The Open Hydrology Journal最新文献_第5页

Stability and Bifurcation Analysis of Reservoir Sedimentation Management 水库沉降管理的稳定性与分岔分析

The Open Hydrology Journal Pub Date : 2010-12-21 DOI: 10.2174/1874378101004010102

R. Huffaker, D. Rider, R. Hotchkiss

{"title":"Stability and Bifurcation Analysis of Reservoir Sedimentation Management","authors":"R. Huffaker, D. Rider, R. Hotchkiss","doi":"10.2174/1874378101004010102","DOIUrl":"https://doi.org/10.2174/1874378101004010102","url":null,"abstract":"The alarming loss of water storage capacity to sedimentation in reservoirs worldwide is prompting a paradigm shift toward sustainable management. Previous research has investigated the physical capability of various technologies to control reservoir sediment, and formulated economic rules governing their optimal sustainable use. We ask the next rele- vant questions: Is sustainable reservoir management structurally stable for particular technologies, or do thresholds exist such that small perturbations in key management parameters abruptly unleash dynamics driving the reservoir toward ex- tinction? What are the dynamic properties of reservoirs in transition? We uncover a saddle-node bifurcation for the par- ticular case of a multi-purpose public reservoir manager who adopts the environmentally friendly 'hydrosuction-dredging' sediment removal technology. Beyond the bifurcation threshold, sustainable management abruptly gives way to eventual loss of storage capacity to sedimentation. Reservoirs throughout the world suffer from sedimenta- tion. Examples include estimated annual storage capacity losses of 2.3% in China (2), 0.5% in India (2), and 1% worldwide (3). Specific examples are catalogued by Batuca and Jordaan (4). These include the Cir-lurtsk Reservoir on the Sulak River (Russia) which was 95% sedimented in 7 years; the Gumati Reservoir on the Vakhs River (Georgia) which was 90% sedimented in 11 years; and the Zemo Af- char Reservoir at the confluence of the Kura and Aragi Riv- ers (Russia) which lost 44% of its initial storage capacity in the first 2 years, 32% in the next 8 years, and 3.5% up to 1967. Other examples include the Tarbela Dam on the Indus River—the most important facility of its kind in Pakistan— which lost 20% of its storage capacity after 23 years of op- eration (5); and the Matilija Dam in California whose storage capacity decreased from 7,000 acre feet in 1947 to less than 500 acre feet by 2005 (6).","PeriodicalId":247243,"journal":{"name":"The Open Hydrology Journal","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133836837","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

Estimating soil salinity over a shallow saline water table in semiarid Tunisia. 在半干旱的突尼斯估算浅层含盐地下水位的土壤盐度。

The Open Hydrology Journal Pub Date : 2010-11-26 DOI: 10.2174/1874378101004010091

F. Bouksila, M. Persson, R. Berndtsson, A. Bahri, I. Hamba

{"title":"Estimating soil salinity over a shallow saline water table in semiarid Tunisia.","authors":"F. Bouksila, M. Persson, R. Berndtsson, A. Bahri, I. Hamba","doi":"10.2174/1874378101004010091","DOIUrl":"https://doi.org/10.2174/1874378101004010091","url":null,"abstract":"Rapid and reliable observations of soil electrical conductivity are essential in order to maintain sustainable irri- gated agriculture. Direct measurement of the electrical conductivity of saturated soil paste (ECe), however, is tedious and time consuming. Therefore, there are needs to find efficient indirect methods to predict the soil salinity from other readily available observations. In this paper we explore the application of multiple linear regression (MLR) and artificial neural networks (ANN) to predict ECe variation from easily measured soil and groundwater properties under highly complex and heterogeneous field conditions in semiarid Tunisia. We compare two methods for dividing the data set into training and validation sub-sets; a statistical (SD) and a random data set division (RD), and their effect on model performance. The in- put variables were chosen from the plot coordinates, groundwater table properties (depth, electrical conductivity, pie- zometric level), and soil particle size at 5 depths. The results obtained with ANN and MLR indicate that the statistical properties of data in the training and validation sets need to be taken into account to ensure that optimal model perform- ance is achieved. The SD can be considered as a solution to resolve the problem of over-fitting a model when using ANN. For the SD, the determination coefficient (R 2 ) when using an ANN model varied from 0.85 to 0.88 and the root mean square error from 1.23 to 1.80 dS m -1 . Because of the complexity of the field soil salinity process and the spatial variabil- ity of the data, this clearly indicates the potential to use ANN models to predict ECe.","PeriodicalId":247243,"journal":{"name":"The Open Hydrology Journal","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128654096","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: 16

Characterization methods for small estuarine systems in the mid-Atlantic region of the United States. 美国中大西洋地区小型河口系统的表征方法。

The Open Hydrology Journal Pub Date : 2010-11-06 DOI: 10.2174/1874378101004010065

J. F. Paul, J. Kiddon, C. Strobel

{"title":"Characterization methods for small estuarine systems in the mid-Atlantic region of the United States.","authors":"J. F. Paul, J. Kiddon, C. Strobel","doi":"10.2174/1874378101004010065","DOIUrl":"https://doi.org/10.2174/1874378101004010065","url":null,"abstract":"Various statistical methods were applied to spatially discrete data from 14 intensively sampled small estuarine systems in the mid-Atlantic U.S. The number of sites per system ranged from 6 to 37. The surface area of the systems ranged from 1.9 to 193.4 km 2 . Parameters examined were depth, bottom temperature, bottom salinity, surface chlorophyll a, bottom dissolved oxygen, lead concentration in sediments, silt-clay content of sediments, and number of infaunal ben- thic species. Statistical methods included means, standard deviations, coefficients of variation, empirical cumulative dis- tribution functions, and contours determined by bivariate interpolation and interpolation by kriging. All of these methods were found to be appropriate depending upon the purpose of the characterization. Contouring was applied only to those systems with at least 23 discrete sample sites (7 systems). Cross-validation and randomization techniques were used to compare the two interpolation methods. Kriging was advantageous over bivariate interpolation when moderate to strong spatial correlation existed in the residuals (that is, after removal of the spatial trend with a nonparametric regression model). When kriging was conducted, the removal of the trend was necessary if the stationarity assumption was to be valid. The Delaware/Maryland coastal bays are shallow, well-mixed (horizontally and vertically) systems that exhibit little or no spatial correlation for the parameters examined. The South and Severn Rivers, subsystems of the Chesapeake Bay, exhibited moderate to strong spatial dependence for some parameters. Randomization techniques were used to evaluate the effect of decreasing the number of sites in kriged parameters. Based upon these randomizations, it was found that 23 discrete sites could be used for kriging in estuaries with characteristics similar to those in the mid-Atlantic and if the sam- ples were collected with a comparable design.","PeriodicalId":247243,"journal":{"name":"The Open Hydrology Journal","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132652246","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

Testing computational algorithms for unsaturated flow. 测试非饱和流动的计算算法。

The Open Hydrology Journal Pub Date : 2010-03-20 DOI: 10.2174/1874378101004010227

F. Tracy

引用次数: 4

Hydrological Modelling in the Lake Tana Basin, Ethiopia Using SWAT Model 利用SWAT模型在埃塞俄比亚塔纳湖流域进行水文模拟

The Open Hydrology Journal Pub Date : 2008-09-18 DOI: 10.2174/1874378100802010049

S. Setegn, R. Srinivasan, B. Dargahi

引用次数: 298

Exceptional Rainfall Characteristics Related to Erosion Risk in Semiarid Tunisia 与半干旱突尼斯的侵蚀风险相关的异常降雨特征

The Open Hydrology Journal Pub Date : 2008-05-30 DOI: 10.2174/1874378100802010025

S. Jebari, R. Berndtsson, A. Bahri, M. Boufaroua

{"title":"Exceptional Rainfall Characteristics Related to Erosion Risk in Semiarid Tunisia","authors":"S. Jebari, R. Berndtsson, A. Bahri, M. Boufaroua","doi":"10.2174/1874378100802010025","DOIUrl":"https://doi.org/10.2174/1874378100802010025","url":null,"abstract":"The Tunisian Dorsal area is representative of the semiarid Mediterranean region in terms of water resources availability as well as exceptional rainfall characteristics, runoff generation, and soil loss risk. In this context, soil properties, surface management practices together with highly intensive rainfall make the soils vulnerable to erosion. If the exceptional rainfall characteristics are linked to different erosion types, the erosion risk could be evaluated in a simple and straightforward way. In this regard, a short time-scale rainfall data base from the Dorsal area was analysed in the paper. The procedure used involves finding a representative duration between 1-60 min for the exceptional rainfall characteristics. Rainfall intensities of different return periods are then related to the different erosion types. The identified exceptional rainfall durations between 1-60 min were analyzed in terms of number of events, depth, average intensity and maximum intensity. Results show that the 15-min duration maximum intensity can be used to evaluate erosion risk based on soil erosion type. The developed methodology can be used to evaluate erosion risk in semiarid regions based on exceptional rainfall characteristics. In practical terms the results can be used to better manage catchments that are vulnerable to soil erosion. (Less)","PeriodicalId":247243,"journal":{"name":"The Open Hydrology Journal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130213169","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: 33

The Geometry of Soil Crack Networks 土壤裂缝网络的几何结构

The Open Hydrology Journal Pub Date : 2008-03-30 DOI: 10.2174/1874378100802010034

V. Chertkov

引用次数: 12

Spatial Distribution of Water Quality and Load Units in the Iinashi River Basin, Shimane Prefecture, Japan 日本岛根县林石河流域水质及负荷单元的空间分布

The Open Hydrology Journal Pub Date : 2008-03-24 DOI: 10.2174/1874378100802010015

H. Somura, D. Nakayama, M. Aizaki, Y. Seike, M. Okumura, Kumiko Nishikata

{"title":"Spatial Distribution of Water Quality and Load Units in the Iinashi River Basin, Shimane Prefecture, Japan","authors":"H. Somura, D. Nakayama, M. Aizaki, Y. Seike, M. Okumura, Kumiko Nishikata","doi":"10.2174/1874378100802010015","DOIUrl":"https://doi.org/10.2174/1874378100802010015","url":null,"abstract":"The spatial distributions of water quality and load units were determined for each small sub basin of the Iinashi River basin as a first step in water environment management. In addition, a GIS database was established to comprehensively resolve the issue of water quality degradation. It was found the concentrations of water quality parameters in the Iinashi River basin were relatively low at almost all sampling points. The average concentrations of each parameter are 1.86 mg·L -1 of chemical oxygen demand, 0.73 mg·L -1 of dissolved organic carbon, 18.5 % of biodegradation ability, 6.58 mg·L -1 of silica, 519.8 μgN·L -1 of total nitrogen, and 27.4 μgP·L -1 of total phospho- rus. In addition, the load units discharged from the small watersheds were obtained. The load units varied greatly regardless of similar land use in the basin. Moreover, discharged loads from observation point 1-31 in the Yamasa River basin were higher than those from observation point 1-5 in the upstream of the Iinashi River basin regardless of high percentage of forest area (91.51%), low percentage of agricultural land (2.3%) and low population density (24 people·km -2 ). Finally, the discharged loads from observation point 1-3 were de- termined as 53.2 g·ha -1 ·day -1 of suspended solid, 45.4 g·ha -1 ·day -1 of chemical oxygen demand, 20.9 g·ha -1 ·day -1 of dissolved organic car- bon, 8.1 g·ha -1 ·day -1 of particulate organic carbon, 16.3 g·ha -1 ·day -1 of total nitrogen, 5.0 g·ha -1 ·day -1 of dissolved organic nitrogen, 1.3 g·ha -1 ·day -1 of particulate organic nitrogen, and 0.3 g·ha -1 ·day -1 of total phosphorus.","PeriodicalId":247243,"journal":{"name":"The Open Hydrology Journal","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128723915","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

WaterBase: SWAT in an Open Source GIS WaterBase:开源GIS中的SWAT

The Open Hydrology Journal Pub Date : 2008-01-14 DOI: 10.2174/1874378100802010001

C. George, L. León

引用次数: 46

The Soil Reference Shrinkage Curve 土壤参考收缩曲线

The Open Hydrology Journal Pub Date : 2007-12-06 DOI: 10.2174/1874378100701010001

V. Chertkov

{"title":"The Soil Reference Shrinkage Curve","authors":"V. Chertkov","doi":"10.2174/1874378100701010001","DOIUrl":"https://doi.org/10.2174/1874378100701010001","url":null,"abstract":"A recently proposed model showed how a clay shrinkage curve is transformed to the soil shrinkage curve at the soil clay content higher than a critical one. The objective of the present work was to generalize this model to the soil clay content lower a critical one. I investigated (i) the reference shrinkage curve, that is, one without cracks; (ii) the superficial layer of aggregates, with changed pore structure compared with the intraaggregate matrix; and (iii) soils with sufficiently low clay content where there are large pores inside the intraaggregate clay (so-called lacunar pores). The methodology is based on detail accounting for different contributions to the soil volume and water content during shrinkage. The key point is the calculation of the lacunar pore volume variance at shrinkage. The reference shrinkage curve is determined by eight physical soil parameters: (1) oven-dried specific volume; (2) maximum swelling water content; (3) mean solid den- sity; (4) soil clay content; (5) oven-dried structural porosity; (6) the ratio of aggregate solid mass to solid mass of intraag- gregate matrix; (7) the lacunar factor that characterizes the rate of the lacunar pore volume change with water content; and (8) oven-dried lacunar pore volume. The model was validated using available data. The model predicted value of the slope of the reference shrinkage curve in the basic shrinkage area is equal to unity minus the lacunar factor value, and is be- tween unity and zero in the agreement with observations.","PeriodicalId":247243,"journal":{"name":"The Open Hydrology Journal","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130350484","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: 21