• Title/Summary/Keyword: Rural watersheds

Search Result 97, Processing Time 0.029 seconds

Applications of AGNPS model with rural watersheds having complex land use characteristics (복합 토지이용 특성의 농촌유역에 대한 농업비점원오염모형의 적용)

  • 조재필;박승우;강문성
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 1998.10a
    • /
    • pp.353-358
    • /
    • 1998
  • GRASS-AGNPS model integrated with GIS was applied to rural watersheds having complex land use characteristics and evaluated for its applicability through calibration using observed data. The analyses of raster encoding accuracy and model behavior to runoff, sediment yields and nutrient loads for different cell-size showed that 150 m cell size indicated reasonable applicability of the model. Simulated runoff was in a good agreement with the observed data and simulated peak runoff rate was larger than the observed data. The sediment yield simulated by modified AGNPS model using irregular cell for forest area were less than that of the regular cell method. In predicting sediment yields, the result showed a different trend at each representative rural watershed. Nutrient loads simulated by the model were significantly different from the observed data.

  • PDF

Conjunctive Use of SWAT and WASP Models for the Water Quality Prediction in a Rural Watershed (농촌유역 하천의 수질예측을 위한 SWAT모형과 WASP모형의 연계운영)

  • 권명준;권순국;홍성구
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.45 no.2
    • /
    • pp.116-125
    • /
    • 2003
  • Predictions of stream water quality require both estimation of pollutant loading from different sources and simulation of water quality processes in the stream. Nonpoint source pollution models are often employed for estimating pollutant loading in rural watersheds. In this study, a conjunctive application of SWAT model and WASP model was made and evaluated for its applicability based on the simulation results. Runoff and nutrient loading obtained from the SWAT model were used for generating input data for WASP model. The results showed that the simulated runoff was in good agreement with the observed data and indicated reasonable applicability. Loading for the water quality parameters predicted by WASP model also showed a reasonable agreement with the observed data. It is expected that stream water quality could be predicted by the coupled application of the two models, SWAT and WASP, in rural watersheds.

An Integrated Flood Simulation System for Upstream and Downstream of the Agricultural Reservoir Watershed (농촌 유역 저수지 상·하류 통합 홍수 모의 시스템 구축 및 적용)

  • Kwak, Jihye;Kim, Jihye;Lee, Hyunji;Lee, Junhyuk;Cho, Jaepil;Kang, Moon Seong
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.65 no.1
    • /
    • pp.41-49
    • /
    • 2023
  • To utilize the hydraulic and hydrological models when simulating floods in agricultural watersheds, it is necessary to consider agricultural reservoirs, farmland, and farmland drainage system, which are characteristics of agricultural watersheds. However, most of them are developed individually by different researchers, also, each model has a different simulation scope, so it is hard to use them integrally. As a result, there is a need to link each hydraulic and hydrological model. Therefore, this study established an integrated flood simulation system for the comprehensive flood simulation of agricultural reservoir watersheds. The system can be applied easily to various watersheds because historical weather data and the SSP (Shared Socio-economic Pathways) climate change scenario database of ninety weather stations were built-in. Individual hydraulic and hydrological models were coded and coupled through Python. The system consists of multiplicative random cascade model, Clark unit hydrograph model, frequency analysis model, HEC-5 (Hydrologic Engineering Center-5), HEC-RAS (Hydrologic Engineering Center-River Analysis System), and farmland drainage simulation model. In the case of external models with limitations in conceptualization, such as HEC-5 and HEC-RAS, the python interpreter approaches the operating system and gives commands to run the models. All models except two are built based on the logical concept.

Comparison of Discharge Characteristics of NPS Pollutant Loads from Urban, Agricultural and Forestry Watersheds (도시, 농촌 및 임야유역으로부터 배출되는 비점원 오염부하의 특성비교)

  • Yur, Joonghyun;Kim, Geonha
    • Journal of Korean Society on Water Environment
    • /
    • v.21 no.2
    • /
    • pp.184-189
    • /
    • 2005
  • Impacts of non-point source pollution on water quality are well known. In this paper, effects of land use, precipitation characteristics, discharge characteristics on non-point source pollutant loadings at urban, agricultural and forestry watersheds were discussed. Rainfall runoffs from fifteen rainfall events were sampled and analysed at two urban watersheds, one rural watershed, and one forestry watershed. EMCs (Event Mean Concentration) were calculated based on monitored flow rates and concentrations. Statistical analysis carried out with runoff loadings and affecting variables indicated that runoff loadings are weakly correlated with the rainfall intensity and the dry days before rainfall events while showed no correlations with rainfall depth nor runoff quantity. By comparing EMCs between study watersheds on log-normal cumulative probability scale, EMCs ranking were in the descending order of urban watershed>agricultural watershed>forestry watershed for SS, TCOD, TN, and TP.

Hydrologic Modeling for Agricultural Reservoir Watersheds Using the COMFARM (COMFARM을 이용한 농업용저수지 유역 수문 모델링)

  • Song, Jung-Hun;Park, Jihoon;Kim, Kyeung;Ryu, Jeong Hoon;Jun, Sang Min;Kim, Jin-Taek;Jang, Taeil;Song, Inhong;Kang, Moon Seong
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.58 no.3
    • /
    • pp.71-80
    • /
    • 2016
  • The component-based modeling framework for agricultural water-resources management (COMFARM) is a user-friendly, highly interoperable, lightweight modeling framework that supports the development of watershed-specific domain components. The objective of this study was to evaluate the suitability of the COMFARM for the design and creation of a component-based modeling system of agricultural reservoir watersheds. A case study that focused on a particular modeling system was conducted on a watershed that includes the Daehwa and Dangwol serial irrigation reservoirs. The hydrologic modeling system for the study area was constructed with linkable components, including the modified Tank, an agricultural water supply and drainage model, and a reservoir water balance model. The model parameters were each calibrated for two years, based on observed reservoir water levels. The simulated results were in good agreement with the observed data. In addition, the applicability of the COMFARM was evaluated for regions where reservoir outflows, including not only spillway release but also return flow by irrigation water supply, substantially affect the downstream river discharge. The COMFARM could help to develop effective water-management measures by allowing the construction of a modeling system and evaluation of multiple operational scenarios customized for a specific watershed.

Application of RUSLE to Estimate Annual Soil Loss from Small Agricultural Watersheds (농업 소유역의 토양유실량 예측을 위한 RUSLE의 적용)

  • 최중대;양재의;최병용;최경진
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 1999.10c
    • /
    • pp.771-776
    • /
    • 1999
  • RUSLE was applied to estimate annual soil loss from two small agricultural watersheds in Kangwon-do, Korea. GIS input parameters were prepared by using DEMs and soil maps prepared by the NGIS project and Rural Development Adminstration, respoctively. RUSLE parameters were prepared based on existing data and equations. Estimated annual soil loss was graphically presented to easily visualize the large soil loss area. Uplands and vineyards proved to be the two greatest sources for soil erosion. It was suggested to develop effective management practices to reduce the soil erosion from uplands and vineyards.

  • PDF

The Land Cover Changes at the Small Watersheds Using the Multi-temporal Satelite Images (다시기 위성영상을 이용한 소유역의 토지피복변화 평가)

  • Kang, Moon-Seong;Park, Seung-Woo
    • Journal of Korean Society of Rural Planning
    • /
    • v.6 no.2 s.12
    • /
    • pp.50-58
    • /
    • 2000
  • The purposes of the study were to detect and evaluate the historical land use and land cover changes on the Balan watersheds from three thematic mapper (TM) data, which were taken in 1985, 1993, and 1996. The supervised and unsupervised classification methods were adopted to classify five land cover categories: Paddy, upland, forest, residential, and water. The results indicated residential areas increased significantly during the past eleven years, Forest and paddy were converted to the urban areas. Future land cover patterns were forecasted using a Markov chain method, and the simulated land coiler change ratios presented.

  • PDF

Evaluation of Organic Matter Flow in Rural Watersheds (농촌유역에서의 유기물 흐름의 평가-충북 청원군 가덕면 유역을 대상으로)

  • 오광영;김진수
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 1999.10c
    • /
    • pp.676-681
    • /
    • 1999
  • The organic matter flow in rural watershed in Chongwon-gun , Chungbuk, was evaluated, The study watershed is about 67$\textrm{km}^2$ in area and its population was 7,000 in 1996. The amount of inflow in the study area exceeds the amount of outflow by 534kg/ha , and the livestock feed account for 90 percent of the amount of inflow. The loading of organic matter by livestock waste amounts to 51 percent of total loading to agricultural land and the enviornment. The increase in recycling of livestock waste is essential for the management of orgainc matter in the rural watershed.

  • PDF

Patterns of Forest Landscape Structure due to Landcover Change in the Nakdong River Basin (토지이용변화에 따른 낙동강 유역 산림경관의 구조적 패턴 분석)

  • Park, Kyung-Hun;Jung, Sung-Gwan;Kwon, Jin-O;Oh, Jeong-Hak
    • Journal of Korean Society of Rural Planning
    • /
    • v.11 no.4 s.29
    • /
    • pp.47-57
    • /
    • 2005
  • The goal of this research is to evaluate landscape-ecological characteristics of watersheds in the Nakdong River Basin by using Geogaphic Information System (GIS) and landscape indices for integation of spatio-temporal informations and multivariate statistical techniques for quantitative analysis of forest landscape. Fragmentation index and change matrix techniques using factor analysis and grid overlay method were used to efficiently analyze and manage huge amount of information for ecological-environmental assessment (land-cover and forest landscape patterns). According to the results based on the pattern analysis of land-cover changes using the change detection matrix between 1980s and 1990s, addition on 750km$^2$ became urbanized areas. The altered 442.04km$^2$ was agricultural areas which is relatively easy for shifting of land-use, and 205.1km$^2$ of forests became urbanized areas, and average elevation and slope of the whole altered areas were 75m and 4$^{\circ}$. On the other hand, 120km$^2$ of urban areas were changed into other areas (i.e., agricultural areas and green space), and fortunately, certain amount of naturalness had been recovered. But still those agricultural areas and fallow areas, which were previously urban areas, had high potential of re-development for urbanization due to their local conditions. According to the structural analysis of forest landscape using the landscape indices, the forest fragmentation of watersheds along the main stream of the Nakdong River was more severe than my other watersheds. Furthermore, the Nakdong-sangju and Nakdong-miryang watersheds had unstable forest structures as well as least amount of forest quantity. Thus, these areas need significant amount of forest through a new forest management policy considering local environmental conditions.