Journal of Korea Water Resources Association最新文献_第8页

A point-scale gap filling of the flux-tower data using the artificial neural network 利用人工神经网络对通量塔数据进行点尺度的间隙填充

Journal of Korea Water Resources Association Pub Date : 2020-11-01 DOI: 10.3741/JKWRA.2020.53.11.929

Hyunho Jeon

{"title":"A point-scale gap filling of the flux-tower data using the artificial neural network","authors":"Hyunho Jeon","doi":"10.3741/JKWRA.2020.53.11.929","DOIUrl":"https://doi.org/10.3741/JKWRA.2020.53.11.929","url":null,"abstract":"In this study, we estimated missing evapotranspiration (ET) data at a eddy-covariance flux tower in the Cheongmicheon farmland site using the Artificial Neural Network (ANN). The ANN showed excellent performance in numerical analysis and is expanding in various fields. To evaluate the performance the ANN-based gap-filling, ET was calculated using the existing gap-filling methods of Mean Diagnostic Variation (MDV) and Food and Aggregation Organization Penman-Monteith (FAO-PM). Then ET was evaluated by time series method and statistical analysis (coefficient of determination, index of agreement (IOA), root mean squared error (RMSE) and mean absolute error (MAE). For the validation of each gap-filling model, we used 30 minutes of data in 2015. Of the 121 missing values, the ANN method showed the best performance by supplementing 70, 53 and 84 missing values, respectively, in the order of MDV, FAO-PM, and ANN methods. Analysis of the coefficient of determination (MDV, FAO-PM, and ANN methods followed by 0.673, 0.784, and 0.841, respectively.) and the IOA (The MDV, FAO-PM, and ANN methods followed by 0.899, 0.890, and 0.951 respectively.) indicated that, all three methods were highly correlated and considered to be fully utilized, and among them, ANN models showed the highest performance and suitability. Based on this study, it could be used more appropriately in the study of gap-filling method of flux tower data using machine learning method.","PeriodicalId":224359,"journal":{"name":"Journal of Korea Water Resources Association","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127811534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improvement of agricultural water demand estimation focusing on paddy water demand 改进以水稻需水量为中心的农业需水量估算方法

Journal of Korea Water Resources Association Pub Date : 2020-11-01 DOI: 10.3741/JKWRA.2020.53.11.939

Chang-Kun Park

{"title":"Improvement of agricultural water demand estimation focusing on paddy water demand","authors":"Chang-Kun Park","doi":"10.3741/JKWRA.2020.53.11.939","DOIUrl":"https://doi.org/10.3741/JKWRA.2020.53.11.939","url":null,"abstract":"Currently, the demand for farmland is steadily decreasing due to changes in the agricultural environment and dietary life. In line with this, the government adopted an integrated water management with the enactment of the Framework Act on Water Management on June 2019. Therefore, it is required to take a closer look at agricultural water demand that accounts for 61% of water use for efficient water resources management. In this study, the overal process was evaluated for estimating agricultural water demand. More specifically, agricultural water demand for paddy field, which comprises 67% to 87% of agricultural water demand, was reviewed in detail. The biggest issue in estimating the paddy field water demand is the selection of the method for potential evapotranspiration. FAO recommends Penman-Monteith, but, currently, our criteria suggest a modified Penman equation that shows over estimation. Also, the crop coefficient, which is the main factor in evaluating evapotranspiration, has an issue that does not consider the current climate and crop varieties because it was developed 23 years ago. Comparing the Modified Penman and Penman-Monteith equations using the data from Jeonju National Weather Service, the modified Penman equation showed a big difference compared to the Penman-Monteith equation. When the crop coefficient was applied, the difference between late May and late August increased, where the amount of evapotranspiration was high. The estimation process was applied to four study reservoirs in Gimje. Comparing the estimated water demand with the supplied water record from reservoirs, the results showed that the estimation accuracy depends on not just the potential evapotranspiration, but also the standard water storing level in paddy fields.","PeriodicalId":224359,"journal":{"name":"Journal of Korea Water Resources Association","volume":"7 11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132367383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Assessment of a rain barrel sharing network in Korea using storage-reliability-yield relationship 利用存储-可靠性-产量关系对韩国雨桶共享网络进行评估

Journal of Korea Water Resources Association Pub Date : 2020-11-01 DOI: 10.3741/JKWRA.2020.53.11.961

Youjeong Kwon

引用次数: 0

Experimental analysis on the channel adjustment processes by weir removal 消堰调整河道过程的实验分析

Journal of Korea Water Resources Association Pub Date : 2020-11-01 DOI: 10.3741/JKWRA.2020.53.11.951

C. Jang

{"title":"Experimental analysis on the channel adjustment processes by weir removal","authors":"C. Jang","doi":"10.3741/JKWRA.2020.53.11.951","DOIUrl":"https://doi.org/10.3741/JKWRA.2020.53.11.951","url":null,"abstract":"This study investigates the adjustment processes of the rivers after weir removal through laboratory experiments. Delta upstream eroded rapidly by flow at the initial stage of the experiments and the knickpoint migrates upward. Moreover, the knickpoint moves fast upward on the condition of alternate bars. The head cutting in the bed is developed fast at the initial stage. However, the erosion speed in the bed decreases with time. The well developed alternate bars migrates with keeping their shape downstream, and the bars affect the channel downstream to adjust new environments after weir removal. Maximum scouring depth downstream and the migration speed decrease over time after removing the weir. The scouring depth in the channel without alternate bars migrates with speed. However, the depth in the channel with alternate bars migrates slow downstream. The channel with alternate bars, in turn, is adjusted well to the new equilibrium states. The maximum scouring depth migrates downstream with time, and the scouring depth and its migration speed decreases with time. The dimensionless maximum scouring depth decreases with the migration speed of dimensionless maximum scouring depth because the deeply scoured places capture the sediments from upstream and the migration speed is slow as the places are filled with them. The dimensionless maximum scouring depth is shallow as the dimensionless backfilling speed is high. The dimensionless maximum scouring depth decreases rapidly less than 5 of dimensionless backfilling speed. However, the depth decreases slow more than 5 of it.","PeriodicalId":224359,"journal":{"name":"Journal of Korea Water Resources Association","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127414978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Appraisal of spatial characteristics and applicability of the predicted ensemble rainfall data 综合降雨预报资料的空间特征及适用性评价

Journal of Korea Water Resources Association Pub Date : 2020-11-01 DOI: 10.3741/JKWRA.2020.53.11.1025

Sang Hyup Lee

{"title":"Appraisal of spatial characteristics and applicability of the predicted ensemble rainfall data","authors":"Sang Hyup Lee","doi":"10.3741/JKWRA.2020.53.11.1025","DOIUrl":"https://doi.org/10.3741/JKWRA.2020.53.11.1025","url":null,"abstract":"This study attempted to evaluate the spatial characteristics and applicability of the predicted ensemble rainfall data used for heavy rain alarms. Limited area ENsemble prediction System (LENS) has 13 rainfall ensemble members, so it is possible to use a probabilistic method in issuing heavy rain warnings. However, the accessibility of LENS data is very low, so studies on the applicability of rainfall prediction data are insufficient. In this study, the evaluation index was calculated by comparing one point value and the area average value with the observed value according to the heavy rain warning system used for each administrative district. In addition, the accuracy of each ensemble member according to the LENS issuance time was evaluated. LENS showed the uncertainty of over or under prediction by member. Area-based prediction showed higher predictability than point-based prediction. In addition, the LENS data that predicts the upcoming 72-hour rainfall showed good predictive performance for rainfall events that may have an impact on a water disaster. In the future, the predicted rainfall data from LENS are expected to be used as basic data to prepare for floods in administrative districts or watersheds.","PeriodicalId":224359,"journal":{"name":"Journal of Korea Water Resources Association","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127431469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Groundwater evaluation in the Bokha watershed of the Namhan River using SWAT-MODFLOW 基于SWAT-MODFLOW的南汉江博卡流域地下水评价

Journal of Korea Water Resources Association Pub Date : 2020-11-01 DOI: 10.3741/JKWRA.2020.53.11.985

Daeyoung Han

引用次数: 0

Verification of precipitation enhancement by weather modification experiments using radar data 利用雷达资料进行人工影响天气试验对增雨效果的验证

Journal of Korea Water Resources Association Pub Date : 2020-11-01 DOI: 10.3741/JKWRA.2020.53.11.999

Yonghun Ro

{"title":"Verification of precipitation enhancement by weather modification experiments using radar data","authors":"Yonghun Ro","doi":"10.3741/JKWRA.2020.53.11.999","DOIUrl":"https://doi.org/10.3741/JKWRA.2020.53.11.999","url":null,"abstract":"Weather modification research has been actively performed worldwide, but a technology that can more quantitatively prove the research effects are needed. In this study, the seeding effect, the efficiency of precipitation enhancement in weather modification experiment, was verified using the radar data. Also, the effects of seeding material on hydrometeor change was analyzed. For this, radar data, weather conditions, and numerical simulation data for diffusion were applied. First, a method to analyze the seeding effect in three steps was proposed: before seeding, during seeding, and after seeding. The proposed method was applied to three cases of weather modification experiments conducted in Gangwon-do and the West Sea regions. As a result, when there is no natural precipitation, the radar reflectivity detected in the area where precipitation change is expected was determined as the seeding effect. When natural precipitation occurs, the seeding effect was determined by excluding the effect of natural precipitation from the maximum reflectivity detected. For the application results, it was found that the precipitation intensity increased by 0.1 mm/h through the seeding effect. In addition, it was confirmed that ice crystals, supercooled water droplets, and mixed-phase precipitation were distributed in the seeding cloud. The results of these weather modification research can be used to secure water resources as well as for future study of cloud physics.","PeriodicalId":224359,"journal":{"name":"Journal of Korea Water Resources Association","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122731193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization of PRISM parameters using the SCEM-UA algorithm for gridded daily time series precipitation 基于SCEM-UA算法的栅格日时间序列降水PRISM参数优化

Journal of Korea Water Resources Association Pub Date : 2020-10-01 DOI: 10.3741/JKWRA.2020.53.10.903

Yong-TakPark MoonhyungKwon Hyun-Han Kim

引用次数: 2

Experimental study on non-linear throughflow characteristics of rockfill gabion weir 石笼堰非线性通流特性试验研究

Journal of Korea Water Resources Association Pub Date : 2020-10-01 DOI: 10.3741/JKWRA.2020.53.10.861

IlyeongLee JaejoungKim Gyoo bum Han

引用次数: 0

Statistical investigation on size distribution of suspended cohesive sediment 悬浮黏性泥沙粒径分布的统计研究

Journal of Korea Water Resources Association Pub Date : 2020-10-01 DOI: 10.3741/JKWRA.2020.53.10.917

B. Park

引用次数: 0