Submitted for publishing in Elsevier’s Journal on Agricultural Systems

Paper # 1
Full text 51k

 Analytic hierarchy process in selecting the best irrigation method 

Srdjevic B., and Jandric Z.

 Abstract

Selection of the best irrigation method for a given field conditions is a complex decision making problem. It is influenced by many factors such as crop density, growing conditions, water quality or  topography, but it is also subject of judgments to be made by more or less experienced farmer or decision maker. In turn, consistent reasoning and a method of deriving solution (decision) by person(s) involved may become critical. A major issue of related decision process is how to manipulate decision factors efficiently and to assure consistency of the whole process, particularly of that part in which decision maker determines intensity of mutual dominance between factors. To handle a problem and trustworthy find the relative importance of objectives, sub objectives and alternatives with respect to stated overall goal, and all this in real field conditions, the Analytical Hierarchy Process (AHP) appears to be a good choice. In specific assessments described here AHP plays a role of efficient supporter to the decision maker in selecting the best irrigation method. Decision alternatives considered in the article are four methods of agricultural irrigation: border, furrow, sprinkler and trickle. They were mutually compared with respect to 7 criterions: crop density, sensibility to diseases, growing conditions, slope, infiltration rate, water quality and skills of labour. Brief description of AHP is followed by results of its application in selecting the best irrigation method. Comparison of AHP’s results with results obtained by two other evaluating methods is also given. 

31. International Geological Congress Rio de Janeiro, Brazil, August 6-17, 2000.

Paper # 2
Full text 83k

Analytic hierarchy process (AHP) in selecting best groundwater pond 

Jandric Z., and Srdjevic B.

Abstract

Selection of the best source/pond for water supply from aquifer systems may be understood as ultimate decision after systematic evaluation of appropriate alternatives is performed and related decision space is created. To choose the one for specific situation in a region and to claim that it is the best or at least the favorite one, systems approach appears necessary to be applied. The main reason is that it preserves all important issues are included such as: ponds’ capacities, water quality, technical accessibility, protection and environmental impacts, exploitation economy, sociological influences etc. Besides, systems approach assures consistency of applied evaluating technique with decision-making process itself. In fact, the major issue is how to relate a variety of factors, i.e. to recognize their impacts and importance in real field conditions, and finally to determine dominance of one factor to another by investigating different dominant/weak structures. 

 The Analytic Hierarchy Process (AHP) appears to be a flexible decision making tool for multicriteria problems such as selection of the best groundwater supply pond. It enables decomposition of a problem into hierarchy and assures that both qualitative and quantitative aspects of a problem are incorporated in evaluation process. AHP has been successfully applied in a recent case study for evaluating potential ponds in the Danube river valley in Vojvodina Province, Yugoslavia. Results of it’s application are presented in brief and followed by extended discussion.  

29th IAH Congress “Hydrogelogy and land use management”, pp. 867-873, Bratislava, Slovak Republic, 1999.

Paper #3
Full text 57k

Strategy of water supply in Vojvodina Province, Yugoslavia 

Mijatovic B., and Srdjevic B.

Abstract

The great intensity of groundwater exploitation for water supply in Vojvodina Province in Yugoslavia has been provided from deep aquifers. More than 5.5 m³/s comes from those aquifers, which belong to a subartesian and artesian type, and from depths varying from 60 m to more than 250 m. Due to intensive long-term groundwater production, the actual pumping levels at numerous deep wells, used for supplying cities, have declined more than 30 m. It is evident that problems of over-exploitation of deep aquifers in Vojvodina can not be efficiently resolved by continuing such groundwater stressful pumping regime. Therefore, it is necessary to initiate an approach to a new strategy for water supply by the powerful systems of free aquifers in the riparian zones of the Danube river and other rivers in the Province. Recently it was proved that there are great possibilities for using groundwater at Danube river riparian zone known as Kovin-Dubovac sector. It’s renewable annual reserves of groundwater surpass the present exploitation capacities of all facilities for water supply in Vojvodina. The new strategy of water supply will be contributed by radical restriction of groundwater exploitation of deep aquifers and by saving the available reserves from further abuse. The new approach will be powered by intensive application of modern systems analysis and decision support techniques followed by systematic assessment of  groundwater regime and dynamic balance with surface waters by advanced mathematical modeling and simulation.

Pannonian Applied Mathematical Meeting (PAMM), pp. 1-6 Ballatonalmadi, Hungary, May 7-10, 1998.

Paper # 4
Full text 31k

 Firm water and shortage index in water systems performance analysis 

Srdjevic B., and Obradovic D.

Abstract

The annual firm water yield and distribution shortage index represent the important systems analysis issues common for studies related to performance analysis and reservoirs’ control within large-scale water resources systems. Simulation and mixed optimization/simulation are typical techniques used in such analyses, whilst computed surface reservoirs’ storages are always ‘measured’ with respect to some prespecified targets, preferences or simply ‘wishes’. Systems approach helps to select and apply appropriate methods to define tolerant deviations from the targets and to recognize favorable and not-favorable system statuses. In this way it enables computing certain performance indices which describe system’s, and particularly reservoirs’, performance in long-term sense. As a consequence, control strategies applied in simulation or other models may be evaluated in more sophisticated manner and decisions can be significantly rationalized and judged.

2nd International Conference on Environmental Management (ICEM2), pp. 163-169 Wollongong, Australia, February10-13, 1998.

Paper # 5
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Geo-ecological database and computer-aided decision support system
of the Fruska Gora National Park, Yugoslavia 

Srdjevic B., Mijatovic B., and Radovic B.

Abstract

The management and environmental protection of Yugoslav national parks is becoming an important part of general strategy adopted at federal government level to improve status and rationalize exploitation of national resources. The Fruska Gora National Park is very beautiful park attracting various tourists. The park is faced with different human-influenced destructive processes and needs improved water monitoring and use. To solve the problems, a decision was made to develop computer-oriented environment for advanced monitoring and control of the Fruska Gora water resources which would be followed by activities related to other natural resources, i.e. land, forests, wildlife, etc. This paper in brief presents results of this initial phase, having as the main subject the Geo-Ecological Database and the Computer-Aided Decision Support System, both developed for efficient management of the Fruska Gora National Park.

4th Balkan Conference on Operational Research Thessalonica, Greece, October 20 - 23, 1997.

Paper # 6
Full text 226k

Transportation problem - standard vs network linear programming:
2. the primer 

Srdjevic B., and Zoranovic T.

Abstract

This paper presents continued general discussion on two methods for solving transportation problems: standard and network linear programming. Particular attention here is put on modeling and computing issues related to both methods. Simple illustrative example is used to demonstrate how transportation problem may be attacked by two related solvers, Simplex and Out-of-kilter. Specific notes are given on knowledge analyst has to be armed with in order to be able to apply the network approach and use network methods and solvers.

Journal Acta Horticulturae, pp. 245-250, No. 449, Vol. 1, ISHS 1997, Netherlands

Paper # 7
Full text 62k

On the use of systems analysis in horticultural crops irrigation 

Srdjevic B.

Abstract

This paper discusses possible alternatives for performing evaluation procedure related to selecting potentially acceptable irrigation methods. The weighting coefficient method is proposed as an alternative to the equal importance method introduced by Holzapfel et al. (1985). Both methods were tested on two small farms in the Province of Vojvodina in Yugoslavia, with assumed nearly the same field conditions and selecting crop, land and labor parameters.

IFAC/ISHS 3rd International Workshop on Mathematical and Control Applications in Agriculture and Horticulture, pp. 97-102,  Hannover, Germany, September 28 - October 2, 1997.

Paper # 8
Full text 99k

Reliability and risk in agricultural irrigation 

Srdjevic B., and Obradovic D.

Abstract

The reliability-risk (RR) concept is discussed with respect to a problem of evaluating reservoirs’ performance Reliability and risk are typical modern performance indices used in evaluations of irrigating systems long-term dynamical behavior. In these evaluations different priorities of irrigating deliveries within the system play an important role. By adopting related ’demand priority matrix’ as part of the simulation model, and by recognizing so-called acceptable and unacceptable system’s states it is possible to derive the information on system operating reliability and risk once simulation on long-term basis is completed. Starting from relative importance of each delivering point for a system and it’s functional relation to other demand points and sources of water, different approaches has been suggested for determining RR on system, subsystems and local points level.

3rd Balkan Conference on Operational Research Thessalonica, Greece, October 16 - 19, 1995.

Paper # 9
Full text 126k

Transportation problem - standard vs network linear programming:
1. general scope  

Srdjevic B.

Abstract

Probably the most important and interesting in operational research and systems analysis is the class of transportation problems (TPs). Large scale and particularly dynamical TPs, closed and opened, need very careful analysis before appropriate salvation procedure and method should be selected. Acting in this course, discussion in this paper is devoted to general characteristics and issues related to implementation of two possible procedures: standard linear programming and network linear programming. Assuming the use of two well known and popular LP solvers, simplex and out-of-kilter, consistent with either of those two approaches, discussion puts a stress on modeling issues before algorithms should effectively be applied. Advantages and disadvantages of two LP approaches and solvers are also identified in order to help eliminating subjective judgments on which one to select for practical use in solving transportation problems.        

7th IFAC’s Symposium on Large Scale Systems: Theory and Applications, pp. 609-613 London, UK, 10 - 13 July, 1995.

Paper # 10
Full text 192k

Reliability-risk concept in evaluating control strategies for
multireservoir water resources system 

Srdjevic B., and Obradovic D.

Abstract

The reliability-risk (RR) concept is discussed with respect to a problem of evaluating reservoirs’ performance within large-scale water resources system. Particular attention is given to an issue of adopting the ’demand priority matrix’ (as part of the simulation model), and applying it to determine so-called acceptable and unacceptable system’s states where system states are reservoirs’ storage levels. Starting from relative importance of each demand point for a system and it’s functional relation to upsteram source points (reservoirs), different approaches has been suggested for determining RR and other relevant performance descriptors for the integral system, subsystems and single reservoirs.