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Izračuni nizkih pretokov so bistvenega pomena pri spremljanju vodotokov in zagotavljanju njihove kakovosti, saj so življenjsko okolje za mnoge živali in rastline. Na razpolago je več različnih kazalnikov izračunavanja nizkih pretokov, kot so npr. krivulja trajanja pretokov, deficit vodnega toka, indeks baznega odtoka, petindevetdesetodstotni pretok Q95, srednji letni minimum itd. V ZDA za izračun nizkih pretokov najpogosteje uporabljajo dve metodi, in sicer hidrološko (xQy) in biološko (xBy). Izračun nizkih pretokov po obeh metodah omogoča program DFLOW. Hidrološka metoda je statistična, biološka metoda pa je empirična in temelji neposredno na kriterijih za kakovost vodnega življenja. Kriteriji so izraženi v obliki dveh koncentracij namesto ene, tako da lahko bolj natančno odražajo toksikološka in dejanska stanja vodotoka. Koncentraciji sta CCC, ki določa dovoljeno stalno koncentracijo onesnaževal v vodotoku in CMC, ki določa maksimalno koncentracijo onesnaževal v vodotoku. V diplomski nalogi so narejeni izračuni nizkih pretokov in odstopanj s programom DFLOW za 56 vodomernih postaj po Sloveniji. Za izračunane pretoke 4B3, 7Q10, 1B3 in1Q10 sta bili narejeni analiza ter primerjava z izračunanim Q95. Izkazalo se je, da so izračunani pretoki v programu DFLOW v primerjavi s Q95 bistveno nižji. Za izbranih 15 vodomernih postaj pa je bila narejena še primerjava z ekološko sprejemljivim pretokom po slovenski metodologiji in metodah izbranih evropskih držav. Najmanjše razlike pretokov 4B3, 7Q10, 1B3 in1Q10 smo dobili pri primerjavi s povratnim odvzemom po slovenski metodologiji in avstrijski metodi Q361. The calculation of low flows is crucial for monitoring streams and ensuring their quality, because they are habitat for many animals and plants. There is a number of different indices for calculation of low flows, such as flow duration curve, streamflow deficit, base flow index, ninety-five percentile flow Q95 mean annual minima etc. In USA most commonly used methods for calculation of low flows are hydrological (xQy) and biological (xBy). Both methods can be implemented with DFLOW software. Hydrological method is statistical, biological one is empirical and uses aquatic life water quality criteria directly for its implementation. Criteria are expressed as two concentrations, instead of one, so that criteria can more exactly reflect toxicological and practical realities. The two concentrations are CCC, which provides the highest concentration of pollutants that could be maintained indefinitely in the stream and CMC, which determines maximum concentration of pollutants in the stream. In graduation thesis calculations of low flows and excursions with DFLOW sofware are conducted for 56 Slovenian gauging stations. For calculated flows 4B3, 7Q10, 1B3 and 1Q10 an analysis and comparison with calculated Q95 were made. It has turned out that the calculated flows with software DFLOW compared to Q95 are significantly lower. For 15 selected gauging stations a comparison with ecologically acceptable flow by the Slovenian methodology and methods of selected European countries was also made. The smallest difference have occurred by comparison of flows 4B3, 7Q10, 1B3 and 1Q10 with the return withdrawal by the Slovenian methodology and Austrain method Q361.

[EN] The need to perform a flood defense study comes due to the consequences of torrential rains which happens in the last reach of Mora Ravine. located in the municipallity of Tarragona (Cataluña). The current situation is analyzed and measures are proposed in order to garantee an adequate protection level, trying to minimize the environmental impact, the execution time and the cost. Applying the given pluviometric data and the information about the catchment area, a stadistical study is done, so as to determine the maximum annual precipitation, for the study return periods of 10, 100 and 500 years. After that, an hydrological study is implemented, using the initial topographical and cartographic information, the distribution of land use and the visit to the area. The aim of this study is to obtain the discharge from the catchment, at the drainage point, to the study area. In order to realize it, a pseudo-distributed hydrological method is utilized, through HEC-HMS software. The informatical tool requires some initial parameters, so as to start the simulation. This data consist on weather information, production parameters and water propagation parameters. It is remarkable the need of an accurate estimation of the threshold runoff, taking into account the land preceding humidity. Finally, the outflow hydrographs are obtained for each studied return period. Once the inflow is known, a lamination study is performed. using Excel program. This study is performed to evaluate the outflow oscillation , after the runoff crosses the different drainage works and the natural land basins. As a result of the lamination study, the outflow hydrographs of the last drainage work are achieved. These are different of the previous ones, due to the lamination process. Later, the hydraulic analysis of the existing canalization is implemented, in order to determine the maximum hydraulic capacity which this channel is able to handle. This calculated capacity is compared with the discharge obtained in the preceding study. Due to the detected problems, solutions are proposed, using as design return period 100 years. The measures to apply are the following: the last drainage work enlargement, the restoration of the existing channel and the execution of a new canalization. After that, their economical evaluation is done. In conclusion, the proposed solutions allow an adequate hydraulic operation of the the whole study area of the Mora Ravine., [CA] La realizació d'aquest estudi de defensa contra les inundacions sorgeix de la necessitat d'analitzar l'incidènsia de les avingudes que tenen lloc en el tram final del Barranc de la Mora, situat en el terme municipal de Tarragona (Catalunya). Es diagnostica la situació actual i es proposen les actuacions que garanteixen un nivell de protecció adecuat, intentant minimitzar l'impacte ambiental, el temps d'ejecució i el cost. Utilitzant les dades pluviométriques facilitades i l'informació sobre la conca vertent, es du a terme un anàlisi estadístic per a determinar les avingudes asociades als períodes de retorn d'estudi, de 10, 100 i 500 anys. Gràcies a la visita de camp realitzada, l'informació de partida topogràfica, cartogràfica, d'usos del sòl i l'avaluació pluviomètrica, es realitza un estudi hidrològic per a l'obtenció del caudals en el punt de desaigüe de la conca vertent a la zona d'estudi. Per a això, es realitza la simulació en el software HEC-HMS, empleant un model hidrològic pseudodistribuït. El programa requereix d'una sèrie de paràmetres per a iniciar la simulació, aquestos son, dades meteorològiques, paràmetres de producció i paràmetres de propagació de canalitzacions. Es destaca que, es necessaria l'estimació dels umbrals d'escorretia, de manera que, es tinga en compte l'humetat antecedent del terreny. Finalment s'obtenen els hidrogrames d'eixida per a cada període de retorn estudiat. Una vegada coneguts els caudals entrants a la zona d'estudi, es realitza un Estudi de Laminació, per mitjà del programa informàtic Excel, s'analitza la variació produida en el caudals d'eixida, després de creuar les diverses obres de drenatge i les despressions naturals del terreny. Així, s'obtenen els hidrogrames d'eixida després de l'obra de drenatge del ferrocarril, distints als d'entrada a causa del procès de laminació. Posteriorment, es realitza un Estudi Hidràulic de la canalització existent per a la determinació de la capacitat màxima hidràulica que pot evacuar. Aquesta es comparada amb els caudals pic de l'estudi previ. Dada l'existència d'una problemática es plantegen solucions per a pal·liar la situació actual, empleant com a període de retorn de diseny el de 100 anys. Les mesures a aplicar son, l'ampliació de l'obra de drenatge transversal del ferrocarril, la restauració de la canalització existent i l'ejecució d'una nova canalització, així com la seua valoració económica. En definitiva, amb les solucions plantejades es consegueix un adequat funcionament hidràulic en la totalitat del tram final del Barranc de la Mora., [ES] La realización de este estudio de defensa contra las inundaciones surge de la necesidad de analizar la incidencia de las avenidas que tienen lugar en el tramo final del Barranco de la Mora, situado en el término municipal de Tarragona (Cataluña). Se diagnostica la situación actual y proponen las actuaciones que garanticen un nivel de protección adecuado, intentando minimizar el impacto ambiental, tiempo de ejecución y coste. Utilizando los datos pluviométricos facilitados e información sobre la cuenca vertiente, se lleva a cabo un análisis estadístico para determinar las avenidas asociadas a los periodos de retorno de estudio, de 10, 100 y 500 años. Gracias a la visita de campo realizada, la información de partida topográfica, cartográfica, de usos del suelo y la evaluación pluviométrica, se realiza un estudio hidrológico para la obtención de los caudales en el punto de desagüe de la cuenca vertiente a la zona de estudio. Para ello, se realiza la simulación en el software HEC-HMS, empleando un modelo hidrológico pseudo-distribuido. El programa requiere de una serie de parámetros para iniciar la simulación, éstos son, datos meteorológicos, parámetros de producción y parámetros de propagación de cauces. Se destaca que, es necesaria la estimación de los umbrales de escorrentía, de forma que, se tenga en cuenta la humedad antecedente del terreno. Finalmente se obtienen los hidrogramas de salida para cada periodo de retorno estudiado. Una vez conocidos los caudales entrantes en la zona de estudio, se realiza un Estudio de Laminación, con el programa informático Excel, para el análisis de la variación producida en los caudales de salida, tras cruzar las diversas obras de drenaje y las depresiones naturales del terreno. Así, se obtienen los hidrogramas de salida tras la obra de drenaje del ferrocarril, distintos a los de entrada a causa del proceso de laminación. Posteriormente, se realiza un Estudio Hidráulico del encauzamiento existente para la determinación de la capacidad máxima hidráulica que éste puede trasegar. Ésta es comparada con los caudales pico del estudio previo. Dada la existencia de una problemática se plantean soluciones para paliar la situación actual, empleando como periodo de retorno de diseño el de 100 años. Las medidias a aplicar son, la ampliación de la obra de drenaje transversal del ferrocarril, la restauración del encauzamiento existente y la ejecución de un nuevo encauzamiento, así como su valoración económica. En definitiva, con las soluciones planteadas se consigue el buen funcionamiento hidráulico en la totalidad del tramo final del Barranco de La Mora.

Impactos sócio-ambientais negativos têm colocado a gestão do meio ambiente e dos recursos hídricos em cheque. Produção econômica intensiva, especialmente onde existem hidrelétricas, tem conduzido à perda de abundância e riqueza de espécies e conseqüente diminuição de produção de serviços ambientais à sociedade. Em contrapartida, avanços científicos em ecologia têm demonstrado que a conservação de regimes hidrológicos é o caminho para conservação de ecossistemas e para manutenção da produção de serviços ambientais. É neste contexto que cresce em importância a ferramenta de vazões ambientais, que tem como propósito compatibilizar interesses dos diferentes setores de produção, ao manter em corpos d’água regimes hidrológicos que produzam melhores resultados sócio-econômicos com menores impactos ambientais. O objetivo desta pesquisa é propor um método para a escolha de vazões ambientais, especialmente em regiões com escassez de informações ecológicas. O método proposto fundamenta-se na relação de influência direta entre conservação de regimes hidrológicos, conservação de ecossistemas e produção de serviços ambientais. Para isto, as alterações de regimes hidrológicos são quantificadas para qualificar o grau de conservação do ambiente e de produção econômica por serviços ambientais. O método consiste em diagnosticar alterações hidrológicas, elaborar potenciais regras de vazões ambientais, simular numericamente sua aplicação e prognosticar seus impactos via estudos de alteração hidrológica e de produção econômica por atividades antrópicas. A aplicação da metodologia foi dividida em dois estudos de casos. No primeiro, foram analisadas vazões ambientais para o projeto de aproveitamento hidrelétrico de Belo Monte, no rio Xingu, que ainda não sofre de alterações significativas do regime hidrológico. O segundo estudo consistiu do estudo do grau e da extensão de alteração do regime hidrológico pelo aproveitamento múltiplo da Usina de Manso, no rio Manso, afluente ao rio Cuiabá que drena ao Pantanal. Como resultado, o método mostrou ser flexível a diferentes configurações de disponibilidade de informação, além de possibilitar a escolha de vazões ambientais de forma transparente, colaborativa e participativa. A confiabilidade do método, no entanto, depende da representatividade das informações hidrológicas e do grau de incertezas quanto à relação entre alteração hidrológica, degradação de ecossistemas e perda de produção econômica, quando dados ecológicos são escassos. The natural flow paradigm has not been considered in the Brazilian water resources and environmental management systems yet. Environmental flows studies have just been considered by Brazilian scientific community with too few, if any, experimental studies being undertaken. However, such a tool needs to be considered urgently, once environmental flows sustain ecosystem and their environmental services, which are of great importance to society. This thesis aims to propose a method to subsidize environmental flows selection, especially in regions where ecological data is scarce. We have based such method on the direct influential relation between flow regime alteration, ecosystem degradation and environmental services loss, applying hydrologic alteration indices as proxies of ecosystems degradation and environmental services loss. This new method consists on diagnosing hydrologic alteration, developing potential environmental flows rules, numerically simulate them and assessing theirs impacts on hydrologic alteration and economic production by human activities. The method application was split in two case studies in order to use different sets of its techniques. The former study consisted on assessing environmental flows downstream the projected UHE Belo Monte, located in the Xingu river, a tributary to the Amazon river. In this study only one flow station was applied with its “naturalized” flows as a benchmark. The latter study consisted on assessing the degree and extension of APM Manso dam hydrological impacts, located in a tributary to the Brazilian Pantanal. In this study, data from different stations where used as benchmarks. As a result, this hydrological method showed flexibility to work with different information settings, while it could be applied in a transparent, participative and collaborative approach. However, its confidence relies on hydrological data representativity and on the uncertainty over the relation between hydrological alteration, ecosystems degradation and loss of environmental services, when ecological data are scarce.

Akarsu havzalarında, debinin akarsu yatak kapasitesini aşması halinde sular yatak dışına taşar ve bu olay taşkın olarak adlandırılır. Yurdumuzda meydana gelen taşkın olayları incelendiğinde taşkınların, erozyona maruz bulunan, üzerinde bitki örtüsü tahrip olmuş veya yok olmuş su havzalarında ve de taşkın koruma yapılarının olmadığı akarsularda ortaya çıktığı görülmektedir. Eğimli ve çıplak arazilerde yağış sularının büyük bir bölümü yüzeysel akışa geçerek kısa sürede yüksek akış hızına ulaşmaktadır. Erozyon sonucu katı madde ile yüklenen taşkınlar, can ve mal kaybına neden olmaktadır. Bu yüzden taşkınlar Türkiye için, gerek arazi yapısı gerek çarpık kentleşme ve orman arazilerinin tahribatı neticesiyle depremlerden sonra gelen en önemli doğal afet olmuştur. Taşkınlar, büyük debi, büyük hızlar ve yüksek su seviyeleri ile karakterize edildiğinden, akarsular üzerinde inşa edilecek tüm yapılar için bu taşkın karakteristiklerinin bilinmesi ve bu karakteristiklere göre önlemlerin alınması gerekir. DSİ' nin 1998 yılında yayınlamış olduğu Türkiye' de son otuz yılda gözlenen taşkın olayları envanterine göre 1970-1997 yılları arasında 626 taşkın olayı meydana gelmiştir. Tüm bu taşkınlarda oluşan maddi zarar 1,6 milyon dolardır. Taşkın ötelenmesi, akarsu yatağı, kapalı mecra veya biriktirme haznelerinde ilerleyen taşkın dalgasının zamana ve konuma bağlı değişiminin matematiksel olarak belirlenmesidir. Taşkın ötelenme hesaplan, hidrolik ve hidrolojik olarak ikiye ayrılır. Hidrolik metotlar kütle ve momentum korunum prensibine dayanırken hidrolojik metotlar sadece kütlenin korunum prensibine dayanır. Çalışmada 4 kasım 1995 yılında Aksu Akarsuyu' nun bir kolu olan Sütçüler Değirmendere' de meydana gelen, can ve mal kaybına yol açan taşkın olayı dikkate alınmıştır. Yatakta oluşan taşkın piklerinin matematiksel olarak modellenmesinde hidrolojik metotlardan biri olan Muskingum modeli kullanılmıştır. Elde edilen sonuçlar ile DSİ. 18. Bölge Müdürlüğü tarafından ölçülmüş olan taşkın pik değerleri karşılaştırılmış ve karşılaştırma sonucunda sonuçların uyum içerisinde olduğu görülmüştür. ANAHTAR KELİMELER: Taşkın ötelenmesi, Muskingum Modeli, Açık kanal, Hidrolojik metot, Hidrolik metot, Kararsız akım In river basins, the flooding event occurs when the discharge of water running through of a river is more than a river capacity and this is called the water overflow. When the flooding event occured in Turkey are studied, it is observed that floods are occured in water basins which are under erosion, and have a plant cover which is destroyed or disappeared and rivers which do not have flood protection facilities. Large amount of rainfall start to run on surface and reach high current speeds in a short time in lands with slope and no plants. The floods loaded with sediment as a result of erosion cause life and property losses. Therefore, floods are the most important natural disasters for Turkey after earthquakes because of land shapes, unusual urban and destrution of forest areas. Since floods are characterized by large amount of discharges, high speeds, and high water levels, these flood characteristics should be known and preventive actions must be taken for all buildings to be built in river basins. 626 flood events are monitored from 1970 to 1997 according to the inventory of flood events observed in last thirty years which is published by DSI in 1998. The monetary loss is $1.6 million because of these floods. Flood routing is determined mathematically based on time and place of moving of flood waves in river basins, closed channels, or collection tanks. Flood routing calculations can be classified into two groups which are hydraulic and hydrologic methods. While the hydraulic methods are based on conservation of mass and momentum, the hydrological methods are only based on conservation of mass. In this study, the flood which occured in Sütçüler Değirmendere, a branch of the Aksu River, and cause loss of lives and properties in November 4th, 1995 is considered. The Muskingum Model, one of the hydrological methods, was used to mathematical modelling of the flood peaks occured in the river. The results of this model were compared to the results which were measured by DSI 18th Regional Office and an agreement between these values was obtained. Key Words: Flood routing, Muskingum Model, Open channel, Hydrologic method, Hydraulic method, Unsteady flow. 105

öz ÖLÇEK VE GRİD BOYUTUNUN HİDROLOJİK ÇALIŞMALARDA ETKİSİ Onur PAŞAOĞULLARI Yüksek Lisans, İnşaat Mühendisliği Bölümü Tez Yöneticisi : Doç. Dr. Nurünnisa USUL Nisan 2002, 152 sayfa Topografyayı esas alan hidrolojik modellerin hassasiyeti, elde edilen sayısal yükseklik modelinin (SYM) hassasiyetine bağlıdır. SYM'den elde edilen havza parametreleri hidrolojik modeller için girdiyi oluşturmaktadır. Grid boyutunun ve ölçeğin havza parametreleri ve sentetik birim hidrograf üzerindeki etkisinin incelendiği bu çalışmada, 1/5000, 1/25000 ve 1/100000 ölçeklerinde eşyükselti eğrileri ile değişik grid boyutlarında oluşturulan SYM'ler kullanılmıştır. Çalışma alanları, İç Anadolu Bölgesinde Konya civarındaki Tarasçı-Glabbera Deresi, Çiftliközü-Karabalçık Deresi, ve Çumra-Cicek Deresi havzalarıdır. Grid boyutunun etkisi havza alanı büyüdükçe görülmektedir. Değişik boyutlardaki havzalar için hidrolojik modellemelere uygun grid boyutu ve ölçek belirlenmiştir. Grid boyutunun ve ölçeğin sentetik birim hidrograf üzerindeki etkisi sadece orta büyüklükteki havza için araştırılabilmiştir. Anahtar Kelimeler: CBS, SYM, Grid Boyutu, Ölçek, Hidrolojik Havza Parametreleri, Sentetik Birim Hidrograf, Konya. iv ABSTRACT EFFECT OF SCALE AND GRID SIZE FOR HYDROLOGICAL STUDIES Onur PAŞAO?ULLARI Ms, Department of Civil Engineering Supervisor: Assoc. Prof. Dr. Nurünnisa USUL April 2002, 152 pages The accuracy of the topography-based hydrologic modeling depends on the accuracy of the Digital Elevation Model (DEM) derived. The basin parameters obtained from DEMs are the inputs for hydrologic models. The effects of the grid size and the scale on the geomorphologic basin parameters and synthetic unit hydrograph are investigated. In this study, DEMs generated from contour data of 1/5000, 1/25000 and 1/100000 scales with different grid sizes are used. The case study areas are Tarasçı- Glabbera Creek Basin, Çiftliközü-Karabalçık Creek Basin, and Çumra- Cicek Creek Basin, which are all in Konya Region in Middle Anatolia. The effect of grid size is observed as the area of the basin increases. Suitable grid size and scale for hydrologic modeling are obtained for different sized basins. The effect of grid size on synthetic unit hydrograph is investigated for the medium sized basin of the study. Keywords: GIS, DEM, Grid Size, Scale, Hydrologic Basin Parameters, Synthetic Unit Hydrograph, Konya. Ill 152

Bu çalışmada, Türkiye'de dar vadilere uygulanmış ince ve uzun göle sahip öç barajda (Deriner, Berke, Kayraktepe), üç farklı pike sahip giren akım hidrografı ve herbiri için üç farklı dolusavak genişliği alınarak hidrolojik ve hidrolik metodlarla taşkın ötelemesi yapılmış ve çıkan akım hidrografları karşılaştırılmıştır. Toplam 27 kombinasyondan her iki metod sonucunda çıkan akımlar arasındaki farkın pik değerlerde en fazla olduğu gözlenmiştir. Sözü edilen farkın, giren akımın büyüklüğüne bağlı olarak dolusavak genişliği küçüldükçe arttığı ve ince-uzun göle sahip reservuarlar için hidrolojik öteleme sonucundaki çıkan akım pikinin %2'si ile % 10'u arasında değiştiği saptanmıştır. Tahmin edildiği gibi hidrolik ötelemedeki çıkan akım piki hidrolojik ötelemedeki çıkan akım pikinden daha küçük olmuştur. İnce uzun göle sahip reservuarlarda bile bu fark en fazla %10 oranına ulaştığına göre ince-uzun olmayan göllerde hidrolojik öteleme ile daha gerçekçi öteleme olan hidrolik öteleme sonuçları birbirine oldukça yakın olması gerekir. Bu çalışma sonucunda ince uzun göle sahip barajlar için, hidrolojik öteleme yöntemi ile bulunmuş olan çıkan akım hidrografını hidrolik öteleme sonucundaki çıkan akım hidrografına yaklaştıran basit bir model geliştirilmiştir. Bu modifikasyon modeli çok fazla data yükü getirmemektedir. Hidrolojik öteleme yönteminde gerekli olan dataya ek olarak toplam reservuar uzunluğu veya reservuar uzunluğu ve ona karşılık gelen kot ilişkisi gerekmektedir. Ayrıca, sözü edilen model daha gerçekçi öteleme olan hidrolik ötelemenin hesap yükünü de ortadan kaldırmıştır. The outflow hydrographs computed by both hydrologic routing (level-pool routing) and by hydraulic routing for three dams having considerably long lakes within narrow valleys in Turkey (Deriner, Berke, and Kayraktepe) were compared for three inflow hydrographs of different peaks with three unregulated ogee spillways of different capacities within considerably wide intervals and yet at reasonable proportions. Out of the total of 27 such combinations, it was observed that the difference between those outflow hydrographs was the greatest at the peak value. The difference grew larger as the spillway capacity became smaller relative to the magnitude of the inflow hydrograph, and it changed between 2 to 10% of the peak of the outflow by hydrologic routing, for these three thin-and-long reservoirs. The peak of the outflow by hydraulic routing turned out to be smaller than that by hydrologic routing for all the 27 different routing cases, as expected. The difference being at most about 10% even for such long lakes was considered to indicate that the level-pool routing for reservoirs of short valleys should yield outflow hydrographs reasonably close to the real ones. A simple model was suggested to modify the outflow hydrograph computed by the hydrologic routing for long and thin reservoirs. The modified model does not require any excessive data. The only extra information is the total length of the reservoir or its values versus elevation in tabular form. The modified hydrologic routing suggested herein does not require an excessive load of computations. It simply suggests to lower at reasonable values the flowrates computed by the classical hydrologic routing. 72

The complexities of hydrological phenomena, the causes that lead to these complexities, and the essences and defects of reductionism are analyzed. The driving forces for the development of hydrology and the formation of branch subjects of hydrology are discussed. The theoretical basis and limitations of existing hydrology are summarized. Existing misunderstandings in the development of the watershed hydrological model are put forward. Finally, the necessity of the expansion of hydrology from linear to nonlinear is discussed.