Tourism and sustainable economic development

The interest in sustainable tourism reflects the growing recognition that the industry, tourists and natural resources are inter-linked and that these elements depend each other for successful long term sustainability at appropriate decision-making levels. While much research has been done on how to progress towards more sustainable kind of tourism, much needs to be undertaken to foster the practical application of the concept. This paper is part of this ongoing effort. Having expressed the exigency to build the debate on sustainable tourism on sound economic foundations, and having outlined the capacity of economists to provide such theoretical foundations by stretching the orthodox economic theory to incorporate sustainable issues, the paper shows the evolution of European policy for sustainable tourism together with an analysis of strategies and instruments which appear to be necessary if we are to reconcile tourism development with the protection and conservation of the environment.

Water demand management in Mediterranean regions

Water sustainability needs a balance between demand and availability: 1) Water demand management: demand may be managed by suppliers and regulations responsible persons, using measures like invoicing, consumptions measurement and users education in water conservation measures; 2) Augmentation of water supply: availibility may be augmented by infrastructural measures, waste water reuse, non-conventional resources and losses reduction. Water Demand Management is about achieving a reduction in the use of water resources, normally through increased efficiency of water application. The main objective of this paper is the application of these concepts to Mediterranean regions.

Towards Tourism Sustainability: General Aspects and Empirical Evidence of the Italian Experience at Decentralized Level, with Specific Reference to Sicily

AbstractEven though the concepts and observations underlying sustainability are not a novelty, sustainable development was given impetus and made popular in 1987 by the Brundtland Report. This report introduced development policies and strategies that acknowledged the importance of resource and environmental constraints and the limitations imposed on growth patterns. Although sustainable development proved difficult to define and make operative, the concept was progressively applied to those economic sectors which had major detrimental effects on income, employment and wealth. Sustainable tourism was effectively one part of the effort to take full account of the current and future economic, social and environmental impacts of the sector, addressing the needs of visitors, industry, environment and host communities. After reviewing the main questions referring to the environmental, economic and social aspects of tourism development, this paper tries to identify a balanced indicator showing the impact of tourist accommodation facilities and related infrastructure in Sicily in terms of the three fundamental pillars of sustainability. Based on this indicator, the ranking of the nine Sicilian provinces is provided. In a wider perspective, the proposed approach is applied to make a comparison of tourism sustainability in Sicily and in other Italian regions

Comparison Of Various Phased Approaches For The Constrained Minimum-Cost Design Of Water Distribution Networks

This work is aimed at analyzing and comparing three different phased approaches for constrained minimum-cost design of water distribution networks: the single-step design with demand feedback, the multi-step design without demand feedback and the multi-step design with demand feedback. The difference between the single-step design and the multi-step design lies in the fact that whereas the former entails optimizing a single construction step at a time, i.e. the current construction phase, the latter is based on the phasing of construction and then is aimed at optimizing the current construction phase and all the subsequent phases, included inside a certain temporal horizon, simultaneously. The demand feedback is here used as a pragmatic tool for updating the forecast at some specific time instant of the future demand growth: such an update is performed by setting the future demand growth equal to that really observed in the previous time step. Alternatively, the predicted demand growth rate at the generic time instant can be kept equal to the value assumed at the time instant when the generic node appears, without taking account of the demand variation really observed in time in the node (absence of demand feedback). Applications to a real case study show that the multi-step design with the demand feedback is the most reliable because it makes it possible to reduce the overall construction costs while attenuating the occurrence of pressure deficits in the various construction steps of the network

Minimum transport-driven algorithm for water distribution network partitioning

Abstract This paper presents a novel algorithm driven by the minimization of the transport function for the partitioning of water distribution networks (WDNs) into district metered areas (DMAs). The algorithm is based on the linear programming (LP) embedded inside a multi-objective genetic algorithm, which enables engineering criteria, such as the minimization of the boundary pipes and the maximization of the uniformity of DMAs, to be considered in the partitioning. Furthermore, the application of the algorithm on the dual network topology based on segments and valves guarantees that configurations of DMAs that respect the real positions of isolation valves for WDN partitioning are obtained. After being described on a small WDN, it is successfully validated on a large size WDN, proving better performance than other algorithms in the scientific literature for the generation of engineeringly appealing DMA configurations, with almost identical hydraulic performance to the unpartitioned WDN

Exploring numerically the benefits of water discharge prediction for the remote RTC of WDNs

This paper explores numerically the benefits of water discharge prediction in the real time control (RTC) of water distribution networks (WDNs). An algorithm aimed at controlling the settings of control valves and variable speed pumps, as a function of pressure head signals from remote nodes in the network, is used. Two variants of the algorithm are considered, based on the measured water discharge in the device at the current time and on the prediction of this variable at the new time, respectively. As a result of the prediction, carried out using a polynomial with coefficients determined through linear regression, the RTC algorithm attempts to correct the expected deviation of the controlled pressure head from the set point, rather than the currently measured deviation. The applications concerned the numerical simulation of RTC in a WDN, in which the nodal demands are reconstructed stochastically through the bottom-up approach. The results prove that RTC benefits from the implementation of the prediction, in terms of the closeness of the controlled variable to the set point and of total variations of the device setting. The benefits are more evident when the water discharge features contained random fluctuations and large hourly variations.Enrico Creac