Josef Fürst

Coding of watershed and river hierarchy to support GIS-based hydrological analyses at different scales

A procedure is presented to automatically assign a modified Pfafstetter code to a stream network and its associated watersheds. The first step is to build a topological network according to the object-oriented Arc Hydro framework definition in ArcGIS. These network relations are then mapped into a code that fully represents the stream hierarchy of a basin in a single attribute. Its use does not depend on ArcGIS object orientation and facilitates simple hierarchical aggregation and querying using only the attribute tables of shapefile versions of the stream network and watershed datasets. The code was implemented for the whole of Austria to support the flexible presentation and user-defined aggregation of water balance results in the digital version of the Hydrological Atlas of Austria.

Analysis of spatio-temporal land cover changes for hydrological impact assessment within the Nyando River Basin of Kenya

The spatio-temporal changes in the land cover states of the Nyando Basin were investigated for auxiliary hydrological impact assessment. The predominant land cover types whose conversions could influence the hydrological response of the region were selected. Six Landsat images for 1973, 1986, and 2000 were processed to discern the changes based on a methodology that employs a hybrid of supervised and unsupervised classification schemes. The accuracy of the classifications were assessed using reference datasets processed in a GIS with the help of ground-based information obtained through participatory mapping techniques. To assess the possible hydrological effect of the detected changes during storm events, a physically based lumped approach for infiltration loss estimation was employed within five selected sub-basins. The results obtained indicated that forests in the basin declined by 20% while agricultural fields expanded by 16% during the entire period of study. Apparent from the land cover conversion matrices was that the majority of the forest decline was a consequence of agricultural expansion. The model results revealed decreased infiltration amounts by between 6% and 15%. The headwater regions with the vast deforestation were noted to be more vulnerable to the land cover change effects. Despite the haphazard land use patterns and uncertainties related to poor data quality for environmental monitoring and assessment, the study exposed the vast degradation and hence the need for sustainable land use planning for enhanced catchment management purposes.

Distributive fairness considerations in sustainable project selection

Abstract This work develops general fairness measures that may be used as criteria for sustainable project selection. Sustainable development, fair allocation objectives and empirical distance-based measures of fairness, and their evaluation are discussed. Generalized fairness measures are developed and extended for both intratemporal and intertemporal fairness comparisons. A preliminary application of the extended distance based fairness measures is then performed for a case study of the selection of an electricity supply project. The case study involves selecting between a dispersed diesel energy supply and centralized energy supply with land line energy distribution. Due to data limitations, the perceived fairness is measured in terms of the annual energy costs per megawatt-hour that result from implementing each alternative. The applied fairness measures indicate that intratemporal fairness, in terms of the distribution of user unit costs, may be increased by choosing the land line alternative and tha...

Distributive fairness as a criterion for sustainability: evaluative measures and application to project selection

SUMMARY In evaluating civil engineering projects and management alternatives, the distribution of project impacts among groups in the same generation (intratemporal impact distributions) and between groups in different generations (intertemporal impact distributions) may be used as indicators of project viability and potential sustainability. Empirical measures of distributive fairness among groups at one point in time have typically been applied in project selection. These measures are often based on one of three views of fairness, namely allocation of impacts based on equality, equity, or need. The appropriateness of these measures for different applications may be determined based on whether they meet a set of required characteristics. This paper classifies the common distributive fairness measures for impact distributions at one point in time, describes the required characteristics of each measure, and extends these measures for considering impact distributions that are experienced over time. New meas...

Regional Frequency Analysis of Extreme Groundwater Levels

Flood risk is generally perceived as being a consequence of surface water inundation. However, large damage is also caused by high groundwater levels. In surface hydrology, statistical frequency analysis is a standard tool to estimate discharge with a given return period or exceedance probability. First, a suitable probability distribution is fit to a series of annual maximum peaks. Second, this distribution is used to determine the discharge corresponding to the desired return period. Where only short series of recorded data are available, the estimates can often be improved by regional frequency analysis (RFA). Unfortunately, there is little information in the literature on analogous approaches for the estimation of extreme groundwater levels. In this contribution, the applicability of l-moments-based RFA for the estimation of extreme groundwater levels is investigated. The main issues specific to groundwater levels are (1) appropriate transformation of the data, (2) criteria for identification of statistically homogeneous regions, (3) consideration of correlation between sites, and (4) choice of distribution function. This study is based on data from more than 1100 observation sites in four shallow Austrian Aquifers with a record length of 10 to 50 years. Results show that homogeneous regions for l-moments-based RFA can be identified covering about one half of the total area of the aquifers. The confidence intervals for the 30- and 100-year return levels can be significantly reduced by RFA. Out of the four investigated distribution functions, none is to be preferred generally.

The simulation of groundwater flow velocity random fields by the method of partitioning and randomization of the spectrum

Due to the heterogeneity of aquifers, groundwater flow velocity fields can be viewed as vector random fields (v.r.f.). For the application of Monte Carlo methods to investigate problems of pollutant transport, the efficient generation of v.r.f. with prescribed covariance structure is an important task. The subject of this paper is the simulation of v.r.f. with a given spectral tensor. We adopt a method that combines two principles: spectral domain partitioning and spectrum randomization (SDP/SR). The SR principle allows to reproduce exactly the covariance structure of the v.r.f., which is of particular importance for Monte Carlo simulation, such as random walk particle tracking. Following this methodology, replicates of the v.r.f. can be generated using a cosine series. Once the coefficients of the series were determined, the v.r.f. can be computed at any point of its domain by mere evaluation of the cosine terms. The method does not require a computational grid and is computationally more efficient than, e.g., Gaussian conditioning.

Der Hydrologische Atlas Österreichs: Von der Idee zum Produkt

KurzfassungIn diesem Beitrag wird eine Darstellung der Inhalte und der kartografischen Gestaltung des Hydrologischen Atlasses Österreichsgegeben. Dieser liegt als Kartenwerk vor, das durch eine digitale Variante ergänzt wird. Der Atlas enthält mit der zweiten Lieferung insgesamto Kartentafeln und wendet sich mit seinen Daten und Analysen sowohl an alle im Wasser-und Umweltbereich arbeitenden Fachleute als auch an ein breites umweltbewusstes Publikum. In diesem Beitrag werden die thematischen Inhalte, die Organisationsstruktur für die Umsetzung und Qualitätssicherung, an Hand einiger Karten die Methodik und die Folgerungen für Österreich, und schließlich die geplanten Arbeiten dargestellt.SummaryThis article describes the contents and the design of the Hydrological Atlas of Austria, a cartographic work supplemented by digital version. With the second instalment being complete, the Atlas now includes a total of 40 map plates, its data and analyses being aimed at specialists in the domains of water and environment as well as the environmentally aware public in general. The article discusses the topics dealt with, the organisational structure for implementation and quality assurance and, using several maps, the methods and implications for Austrian hydrology, as well as planned future action.

Development of a University Training Center for Environmental GIS Applications in Poland

A training center for environmental GIS applications was established at the Warsaw Agricultural University (WAU) in a cooperative effort of nine Polish and nine western European universities, as well as public authorities and private consulting companies. The project was part of the “Structural Joint European Project” entitled “Joint Curricula Development for Sil and WAter Resources Protection (SWARP)”, and funded under the framework of the TEMPUS program. In compliance with TEMPUS guidelines and national Polish priorities, promotion of GIS technology for environmental management was assigned a high priority, reflected in the specific objectives for the GIS training center: (1) to become a center of competence for environmental GIS applications, with up-to-date resources of hardware, software, staff and expertise; and (2) to promote the integration of GIS technology for environmental management into the educational programs of the partner institutions. This paper describes how support for hardware and software equipment, curricula development, transfer of expertise through intensive short courses and a staff mobility program was used to increase GIS infrastructure in Poland.

Ein geographisches Informationssystem als Basis für ein Entscheidungshilfesystem für wasserwirtschaftliche Probleme - Kopplung eines GIS mit einem Grundwassermodell

Der vorliegende Beitrag befast sich mit der Nutzung eines Geographischen Informationssystems (GIS) als Grundlage fur ein Entscheidungs- hilfesystem fur wasserwirtschaftliche Probleme. Besonders betont wird der Vorteil der gemeinsamen Datenbasis fur raumbezogene Daten beim Einsatz des Systems in interdisziplinaren Studien. Als Beispiel fur die Integration von existierenden hydrologischen Modellen in das konzipierte Entscheidungshilfesystem wird die Kopplung eines numerischen Grundwassermodells mit dem GIS ARC/INFO gezeigt.