The compilation, collection, analysis, and simulation of UPRP streamflow and water-quality information were undertaken in order to assess the expected levels and variability of the quantity and quality of the surface waters in relation to the meteorology and hydrology of the area--the intended objectives of the project--and the modes of system operation. Under the two major phases of the study, important aspects which were examined were the availability and adequacy of the data base, and the applicability of modeling schemes to simulate the observed properties of the data. The major objective in the operational hydrology phase was to test the applicability of operational hydrology in a tropical environment. A stochastic model was fitted to the streamflow data of the extended UPRP inflows in order to serve as a generator of synthetic monthly streamflows which are used as inputs to operational studies of the project. As an initial requirement, the historical record was augmented by means of regional estimation techniques and a statistical data augmentation scheme. The percent deviation method of data augmentation was selected and applied, based on the results of a comparison of four augmentation methods. Two normalizing transformations were applied on the augmented-historical data in order to express them as statistical variables amenable to synthesis. These were the logarithmic transformation and Harter's table interpolation scheme. A time series analysis applied on the normalized data prescribed the adoption of the separate-monthly Matalas model for synthesis. The application of the model yielded synthetic streamflows which satisfactorily reproduced the correlation coefficients, means, and standard deviations of the augmentedhistorical monthly flows. Model extensions and refinements were recommended in order to surmount model limitations. In general, the applicability of operational hydrology in a tropical environment has been demonstrated. The quality of the UPRP surface water was characterized in order to provide background information which is essential in determining the suitability of the water for fishery development in the reservoir, for irrigation, and for domestic and industrial use. The Pantabangan reservoir was characterized in terms of observed patterns of temperature, dissolved oxygen, and salinity. An annual cycle was observed which exhibits intermittently disturbed and moderate stratification in the wet season, full circulation and isothermal condition during the cool, windy, and dry months, and a short warm period favorable to stratification prior to the heavy rains. Atmospheric reaeration was identified to be the major contributor of dissolved oxygen to the reservoir water. The application of the Markofsky-Harleman predictive model for reservoir temperature and dissolved oxygen emphasized the need for substantial data on the hydrology, meteorology, hydrodynamics, and water quality in the reservoir which are required as model inputs. The best agreement between observed and predicted temperature and DO was obtained for cool, windy, and dry months of December to February. Limitations in the input data and in the assumed parameters were observed. The available and collected water-quality data in the reservoir and streams of the UPRP indicated a salinity level as low as or less than 100 ppm in the headwaters to as high as 300 ppm in the outflows from the irrigation service area. The surface water is essentially the alkaline-bicarbonate type. The heavy runoff during the wet season produces a dilution of the TDS, but causes the conveyance of considerable amounts of sediment to the reservoir and river channels. An approximate salt balance for the project area yielded estimates of net amounts of salts leached from the area per season.

In this thesis, we improved our understanding of the effects of hydrology, stream hydraulics, and temperature on juvenile Atlantic salmon (Salmo salar L.) habitat. We demonstrated the key role played by stream morphology and flow regime on in-channel hydraulics and consequently on salmonid habitat. Additionally, we showed how riparian afforestation has potential to moderate climate change effects on stream temperature preserving freshwater ecosystems. The Girnock Burn is an upland Scottish river that has been intensively studied to investigate flow generation processes and stream temperature, and has served as a long-term monitoring site for Atlantic salmon population dynamics since 1966. The general approach applied consisted of combining different types of models including: hydraulic, fish habitat, hydrological and heat transfer models with long-term hydrological and climatic data sets, and digital terrain models (DTMs) at different spatio-temporal scales. Our results showed that the extensive presence of roughness elements (e.g. boulders and cobbles) is capable to provide some refuge areas for juvenile salmon fry for a wide range of flows. However, under extreme flow conditions, in-channel hydraulics might represent a limiting factor. Significant inter-site differences occurred and were consistent throughout the years. Evidence of long-term trend in fry habitat quality could be identified only in summer. Since more extreme flow regimes are expected in the future as a result of climate change, we also proposed a novel analytical approach that allowed us to assess the effects of hydroclimatic variation on fish populations outside the range of observations. Finally, we showed the potential of afforestation to reduce daily stream temperature range, moderating both low and high peaks of more than 2 ○C. This makes riparian shading a valuable mitigation strategy to contrast global warming effects on stream temperatures that should be considered for a sustainable catchment management.

Thesis (M.S.)--California State University, Chico. / Includes abstract. "Located in the Chico Digital Repository." Includes bibliographical references (p. 49-51).

Thesis (M. Phil.)--University of Hong Kong, 1982.

Ephemeral streamflow infiltration through alluvial channels has been identified as an important source of aquifer replenishment in arid and semi-arid environments. In this dissertation, two field methods were developed for monitoring streamflow timing in ephemeral stream channels. The first streamflow timing method exploits differences in the advective and conductive thermal transport mechanisms during the presence and absence of streamflow. The second method of streamflow timing utilized the relationship between soil water content and electrical conductance. Electrical resistance sensors were designed to detect saturated soil conditions and thus to infer streamflow timing during periods of saturation. Both methods were field-tested in Rillito Creek, Tucson, Arizona. The electrical resistance method proved more suitable than the temperature method because it was not depth dependent and was able to more accurately infer streamflow timing with less data post processing. Transient and steady state infiltration fluxes were simulated in a coarse-grained alluvial channel to determine the relative contribution the onset of streamflow provides to potential recharge. Water content, temperature, and pore pressure measurements were incorporated into a variably saturated heat and fluid transport model to simulate infiltration. Infiltration fluxes at the onset of streamflow were about 2-3 orders of magnitude higher than steady state fluxes and were inversely proportional to antecedent water content. The time duration from the onset of streamflow to steady-state infiltration ranged from 1.8 to 20 hours. Two transient and steady state periods were observed indicating a lower permeable layer at depth. During steady state periods, infiltration fluxes averaged 0.33 meters per day and ranged from 0.14 to 0.45 meters per day. A long-term decline was observed in all three events. Higher frequency diurnal and episodic changes were prompted by fluctuations in atmospheric temperature and discharge. The simulated steady state values were consistent with the effective vertical conductivity values (0.22 meters per day) of an underlying less permeable layer. The average contribution from the cumulative transient infiltration for the events was approximately 18 percent. Therefore, it is apparent that potential recharge calculations for alluvial channels that do not consider infiltration during the onset transient period may underestimate the true potential for recharge.

A perennial streamflow hydrograph, when measured at the outlet of a basin, continuously and without interruption, can be considered as an integral measure of hydrologic responses. Some of the theoretical and practical aspects of treating streamflow hydrographs as integral indicators of basin properties are addressed in this dissertation. This dissertation is divided into two parts. In the first part, a framework to identify and evaluate whether a streamflow variable is consistent and distinguishable in a given time scale and therefore can be considered as a streamflow index, is developed. The suggested framework is evaluated using as an example two streamflow variables that describe some aspects of the hydrograph shape. In the second part of the dissertation, the utilization of these streamflow indices in hydrologic model parameter estimation is demonstrated. It is assumed that streamflow indices that are evaluated on long streamflow records include large variability of climatic scenarios. Therefore, regardless of climate variability, the consistency and distinguishability are maintained the indices are more related to physical properties of a basin. Consequently, the problem of estimating model parameters that are related to basin properties can be approached by a comparison of indices between the observed and simulated streamflow. Three case studies are presented: the first demonstrates that using the streamflow index which describes the shape of the hydrograph in the parameter estimation processes improves consistency of prediction skill of the 5-parameter HYMOD model in the Leaf River, Mississippi. The second case study explores an important property of the shape descriptors as being relatively insensitive to errors in the data. Such property can be potentially used to identify key sources of uncertainty and to select model parameters that are less affected by data errors. In the final case study, the shape descriptors were used to derive the parameters of the gamma function as a model for the basin's Instantaneous Unit Hydrograph (IUH).

published_or_final_version / Civil Engineering / Master / Master of Philosophy

No description available.

Thesis (M.S.)--University of Nevada, Reno, 2006. / "Fall, 2006." Includes bibliographical references (leaves 66-67). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.