Okan Fistikoglu

Integration of GIS with USLE in Assessment of Soil Erosion

A Geographic Information System (GIS) has been integrated with the USLE (Universal Soil Loss Equation) model in identification of rainfall-based erosion and the transport of nonpoint source pollution loads to the Gediz River, which discharges into the Aegean Sea along the western coast of Turkey. The purpose of the study is to identify the gross erosion, sediment loads, and organic N loads within a small region of the Gediz River basin. Similar studies are available in literature, ranging from those that use a simple model such as USLE to others of a more sophisticated nature. The study presented here reflects the difficulties in applying the methodology when the required data on soil properties, land use and vegetation are deficient in both quantity and quality, as the case is with most developing countries.

Statistical Downscaling of Monthly Precipitation Using NCEP/NCAR Reanalysis Data for Tahtali River Basin in Turkey

Statistical downscaling methods describe a statistical relationship between large-scale atmospheric variables such as temperature, humidity, precipitation, etc., and local-scale meteorological variables like precipitation. This study examines the potential predictor variables selected from the National Center for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) reanalysis data set for downscaling monthly precipitation in Tahtali watershed in Turkey. An approach based on the assessment of all possible regression types was used to select the predictors among the NCEP reanalysis data set, and artificial neural network (ANN)–based downscaling models were designed separately for each station in the basin. The results of the study showed that precipitation, surface and sea level pressures, air temperatures at surface, 850-, 500-, and 200-hPa pressure levels, and geopotential heights at 850- and 200-hPa pressure levels are the most explanatory NCEP/NCAR parameters for the study a...

Integrated technologies for environmental monitoring and information production

Preface. List of Contributors. I: Introduction. Integrated Data Management: Where are We Headed? N.B. Harmancioglu. The Conversion of Data into Information for Public Participation in Decision Making Processes M.B. Abbott. Challenges in Transboundary and Transdisciplinary Environmental Data Integration in a Highly Heterogeneous and Rapidly Changing World T. Maurer. Information Technology and Environmental Data Management M. Santos. II: Objectives and Institutional Aspects of Environmental Data Management. Information-Integration-Inspiration P. Geerders. Ocean Teacher: A Capacity Building Tool for Oceanographic Data and Information Management G. Reed. III: Design of Data Collection Networks. Environmental Monitoring Time Scales: From Transient Events to Long-Term Trends P.H. Whitfield. Regional Streamflow Network Analysis Using the Generalized Least Square Method: A Case Study in the Kizilirmak River Basin A.U. Sorman. Automated Water Quality Monitoring in Water Distribution Networks Y.A. Papadimitrakis, S.D. Ozkul. IV: Statistical Sampling. Uncertainty in Environmental Analysis V.P. Singh, et al. Physics of Environmental Frequency Analysis W.G. Strupczewski, et al. Assessment of Outliers in Statistical Data Analysis B. Onoz, B. Oguz. V: Physical Sampling and Presentation of Data. Modern Data Types for Environmental Monitoring and Water Resources Management G.A. Schultz. Assessing the Applicability of Hydrologic Information from Radar Imagery F.P.de Troch, et al. Integrated Satellite Airborne Technology for Monitoring Ice Cover Parameters and Ice-Associated Forms of Seals in the Arctic V.V. Melentyev, et al. VI: Environmental Databases. Integrated Application of United Kingdom National River Flow and Water Quality Databases for Estimating River Mass Loads I.G. Littlewood. Integrated Multidisciplinary Marine Environmental Databases V.L. Vladimirov, et al. Regional Environmental Changes: Databases and Information K.A. Karimov, R.D. Gainutdinova. Environmental Health Indicators in Europe: A pilot Project D. Dalbokova, M. Krzyanowski. VII: Data Processing, Analysis and Modeling. Downscaling of Continental-Scale Atmospheric Forecasts to the Scale of a Watershed for Hydrologic Forecasting M.L. Kavvas, et al. Upscaling Surface Flow Equations Depending upon Data Availability at Different Scales G. Tayfur. Integration of Intelligent Techniques for Environmental Data Processing E. Charou, et al. Integrated Use of Monitoring and Modeling in Water Resources Research G. Mendicino. VIII: Remote Sensing and GIS. DBMS/GIS Applications in Integrated Marine Data Management N.N. Mikhailov, A.A. Vorontsov. The Use of Satellite Remote Sensing Data in Numerical Modeling of the North Pacific Circulation V. Kuzin, et al. Application of GIS Technology in Hydrometeorological Modeling A. Vorontzov, et al. Satallite Observation of Aral Sea S.V. Stanichny, et al. Remote Sensing of the Lacustrine Environment: Data Sources and Analysis S.V. Semovski. IX: Transfer of Data into Information. From Data Management to Decision Support K. Fedra. Urban Drainage, Development Planning and Catchment Flood Management GIS Contrasts in the U.K. J.C. Packman. Metadata as Tools for Integration of Environmental Data and Information Production E. Vyazilov, et al. Perspective Decisions and Examples on the Access and Exchange of Data and Information Products Using Web and XML Application

Evaluating climate change effects on runoff by statistical downscaling and hydrological model GR2M

The main purpose of this study is to evaluate the impacts of climate change on Izmir-Tahtali freshwater basin, which is located in the Aegean Region of Turkey. For this purpose, a developed strategy involving statistical downscaling and hydrological modeling is illustrated through its application to the basin. Prior to statistical downscaling of precipitation and temperature, the explanatory variables are obtained from National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data set. All possible regression approach is used to establish the most parsimonious relationship between precipitation, temperature, and climatic variables. Selected predictors have been used in training of artificial neural networks-based downscaling models and the trained models with the obtained relationships have been operated to produce scenario precipitation and temperature from the simulations of third Generation Coupled Climate Model. Biases from downscaled outputs have been reduced after downscaling process. Finally, the corrected downscaled outputs have been transformed to runoff by means of a monthly parametric hydrological model GR2M to assess the probable impacts of temperature and precipitation changes on runoff. According to the A1B climate scenario results, statistically significant trends are foreseen for precipitation, temperature, and runoff in the study basin.

Hydrospatial Approach to Assist Decision Making on Reservoir Protection Zones

Protection zones established for stream drainage systems or water supply reservoirs serve as a major protection measure to reduce water contamination. In essence, a number of physical, chemical, and/or biological processes act together or separately in these areas to reduce a contaminant’s concentration or to convert it to a less threatening form. Yet, time is an important criterion for these processes to occur, as there is less potential for the concentration of a contaminant to be reduced when there is a shorter time of travel between the point where the contaminant enters the stream and the reservoir intake point. In this regard, this study employs the time component of flow among a set of spatial criteria that commonly target assessments of functionality and effectiveness for potential protection zones in a watershed. Such criteria could be practically evaluated in a multicriteria decision-making framework for a proper design of protection zones. The approach is expected to contribute to protection zo...

Modeling of Environmental Processes

Modeling is the stage when data are transferred into information required for environmental management. Thus, it constitutes an essential component of the decision making process. In recent years, the adoption of integrated approaches to environmental management has also changed the way environmental models are structured and employed. A good example for this development is the case of hydrologie models which evolved from simple models simulating individual processes in a basin to the current comprehensive watershed models of an integrated nature. This chapter reviews the evolution of environmental models particularly for the case of hydrologie and watershed models. The currently used models are reviewed with respect to their purpose and content. Finally, the future of modeling is evaluated in consideration of current environmental problems and expected solutions.

Designating Restricted Areas around Drinking Water Sources through an Index-Based Spatial Approach

AbstractThe design of protection/restriction zones around drinking water bodies is not a simple task, as there are many processes that govern transfer of pollutants in corresponding catchments. The width of the protected area is one of the basic factors to be considered when setting up and managing the zones. The presented approach provides a practical methodology for deciding on an optimum protection distance. Its most distinctive outcome is the feasibility of defining protection zones of variable distances for the applications in different catchments, all based on a single scientific reasoning. It basically considers flow travel times within protection zones, subsurface buffer depths, potential diffuse pollution risks from land uses, sediment-bound pollution, and the total utility of land as a resource. Different weighting schemes for merging various factors together and associated sensitivities on the outputs are further examined for providing more realistic assessments than the equiponderant use of th...

Selection of Variables to be Sampled

The selection of water quality variables to be sampled is a highly complicated issue since there are several variables to choose from. A brief discussion on current selection procedures is already presented in Sections 2.2 and 2.3.5 of Chapter 2.

Assessment of Sampling Sites

Assessment of an existing network starts with a review of monitoring objectives along with a thorough survey of social, legal, economic, political, administrative, and operational constraints. The next step is devoted to the evaluation of technical features that make up a network. This is the stage where sampling sites and frequencies, variables sampled and sampling duration are assessed.

Network Assessment and Redesign

Two major conclusions to be drawn from the review presented in Chapter 2 are that: a) significant problems exist in available water quality data; b) current monitoring networks reflect several shortcomings that hinder their efficiency and cost-effectiveness. The inevitable consequence of these two problems is the significant gap between information needs on water quality and the information produced by current systems of data collection. This difficulty has led to a critical assessment of methodologies used in network design. Eventually, the majority of developed and developing countries have started to evaluate their current monitoring practices and to redesign their networks (National Research Council, 1994; Ward, 1996; Ward et al., 1989 and 1994; WMO, 1994; Whitfield, 1997; Villars and Groot, 1997; Adriaanse et al., 1995; Niederlander et al., 1996; Harmancioglu and Alpaslan, 1997). Thus, what had earlier been a “design” problem in water quality monitoring has recently turned out to be an “assessment and redesign” problem. This current trend in network design underlies the basic approach adopted in this work, namely that the “design” process is treated within an “assessment and redesign” perspective.