Proceedings of 4th International Electronic Conference on Water Sciences最新文献

Comparison of Statistical and Machine Learning models for pipe failure modeling in Water Distribution Networks (WDN) 供水管网失效建模中统计模型与机器学习模型的比较

Proceedings of 4th International Electronic Conference on Water Sciences Pub Date : 2019-11-12 DOI: 10.3390/ecws-4-06441

Mónica Giraldo, J. Rodríguez

{"title":"Comparison of Statistical and Machine Learning models for pipe failure modeling in Water Distribution Networks (WDN)","authors":"Mónica Giraldo, J. Rodríguez","doi":"10.3390/ecws-4-06441","DOIUrl":"https://doi.org/10.3390/ecws-4-06441","url":null,"abstract":"The application of statistical and Machine Learning (ML) models plays a critical role in planning and decision support processes for WDNs management. Failure models can provide valuable information for prioritizing the system rehabilitation even in data scarcity scenarios (such as developing countries). Few studies analyze the performance of more than two models and examples of case studies in developing countries are insufficient. A more comprehensive analysis of models' performance and limitations is necessary for an adequate prediction of pipe failure. This study compares various statistical and ML models to provide useful information to practitioners for the selection of a suitable pipe failure model according to information availability and network characteristics. Three statistical models (i.e. Linear, Poisson, and Evolutionary Polynomial Regressions) were used for failure prediction in groups of pipes. The K-means clustering approach was applied to improve the performance of the statistical models. ML approaches, particularly Gradient Boosted Tree (GBT), Bayes, Support Vector Machines and Artificial Neuronal Networks (ANNs), were compared in predicting individual pipe failure rates. The proposed approach was applied to a WDN in Bogotá (Colombia). The results of the statistical models showed that the cluster-based prediction model reduces the prediction error of pipe failures. Regarding ML models, all methods but the ANNs showed acceptable performance. The GBT approach had the best performing classifier.","PeriodicalId":414498,"journal":{"name":"Proceedings of 4th International Electronic Conference on Water Sciences","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133462592","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

A tool to estimate the location of high conductivity channels in heterogeneous porous media 一种在非均质多孔介质中估计高导电性通道位置的工具

Proceedings of 4th International Electronic Conference on Water Sciences Pub Date : 2019-11-12 DOI: 10.3390/ecws-4-06425

Calogero B. Rizzo, F. D. Barros

{"title":"A tool to estimate the location of high conductivity channels in heterogeneous porous media","authors":"Calogero B. Rizzo, F. D. Barros","doi":"10.3390/ecws-4-06425","DOIUrl":"https://doi.org/10.3390/ecws-4-06425","url":null,"abstract":"Solute transport in groundwater is characterized by a high level of uncertainty since it is impossible to completely measure the spatial distribution of key soil properties, such as the hydraulic conductivity. Several studies have shown how an heterogeneous hydraulic conductivity field may lead to the formation of preferential channels (or high conductivity channels) in which the solute flows. Given a realization of the hydraulic conductivity field, it is possible to estimate the location of preferential channels using a graph-theory based method. The minimum hydraulic resistance and least resistance path are efficiently computed, so that these metrics can be effectively employed to assess the uncertainty of preferential flows using computationally intensive stochastic methods, such as Monte-Carlo simulations. For example, these metrics can be used for site characterization, choosing locations where to sample the hydraulic conductivity in order to reduce the uncertainty of high conductivity channels. As a consequence, our preliminary studies displayed more than 40% reduction on first arrival time uncertainty, when compared to a regular grid sampling protocol with the same number of sampling locations. The iterative sampling strategy can be reproduced using LazyMole, an open-source tool implementing the algorithms to compute the minimum hydraulic resistance and least resistance path for a given hydraulic conductivity field.","PeriodicalId":414498,"journal":{"name":"Proceedings of 4th International Electronic Conference on Water Sciences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122007574","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

Impact of water abstraction on water balance of Lake Ziway, Ethiopia 采水对埃塞俄比亚齐威湖水量平衡的影响

Proceedings of 4th International Electronic Conference on Water Sciences Pub Date : 2019-11-12 DOI: 10.3390/ecws-4-06421

Goshime Demelash Wondimagegnehu, A. Haile, R. Absi, B. Ledésert

{"title":"Impact of water abstraction on water balance of Lake Ziway, Ethiopia","authors":"Goshime Demelash Wondimagegnehu, A. Haile, R. Absi, B. Ledésert","doi":"10.3390/ecws-4-06421","DOIUrl":"https://doi.org/10.3390/ecws-4-06421","url":null,"abstract":"The available water volume of Lake Ziway in Ethiopia is declining at an alarming rate which hinders the lake services for a wide variety of sectors. However, there is a lack of systematic study to evaluate the contribution of water withdrawal by various sectors to the decline in the lake actual storage. In this study, we conducted a Water Abstraction Survey (WAS) to estimate actual water withdrawal from the lake. We applied a water balance model to evaluate the isolated impact of water withdrawal on the lake water volume and level. Three development pathways were simulated and the likely impact of these pathways on the lake water volume and level were assessed. Results indicate that water withdrawal for irrigation and domestic has significantly contributed to the change in the actual storage of Lake Ziway. Under full development pathways, irrigation water withdrawal from the lake is estimated to be 95.3 MCM. This will cause the mean annual water level of the lake to drop by 0.94 m, which yield with 38 km2 reduction of the surface area of the lake. Overall, this will result in a reduction of mean annual lake volume by 405 MCM, which accounts for 26% of the average lake volume. Hence, our result indicates that the current impact of water abstraction on Lake Ziway storage is substantially large and will exacerbate in the future. This calls serious action on the management of water abstraction from the lake.","PeriodicalId":414498,"journal":{"name":"Proceedings of 4th International Electronic Conference on Water Sciences","volume":"36 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116536974","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

Fabrication of ZrO2/ceramic nanocomposite for water purification 水净化用ZrO2/陶瓷纳米复合材料的制备

Proceedings of 4th International Electronic Conference on Water Sciences Pub Date : 2019-11-12 DOI: 10.3390/ecws-4-06437

M. Rabbani, Gita Jafarnejad

{"title":"Fabrication of ZrO2/ceramic nanocomposite for water purification","authors":"M. Rabbani, Gita Jafarnejad","doi":"10.3390/ecws-4-06437","DOIUrl":"https://doi.org/10.3390/ecws-4-06437","url":null,"abstract":"In this study, ZrO2 nanoparticles were prepared by successful microwave irradiation cohesive method. Compared to conventional methods, the advantages of microwave synthesis, very short reaction time and small particle production with narrow size distribution, high purity, efficient heating, environmentally friendly, cost-effective, uniform and special heat distribution and increase the speed of the reaction. On the other hand, ZrO2 is a highly resistant material to crack and fracture propagation, high thermal expansion, excellent conductivity and low thermal conductivity. In this type of synthesis, the aqueous solution containing Zr(NO3)4.5H2O and NaOH was exposed to 650 W microwave radiation. The obtained sediments were characterized by FT-IR and UV-vis analyzes. The sediments were uniformly coated on a ceramic membrane and a very thin layer formed by a wet layer on the substrate. The evaporation and drying process was performed under constant conditions. In this work, the ceramic membrane was used because of its apparent advantages, including high stability, long life, high flux and low deposition. The results showed that according to the XRD diagram based on the Shearer equation, the ZrO2 nanoparticles had crystalline order and sharp and distinct peaks. The FE-SEM images also showed that the morphology of the tubular structure was oriented towards the tetragonal and nanoparticles with dimensions less than 100 nm on the ceramic surface.","PeriodicalId":414498,"journal":{"name":"Proceedings of 4th International Electronic Conference on Water Sciences","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115522347","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: 3

Untangling The Main Drivers Of Hydromorphological Alteration In Greek Rivers 解开希腊河流水文形态变化的主要驱动因素

Proceedings of 4th International Electronic Conference on Water Sciences Pub Date : 2019-11-12 DOI: 10.3390/ecws-4-06422

K. Stefanidis, K. Gritzalis, Theodora Kouvarda, Anna Latsiou, Anastasia Lampou, E. Dimitriou

引用次数: 0

Utilization of Global Climate Models (GCMs) to Study Precipitation Extremes in Pakistan 利用全球气候模式研究巴基斯坦极端降水

Proceedings of 4th International Electronic Conference on Water Sciences Pub Date : 2019-11-12 DOI: 10.3390/ecws-4-06419

Q. Khan, Faisal Baig, Serin Darwish, Ahmed Agiel

{"title":"Utilization of Global Climate Models (GCMs) to Study Precipitation Extremes in Pakistan","authors":"Q. Khan, Faisal Baig, Serin Darwish, Ahmed Agiel","doi":"10.3390/ecws-4-06419","DOIUrl":"https://doi.org/10.3390/ecws-4-06419","url":null,"abstract":": Global Climate Model (GCM) downscaling projections of climate is important for future impact of climate change. The impact of climate change on the precipitation is studied using modeling, and observations. The rainfall trend was examined across Pakistan using Global Climate Model (GCM) data from period of 1991 to 2012. Downscaling was done on the basis of ascertained relationships between historical observed precipitation records from 36 stations of Pakistan Meteorological Department (PMD). Mann-Kendall test and Taylor Diagrams were used to analyze the data. All of the selected precipitation products were validated at monthly, seasonal and annual time scales utilizing PMD data. The outcomes illustrated that: (1) the precipitation estimates from MIROC, ECHAM and CanESM products correlated well with the referenced PMD observations at monthly time scale. (2) Compared to the MIROC and CanESM, the precipitation estimates from ECHAM were more consistent in all seasons mainly in the winter season with lowest relative bias (2.61%) and highest Correlation Coefficient (0.92); (3) ECHAM showed an apparent dominance over MIROC and CanESM products in order to detain spatial distribution of precipitation over Pakistan. The results exposed a declining trend (-1.18 mm/decade) over southern part of the country, while northern area showed growing trends. The diminishing trend may be featured to the existence of drought period for next few years in various part of country. The results also indicate spatial and temporal change in precipitation.","PeriodicalId":414498,"journal":{"name":"Proceedings of 4th International Electronic Conference on Water Sciences","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121772003","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