ebru eris

Önyüzü Beton Kaplamalı Kaya Dolgu Barajlar ve Dinamik Etkiler Altındaki Davranışları

Handbook of Engineering Hydrology (Three-Volume Set)

Evaluation of an erosion-sediment transport model for a hillslope using laboratory flume data

Journal of Arid Land, 2014

ABSTRACT Climate change can escalate rainfall intensity and cause further increase in sediment tr... more ABSTRACT Climate change can escalate rainfall intensity and cause further increase in sediment transport in arid lands which in turn can adversely affect water quality. Hence, there is a strong need to predict the fate of sediments in order to provide measures for sound erosion control and water quality management. The presence of microtopography on hillslopes influences processes of runoff generation and erosion, which should be taken into account to achieve more accurate modelling results. This study presents a physically based mathematical model for erosion and sediment transport coupled to one-dimensional overland flow equations that simulate rainfall-runoff generation on the rill and interrill areas of a bare hillslope. Modelling effort at such a fine resolution considering the flow connection between interrill areas and rills is rarely verified. The developed model was applied on a set of data gathered from an experimental setup where a 650 cm×136 cm erosion flume was pre-formed with a longitudinal rill and interrill having a plane geometry and was equipped with a rainfall simulator that reproduces natural rainfall characteristics. The flume can be given both longitudinal and lateral slope directions. For calibration and validation, the model was applied on the experimental results obtained from the setup of the flume having 5% lateral and 10% longitudinal slope directions under rainfall intensities of 105 and 45 mm/h, respectively. Calibration showed that the model was able to produce good results based on the R 2 (0.84) and NSE (0.80) values. The model performance was further tested through validation which also produced good statistics (R 2=0.83, NSE=0.72). Results in terms of the sedigraphs, cumulative mass curves and performance statistics suggest that the model can be a useful and an important step towards verifying and improving mathematical models of erosion and sediment transport.

Stochastic modeling of Lake Van water level time series with jumps and multiple trends

Hydrology and Earth System Sciences, 2013

In 1990s, water level in the closed-basin Lake Van located in the Eastern Anatolia, Turkey has ri... more In 1990s, water level in the closed-basin Lake Van located in the Eastern Anatolia, Turkey has risen up about 2 m. Analysis of the hydrometeorological shows that change in the water level is related to the water budget of the lake. In this study, a stochastic model is generated using the measured monthly water level data of the lake. The 5 model is derived after removal of trend and periodicity in the data set. Trend observed in the lake water level time series is fitted by mono-and multiple-trend lines. For the multiple-trend, the time series is first divided into homogeneous segments by means of SEGMENTER, segmentation software. Four segments are found meaningful practically each fitted with a trend line. Two models considering mono-and multiple-trend 10 time series are developed. The multiple-trend model is found better for planning future development in surrounding areas of the lake. 20 on the population residing around the lake . Another example is Lake Urmia from northwestern Iran, one of the largest hypersaline lakes in the world. Due to drought and increased demands for agricultural water in the lake's basin, the salinity of the lake has risen to more than 300 g L −1 during recent years, and large areas of the lake bed have been desiccated . The instrumental 25 record of the water level oscillations in the Caspian Sea that covers a period starting 2354 Abstract 2363

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Laboratory experiments of sediment transport from bare soil with a rill

Hydrological Sciences Journal, 2013

ABSTRACT Mathematical models developed for quantification of sediment transport in hydrological w... more ABSTRACT Mathematical models developed for quantification of sediment transport in hydrological watersheds require data collected through field or laboratory experiments, but these are still very rare in the literature. This study aims to collect such data at the laboratory scale. To this end, a rainfall simulator equipped with nozzles to spray rainfall was constructed, together with an erosion flume that can be given longitudinal and lateral slopes. Eighty experiments were performed, considering microtopographical features by pre-forming a rill on the soil surface before the start of each experiment. Medium and fine sands were used as soil, and four rainfall intensities (45, 65, 85 and 105 mm h-1) were applied in the experiments. Rainfall characteristics such as uniformity, granulometry, drop velocity and kinetic energy were evaluated; flow and sediment discharge data were collected and analysed. The analysis shows that the sediment transport rate is directly proportional to rainfall intensity and slope. In contrast, the volumetric sediment concentration stays constant and does not change with rainfall intensity unless the slope changes. These conclusions are restricted to the conditions of experiments performed under rainfall intensities between and 105 mm h-1 for medium and fine sands in a 136-cm-wide, 650-cm-long and 17-cm-deep erosion flume with longitudinal and lateral slopes varying between 5 and 20%.

A rainfall simulator for laboratory-scale assessment of rainfall-runoff-sediment transport processes over a two-dimensional flume

CATENA, 2012

ABSTRACT A rainfall simulator is an ideal tool for infiltration, soil erosion, and other related ... more ABSTRACT A rainfall simulator is an ideal tool for infiltration, soil erosion, and other related research areas for replicating the process and characteristics of natural rainfall. In this study, a laboratory-scale rainfall simulator is developed. Rainfall characteristics including the rainfall intensity and its spatial uniformity, raindrop size, raindrop velocity, and kinetic energy confirm that natural rainfall conditions are simulated with sufficient accuracy. Pressure nozzles are used to spray water corresponding to rainfall intensities ranging from 45 to 105 mm h− 1. The simulator produces rainfall with uniformity coefficient changing between 82 and 89%. The raindrops falling with an initial velocity from a height of 2.43 m have median diameters of 2.2–3.1 mm. The impact velocities of the median size raindrops deviate from their terminal velocities with a relative error between 6 and 15%. The accompanying erosion flume can be given slope up to 20% in lateral and longitudinal directions. During the experiments, flow measurement is taken from two outlets at the end of the flume to distinguish the contribution of interrill areas into rills. Experiments result in typical rainfall-induced hydrographs and sedigraphs observed under natural conditions. This shows the ability of the rainfall simulator for use in sediment transport processes over hillslopes.

Estimation of Hydraulic Modeling Parameters of Poorly Gauged Basins Using Remote Sensing and GIS

by Ugur Alganci and ebru eris

WSEAS International …, 2010

According to the increasing population, pollution of the natural reserves, global climate changin... more According to the increasing population, pollution of the natural reserves, global climate changing effects, distractions due to disasters make it indispensable to explore and research the Earth faster and cheaper. In comparison to conventional methods, integration of Remote Sensing (RS) and Geographical Information Systems (GIS) offer faster and economical solutions. Recently, for the hydrology and water resource studies and researches, RS and GIS are being used. Eastern Black Sea region where the study area is located in is a mountainous area. This type of places is hard or impossible to reach to acquire data by terrestrial measurement. However, by using integration of RS and GIS even those kinds of basins can be modeled. In small and poorly gauged basins by using different kinds of geostatistical methods, isohyets can be generated. By Digital Elevation Model (DEM), topographic features of the area can be obtained. Besides, by applying image classification to multispectral satellite data, current land use can be determined. Integrating all these data, basin area can be modeled assisted by GIS. In this study, for the classification of the study area IRS P6 multispectral satellite data with 5.8 m spatial resolution are used and to derive the Digital Elevation Model IRS P5 stereo satellite data with 2.5 m spatial resolution is used. The basin characteristics are mathematically modeled. Using DEM, which is generated from satellite data, isohyets map which is created by using one of the geostatistical methods Kriging, and basin characteristics, mean annual flows are estimated by the help of multiple regression analysis.

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Akım Ölçümleri Olmayan Akarsu Havzalarında Hidroelektrik Potansiyelin Belirlenmesine Yönelik Uzaktan Algılama ve CBS ile Hidrolojik Modelleme

by ebru eris and Ugur Alganci

hkmo.org.tr

Hidroloji ve su kaynakları çalışmalarında son yıllarda Uzaktan Algılama (UA) yöntemleri ile sağla... more Hidroloji ve su kaynakları çalışmalarında son yıllarda Uzaktan Algılama (UA) yöntemleri ile sağlanan uydu görüntüleri ve Coğrafi Bilgi Sistemleri (CBS) kullanılmaktadır. Uydu verileri ile yersel ölçümlere göre hızlı ve ekonomik çözümler elde edilebilmektedir. Bu çalışmada Solaklı Havzası için arazi kullanımının belirlenmesi amacıyla IRS P6, Sayısal Yükseklik Modeli (SYM)'nin oluşturulması amacı ile de stereo IRS P5 uydu verisi kullanılmıştır. SYM kullanılarak havzanın akış yönü ve yüzey akış haritaları oluşturulmuştur. Sonraki aşamada SYM, CBS yazılımda analiz edilerek havzanın sentetik drenaj ağı oluşturulmuştur. Bu drenaj ağı üzerinde, kolların kesişim noktaları üzerinde belirlenen istasyon noktalarını besleyen alt havzalar, CBS ortamında belirlenmiştir. Son aşamada alt havzalara ait topografik parametreler hesaplanmıştır. Havzada ve komşu havzalardaki meteoroloji istasyonlarının yağış verileri kriging yöntemi ile değerlendirilip havzaya ait eşyağış haritası oluşturulmuştur. Topografik parametreler ve eşyağış eğrilerinden elde edilen ortalama alansal yağış bilgileri çoklu regresyonla elde edilen akım denkleminde kullanılarak istasyon noktalarına ait akım değerleri hesaplanmıştır.

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Homogeneity and Trend Analysis of Hydrometeorological Data of the Eastern Black Sea Region, Turkey

Journal of Biophysical Chemistry

Eastern Black Sea Region in northeastern part of Turkey has the highest precipitation total in th... more Eastern Black Sea Region in northeastern part of Turkey has the highest precipitation total in the country, approaching 2500 mm per a year. It is therefore an important region as it frequently encounters with flash floods due to heavy rains. For future planning of water resources, environment and urbanization, it is important to know the expected behavior of hydrometeorological processes, mainly precipitation and flow. Due to these facts, in this study, homogeneity of long-term annual precipitation and streamflow series of the Eastern Black Sea Region, Turkey is checked using double mass curve method and trends are determined by means of the Mann-Kendall test. The data network consists of 38 precipitation gauging stations and 40 flow gauging stations across the Eastern Black Sea Region. It is found that 27 precipitation stations out of 38 are homogeneous and no trend is available. Out of the remaining stations, nine are found non-homogeneous and four with trend. For annual flow data, it is found that 22 stations out of 40 are homogeneous and no trend is available. The remaining 18 stations are found non-homogeneous, among which 5 stations have trend at the same time.

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Akım Ölçümleri Olmayan Akarsu Havzalarında Hidroelektrik Potansiyelin Belirlenmesine Yönelik Uzaktan Algılama ve CBS ile Hidrolojik Modelleme

by ebru eris and H Gonca Aydogdu Coskun

hkmo.org.tr

Hidroloji ve su kaynakları çalışmalarında son yıllarda Uzaktan Algılama (UA) yöntemleri ile sağla... more Hidroloji ve su kaynakları çalışmalarında son yıllarda Uzaktan Algılama (UA) yöntemleri ile sağlanan uydu görüntüleri ve Coğrafi Bilgi Sistemleri (CBS) kullanılmaktadır. Uydu verileri ile yersel ölçümlere göre hızlı ve ekonomik çözümler elde edilebilmektedir. Bu çalışmada Solaklı Havzası için arazi kullanımının belirlenmesi amacıyla IRS P6, Sayısal Yükseklik Modeli (SYM)'nin oluşturulması amacı ile de stereo IRS P5 uydu verisi kullanılmıştır. SYM kullanılarak havzanın akış yönü ve yüzey akış haritaları oluşturulmuştur. SYM, CBS yazılımda analiz edilerek havzanın sentetik drenaj ağı oluşturulmuştur. Bu drenaj ağı üzerinde, kolların kesişimlerinde belirlenen istasyon noktalarını besleyen alt havzalar, CBS ortamında belirlenmiştir. Son aşamada alt havzalara ait topografik parametreler hesaplanmıştır. Havzada ve komşu havzalardaki meteoroloji istasyonlarının yağış verileri kriging yöntemi ile değerlendirilip havzaya ait eşyağış haritası oluşturulmuştur. Topografik parametreler ve ortalama alansal yağış bilgileri çoklu regresyonla elde edilen akım denkleminde kullanılarak istasyon noktalarına ait akım değerleri hesaplanmıştır.

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Estimation of Basin Parameters and Precipitation Distribution of Solakli Basin, Turkey

by ebru eris and H Gonca Aydogdu Coskun

wseas.us

Solakli Basin is located Eastern Black Sea region where high mountain ranges run parallel to the ... more Solakli Basin is located Eastern Black Sea region where high mountain ranges run parallel to the coast in the north. Such a mountainous terrain, it is generally hard or impossible to reach to acquire data by terrestrial measurement. However, today, by using integration of Remote Sensing and Geographic Information Systems even those kinds of basins can be modelled. These techniques provide to derive basin, land use and/or soil type characteristics in an accurate and quick way, particularly for water resources assessment studies. In addition to basin characteristics, spatial distribution of precipitation is also important for these types of studies.

format_quoteSupervised classification using Maximum Likelihood algorithm yielded high accuracy in land cover mapping, validated with ground truth data.format_quote

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Trend analysis of sea levels along Turkish coasts

wsprod.colostate.edu

Sea level changes can be considered as an indicator of environmental and climate change. Sea leve... more Sea level changes can be considered as an indicator of environmental and climate change. Sea level becomes a factor of anxiety to those who fear the possible consequences of the earth warmed as a result of the buildup of greenhouse gases. Despite the cities along coastal lines cover less than five percent of the total surface area of Turkey; their total population is over 30 million with a rapid growing rate. A significant change in sea levels is extremely important to the coastal communities in Turkey. In literature, linear secular trends in annual mean sea level data are calculated as the least squares linear regression to a bivariate distribution of the data value versus year. The length of the time series is recommended to be 60 years or longer which sometimes is permitted to be as low as 25 years. In this study, we use a nonparametric approach to determine trends in sea levels as the available data comprises of rather short record length. At the same time, the nonparametric methods are more tolerable for the short records, computationally simpler and distribution-free. Therefore we investigated trend behaviors in sea level data measured along the Mediterranean, Aegean and Black Sea coasts of Turkey using nonparametric Mann-Kendall test. Annual sea level records, observed for eight typical stations, were used for the purpose of trend detection. As a result, five out of eight stations showed an upward trend as one of them showed a downward trend. No trend was found for the remaining stations. We also fitted a least squared line to quantify rate of change in seal level. Among the stations showing positive trends, the highest rate of change was computed in Trabzon (the Black Sea station) whereas the lowest was computed in Kar ıyaka (the Aegean Sea station). The results confirmed a strong signal of sea level rise at global scale.

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Estimation of Hydraulic Modeling Parameters of Poorly Gauged Basins Using Remote Sensing and GIS

WSEAS International …, Jan 1, 2010

According to the increasing population, pollution of the natural reserves, global climate changin... more According to the increasing population, pollution of the natural reserves, global climate changing effects, distractions due to disasters make it indispensable to explore and research the Earth faster and cheaper. In comparison to conventional methods, integration of Remote Sensing (RS) and Geographical Information Systems (GIS) offer faster and economical solutions. Recently, for the hydrology and water resource studies and researches, RS and GIS are being used. Eastern Black Sea region where the study area is located in is a mountainous area. This type of places is hard or impossible to reach to acquire data by terrestrial measurement. However, by using integration of RS and GIS even those kinds of basins can be modeled. In small and poorly gauged basins by using different kinds of geostatistical methods, isohyets can be generated. By Digital Elevation Model (DEM), topographic features of the area can be obtained. Besides, by applying image classification to multispectral satellite data, current land use can be determined. Integrating all these data, basin area can be modeled assisted by GIS. In this study, for the classification of the study area IRS P6 multispectral satellite data with 5.8 m spatial resolution are used and to derive the Digital Elevation Model IRS P5 stereo satellite data with 2.5 m spatial resolution is used. The basin characteristics are mathematically modeled. Using DEM, which is generated from satellite data, isohyets map which is created by using one of the geostatistical methods Kriging, and basin characteristics, mean annual flows are estimated by the help of multiple regression analysis.

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Effect of coastline configuration on precipitation distribution in coastal zones

Hydrological Processes, Jan 1, 2009

The effects of coastline, together with the other geographical and topographical factors such as ... more The effects of coastline, together with the other geographical and topographical factors such as longitude, latitude, elevation and distance from sea, on mean annual precipitation are investigated for the coastal area of the eastern Black Sea region. In this location, mountains run parallel to the sea coast. The coastline configuration is represented by a new variable, the coastline angle. A multiple linear regression (MLR) analysis is performed on mean annual precipitation recorded in coastal and inland gauges. In the study area, three variables-longitude, latitude and coastline angle-can explain 81% of the spatial variability of precipitation for the coastal gauges and 93% of that for the inland gauges. When the entire study area considered, without grouping the gauges, 80% of the spatial variability is explained by these variables.

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Remote Sensing and GIS Innovation with Hydrologic Modelling for Hydroelectric Power Plant (HPP) in Poorly Gauged Basins

by ebru eris and H Gonca Aydogdu Coskun

Water resources …, Jan 1, 2010

Within the last two decades, modelling of rainfall-runoff has become an important topic in water ... more Within the last two decades, modelling of rainfall-runoff has become an important topic in water resources assessment due to increasing water demand and energy, particularly in the determination of hydropower potential. In addition to remote sensing (RS) and geographical information systems (GIS), with the development on satellite technologies, it becomes possible to asses rapid and economic solutions to determine a practical rainfall-runoff relation, particularly poorly gauged or ungauged basins. In this paper, Solakli Watershed which is located in Eastern Black Sea Region of Turkey is selected as the study area. To determine the hydroelectric water potential in a poorly gauged basin, basin boundary and area, minimum

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Trend Analysis of Sea Levels Along Turkish Coast

Sea level changes can be considered as an indicator of environmental and climate change. Sea leve... more Sea level changes can be considered as an indicator of environmental and climate change. Sea level becomes a factor of anxiety to those who fear the possible consequences of the earth warmed as a result of the buildup of greenhouse gases. Despite the cities along coastal lines cover less than five percent of the total surface area of Turkey; their total population is over 30 million with a rapid growing rate. A significant change in sea levels is extremely important to the coastal communities in Turkey. In literature, linear secular trends in annual mean sea level data are calculated as the least squares linear regression to a bivariate distribution of the data value versus year. The length of the time series is recommended to be 60 years or longer which sometimes is permitted to be as low as 25 years. In this study, we use a nonparametric approach to determine trends in sea levels as the available data comprises of rather short record length. At the same time, the nonparametric methods are more tolerable for the short records, computationally simpler and distribution-free. Therefore we investigated trend behaviors in sea level data measured along the Mediterranean, Aegean and Black Sea coasts of Turkey using nonparametric Mann-Kendall test. Annual sea level records, observed for eight typical stations, were used for the purpose of trend detection. As a result, five out of eight stations showed an upward trend as one of them showed a downward trend. No trend was found for the remaining stations. We also fitted a least squared line to quantify rate of change in seal level. Among the stations showing positive trends, the highest rate of change was computed in Trabzon (the Black Sea station) whereas the lowest was computed in Kar ıyaka (the Aegean Sea station). The results confirmed a strong signal of sea level rise at global scale.

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Modeling Monthly Mean Flow in a Poorly Gauged Basin by Fuzzy Logic

CLEANSoil, Air, …, Jan 1, 2009

The estimation of the monthly mean flow is a critical issue in many water resource development pr... more The estimation of the monthly mean flow is a critical issue in many water resource development projects. However, in practice the mean flow is not easily determined in ungauged and poorly gauged basins. Therefore, in the literature, various flow estimation methods have been developed recently for mountainous regions which are generally ungauged or poorly gauged basins. In this study a fuzzy logic model based on the Mamdani approach was developed to estimate the flow for poorly gauged mountainous basins. This model was applied to the Solakli Basin which is located in the Eastern Black Sea Region of Turkey. Limited rainfall and flow data are available for this basin. In addition to these variables, the stream and time coefficients were introduced and used as variables for modeling. The data was divided into training and testing phases. The model results were compared with the measured data. The comparison depends on seven statistical characteristics, four different error modes and the contour map method. It was observed that the fuzzy model developed in this study yielded reliable results.

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Filtered smoothed minima baseflow separation method

Journal of Hydrology, Jan 1, 2009

The smoothed minima baseflow separation method of the United Kingdom Institute of Hydrology (UKIH... more

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