A decision methodology for the resource utilization of rangeland watersheds

Degradation of rangeland resources leading to the desertification process is viewed in terms of human and climatic influences. While climatic impacts are important, resource utilization as practiced by man is the major cause of desertification. A multi-objective .decision methodology is developed here which is intended for the analysis of alternative management plans of rangeland watersheds under climatic variability. First, a system model is employed to portray the dynamics of a rangeland as it would respond to climatic changes and different grazing intensities. This approach allows for an interaction of inputs such as rainfall, solar radiation, and temperature with the state of the system which is a range condition index, and with outputs such as production and sediment yield. A simulation package is developed to implement the system model by actually using available data and providing some output values for production and sediment yield. At this stage a number of alternative management plans are identified. The information obtained from the simulation as well as other information of interest are represented by performance criteria, leading to an array of alternative versus criteria. Then, management plans need to be evaluated as they would impact the criteria. A multiobjective decision making technique is selected to perform the analysis for an identification of prefered management alternatives.hydrology collectio

Simulation of Rangeland Resource Dynamics Using Historical Rainfall Data

From the Proceedings of the 1984 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 7, 1984, Flagstaff, ArizonaThis article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]

Two solution methods for dynamic game in reservoir operation

Mehran Homayoun-far, Arman Ganji, Davar Khalili, Jeff Harri

A fuzzy stochastic dynamic nash game analysis of policies for Mmnaging water allocation in a reservoir system

In this paper a fuzzy dynamic Nash game model of interactions between water users in a reservoir system is presented. The model represents a fuzzy stochastic noncooperative game in which water users are grouped into four players, where each player in game chooses its individual policies to maximize expected utility. The model is used to present empirical results about a real case water allocation from a reservoir, considering player (water user) non-cooperative behavior and also same level of information availability for individual players. According to the results an optimal allocation policy for each water user can be developed in addition to the optimal policy of the reservoir system. Also the proposed model is compared with two alternative dynamic models of reservoir optimization, namely Stochastic Dynamic Programming (SDP) and Fuzzy-State Stochastic Dynamic programming (FSDP). The proposed modeling procedures can be applied as an appropriate tool for reservoir operation, considering the interaction among the water users as well as the water users and reservoir operator.A. Ganji, D. Khalili, M. Karamouz, K. Ponnambalam and M. Java

Actor Network Theory Approach and its Application in Investigating Agricultural Climate Information System

Actor network theory as a qualitative approach to study complex social factors and process of socio-technical interaction provides new concepts and ideas to understand socio-technical nature of information systems. From the actor network theory viewpoint, agricultural climate information system is a network consisting of actors, actions and information related processes (production, transformation, storage, retrieval, integration, diffusion and utilization, control and management), and system mechanisms (interfaces and networks). Analysis of such systemsembody the identification of basic components and structure of the system (nodes) –thedifferent sources of information production, extension, and users, and the understanding of how successfully the system works (interaction and links) – in order to promote climate knowledge content and improve system performance to reach agricultural development. The present research attempted to introduce actor network theory as research framework based on network view of agricultural climate information system

Sensitivity of Calibrated Parameters and Water Resource Estimates on Different Objective Functions and Optimization Algorithms

The successful application of hydrological models relies on careful calibration and uncertainty analysis. However, there are many different calibration/uncertainty analysis algorithms, and each could be run with different objective functions. In this paper, we highlight the fact that each combination of optimization algorithm-objective functions may lead to a different set of optimum parameters, while having the same performance; this makes the interpretation of dominant hydrological processes in a watershed highly uncertain. We used three different optimization algorithms (SUFI-2, GLUE, and PSO), and eight different objective functions (R2, bR2, NSE, MNS, RSR, SSQR, KGE, and PBIAS) in a SWAT model to calibrate the monthly discharges in two watersheds in Iran. The results show that all three algorithms, using the same objective function, produced acceptable calibration results; however, with significantly different parameter ranges. Similarly, an algorithm using different objective functions also produced acceptable calibration results, but with different parameter ranges. The different calibrated parameter ranges consequently resulted in significantly different water resource estimates. Hence, the parameters and the outputs that they produce in a calibrated model are “conditioned” on the choices of the optimization algorithm and objective function. This adds another level of non-negligible uncertainty to watershed models, calling for more attention and investigation in this area