ( Younshik Park ),김종건 ( Jonggun Kim ),임경재 ( Kyoung Jae Lim ),김기성 ( Ki-sung Kim ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

There have been serious soil erosion and water pollution problems caused by highland agriculture practices at Doam-dam watershed. Especially agricultural activities, chemical and organic fertilizer and pesticide applications, soil reconditioning to maintain soil fertility are known as primary causes of soil erosion and water qaulity degradation in the receiving water bodies. Among these, soil reconditioning can accelerate soil erosion rates. To develop soil erosion prevention practices, it is necessary to first estimate the soil erosion from the watershed. Thus, the Universal Soil Loss Equation (USLE) model has been developed and utilized to assess soil erosion. However, the USLE model cannot be used at watershed scale because it does not consider sediment delivery ratio (SDR) for watershed application. For this reason, the Sediment Assessment Tool for Effective Erosion Control (SATEEC) was developed to assess the sediment yield at any point in the watershed. The USLE-based SATEEC system can estimate the SDR using area-based SDR and slope-based SDR module. In this study, the SATEEC system was used to estimate soil erosion and sediment yield at the Doam-dam watershed using the soil properties from reconditioned agricultural fields. Based on the soil sampling and analysis, the USLE K factor was calculated and used in the SATEEC system to analyze the possible errors of previous USLE application studies using soil properties from the digital soil map, compared with that using soil properties obtained in this study. The estimated soil erosion at the Doam-dam watershed without using soil properties obtained in the soil sampling and analysis is 1,791,400 ton/year (123 ton/ha/year), while the soil erosion amounts is 2,429,900 ton/year (166.8 ton/ha/year) with the use of soil properties from the soil sampling and analysis. There is 35% increases in estimated soil erosion and sediment yield with the use of soil properties from soil reconditioned agricultural fields. Since significant amounts of soil erosion are known to be occurring from the agricultural fields, the soil erosion and sediment yield from only agricultural fields was assessed. The soil erosion rate is 45.9 ton/ha/year without considering soil properties from soil reconditioned agricultural fields, while 105.3 ton/ha/year after considering soil properties obtained in this study, increased in 129%. This study shows it is very important to use correct soil properties to assess soil erosion and sediment yield simulation. It is recommended that further studies are needed to develop environment friendly soil reconditioning method should be developed and implemented to decrease the speed of soil erosion rates and water quality degradation.

토양침식모형의 국내 적용가능성 평가

심우진(Woo Jin Shim),박수진(Soo Jin Park) 대한지리학회 2018 대한지리학회지 Vol.53 No.1

우리나라는 높은 산지 비율과 인구밀도, 여름철 집중호우로 인한 토양침식의 위험성이 높다. 토양침식은 토지의 지속가능성을 저해하는 주요 요소로, 최근에는 토양침식 추정 모형이 광범위하게 활용되고 있다. 그러나 모형은 반영하는 변수에 따라 추정 결과의 차이가 크기 때문에 실제 발생하는 침식량을 산정하는 것으로 보기 어렵다. 특히 대부분의 모형이 단기적인 환경변수들을 활용하기 때문에, 장기간에 걸쳐서 나타나는 침식량의 추정에 한계가 있는 것으로 보고되고 있다. 본 연구에서는 <SUP>137</SUP>Cs 기법을 이용하여 연구지역의 1960년대 이후 평균 침식량을 살펴본 후 국내 토양침식 연구에서 가장 많이 활용되는 RUSLE(Revised Universal Soil Loss Equation)와 매개변수를 공유하는 USPED(Unit Stream Power-based Erosion Deposition) 두 모형과 비교하여 토양침식 모형의 국내 적용가능성을 평가하였다. <SUP>137</SUP>Cs기법을 통한 침식량 분석 결과, 연구지역은 1960년대 중반 이후 평균 28.97ton/ha의 침식이 발생하고 있는 것으로 나타났다. 이를 토지 이용 별로 살펴보면 경작지의 침식량은 67.58ton/ha/yr, 산지는 0.02ton/ha/yr으로 분석되었다. RUSLE모형과 USPED모형이 추정한 연구 지역의 연 평균 침식량은 각각 21.28ton/ha, 12.82ton/ha로 약 2배의 격차가 나타난다. <SUP>137</SUP>Cs기법을 기준으로 두 모형의 침식추정량을 비교한 결과, RUSLE의 연 평균 침식량은 0.73배, USPED는 0.43배 더 낮게 추정했다. 침식의 공간적 분포형태는 RUSLE가 실제 발생하는 침식 및 퇴적의 분포 형태를 USPED에 비해 더 잘 추정했다. 그러나 두 모형 모두 산지에서 보다 경작지의 침식량이 월등히 높은 현실에 맞지 않게, 경작지의 침식 추정량을 산지보다 부정확하게 추정했다. 이는 토양 침식 추정 모형이 국내의 집약적인 토지이용과 중단기 기간의 침식 현상을 종합적으로 반영하지 못하고 있다는 결과이다. 국내 상황에 맞는 변수 개발 및 모형 보정 등의 보완 과정이 선행되어야 하고 토양침식 연구에 모형의 적용과 해석에 비판적인 시각이 필요할 것이다. In the case of South Korea, there is a high risk of soil erosion caused by torrential rains of summer, high mountain rate, and population density. There are several ways to study soil erosion. Recently, soil erosion estimation model is most commonly used to study. However, the results of the soil erosion model are predicted value, not observed one. In particular, since most of the models utilize short-term environmental variables, it is reported that there is a limit to the estimation of erosion amount over a long period of time. Therefore, in this study, the <SUP>137</SUP>Cs method is used calculating a soil erosion and spatial distribution to identify the soil erosion estimation model that suits domestic condition, and compared with the soil erosion estimation models applied by RUSLE and USPED. The result of this study is summarized as follows. First of all, the annual average of soil erosion amount is 28.97ton/ha in the study area, Since each type of land use, the cultivated area has the annual 67.58ton/ha, forest area occurred 0.02ton/ha of soil erosion amount. Secondly, the average annual soil erosion amount of the study area estimated by RUSLE model and the USPED model resulted as 21.28ton/ha and 12.82ton/ha, respectively. RUSLE model estimated adequately in soil erosion amount and the spatial distribution patterns than USPED model. However, both models estimated incorrectly in the erosion of cultivated land. This result shows that the soil erosion estimation model does not fully reflect the intensive land use in Korea and the medium- and short-term soil erosion. Therefore, development of variables and calibration of models that are appropriate to the domestic situation would be necessary, and a critical view on applying and interpreting models in soil erosion research would be needed.

효율적 표토 관리를 위한 표토침식지표 연구

정영훈 ( Younghun Jung ),금동혁 ( Donghyuk Kum ),한정호 ( Jeongho Han ),장춘화 ( Chunhwa Jang ),양재의 ( Jaye Yang ),임경재 ( Kyoungjae Lim ),김기성 ( Kisung Kim ) 한국물환경학회 2015 한국물환경학회지 Vol.31 No.5

The existing standard for soil erosion risk assessment has limitations in sustainable topsoil management since the fixed criteria are applied to determination of soil erosion risk areas regardless of land use types. It may not be necessary to apply soil erosion best management practices to agricultural areas with high potential of soil erosion because human or economic damage derived from soil erosion might be tiny in that region. Furthermore, the fixed criterion with absolute values can select too many hot spots of soil erosion to conduct efficient soil erosion management. Thus, objective of this study was to suggest the relative criteria using statistical analysis for efficient soil erosion management. In future, the relative indices for soil erosion prevention should be improved to provide a priority of soil erosion management considering economic damage from soil erosion or functional values of soil with quantitative soil erosion. Additional researches will be needed to reflect a regional characteristics and to consider various land use types and different criteria.

표토유실 보전을 통한 온실가스배출 저감과 수자원 보전 기능의 산출 및 정책제안

오승민,김혁수,이상필,이종건,정석순,임경재,김성철,박윤식,이기하,황상일,양재의 한국지하수토양환경학회 2017 지하수토양환경 Vol.22 No.6

Soil erosion is often extreme in Korea due to high rainfall intensities and steep slopes, and climate change has also increased the risk of erosion. Despite its significane, erosion-induced soil organic carbon (SOC) emission and water resource loss are not well understood, along with the lack of an integrated surface soil erosion protection policy. Therefore, to design adequate protection policies, land users, scientists, engineers and decision makers need proper information about surface soil and watershed properties related to greenhouse gas emission potential and water conservation capability, respectively. Assuming the total soil erosion of 346 Tg yr−1, soil organic matter (SOM) content of 2% (58% of SOM is SOC), and mineralization rate of 20% of the displaced carbon, erosion-induced carbon emission could reach 800 Gg C yr−1. Also the available water capacity of the soil was estimated to be 15.8 billion tons, which was 14 times higher than the yearly water supply demand in Seoul, Korea. Therefore, in order to prevent of soil erosion, this study proposes a threestage plan for surface soil erosion prevention: 1) classification of soil erosion risk and scoring of surface soil quality, 2) selection of priority areas for conservation and best management practices (BMP), and 3) application of BMP and post management.

Study on Soil Erosion and Physical Characteristics of Jeju Volcanic Ash Soils Under a Rainfall Simulator Condition

Won-Pyo Park,Ho-Jun Kang 한국토양비료학회 2019 한국토양비료학회지 Vol.52 No.1

The objective of this study is to determine the effects of physical properties of soils on soil erosion under a rainfall simulator. The soil samples were collected from five sites of dark brown soil (DBS), six sites of very dark brown volcanic ash soil (VDBAS), and eight sites of black volcanic ash soil (BVAS) in Jeju Island. The rainfall simulator, which ran for 30 minutes at a slope gradient of 10%, determined the amounts of soil erosion, infiltrated water, and runoff water. The particle size distribution, water-stable aggregates distribution, bulk density, organic matter content, and saturated hydraulic conductivity in soils were analyzed as well. The amounts of soil erosion gradually increased and reached a steady state after 20 minutes. The amounts of soil erosion in BVAS were higher than that in other soils. It also correlated positively with the amounts of runoff water and related negatively to the amounts of infiltrated water. The amounts of soil erosion in DBS and BVAS had a significant negative correlation with some particle size fractions and saturated hydraulic conductivity (p < 0.05). A significant positive correlation was observed between the amounts of soil erosion and the water-stable aggregates with the size smaller than 1 mm in DBS and VDVAS (p < 0.05). The bulk density and organic matter content did not significantly affect the amount of soil erosion. These results concluded that the physical properties of soils affecting the amount of soil erosion varied among the color of soils in Jeju Island. It is suggested that the values of soil erodibility factor for the volcanic ash soils of Jeju Island need to be estimated with an alternative algorithm to predict the amount of soil erosion.

SWAT과 SATEEC 모형을 이용한 토양유실량 비교

박윤식,김종건,허성구,김남원,안재훈,박준호,김기성,임경재,Park, Youn-Shik,Kim, Jong-Gun,Heo, Sung-Gu,Kim, Nam-Won,Ahn, Jae-Hun,Park, Joon-Ho,Kim, Ki-Sung,Lim, Kyung-Jae 한국농공학회 2008 한국농공학회논문집 Vol.50 No.1

Soil erosion is a natural process and has been occurring in most areas in the watershed. However, accelerated soil erosion rates have been causing numerous environmental impacts in recent years. To reduce soil erosion and sediment inflow into the water bodies, site-specific soil erosion best management practices(BMPs) need to be established and implemented. The most commonly used soil erosion model is the Universal Soil Loss Equation(USLE), which have been used in many countries over 30 years. The Sediment Assessment Tool for Effective Erosion Control(SATEEC) ArcView GIS system has been developed and enhanced to estimate the soil erosion and sediment yield trom the watershed using the USLE input data. In the last decade, the Soil and Water Assessment Tool(SWAT) model also has been widely used to estimate soil erosion and sediment yield at a watershed scale. The SATEEC system estimates the LS factor using the equation suggested by Moore and Burch, while the SWAT model estimates the LS factor based on the relationship between sub watershed average slope and slope length. Thus the SATEEC and SWAT estimated soil erosion values were compared in this study. The differences in LS factor estimation methods in the SATEEC and SWAT caused significant difference in estimated soil erosion. In this study, the difference was -51.9%(default threshold)${\sim}-54.5%$(min. threshold) between SATEEC and non-patched SWAT, and -7.8%(default threshold)${\sim}+3.8%$(min. threshold) between SATEEC and patched SWAT estimated soil erosion.

SWAT과 SATEEC 모형을 이용한 토양유실량 비교

박윤식 ( Park Younshik ),김종건 ( Kim Jonggun ),신용철 ( Shin Yongchul ),안재훈 ( Ahn Jaehun ),박준호 ( Park Joonho ),김기성 ( Kim Ki-sung ),임경재 ( Lim Kyung Jae ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

Soil erosion is a natural process and has been occurring in most areas in the watershed. However, accelerated soil erosion rates have been causing numerous environmental impacts in recent years. To reduce soil erosion and sediment inflow into the water bodies, site-specific soil erosion best management practices (BMPs) need to be established and implemented. The most commonly used soil erosion model is the Universal Soil Loss Equation (USLE), which have been used in many countries over 30 years. The Sediment Assessment Tool for Effective Erosion Control (SATEEC) ArcView GIS system has been developed and enhanced to estimate the soil erosion and sediment yield from the watershed using the USLE input data. In the last decade, the Soil and Water Assessment Tool (SWAT) model also has been widely used to estimate soil erosion and sediment yield at a watershed scale. The SATEEC system estimates the LS factor using the equation suggested by Moore and Burch, while the SWAT model estimates the LS factor based on the relationship between sub watershed average slope and slope length. Thus the SATEEC and SWAT estimated soil erosion values were compared in this study. The differences in LS factor estimation methods in the SATEEC and SWAT caused significant difference in estimated soil erosion. In this study, the difference was -51.9%(default threshold)~-54.5%(min. threshold) between SATEEC and non-patched SWAT, and -7.8%(default threshold)~+3.8%(min. threshold) between SATEEC and patched SWAT estimated soil erosion.

고랭지 농업의 작물별 객토량 변화에 따른 토양유실 저감 분석

허성구 ( Sung Gu Heo ),전만식 ( Man Sig Jun ),박상헌 ( Sang Hun Park ),김기성 ( Ki Sung Kim ),강성근 ( Sung Keun Kang ),옥용식 ( Yong Sik Ok ),임경재 ( Kyoung Jae Lim ) 한국물환경학회 2008 한국물환경학회지 Vol.24 No.2

There is increased soil erosion potential at highland agricultural crop fields because of its topographic characteristics and site-specific agricultural management practices performed at these areas. The agricultural upland fields are usually located at the sloping areas, resulting in higher soil loss, pesticides, and nutrients in case of torrential rainfall events or typhoon, such as 2002 Rusa and 2003 MaeMi. At the highland agricultural fields, the soil reconditioning have been performed every year to decrease damage by continuous cropping and pests. Also it has been done to increase crop productivity and soil fertility. The increased amounts of soil used for soil reconditioning are increasing over the years, causing significant impacts on water quality at the receiving water bodies. In this study, the field investigation was done to check soil reconditioning status for potato, carrot, and cabbage at the Doam-dam watershed. With these data obtained from the field investigation, the Soil and Water Assesment Tool (SWAT) model was used to simulate the soil loss reduction with environment-friendly and agronomically enough soil reconditioning. The average soil reconditioning depth for potato was 34.3 cm, 48.3 cm for carrot, and 31.2 cm for cabbage at the Doam-dam watershed. These data were used for SWAT model runs. Before the SWAT simulation, the SWAT ArcView GIS Patch, developed by the Kangwon National University, was applied because of proper simulation of soil erosion and sediment yield at the sloping watershed, such as the Doam-dam watershed. With this patch applied, the Coefficient of Determination (R2) value was 0.85 and the Nash-Sutcliffe Model Efficiency (EI) was 0.75 for flow calibration. The R2 value was 0.87 and the EI was 0.85 for flow validation. For sediment simulation, the R2 value was 0.91 and the EI was 0.70, indicating the SWAT model predicts the soil erosion processes and sediment yield at the Doam-dam watershed. With the calibrated and validated SWAT for the Doam-dam watershed, the soil erosion reduction was investigated for potato, carrot, and cabbage. For potato, around 19.3 cm of soil were over applied to the agricultural field, causing 146% of more soil erosion rate, approximately 33.3 cm, causing 146% of more soil erosion for carrot, and approximately 16.2 cm, causing 44% of more soil erosion. The results obtained in this study showed that excessive soil reconditioning are performed at the highland agricultural fields, causing severe muddy water issues and water quality degradation at the Doam-water watershed. The results can be used to develop soil reconditioning standard policy for various crops at the highland agricultural fields, without causing problems agronomically and environmentally.