Dam Basin Research Articles

Monthly streamflow estimation using wavelet-artificial neural network model: A case study on Çamlıdere dam basin, Turkey

Data driven techniques have become well-known application in hydrology in which physical processes are highly nonlinear. They require detailed analyses of different input combinations, selecting the appropriate model structures, assigning the optimization parameters etc. Besides, the model performance are also highly correlated with additional analysis techniques. In this study, the value of using different data sets such as air temperature, precipitation, evaporation and streamflow records, evapotranspiration around the basin are investigated to estimate monthly inflows using a multi-layer perceptron network model. Since the noise always exists in the time-series data, Discrete Wavelet Transform (DWT) is applied for data decomposition. Çamlıdere dam basin, which is one of the vital water supply reservoir of the capital city of Turkey, Ankara, is selected as an application area. The model sets are employed using 1960 – 2016 monthly observed data. The reliability of the modelled flows are verified with: coefficient of determination (R2), Nash-Sutcliffe model efficiency (NSME), root mean square error (RMSE) and mean absolute error (MAE). According to the results, instead of increasing input vector number, application of data pre-processing have more impact to capture especially high flows. Decomposed discharge data together with meteorological other inputs perform 0.85 – 0.73 both for R2 and NSME for training and testing periods, respectively.

Instruments of administrative concessions of water use rights in Spain

ABSTRACT Most of the Spanish territory is marked by Mediterranean climatic characteristics, in which rain irregularity and droughts present continuous challenges to water resource managers. Since the end of the 19th century, the country has adopted a management logic based on flow regularization from dam construction and basin water transfers. However, from the Water Framework Directive adopted in 2000, European Union member states are forced to undertake more environmentally oriented management processes, with a focus on improving the ecological status of water bodies. In this sense, economic management tools have been highlighted in the national strategies for compliance with the Water Framework Directive requirements. One of those instruments is the public water use rights permit. This paper aims to present the Spanish panorama of this instrument and contribute to those interested in water management. The work shows that there are several challenges and problems faced by the Spanish management apparatus, particularly regarding continuity of private management of groundwater and insufficient knowledge of numerous wells and volumes of water used. For various reasons, the concessions system faces criticism as to defending the interests of traditional economic sectors.

Plans identify indicators (water, soil and Industry) applicable in Ilam Dam basin water with emphasis on sustainable development

The negligence of development impacts in recent decades has imposed serious problems to great projects due to inattention to the environment. To this end, a positive movement towards the assessment of strategic development effects has been triggered in recent years. This study aims to identify and prioritize executable development projects in the area of drinking water dam of Ilam with the priority of assessing environmental impacts. It is an applied study in terms of objective and a descriptive-analytical study in terms of method. The study population consists of two qualitative and quantitative sections. Experts who are familiar with related issues, problems and impacts of dam making projects constitute the first section while the second one covers specialists who are familiar with the drainage basin of dam. The samples of both sections were selected using purposive sampling method. Data was collected by questionnaire (both open-ended and close-ended questionnaires) and was analyzed using SPSS and Liserl. Finally, 9 important factors were identified as the main title of projects namely: 1) plant product projects, 2) livestock product projects, 3) water, soil and industrial projects, 4) veterinary medicine projects, 5) forest, pasture and watershed management projects, 6) promotion and exploitation projects, 7) economic association projects, 8) production cooperatives for providing agricultural engineering services and 9) job opportunities of agriculture sector. In addition, 82 development-titled projects were extracted to be studied in Ilam dam site.

Hydrologic variability in the Sumjin river dam basin according to typhoon genesis pattern

Hydrologic variability in the Sumjin river dam basin according to typhoon genesis pattern

Future Projection and Uncertainty Analysis of Low Flow on Climate Change in Dam Basins

The low flow is the necessary and important index to establish national water planning, however there are lots of uncertainty in the low flow estimation. Therefore, the objectives of this study are to assess the climate change uncertainty and the effects of hydrological models on low flow estimation. The 5 RCMs (HadGEM3-RA, RegCM4, MM5, WRF, and RSM), 5 statistical post-processing methods and 2 hydrological models were applied for evaluation. The study area were selected as Chungju dam and Soyang river dam basin, and the 30 days minimum flow is used for the low flow evaluation. The results of the uncertainty analysis showed that the hydrological model was the largest source of uncertainty about 41.5% in the low flow projection. The uncertainty of hydrological model is higher than the other steps (RCM, statistical post-processing). Also, VIC model is more sensitive for climate change compared to SWAT model. Therefore, the hydrological model should be thoroughly reviewed for the climate change impact assessment on low flow.

Developing a decision support framework for real‐time flood management using integrated models

Flood risk mitigation during real‐time flood events comprising snowmelt under hydrological uncertainty is particularly challenging. Giving this due consideration, the aim is to develop a Decision Support System (DSS) for the real‐time operation of a reservoir and the channel downstream. This was accomplished with continuous catchment monitoring, runoff forecasting, optimal reservoir decisions, river, and flood inundation analysis. The proposed DSS consists of four major components: (1) Supervisory Control and Data Acquisition (SCADA) system for real‐time monitoring; (2) Hydrologic Engineering Center (HEC) – Hydrological Modelling System (HMS) to simulate rainfall/snowmelt runoff process; (3) HEC – Reservoir Simulation System (ResSim) for operation of the controlled reservoir; and (4) HEC – River Analysis System (RAS) for two‐dimensional unsteady river analysis and flood inundation mapping. After the DSS is set up, a real‐time operation for an extreme case scenario was simulated to test the performance, and flood maps were generated. Yuvacık Dam Basin in Turkey has a robust gauge network but is rather limited in reservoir storage and downstream channel capacity. This is the basis for selection of the area in the study. Results show that the developed DSS is useful for forecasting and reservoir operations, in addition to serving as an early warning system.

Ensemble Flood Forecasting of Typhoons Talas and Roke at Hiyoshi Dam Basin

In order to be able to issue flood warnings not hours but days in advance, numerical weather prediction (NWP) is essential to the forecasting of flood-producing rainfall. The regional ensemble prediction system (EPS), advanced NWP on a local scale, has a high potential to improve flood forecasting through the quantitative prediction of precipitation. In this study, the predictability of floods using the ensemble flood forecasting system, which is composed of regional EPS and a distributed hydrological model, was investigated. Two flood events which took place in a small basin in Japan in 2010 and which were caused by typhoons Talas and Roke were examined. As the forecasting system predicted the probability of flood occurrence at least 24 h beforehand in the case of both typhoons, these forecasts were better than deterministic forecasts. However, the system underestimated the peak of the flooding in the typhoon Roke event, and it was too early in its prediction of the appearance of the peak of the flooding in the Talas event. Although the system has its limitations, it has proved to have the potential to produce early flood warnings.

Deformation features of a super-high arch dam structural system

The interaction among the dam body, dam foundation and dam basin under the collaborative effect of multiple complicated external factors can significantly influence dam deformation. Based on the analysis of the super-high arch dam structural system characteristics, a model for calculating and analysing the dam-body foundation basin was established. The deformation modulus of the dam basin and the comprehensive deformation modulus were inversely calculated. By extensively considering the effect of a complicated load on the super-high arch dam structural system, the distribution features and variation law of dam deformation under different overloading conditions were studied with the overloading approach. Moreover, the actual deformation features of the super-high arch dam structure were analysed based on a super-high arch dam engineering project.

Projection of runoff and sediment yield under coordinated climate change and urbanization scenarios in Doam dam watershed, Korea

A hydro-environmental model chain in the Doam dam basin, Korea, was developed for an impact assessment under the Intergovernmental Panel on Climate Change's A1B scenario. The feasible downscaling scheme composed of an artificial neural network (ANN) and non-stationary quantile mapping was applied to the GCM (Global Climate Model) output. The impacts under climate and land use change scenarios were examined and projected using the Soil and Water Assessment Tool (SWAT) model. The daily SWAT model was calibrated and validated for 2003–2004 and 2006–2008, respectively. Meanwhile the monthly SS (suspended solids) was calibrated and validated for 1999–2001 and 2007–2009, respectively. The simulation results illustrated that under the assumption of 1–5% urbanization of the forest area, the hydrologic impact is relatively negligible and the climate change impacts are dominant over the urbanization impacts. Additionally the partial impacts of land use changes were analyzed under five different scenarios: partial change of forest to urban (PCFUr), to bare field, to grassland, to upland crop (PCFUp), and to agriculture (PCFA). The analysis of the runoff change shows the highest rate of increase, 73.57% in April, for the PCFUp scenario. The second and third highest rate increases, 37.83% and 31.45% in May, occurred under the PCFA and PCFUr scenarios, respectively.

The Effect of Paved Roads on Organic Carbon Content of Soil in Taham Dam Basin

The Effect of Paved Roads on Organic Carbon Content of Soil in Taham Dam Basin

기후변화를 고려한 남강댐 유역의 홍수량 재산정

최근에 기후변화로 인해 극치호우사상들이 증가하고 있으며 이는 토지이용의 증가와 더불어 심각한 홍수를 야기 시키고 있다. 이에 따라 생명과 재산의 안전을 담보하기 위해 건설되는 댐 및 제방 등의 수리구조물에 대한 적절한 설계홍수량의 산정이 매우 중요한 부분으로 평가되고 있다. 본 연구에서는 기상수문에 미치는 기후변화의 영향을 고려해서 남강댐 유역의 홍수량을 재산정하였다. 이를 위해서 시간강우로 상세화 시킨 RCP 4.5와 RCP 8.5의 기후변화 시나리오를 사용하였다. 현재 설계 빈도 값인 200년 빈도와 최대홍수량(PMF)인 10,000년 빈도의 홍수량에 초점을 맞춰 재산정하였다. 기후변화를 반영한 시나리오 값이 현재만을 고려한 값보다 현저히 큰 값을 보여주고 있음을 알 수 있었으며, 특히 RCP 8.5값에서 가장 큰 값을 보여주고 있다. 본 연구결과는 남강댐지역의 안정성이 기후변화에 취약하다는 것을 보여 주었으며 향후 하류지역인 사천만의 피해를 감소시키는 방안을 함께 고려하여 대책이 마련되어져야 할 것으로 판단된다.

원격상관 기후지수를 활용한 1개월 선행 댐유입량 예측

신뢰성 있는 댐유입량의 장기예측은 효율적인 댐운영에 필수적이다. 2000년대 이후 엘리뇨-남방진동(ENSO) 등의 전구기후지수와 지역수문기후와의 원격상관성이 규명되면서, 이를 활용한 미래의 수문조건을 예측하기 위한 연구가 활발히 시도되고 있다. 본 연구에서는 안동댐유역을 대상으로 미국 NOAA에서 제공하는 40개 전구기후지수의 원격상관을 분석하고, 이를 기반으로 1개월 선행 댐유입량의 예측성능 및 활용성을 평가하였다. 본 연구에서는 1) 원격상관을 통해 강수와 기온을 예측하고 SWAT 모델을 이용하여 예측 댐유입량을 산정하는 방법(SWAT-Forecasted), 직접 댐유입량을 예측하는 기법(CIR-Forecasted), 예측시점의 관측값이 과거자료에서 해당하는 순위(rank)에 근거한 방법(Rank-Observed)을 비교하였다. 결과적으로 통계적 방법으로 댐유입량을 직접 예측하는 접근 방식(CIR-Forecasted)이 12월을 제외하고는 다른 방법에 비해 우수한 예측성을 보였다. 이것은 강수량 및 기온 예측정보를 일단위로 상세화하는 가정과 유출모델링과정에서 발생하는 불확실성이 예측결과에 포함되지 않기 때문인 것으로 판단된다. 본 연구결과는 원격상관기반의 1개월 선행 댐유입량 예측이 안동댐 운영에 유용한 정보를 제공할 수 있는 것을 시사하였다.

Evaluation of Error Indices of Radar Rain Rate Targeting Rainfall-Runoff Analysis

AbstractThis study evaluates several error indices of the radar rain rate from the viewpoint of the accuracy of rainfall-runoff analysis. The error indices considered in this study are the mean error (ME), mean absolute error (MAE), normalized standard deviation (NSD), correlation coefficient (CC), bias (BS), and radar rain rate quality criterion (RRQC). These indices were analyzed using the concept of sum of squares (SS) and mean squares (MS) in the analysis of variance (ANOVA), which explains how the bias and random error of the radar rain rate are combined in an error index. Also, these error indices were linked to the errors in the runoff result, such as the total runoff volume, peak flow, and peak time. As an application, two dam basins in Korea were selected, the Chungju Dam basin and the Namgang Dam basin. The radar rain rates from Gwangdeoksan Radar and Gudeoksan Radar were used as input for the rainfall-runoff analysis. Six different rainfall events were applied to secure various rainfall types. ...

Basin/Reservoir System Integration for Real Time Reservoir Operation

This paper demonstrates the basin/reservoir system integration as a decision support system for short term operation policy of a multipurpose dam. It is desired to re-evaluate and improve the current operational regulation of the reservoir with respect to water supply and flood control especially for real time operation. The most innovative part of this paper is the development of a decision support system (DSS) by the integration of a hydrological (HEC-HMS) and reservoir simulation model (HEC-ResSim) to guide the professional practitioners during the real time operation of a reservoir to meet water elevation and flood protection objectives. In this context, a hybrid operating strategy to retain maximum water elevation is built by shifting between daily and hourly decisions depending on real time runoff forecasts. First, a daily hydro-meteorological rule based reservoir simulation model (HRM) is developed for both water supply and flood control risk. Then, for the possibility of a flood occurrence, hourly flood control rule based reservoir simulation model (FRM) is used. The DSS is applied on Yuvacik Dam Basin which has a flood potential due to its steep topography, snow potential, mild and rainy climate in Turkey. Numerical weather prediction based runoff forecasts computed by a hydrological model together with developed reservoir operation policy are put into actual practice for real time operation of the reservoir for March – June, 2012. According to the evaluations, proposed DSS is found to be practical and valuable to overcome subjective decisions about reservoir storage.

Uncertainty Assessment of Future High and Low Flow Projections According to Climate Downscaling and Hydrological Models

The quantitative assessment of change in water availability and appropriate water resources management are needed for corresponding adaptation. However, there are large uncertainties in climate change impact assessment on water resources. In this sense, the aims of this study are to suggest the uncertainty assessment method for climate change impact assessment and to investigate the uncertainty characteristics for high and low flow between downscaling methods and hydrological models. The 5 RCMs (HadGEM3-RA, RegCM4, MM5, WRF, and RSM), 5 statistical post-processing methods (SPP), and 2 hydrological models (HYM) were applied on the Chungju dam basin, Korea. The results of uncertainty analysis showed that RCM has the largest sources of uncertainty in 1-day maximum dam inflow (about 40.7%), while HYM has the largest sources of uncertainty in 30-days minimum dam inflow (about 41.5%). In other words, high flow was mainly effected by RCM and low flow by HYM. The proposed methodology in this study can be used to quantify the uncertainties caused by RCM, SPP, and HYM.

森林限界以上の高標高帯における積雪分布と融雪・流出計算に適用する降雪分布について

Better estimation of snow water equivalents for a dam basin and dam inflow is important for dam operation in cold and snowy regions. In this study, the relationship between snow depth and topography was analyzed using airborne laser scanning data. The linear relationship between snow depth in the forest area and elevation and the relationship between snow depth in the non-forest area like the area above the forest line and overground-openness were clarified. Moreover, three types of snowfall distribution were set and the dam inflow was calculated using snowmelt runoff model. The calculation applied snowfall distribution considered snow depth transport by wind at high elevations had the highest accuracy.

Assessment of Runoff Changes under Climate Change Scenarios in the Dam Basin of Ekbatan, Hamedan Iran

In this study, the uncertainty of the effects of climate change on temperature, rainfall and runoff in the watershed done using the output of models MPEH5, HADCM3 and IPCM4 under two scenarios for 2045-2065 period. After performance of LARS-WG model for downscaling of rainfall and temperature variations, the monthly change rainfall and temperature evaluated for the 2065-2045 period relative to 2010-1983 base period. Results showed that all three models based on two scenarios reduce the amount of rainfall and increases in average temperature in the region. The average annual temperature rise according to the scenario A2, 2/12°C and scenario B1, 1/12°C. The amount of rainfall decreases for the period 2045-2065 under the scenario A2, -6/1 and the scenario B1, -1/4 per cent. To study the effects of climate change on monthly runoff regime, production variables was used to the model of rainfall- runoff IHACRES after that runoff was predicted for the period 2065-2045. The results showed that annual river flow reduced under the A2 scenario -17/2 percent and the B1 scenario -19/4 per cent. The overall results showed that despite the uncertainty in climate models MPEH5, HADCM3 and IPCM4 under the A2 and B1 in the amount of temperature increase and rainfall decreases and negative effects of these changes on the runoff area.

안동댐 유역 기상인자의 시공간분포 추정

This study investigates characteristics of time series spatial distribution on climate factors in Andong Dam basin by estimating precise spatio-temporal distribution of hydro-meteorological information. A spatio-temporal distribution by estimating Semi-Variogram based on spatial autocorrelation was examined using the data from ASOS and 7 hydro-meteorological observatories in Andong Dam basin of upper Nakdonggang River, which were installed and observed by NIMR(National Institute of Meterological Research). Also, temperature and humidity as climate variables were analyzed and it was recognized that there is a variability in watershed area by time and months. Regardless of season, an equal spatial distribution of temperature at 14 o'clock and humidity at 10 o'clock was identified, and nonequal distribution was noticed for both variables at 18 o'clock. From monthly spatial analysis, the most unequal distribution of temperature was seen in January, and the most equal distribution was detected in September. The most unequal distribution of humidity was identified in May, and the most equal distribution was seen in January. Unlike in forest, seasonal spatial distribution characteristics were less apparent;but temperature and humidity had respective characteristics in hydro-meteorology.

강우장 추정을 위한 공간보간기법의 적용성 평가

In recent, the natural disaster like localized heavy rainfall due to the climate change is increasing. Therefore, it is important issue that the precise observation of rainfall and accurate spatial distribution of the rainfall for fast recovery of damaged region. Thus, researches on the use of the radar rainfall data have been performed. But there is a limitation in the estimation of spatial distribution of rainfall using rain gauge. Accordingly, this study uses the Kriging method which is a spatial interpolation method, to measure the rainfall field in Namgang river dam basin. The purpose of this study is to apply KED(Kriging with External Drift) with OK(Ordinary Kriging) and CK(Co-Kriging), generally used in Korea, to estimate rainfall field and compare each method for evaluate the applicability of each method. As a result of the quantitative assessment, the OK method using the raingauge only has 0.978 of correlation coefficient, 0.915 of slope best-fit line, and 0.957 of and shows an excellent result that MAE, RMSE, MSSE, and MRE are the closest to zero. Then KED and CK are in order of their good results. But the quantitative assessment alone has limitations in the evaluation of the methods for the precise estimation of the spatial distribution of rainfall. Thus, it is considered that there is a need to application of more sophisticated methods which can quantify the spatial distribution and this can be used to compare the similarity of rainfall field.

Utilisation of Sepidrud dam basin sediments in fired clay bricks: laboratory scale experiment

The prevailing disposal methods for dam basin sediments are not free from the environmental pollution and the ecological imbalance. At present, a new way to treat the dredged sediments to manufacture bricks is being investigated, prioritizing waste recovery over its deposition in landfills. However, construction materials such as clay bricks must comply with the international and local standards. Considering the perpetual availability of the sediments, particle sizing and their chemical composition and the results of physical and qualification tests on Sepidrud Dam basin sediments it can be concluded that the utilization of basin sediments as a full or partial replacement in clay brick production will lead to the production of quality bricks that meet all the regulatory limits in the standards. This research is novel in view of both increasing the reservoir effective volume capacity and preventing the use of alternative land quarries which are mainly covered by green land.