Um aumento considerável da área de cultivo da cana de açúcar na região central do estado de São Paulo foi verificado durante os últimos anos. A ampliação destas áreas sobre outras formas de uso e ocupação das terras na referida região proporcionam diversas alterações nos ambientes, sobretudo relacionados aos processos geomorfológicos e hidrológicos das bacias hidrográficas. Nesse sentido, estudos fundamentados em modelos matemáticos, estruturados em SIG (Sistema de Informação Geográfica) e que visem analisar o comportamento de fenômenos ambientais frente à expansão da cultura canaviera podem auxiliar órgãos públicos e privados responsáveis pelo gerenciamento e manutenção das atividades agropecuárias na região. Diante disso, o presente trabalho teve como objetivo avaliar os efeitos das alterações do uso e ocupação das terras sobre processos hidrológicos e geomorfológicos na bacia do rio Jacaré Guaçú, localizada na região central do Estado de São Paulo. Mais precisamente, verificou se as mudanças ocorridas no uso e ocupação das terras entre 1987, 2004 e 2013 influenciaram no aumento ou diminuição das perdas de solos por erosão laminar e no regime de vazão fluvial da rede de drenagem do rio Jacaré Guaçú. Dados hidrológicos, pedológicos e de Sensoriamento Remoto foram usados para estruturar em SIG o modelo matemático EUPS (Equação Universal de Perdas de Solo) e estimar as perdas de solo por erosão laminar. Técnicas de estatística foram usadas para verificar a significância nas mudanças de tendência dos dados históricos de vazão fluvial. Os resultados confirmam aumento de perdas de solo por erosão laminar acima de 15 ton. ha-1ano-1 entre 1987, 2004 e 2013. Esses valores ocorreram devido ao aumento de locais destinados à cultura temporária e com solo exposto, ambos vinculados ao cultivo da cana de açúcar. Entre o mesmo período ocorreu a diminuição de locais classificados com perdas de solo compreendidas entre 0 e 3 ton. ha-1ano-1 atrelada, sobretudo a redução de locais destinados às pastagens e com vegetação arbórea na bacia hidrográfica. As perdas de solo classificadas entre 3 e 5, 5 e 10 e 10 e 15 ton. ha-1ano-1 aumentaram entre 1987 e 2004 e diminuíram entre 2004 e 2013. A análise estatística comparativa dos dados fluviométricos evidenciou que não ocorreram mudanças significativas nos padrões de vazões médias, mínimas e máximas mensais entre 1987, 2004 e 2013. / A substantial expansion of sugarcane area in the central region of São Paulo State (Brazil) occurred in last years. The increase of sugarcane cultivation over other forms of land use implies in several changes in the environment mainly related to the geomorphological and hydrological processes in watersheds. Grounded studies on mathematical models, structured in GIS (Geographic Information System) can assist in understanding environmental changes arising the increase of sugarcane cultivation. This data can assist public and private institutions responsible for management and maintenance agricultural activities in this region. Therefore, this study aimed at evaluating the effects of changes in land use about hydrological and geomorphological processes in Jacaré Guaçú stream basin (São Paulo State - Brazil). More precisely, were analyzed the effects of changes in land use between 1987, 2004 and 2013 about laminar erosion process and Jacaré Guaçú river flow. Soil, rainfall and Remote Sensing data were used to structure the mathematical model USLE (Soil Loss Equation Universal) in the GIS (Geographic Information System) and to estimate soil loss by laminar erosion. Statistical techniques were used to evaluate changes in trends from historical data of Jacaré Guaçú river flow. The results confirmed an increase of soil loss by laminar erosion bigger then 15 t. ha-1 year -1 between 1987, 2004 and 2013 within the study area. The increase in local places with temporary culture and exposed soil, both linked to the expansion of sugarcane areas, contributed to these results. Between the same period (1987, 2004 and 2013) there was a decrease in classified locations with soil loss between 0 - 3 t. ha-1 year -1 because of area reduction with pastures and tree vegetation in hidrographic basin. Soil losses classified between 3-5, 5-10 and 10-15 t. ha-1 year -1 increased between 1987 and 2004 and decreased between 2004 and 2013. Statistical analysis showed no significant variation average, maximum and minimum of Jacaré Guaçú river flow between 1987, 2004 and 2013.

A variabilidade climática é um objeto característico da Geografia já que anomalias positivas ou negativas de seus elementos, principalmente precipitação e temperatura, podem afetar de forma significativa a vida da população atingida. Na presente pesquisa, a variabilidade da vazão na bacia amazônica brasileira para o período de 1976 a 2010 é estudada por meio de técnicas estatísticas, tais como correlação linear, regressão linear simples e múltipla, análise de agrupamento e análise de ondeletas. Campos de componentes atmosféricos são apresentados para a compreensão da circulação atmosférica anômala que leva a anomalias de vazão. O objetivo é compreender com mais profundidade possíveis associações entre a variabilidade da vazão fluvial e da temperatura da superfície do mar, TSM, em regiões oceânicas específicas, reconhecendo-se para isso o acoplamento oceano-atmosfera que modula a variabilidade climática global. Este estudo compreendeu o uso de dados de vazão e precipitação do sistema Hidroweb/ANA, dados de TSM, radiação de onda longa e vento do conjunto de dados da Reanálise I, do NCEP/NCAR, e dados de precipitação do Global Precipitation Climatology Project, GPCP. A maior parte das análises considerou o tratamento de dados na escala mensal. O estudo verificou que há variabilidade espacial para a resposta da correlação linear entre a TSM e a vazão na bacia amazônica brasileira, verificada em cada uma das sub-regiões homogêneas definidas para esta pesquisa. Diferenças espaciais também foram verificadas nos resultados dos testes para tendência linear, identificando-se um padrão de tendência positiva da vazão na parte norte da bacia amazônica brasileira, e, negativa na porção sul. Sugere-se que a tendência negativa na porção sul esteja, em parte, associada à expansão das áreas agrícolas e, portanto, à intensificação do desmatamento. Cada uma das sub-regiões apresentou padrões espaciais de correlação linear diferenciados com os oceanos, mas, de forma geral, verifica-se que os eventos ENOS são importantes na definição da variabilidade da bacia amazônica, sendo mais efetivos nas anomalias de vazão das sub-regiões Norte, Amazonas-Foz e Sul, enquanto que a variabilidade da temperatura da superfície do mar no Atlântico Tropical Norte está bem associada à variabilidade da vazão nas sub-regiões Central e Oeste. A análise dos campos atmosféricos médios para anos caracterizados por ENOS neutros permitiu identificar que a sub-região Oeste apresentou resultados de influência de processos climáticos regionais que influenciaram anomalias positivas e negativas de vazão. Desta forma, a hipótese da tese de que, observando-se as particularidades de associação entre a temperatura da superfície do mar e a vazão fluvial para cada sub-região amazônica seria possível elaborar um modelo estocástico de previsão mais adequado a cada sub-região, sendo cada um mais apropriado a cada subregião, exprimindo maior acurácia e significância estatística, foi confirmada. Cada uma das sub-regiões consideradas apresenta intervalos de tempo preferenciais em que a correlação com a superfície dos oceanos é máxima. Assim, conclui-se que a bacia amazônica não pode ser considerada como um todo quanto à análise climática, já que foram confirmadas variabilidades espaciais de tendência linear dos dados de vazão, correlação entre vazão e precipitação e correlação com anomalias da temperatura da superfície do mar. / Climate variability is a characteristic object of geography, as positive or negative anomalies of its elements, especially precipitation and temperature may significantly affect the lives of the population. In this research, the variability of flow in the Brazilian Amazon basin for the period 1976-2010 is studied through statistical techniques such as linear correlation, simple and multiple linear regression, cluster analysis and wavelet analysis. Fields of atmospheric components are presented for comprehending the anomalous atmospheric circulation which leads to flow abnormalities. The objective is to understand more deeply possible associations between the variability of river flow and sea surface temperature, SST, in specific ocean regions, in order to recognize ocean-atmosphere coupling that modulates the global climate variability. This study has encompassed the use of flow and precipitation data of Hidroweb system/ANA, SST data, longwave radiation and wind of NCEP/NCAR Reanalysis I dataset, and precipitation data of Global Precipitation Climatology Project, GPCP. Most of the analyzes considered the treatment of data in the monthly scale. The study found that there is spatial variability to the response of the linear correlation between SST and the flow in the Brazilian Amazon basin seen in each one of the homogeneous subregions defined for this research. Spatial differences were also verified in the results of tests for linear trend, identifying a pattern of positive trend of the flow in the northern part of the Brazilian Amazon basin, and negative in the southern portion. It suggests that the negative trend in the southern portion is partly associated with the expansion of agricultural areas and therefore, the intensification of deforestation of forested areas. Each one of the subregions showed different spatial patterns of linear correlation with the oceans, but in general, ENSO events are important in defining the variability of the Amazon basin, being more effective in flow anomalies of North, Amazonas-Foz and South subregions, whereas the variability of sea surface temperature in the Tropical North Atlantic is well associated with the variability of flow in the Central and West subregions. The analysis of average atmospheric fields for years characterized by neutral ENSO was able to identify that the West subregion presented results of influence of regional climate processes which influenced anomalies of positive and negative flow. Thus, the hypothesis of the thesis that, by observing the association of the particularities between sea surface temperature and river flow for each Amazon subregion would be possible to develop a more appropriate stochastic model to each subregion, being each one more adequate to every subregion, expressing greater accuracy and statistical significance, was confirmed. Each one of the subregions considered presents preferential time intervals at which the correlation to the ocean surface is maximal. Therefore, it is concluded that the Amazon basin cannot be considered as a whole regarding its climate analysis, seeing that spatial variabilities of linear trend of flow data were confirmed, correlation between flow and precipitation and correlation with sea surface temperature anomalies.

The main aim of the thesis was the liquefaction of Únanovka streamflow under the Těšetice dam with the focus on suitable flood protection of the villages of Těšetice, Bantice and Práče.The thesis evaluates the existing condition of the Únanovka streamflow in the river mileage 1.6593 – 6.4103. Calculation of the streamflow capacity was carried out per 1D mathematical model in the HEC-RAS programme for the selected N-year flow from the ČHMÚ hydrological study. Final value of the improved drainage from the dam was determined together with the possible value of water collection. Within the thesis the hydro-ecological monitoring of the watercourse was carried out (HEM analysis 2014).

The development of hydrology and the need of getting exact data increase the demands on hydro metering. Measurement of spot velocities and deriving the flow of water are frequently performed by the workers of Český hydrometeorologický ústav (Czech Hydrometeorological Institute) and other companies. The limited precision of the measuring machines, the imperfection of methods and the influence of human senses cause that we are not able to get the accurate value of quantity. We are just close to the right values. The term uncertainty of measuring determines the interval which is assigned to each measurement and contains the real value of measured quantity. Twenty imminently repeated measurement were done in twelve measuring profiles of the Dyje River and in one profile of the Morava River using the current meters OTT (OTT Hydromet, 2013) type C2 and type C31. We investigated the dependence of uncertainties type A and B in different profile parameter. The measurement was done with the suspension bar with 2 to 4 propeller current-meters. The hydrometric car on the bridge was used in deeper waters. The results were analysed from the point of view of the uncertainties and generalized. Next point of the research was to find out how the frequency of the current meter depends on temperature of water. For this purpose, the specific canal was made in the Faculty of Civil Engineering in Brno (Ústav vodního hospodářství krajiny) and the measuring was done in temperature interval from 1 °C to 24 °C. Repeated measuring was statistically evaluated from the uncertainties point of view. In the thesis, the proposal of elaboration of uncertainties determined by both types of measurement into current methods of determination of uncertainties of the derived flows using the measurement of spot velocity by the propeller current-meter in measuring profiles of the rivers is introduced.

Cette recherche évalue le degré de régulation hydrologique induite par le barrage-réservoir Paso de las Piedras sur la Sauce Grande et quantifie les effets de cette régulation sur la hydrologie, la morphologie et la température de l'eau de la rivière en aval. Le travail de thèse consiste en une évaluation exhaustive et systématique des impacts du barrage-réservoir sur le système fluvial basée sur la compréhension des processus naturels qui se produisent en amont. En plus de fournir des informations sur les impacts hydrologiques, morphologiques et thermiques de la construction du barrage Paso de las Piedras et de l'exploitation de son réservoir, cette étude génère des séries de données climatiques et hydrologiques qui fournissent une base significative sur laquelle fonder des recherches futures. Par ailleurs, cette étude met en place un cadre méthodologique appliqué à l'analyse hydrogéomorphologique des bassins versants non jaugés qui a un grand potentiel d'application dans d'autres bassins de la région similaires ainsi que dans d'autres régions semi-arides du monde. / Despite the regional importance of the Sauce Grande River as main source for water supply and the large capacity of the Paso de las Piedras Reservoir, both the hydrology of the river basin and the effects of the impoundment on the river environment remain poorly evaluated. This study provides the very first assessment of the degree of flow regulation induced by the Paso de las Piedras Dam on the middle section of the Sauce Grande River, and quantifies its impacts on the hydrology, morphology and patterns of water temperature of the river downstream from the impoundment. In addition to providing new information on the response of regulated rivers to upstream impoundment and on the effects of impoundment on the Sauce Grande River specifically, this study generates spatial, climatic and hydrologic data and implements a methodological framework to hydrological assessment of ungauged basins.

From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / Riverflow modeling is believed useful for purposes of decision making with respect to reservoir control, irrigation planning, and flood forecasting and design of structures to contain floods. This author holds the view that present riverflow models in vogue are unsatisfactory because, for one thing, sample simulations according to these models do not resemble observed southwestern river records. The purpose of this paper is to outline a general Markov model which assumes only that rivers have a finite memory. We show how to calibrate the model from river records and then present evidence to support our contention that some success has been realized in mimicking typical flows by our simulation procedure.

The economic growth and the increase in population has led to an increased demand for water for various purposes such as domestic consumption, irrigation, industrial use, power generation, navigation, recreation, and ecological requirements. With the increase in population, the per-capita water availability is continuously decreasing. Due to increase in demand and accompanying scarcity of water the conflict among the potential users of the resource is on raise. Hence, the allocation of the available water resource is a big challenge as the intersect oral and inter-regional water allocation is often competing and conflicting in nature. In the above context a good model to manage the available water resources would require reliable inputs on the available water resources. In the first part of this thesis we compare different techniques that are typically used for modeling the river water flow. Time series analysis (ARIMA) is compared with machine learning techniques such as support-vector regression (SVR) and neural network models. The performance of these techniques is compared by applying them to a long-term time-series data of the inflows of three tributaries of the river Cauvery into the Krishnaraja Sagar reservoir (KRS). Flow data over a period of 30 years from three different observation points established in upper Cauvery river sub-basin is analyzed. Specifically, a multi-layer feed forward network trained with a back-propagation algorithm and support vector regression with epsilon-insensitive loss function is compared with the ARIMA models. It is found that the performance of support vector regression model is superior to those of the other techniques considered. The second part of our thesis is to develop a model for optimal water allocation to the different sectors with the aim of maximizing the total utility of available water resource in a river basin. A hydro-economic modeling framework is developed that incorporates the economic assessment of the value of water. This inter-sectoral allocation problem is studied in the context of enforcing certain minimum water rights to every person for domestic use and a certain minimum irrigation need set out by the contingency plans of the state agriculture department in Cauvery river basin. A non-linear optimization model is built to obtain an optimal inter-sectoral water allocation policy. The study evaluates the economic impact of different parameters of competing demands such as water availability, population, basic water right (quantity), ground water contribution, and crop benefit. The optimal policies that implements the water allocation priorities as set out by the National Water Policy (2012) are compared. Further, results show that the basic water right can be secured for essential needs with optimal management of available surface and ground water resources. In the third part of thesis, we study the conflict of water sharing that arises between sectors/regions. We consider the river water-sharing problem between two agents along a river. Each agent has a stated claim to the river water. The Absolute Territorial Sovereignty (ATS) and Absolute Territorial Integrity (ATI) principles are promoted by different agents along the river as a means to maximize their individual benefit. However, these principles are invariably considered to be unjust by one or more of the other agents. Hence, it is preferred to have a negotiated water treaty that is perceived to be equitable and just by all. A one way downstream stream bilateral bargaining model can be used to guide the negotiated water treaty between the agents. In this bargaining framework we introduce the issue of negative externalities imposed by the upstream agent on the downstream agent/s in the form of pollution and/or flooding. This imposes a cost on the downstream agent to mitigate losses due to the negative externalities. A bargaining model that incorporates the impact of negative externalities is developed to guide the negotiated treaties. We identify individually rational bargaining strategies for a two agents transferable utility one way downstream river water sharing problem. The results characterize the agreement and disagreement points for bilateral trading

Biological invasions are reportedly one of the major contributory factors to biodiversity loss worldwide. The impacts of invasive alien plant (IAP) species on native communities are widely documented in the scientific literature, however, there is still a lack of detailed information on their impacts within the most vulnerable habitats. Riparian habitats are highly dynamic systems and naturally disturbed, making them particularly vulnerable to invasion. Climate change, directly or indirectly, is also predicted to adversely impact river systems, which may subsequently alter invasion rates and the impacts of IAPs. However, the interactions between climate and IAPs and their combined effects on vegetation have rarely been examined. To address these knowledge gaps, this thesis investigates: (1) the role of environmental variables, such as sediment loading or climate-related changes to river flow regime, on the abundance of IAPs within riparian zones; (2) how variation in IAP abundance impacts native vegetation, relative to the effects of native dominant plant species and (3) some of the mechanisms underlying the effects of IAPs in riparian habitats. Historic and recent field survey data were used to investigate changes in riparian vegetation on British rivers during the last 20 years. Analyses indicate that IAPs had a negative but small effect on native plant diversity. Overall, changes in land use and differences in flow regime between recording periods were the most important predictors of plant community change. Specifically, IAPs had a greater probability of being present along lowland rivers that experienced increased frequency of high flow events. On a local scale across rivers in Scotland, the abundance of IAPs was constrained by greater soil moisture in summer, whilst greater abundance was associated with tree-lined banks. Both native dominant species and IAPs negatively affected subordinate species abundance to a greater extent than species richness, although this effect varied spatially with bank elevation. Artificial turf mats were used to quantify viable propagules within riverine sediment deposited over-winter along invaded riverbanks. The data indicate that there is a legacy effect of IAP abundance, with the most invaded sites being associated with higher sediment loading the following year, though, contrary to the general pattern, 12 sediment associated propagules were scarcer at invaded sites. Moreover, lower above-ground native diversity was associated with sites which had been previously invaded. Plant species composition in the propagule bank and above-ground vegetation were highly dissimilar, particularly closest to the water’s edge at highly invaded sites. This suggests that mono-specific stands of IAPs proliferate best under less disturbed environmental conditions, although fluvial disturbance events may be required to create opportunities for initial establishment. The propagule bank contributed very little to the above-ground vegetation, nor did it limit invasion, suggesting that above-ground plant composition is largely dictated by competitive interactions. The findings presented in this thesis suggest that invasion by IAPs is an additional stressor for native vegetation within riparian habitats, modifying above-ground plant communities via competition and suppressing recruitment from the propagule bank. However, native dominant species common in riparian habitats also negatively impact, subordinate species via competition, in some cases equalling the effect of IAPs. Native dominant and IAP species are differently affected by environmental factors operating in the riparian zone, which may provide future opportunities for reducing and managing invasions.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / Southwestern rivers are few in numbers and low in discharge. The physiographic and climatic reasons for this are discussed. To the east of the 100th meridian, rainfall is reliable and agriculture is stable; while to the west, there is a chronic deficit of water, droughts are frequent and lifestyles must be accordingly adjusted. Dam building results in greatly increased silting behind the dam in both the river and its tributaries and accelerated channel erosion below the dam. Total flow must also decrease due to withdrawals and increased evaporation from reservoirs. The correction of apparent errors in measuring the virgin flow of the Colorado River now indicates that this flow is about 15 maf/yr. Current legal allocations total 17.5 maf/yr of river water, including the central Arizona project (cap), which will withdraw 1.2 maf/yr. While the river is being dammed and overallocated beyond all reason, the water table is being mined at the alarming rate of 20 ft/yr. In central Arizona, it has dropped to about 250 ft below the surface, and even if all withdrawals ceased immediately, it would take many centuries of of desert rains before it would return to its former level of 50 ft. The cap water will cancel only about 1/2 of this overdraft annually. A glance at the phoenix area today shows that rain follows neither the farmers plow nor the subdividers bulldozer.