The objective of this study is to compare Large-Scale Particle Image Velocimetry (LSPIV) to conventional methods for measuring discharge. Furthermore, to use the discharge data to create a rating curve at Islandsfallet in Uppsala. To measure discharge, on-site measurements have conventionally been done. Particle tracking allows flow velocimetry measurements without contact with the water. LSPIV works by measuring displacement of tracers through analysing image sequences. Using the free software Fudaa-LSPIV, flow velocity was measured and referenced to ADCP. The ADCP data were additionally used to construct the rating curve allowing to predict the water level/discharge correlation. Particle tracking was found to hold great potential in the Fyris river, and the possibility for setting up LSPIV for continuous discharge measurements should be investigated going forward. Constructing the new rating curve with discharge measurements from ADCP implied the current rating curve not being sufficient by underestimating the discharge levels necessary for a raise in water level implying the need for an updated rating curve. Concluding, does the LSPIV show promising result compared to the ADCP and the rating curve points out a big discrepancy, in higher discharge, between the new and the old rating curve. The rating curve would however need discharge data points in a greater range. / Syftet med detta arbete var att jämföra partikelspårning med mer traditionella metoder för att mäta vattenflöde. Vidare, att använda data för vattenflöde till att skapa en avbördningskurva vid Islandsfallet i Uppsala. För att mäta avrinning, är fältmätningar det konventionella sättet. Partikelspårning tillåter flödesmätningar utan krav på närvarande tekniker på plats. LSPIV fungerar genom att mäta förflyttning av spårelement på ytan genom att analysera sekvenser. Genom att använda gratisprogrammet FudaaLSPIV, mättes vattenflöde och data från ADCP användes som referensdata. Data från ADCP metoden användes också för att skapa en avbördningskurva som tillåter projicering och korrelation av vattennivå samt vattenflöde. Partikelspårning visade sig ha stor potential för Fyrisån och möjligheten att använda LSPIV för kontinuerliga mätningar bör undersökas vidare. Skapandet av den nya avbördningskurvan visade att den nuvarande avbördningskurvan underskattar vattenflödet mot vattennivån och vidare mätningar är nödvändiga för att utveckla avbördningskurvan vidare. Sammanfattningsvis visar LSPIV på positiva resultat i jämförelse med ADCP och avbördningskurvan visar på en stor diskrepans, i högre flöden, mellan den nya och den gamla avbördningskurvan. Avbördningskurvan skulle behöva ett större antal datapunkter för större flödesintervall.

A key piece of information necessary for water management is accurate streamflow information. However, the available data and resources for gathering information vary around the world. This study forms a part of a research effort to improve discharge estimations for a montane rainforest stream located in the San Lorencito headwater catchment in Costa Rica. The aim of this study is to improve the current rating curve where the high flow part is currently ungauged and look at the impact of adding a high flow estimation to the rating curve. When adding information that is not gauged data, it is important to make sure that the information is unbiased. It can also be questioned if information based on less accurate observations will aid a model. The high flow estimation in this study was calculated using the Manning’s equation based on a survey after a flood event in August 2015. Field measurements were performed at the location in February 2017 and were added to the already existing data record from the gauging station dating back to 2015. Based on the previous data together with the new measurements, rating curves and corresponding hydrographs were established. The impact of adding the Manning’s estimation included a statistical assessment and comparison of the different rating curves and hydrographs. Results showed that at higher flows, the rating curve without the Manning’s point estimated higher discharge than the rating curve determined including the Manning’s point. However, at low flows below 0.9 𝑚3/𝑠 (or around a stage of 0.4 𝑚), the rating curve without the Manning’s point is estimating less discharge than the rating curve including the Manning’s point. Error plots and the uncertainty intervals in the graphs illustrate that the uncertainty at high flows are reduces when including a high flow estimation. The results suggest that it is preferable to add information, even if it has a lot of uncertainty, to no information at all. / Pålitlig flödestatistik och god kunskap gällande vattenföringen i vattendrag är mycket viktiga förutsättningarna för att kunna förvalta vattenresurser på ett hållbart sätt. Tyvärr har inte alla länder samma möjligheter och resurser att samla in den nödvändiga informationen vilket leder till att tillgänglig data är begränsad i vissa delar av världen. Denna studie utgör en del av ett forskningsprojekt i Costa Rica vars syfte är att förbättra uppskattningen av vattenföringen för ett vattendrag som rinner genom ett regnskogsområde. Målet med denna studie är att förbättra den nuvarande avbördningskurvan och undersöka effekten av att lägga till uppskattade värden för höga flöden där det för tillfället saknas data. Under februari 2017 genomfördes flödesmätningar på plats i Costa Rica. Mätningarna användes tillsammans med tidigare uppmätt flödesdata för att bestämma avbördningskurva och motsvarande hydrograf. För att uppskatta det höga flödet användes Mannings ekvation. Beräkningar har utgått från en störtflod som skedde i augusti 2015 och parametrar till ekvationen har baserats på de spår vattnet orsakad på terrängen och vegetation som kunde observeras i efterhand. Slutligen har en statistik bedömning genomförts där effekten på avbördningskurvan och hydrografen av att inkludera en vattenföringspunkt beräknad med Mannings ekvation har studerats. Följden av att ta med en Manningspunkt innebar att avbördningskurvan planades ut och inte uppskattade lika drastiska vattenföringar vid höga vattennivåer. Vid låga flöden under 0.9 𝑚3/𝑠 uppskattade däremot avbördningskurvan med Manningspunkten lägre vattenföring än kurvan utan Manningspunkten. Genom att introducera ett uppskattat vattenföringsvärde med Mannings ekvation minskade osäkerheten för avbördningskurvan och hydrografen vid höga flöden. Resultaten antyder att det är fördelaktigt att införa uppskattade värden där det saknas information.

Usualmente la producción de sedimentos en suspensión (Qss) de un río es calculada utilizando datos de caudales medios diarios o mensuales. Considerando que la mayor Qss ocurre durante los eventos de lluvias y también que los caudales medios no son capaces de representar adecuadamente los máximos caudales, principalmente en zonas de alta variabilidad climática, la forma usual de cálculo de Qss puede subestimar esta producción. En este sentido, esta investigación buscó analizar la influencia de la variabilidad temporal de los datos de caudales en el cálculo de la producción de sedimentos. Adicionalmente fue analizada el uso de diferentes tipos de curvas de sedimentos: (i) para todo el periodo de estudio, (ii) por años hidrológicos y (iii) asociación por épocas características (húmedas, semi-húmedas y secas). El estudio fue realizado en la subcuenca del río Torata, ubicada en una zona semiárida al sur del Perú, entre 2100 y 5200 m de altitud con pendiente promedio de 21.0% y alta variabilidad climática, en especial la precipitación que se ve reflejado en los caudales, ya que en un lapso de horas puede variar de 4 a 34 m3/s. El error entre la descarga prevista y estimada para el periodo de estudio (2001-2012) utilizando los diferentes tipos de curvas fue (i) -65.85%, (ii) -15.36% y (iii) -8.74%, presentando mejora en el coeficiente de eficiencia de Nash-Sutcliffe de 0.248 para 0.500. Los resultados mostraron que la diferencia entre la descarga de sedimentos en suspensión total para el periodo calculado con caudales medias mensuales y diarias fue de -92% y -62%, ambos en comparación de producción para valores medios horarios. También fue constatado que el 99.7% de la producción de sedimentos ocurre en temporada de lluvias, inclusive, un único evento de lluvia llegó a producir 80% de la producción anual. Los resultados de esta investigación ponen en manifiesto la importancia de utilizar registros de caudales con escalas pequeñas de tiempo (minutos, horas), que puedan representar la alta variabilidad de los caudales característicos de zonas semiáridas. / The usual methods that calculate the suspended sediment flux (Qss) of rivers employ discharge mean values daily or monthly. As most of the sediments are transported during overflow events and a mean value smooths the flood peak discharge, mainly in high climatic variability areas, the usual method to evaluate the Qss might underestimate the production of river sediments. This paper reports on an analysis of the gauge influence of temporal variability on the sediment yield estimation. Additionally, the use of different types of sediment rate curves was analyzed for (i) the whole time-series data, (ii) per hydrological year, and (iii) per hydrological pattern characterization (flood, intermediary and drought). A study case was conducted in the Torata river sub-catchment, a Peruvian semi-arid area located between altitudes of 2100 and 5200 meters and whose average slope is 21%. The high climatic variability is expressed by the huge river flow amplitude, which ranges from 4 to 34 m3/s in a few hours. The errors for the sediment yield from 2001 to 2012 estimated by the different sediment rating curves were (i) -65,85%, (ii) -15,36% and (iii) -8,74%, with a 0,248 to 0,500 Nash-Sutcliffe efficiency coefficient improvement. The differences between the sediment yield in total suspension for the period calculated monthly and daily were -92% y and -62%, respectively, in comparison with the production for hourly average values. Results show that 99,7% of the sediment are produced during the flood season and a single overflow event could represent 80% of the annual sediment discharge flow. This research highlights the importance of collecting and using discharge data of a short time interval (minutes or hours) to compute and represent the overflow peaks typical of semiarid regions.

The purpose of this study is to analyze how estimates of an important geomorphic parameter, effective discharge, are impacted by the choice of bed material load equations and flow duration curves (FDCs). The Yang (1979), Brownlie (1981), and Pagosa equations developed by Rosgen (2006) were compared for predicting bed material load. To calculate the bed material load using the Pagosa equations, the bedload and suspended load are calculated separately and the results are added together. To compare the effectiveness of the equations, measured bed material load data from the USGS Open-File Report 89-67 were used. Following the calculations, the equation results were compared to the measured data. It was determined that the Pagosa equations performed the best overall, followed by Brownlie and then Yang. The superior performance of the Pagosa equations is likely due to the equations being calibrated. USGS regression equations for FDCs were compared to a method developed by Dr. David Rosgen in which a dimensionless FDC (DFDC) is developed. Weminuche Creek in southwestern Colorado was used as the study site. Rosgen's DFDC method requires the selection of a streamgage for a stream that exhibits the same hydro-physiographic characteristics as the site of interest. An FDC is developed for the gaged site and made dimensionless by dividing the discharges by the bankfull discharge of the gaged site. The DFDC is then made dimensional by multiplying by the bankfull discharge of the site of interest and the resulting dimensional FDC is taken as the FDC of the ungaged site. The USGS regression equations underpredicted the discharges while Rosgen's DFDC method overpredicted them. Rosgen's DFDC method produced more accurate results than the USGS regression equations for Weminuche Creek. To calculate the effective discharge, the FDC was used to develop a flow frequency curve which was then multiplied by the sediment rating curve. Effective discharge calculations were performed for Weminuche Creek using several combinations of bed material load prediction equations and FDCs. The USGS regression equations, Rosgen's DFDC method, and streamgage data were all used in conjunction with the Yang and Pagosa equations. The Brownlie equation predicted zero bed material load for Weminuche Creek, and was thus not used to calculate the effective discharge. When the USGS regression equations were used with the Yang and Pagosa equations, the calculated effective discharge was approximately 4.5 cms for both bed material load prediction equations. When Rosgen's DFDC method and streamgage data were used with the Yang and Pagosa equations, the effective discharge was approximately 13.5 cms. From these results, it was determined that the bed material load prediction equations had little impact on the effective discharge for Weminuche Creek while the FDCs did influence the results.

Cette thèse propose le développement d'une méthodologie permettant l'obtention des débits distribués dans le bassin amazonien à partir des hauteurs d'eau altimétriques. Au vu des derniers travaux et des avancées récentes dans ce domaine, ce travail a particulièrement porté sur les informations connexes pouvant être extraites des résultats. Nous avons utilisé des relations hauteur-débit basées sur l'équation de Manning et optimisées au travers d'un algorithme d'optimisation globale correctement paramétré. Les hauteurs d'eau ont été obtenues à partir des hauteurs altimétriques fournies par les missions ENVISAT et Jason-2, et les débits ont été estimés sur la même période par le modèle MGB-IPH sur l'ensemble du bassin. L'utilisation de l'algorithme d'optimisation SCEM-UA a permis de définir des intervalles a priori pour les paramètres ajustables ainsi que de gérer les notions d'erreur dans les données d'entrée, et d'incertitude dans les paramètres de sortie. Une des productions de ce travail est la construction d'une base de données d'un millier de courbes de tarage avec les intervalles de confiance associés. La validité spatiale de ces courbes de tarage a pu être vérifiée par comparaison avec les débits du modèle ainsi que les débits in situ disponibles. Leur stabilité dans le temps, quant à elle, a été confirmée par notre capacité à estimer des débits cohérents avec des informations de hauteurs d'eau provenant d'autres missions et d'autres périodes que celle à partir de laquelle les relations hauteur-débit avaient été estimées. Ce travail a également mis en évidence, par validation in situ, modélisation inverse et analyse de cas tests sur des rivières synthétiques, la capacité de la méthodologie proposée à identifier les caractéristiques géomorphologiques des sections étudiées. / This thesis proposes the development of a methodology that aims to obtain distributed discharges in the Amazon basin based on satellite altimetry data and modeled discharges. Given recent works and advances, this work focused particularly on the information that can be inferred from the resulting relationships. We used stage-discharge relationships based on Manning's equation that were optimized through a global optimization algorithm adequately configured. Altimetry data was taken from ENVISAT and Jason-2 missions and discharges were estimated for an overlapping period by the MGB-IPH model. A-priori intervals were defined into the SCEM-UA scheme for each optimization's parameter, and the algorithm allowed us to deal with input errors and output uncertainties. We produced a thousand gross database of rating curves and associated confidence intervals. Hydrological coherence was proved by validation with both modeled and in situ discharges. Successfully using an ENVISAT-based RC with Jason-2 data to estimate discharge at a cross-over, we proved that rating curves are not mission-dependent and can be used with any incoming water height data. Geomorphological characteristics of studied section given by our rating curves were validated through comparison with in situ data, inverse modeling of a braided river reach and synthetic rivers test cases.

A generalized non-dimensional mathematical expression has been developed to describe the rating relation of depth and discharge for intermediate and high streamflow of natural and controlled streams. The expressions have been tested against observations from forty-three stations in West-Central Florida. The intermediate-flow region model has also been validated using data from thirty additional stations in the study area. The proposed model for the intermediate flow is a log-linear equation with zero intercept and the proposed model for the high-flow region is a log-linear equation with a variable intercept. The models are normalized by the depth and discharge values at 10 percent exceedance using data published by the U.S. Geological Survey. For un-gauged applications, Q10 and d10 were derived from a relationship shown to be reasonably well correlated to the watershed drainage area with a correlation coefficient of 0.94 for Q10 and 0.86 for d10. The average relative error for this parameter set shows that, for the intermediate-flow range, better than 50% agreement with the USGS rating data can be expected for about 86% of the stations and for the high-flow range, better than 50% for 44% of the stations. Testing the model outside West Central Florida, in some stations at North Florida, and South Alabama and Georgia, show some reasonable relative errors but not as good as the results obtained for West Central Florida. Using a model with a different slope, developed specific for those particular stations improved the results significantly.

Usualmente la producción de sedimentos en suspensión (Qss) de un río es calculada utilizando datos de caudales medios diarios o mensuales. Considerando que la mayor Qss ocurre durante los eventos de lluvias y también que los caudales medios no son capaces de representar adecuadamente los máximos caudales, principalmente en zonas de alta variabilidad climática, la forma usual de cálculo de Qss puede subestimar esta producción. En este sentido, esta investigación buscó analizar la influencia de la variabilidad temporal de los datos de caudales en el cálculo de la producción de sedimentos. Adicionalmente fue analizada el uso de diferentes tipos de curvas de sedimentos: (i) para todo el periodo de estudio, (ii) por años hidrológicos y (iii) asociación por épocas características (húmedas, semi-húmedas y secas). El estudio fue realizado en la subcuenca del río Torata, ubicada en una zona semiárida al sur del Perú, entre 2100 y 5200 m de altitud con pendiente promedio de 21.0% y alta variabilidad climática, en especial la precipitación que se ve reflejado en los caudales, ya que en un lapso de horas puede variar de 4 a 34 m3/s. El error entre la descarga prevista y estimada para el periodo de estudio (2001-2012) utilizando los diferentes tipos de curvas fue (i) -65.85%, (ii) -15.36% y (iii) -8.74%, presentando mejora en el coeficiente de eficiencia de Nash-Sutcliffe de 0.248 para 0.500. Los resultados mostraron que la diferencia entre la descarga de sedimentos en suspensión total para el periodo calculado con caudales medias mensuales y diarias fue de -92% y -62%, ambos en comparación de producción para valores medios horarios. También fue constatado que el 99.7% de la producción de sedimentos ocurre en temporada de lluvias, inclusive, un único evento de lluvia llegó a producir 80% de la producción anual. Los resultados de esta investigación ponen en manifiesto la importancia de utilizar registros de caudales con escalas pequeñas de tiempo (minutos, horas), que puedan representar la alta variabilidad de los caudales característicos de zonas semiáridas. / The usual methods that calculate the suspended sediment flux (Qss) of rivers employ discharge mean values daily or monthly. As most of the sediments are transported during overflow events and a mean value smooths the flood peak discharge, mainly in high climatic variability areas, the usual method to evaluate the Qss might underestimate the production of river sediments. This paper reports on an analysis of the gauge influence of temporal variability on the sediment yield estimation. Additionally, the use of different types of sediment rate curves was analyzed for (i) the whole time-series data, (ii) per hydrological year, and (iii) per hydrological pattern characterization (flood, intermediary and drought). A study case was conducted in the Torata river sub-catchment, a Peruvian semi-arid area located between altitudes of 2100 and 5200 meters and whose average slope is 21%. The high climatic variability is expressed by the huge river flow amplitude, which ranges from 4 to 34 m3/s in a few hours. The errors for the sediment yield from 2001 to 2012 estimated by the different sediment rating curves were (i) -65,85%, (ii) -15,36% and (iii) -8,74%, with a 0,248 to 0,500 Nash-Sutcliffe efficiency coefficient improvement. The differences between the sediment yield in total suspension for the period calculated monthly and daily were -92% y and -62%, respectively, in comparison with the production for hourly average values. Results show that 99,7% of the sediment are produced during the flood season and a single overflow event could represent 80% of the annual sediment discharge flow. This research highlights the importance of collecting and using discharge data of a short time interval (minutes or hours) to compute and represent the overflow peaks typical of semiarid regions.

Ao longo dos anos, vêm sendo desenvolvidos trabalhos comprovando a importância de áreas alagadas naturais para a manutenção e preservação da qualidade das águas e do ecossistema fluvial. Este fato, associado à importância dos sistemas rios-planícies de inundação, fazem com que sua investigação e preservação sejam consideradas prioritárias. O objetivo desta pesquisa é analisar experimentalmente fatores que influenciam hidrogramas, conforme a ecologia fluvial de áreas alagadas da microbacia do rio Jacupiranguinha localizado no Baixo Ribeira do Iguape, SP. A concretização deste objetivo iniciou-se com a definição da área de estudo, bem como sua importância para a região. Foram então instaladas cinco estações linimétricas e uma estação climatológica, e em seguida, com os dados de vazão coletados em campo, foram construídas a curva-chave da entrada da área alagada e as incertezas relativas aos seus parâmetros. A partir desses estudos e com o levantamento topográfico de toda planície de inundação, foi determinada a relação entre áreas inundáveis, vazões e cotas hidrométricas do rio. Além disso, com os dados climatológicos, vazões e vegetação superficial foi possível determinar as componentes (precipitação, escoamento superficial, evaporação e armazenamento) do balanço hídrico da micro-bacia. O monitoramento linimétrico do rio Jacupiranguinha, junto com suas séries históricas e curvas de permanência, possibilitou também o cálculo de sua vazão ecológica. Finalmente foram construídos quadros síntese-conceituais, integrando as relações entre todas as variáveis hidrológicas e limnológicas selecionadas, demonstrando assim a forte associação entre o sistema rio-áreas alagadas. / It is very important to improve our knowledge about the floodplains, which have been proved by studies, since these areas are vital to the maintenance and preservation of the quality of waters and the fluvial ecosystem. This fact, associated with the importance of the wetlands-river system, makes its investigation and preservation to be considered number one priority. The objective of this research is to analyze factors that may influence hydrographs, according to the fluvial ecology of wetlands in micro basin of Baixo Ribeira do Iguape Valley, SP. The work began with the definition of the studied field and its importance to the area. Subsequently, five hydrometric station and one meteorological station were installed, and therefore the rating curve in the entrance of floodplain was calculated along with the uncertainties related to its parameters. With these studies and with the topographic survey, it was possible to find the relation between wetlands, river stage and flow. The climatologically information, the river stage and the superficial covering vegetation are essential factors to determinate the components (precipitation, superficial flow, evaporation and the storage) of the water balance at the micro basis of Jacupiraguinha river. The hydrometric observation of the river along with historical series and the probability-duration curve make it possible to calculate the ecological flow. Finally, conceptual charts integrating the relations between hydrological and limnologicals factors were built showing the strong association with the wetlands-river system.

Hydrological models are used widely and they demand for multiple input variables and observations. One of those variables is Manning’s roughness coefficient. In the current literature the variability of the coefficient poses an unknown uncertainty. This study examines a small river channel located in central Sweden, and aims to determine the variability and uncertainty of the roughness coefficient during diverse vegetation conditions within the channel. During multiple field visits to the location, slope, water level and cross-section examination is performed. With numerical simulation, discharge and roughness coefficients are obtained. With the hydraulic model (HEC-RAS), stage-discharge rating curves are produced and extrapolation is applied to obtain high flows. Manning’s roughness coefficients and their uncertainties are assessed by two different approaches. Determining the coefficient in a simplified sensitivity analysis by using Manning’s equation and calibrating HEC-RAS while applying Mean absolute error (MAE) calculation. The calculated roughness coefficients presents higher range when using Manning’s equation (summer vegetation conditions – 0.2, winter vegetation conditions – 0.095). On the contrary MAE provides values closer to each other (summer – 0.15, winter – 0.11). The obtained results indicate a high variance between summer and winter vegetation conditions, producing 38 cm water level differences during high flows using Manning’s equation and 6 cm difference using the calibration of the model in HEC-RAS. These results confirm that the roughness coefficient cannot be assumed to be constant throughout different seasons as had been assumed widely when applying hydrological modelling. Throughout the study innovative approaches and methods (e.g. back-calculating from Manning’s equation and calibrating HEC-RAS based on observed water levels) are used in order to determine the consequences of ignoring the variability of the roughness coefficient. Due to the study, one can derive that vegetation needs to be considered in having an important impact on the varying roughness coefficient value and it cannot be left as a constant value within hydrological models. / Hydrologiska modeller är vanligt förekommande för bestämning av vattenföringsprognoser, och kräver ett flertal indata variabler och observationer. En av variablerna är Mannings råhetskoefficient, som orsakar en okänd felmarginal i den hydrologiska modellen. Den här studien syftar till att avgöra osäkerheten av felmarginalen samt variationen av Mannings råhetskoefficient. Det görs genom att undersöka en liten bäck i centrala Sverige vid olika vegetationstillstånd. Flera fältundersökningar genomfördes där tvärsnittsmätningar, vattennivå och hydraulisk gradient bestämdes. Från numerisk simulering kan flöde och råhetskoefficienten kalkyleras. Genom den hydrauliska modellen (HEC-RAS) fås ratingkurvor för vattennivå och flöde, där extrapolering görs för de högre flödena. Mannings råhetskoefficient och dess osäkerhet undersöks med två olika tillvägagångssätt. Den första metoden bygger på att använda Mannings ekvation. Den andra metoden bygger på att först genomföra en kalibrering i HEC-RAS och sedan använda kalkylering av medel-absolut-avvikelse, ”Mean absolute error” (MAE). Råhetskoefficienten beräknad med hjälp av Mannings ekvation ger större spridning (sommar – 0.2, vinter – 0.095) än vid användning av MAE beräkning (sommar – 0.15, vinter – 0.11). Resultatet visar en stor skillnad mellan så kallad vinter och sommar vegetation. Skillnaden i vattennivå är 38 cm vid användning av första metoden och 6 cm vid användning av den andra metoden. Resultaten från den här studien visar att råhetskoefficienten inte kan antas vara stabil under olika säsonger, vilket antas vid hydrologisk modellering. Innovativa metoder, så som bak-kalkylering från Mannings ekvation och kalibrering i HEC-RAS baserad på observerade vattennivåer har används för at bestämma utvärdera konsekvenserna av att ignorera variationen av råhetskoefficienten vid modellering. Den här studien visar att variationen av råhetskoefficienten påverkas av vegetationsförhållandet och att koefficienten inte kan antas konstant för korrekt modellering.

Ao longo dos anos, vêm sendo desenvolvidos trabalhos comprovando a importância de áreas alagadas naturais para a manutenção e preservação da qualidade das águas e do ecossistema fluvial. Este fato, associado à importância dos sistemas rios-planícies de inundação, fazem com que sua investigação e preservação sejam consideradas prioritárias. O objetivo desta pesquisa é analisar experimentalmente fatores que influenciam hidrogramas, conforme a ecologia fluvial de áreas alagadas da microbacia do rio Jacupiranguinha localizado no Baixo Ribeira do Iguape, SP. A concretização deste objetivo iniciou-se com a definição da área de estudo, bem como sua importância para a região. Foram então instaladas cinco estações linimétricas e uma estação climatológica, e em seguida, com os dados de vazão coletados em campo, foram construídas a curva-chave da entrada da área alagada e as incertezas relativas aos seus parâmetros. A partir desses estudos e com o levantamento topográfico de toda planície de inundação, foi determinada a relação entre áreas inundáveis, vazões e cotas hidrométricas do rio. Além disso, com os dados climatológicos, vazões e vegetação superficial foi possível determinar as componentes (precipitação, escoamento superficial, evaporação e armazenamento) do balanço hídrico da micro-bacia. O monitoramento linimétrico do rio Jacupiranguinha, junto com suas séries históricas e curvas de permanência, possibilitou também o cálculo de sua vazão ecológica. Finalmente foram construídos quadros síntese-conceituais, integrando as relações entre todas as variáveis hidrológicas e limnológicas selecionadas, demonstrando assim a forte associação entre o sistema rio-áreas alagadas. / It is very important to improve our knowledge about the floodplains, which have been proved by studies, since these areas are vital to the maintenance and preservation of the quality of waters and the fluvial ecosystem. This fact, associated with the importance of the wetlands-river system, makes its investigation and preservation to be considered number one priority. The objective of this research is to analyze factors that may influence hydrographs, according to the fluvial ecology of wetlands in micro basin of Baixo Ribeira do Iguape Valley, SP. The work began with the definition of the studied field and its importance to the area. Subsequently, five hydrometric station and one meteorological station were installed, and therefore the rating curve in the entrance of floodplain was calculated along with the uncertainties related to its parameters. With these studies and with the topographic survey, it was possible to find the relation between wetlands, river stage and flow. The climatologically information, the river stage and the superficial covering vegetation are essential factors to determinate the components (precipitation, superficial flow, evaporation and the storage) of the water balance at the micro basis of Jacupiraguinha river. The hydrometric observation of the river along with historical series and the probability-duration curve make it possible to calculate the ecological flow. Finally, conceptual charts integrating the relations between hydrological and limnologicals factors were built showing the strong association with the wetlands-river system.