Setting the Phosphorus Boundaries for Greek Natural Shallow and Deep Lakes for Water Framework Directive Compliance

Kagalou I, C. Ntislidou, D. Latinopoulos, D. Kemitzoglou, V. Tsiaoussi, and DC Bobori. 2021. Setting the Phosphorus Boundaries for Greek Natural Shallow and Deep Lakes for Water Framework Directive Compliance. Water 13(5):739. https://doi.org/10.3390/w13050739Eutrophication caused by nutrient enrichment is a predominant stressor leading to lake degradation and, thus, the set-up of boundaries that support good ecological status, the Water Framework Directive’s main target, is a necessity. Greece is one of the Member States that have recorded delays in complying with the coherent management goals of European legislation. A wide range of different statistical approaches has been proposed in the Best Practice Guide for determining appropriate nutrient thresholds. To determine the nutrient thresholds supporting the good status of natural Greek lakes, the phytoplankton dataset gathered from the national monitoring programme (2015–2020) was used for shallow and deep natural lakes. The regression analyses were sufficient and robust in order to derive total phosphorus thresholds that ranged from 20 to 41 μg/L in shallow and 15–32 μg/L in deep natural lake types. Nutrient boundaries that encompass the stressors these lakes are subject to, are essential in proper lake management design

Uso combinado de análisis multicriterio y simulación de aguas subterráneas dentro de un marco espacial de toma de decisiones para la asignación óptima del agua de riego

In arid and semiarid areas in the world, including the Mediterranean region, groundwater has been widely and intensively used for irrigation over the last few decades. Practical as well as economic reasons make its use much more preferable, as compared to surface water, especially to individual farmers. Yet, this rapid and largely uncontrolled expansion in groundwater exploitation, which stimulated the socioeconomic development of numerous rural communities, has produced many negative impacts on aquifer degradation and environmental deterioration. The most common remedy to such problems is the application of specific groundwater management policies that can simultaneously meet socioeconomic and environmental protection goals. In this sense, the paper introduces a methodology for an optimal management of irrigation water, by specifically exploring the socioeconomic and environmental impacts of spatially allocated water conservation measures at the watershed level. The analysis is conducted by developing a multi-criteria decision-making framework, consisting of three distinct models: a hydrogeological, an optimization, and a multi-criteria one, which appraises the results of the other two. The proposed methodology is presented through a case study at a rural Greek watershed, in which groundwater is the sole water source for an intensively practiced agriculture. A system of water use quotas is the resource conservation policy instrument that is examined under a decision-making approach. Results show that some specifically designed and spatially non-uniform quota allocation schemes can meet in an optimum way the relevant criteria.Las aguas subterráneas se han usado intensivamente en las regiones áridas y semiáridas del planeta, incluyendo el Mediterráneo. Hay razones económicas y prácticas que las hacen preferibles a las aguas superficiales, especialmente para agricultores individuales. Sin embargo esto ha conducido a una expansión incontrolada del uso de aguas subterráneas que ha estimulado el desarrollo de muchas comunidades rurales, pero que ha producido impactos negativos como degradación en acuíferos y deterioro ambiental. El remedio más común para estos problemas es la aplicación de políticas de gestión de aguas subterráneas que busque satisfacer simultáneamente los objetivos ambientales y socioeconómicos. Este trabajo introduce una metodología explorando los impactos ambientales y socioeconómicos de una asignación de recursos a nivel de acuífero. El análisis se hace desarrollando un esquema multicriterio consistente en tres modelos: hidrogeológico, optimización, y función multicriterio, que evalúa los resultados de los otros dos. La propuesta se aplica a un estudio del caso de un acuífero rural en Grecia, en el cual el agua subterránea es el único recurso disponible para una agricultura intensiva. El instrumento utilizado para la política de conservación es la asignación de cuotas. Los resultados muestran que unas cuotas diseñadas específicamente y repartidas espacialmente de manera no-uniforme pueden servir para alcanzar los objetivos diseñados

Derivation of irrigation water demand functions through linear and non-linear optimisation models: application to an intensively irrigated area in northern Greece

The growing need for sustainable management of water resources has introduced the implementation of water pricing as an indirect method for efficient and sustainable water use. Agriculture is the main consumer of water worldwide but in many countries it is also a very fragile socioeconomic sector. Within this sense, the paper examines the effect of irrigation water pricing on water demand and on farmers' income. The derivation of a demand function through a linear programming model is the most common approach as it is relatively easy to be implemented and has limited data requirements. However, this method does not allow for a possible reduction of water consumption from the maximum level of water productivity in order to attain the maximum economic outcome. Thus, a non-linear model was formulated in order to estimate the best allocation of water and land resources for each crop. The results show significant differences between the two models (the linear and the non-linear), especially at high water prices.</jats:p

Combined use of groundwater simulation and multi-criteria analysis within a spatial decision-making framework for optimal allocation of irrigation water

In arid and semiarid areas in the world, including the Mediterranean region, groundwater has been widely and intensively used for irrigation over the last few decades. Practical as well as economic reasons make its use much more preferable, as compared to surface water, especially to individual farmers. Yet, this rapid and largely uncontrolled expansion in groundwater exploitation, which stimulated the socioeconomic development of numerous rural communities, has produced many negative impacts on aquifer degradation and environmental deterioration. The most common remedy to such problems is the application of specific groundwater management policies that can simultaneously meet socioeconomic and environmental protection goals. In this sense, the paper introduces a methodology for an optimal management of irrigation water, by specifically exploring the socioeconomic and environmental impacts of spatially allocated water conservation measures at the watershed level. The analysis is conducted by developing a multi-criteria decision-making framework, consisting of three distinct models: a hydrogeological, an optimization, and a multi-criteria one, which appraises the results of the other two. The proposed methodology is presented through a case study at a rural Greek watershed, in which groundwater is the sole water source for an intensively practiced agriculture. A system of water use quotas is the resource conservation policy instrument that is examined under a decision-making approach. Results show that some specifically designed and spatially non-uniform quota allocation schemes can meet in an optimum way the relevant criteria

Valuing the services of coastal ecosystems: a meta-analysis of contingent valuation studies

Coastal ecosystems provide many and diverse functions, creating significant environmental values that should be taken into consideration during coastal management decisions. The most widely used method in coastal ecosystem valuation is contingent valuation, a method that can deal with the assessment of direct and indirect ecosystem uses and also of non-use motivations in natural resource economics. In this framework, the main aim of the present paper is to statistically examine the variation of coastal ecosystem values, as derived from 20 contingent valuation case studies. More precisely, this variation is explained by means of a meta-analysis appli-cation (meta-regression analysis), where the dependent variable is the willingness to pay for coastal ecosystems protection (or restoration), whereas the set of explanatory variables comprise three main categories of primary studies ’ characteristics: (a) the environmental characteristics of the reference sites, (b) the site characteristics and (c) the methodological characteristics of the contingent valuation studies. The results of this paper show that all three categories comprise significant factors that explain the heterogeneity in coastal ecosystem values. Moreover, it has been found that specific site characteristics, such as the size of the reference coastal areas and the major environmental threats within these areas, are the most significant determinants of the variation in the willingness to pay. Finally, according to the outcome of a benefit transfer exercise performed on the results of the meta-regression analysis, the accrued set of estimators can be further applied in order to form a generalized benefit transfer function for the assessment of other coastal ecosystems

USING A MARKET-TYPE ALLOCATION SYSTEM TO CONFRONT WATER SCARCITY: AN INTER-DISTRICT APPROACH IN GREECE

This study examines the implication of a market-based system to allocate water regionally in one of the most intensively irrigated areas of Greece. The proposed approach combines elements from administrative allocation and tradable water rights in order to assess several water supply scenarios under growing water scarcity conditions. In this framework, irrigation water demand functions were derived by means of an optimization model that maximizes the expected annual net benefits from water use in agriculture. Then, an inter-district water market model is developed to compute the most effective water allocation at the basin-level. An institutional reform is suggested, that is linked with the creation of effective water users' associations. The aim of this reform is to achieve a functioning and low-cost trading system at the basin level. The results show that significant volumes of water would be traded under various deficit scenarios, mainly due to the spatial heterogeneity in water use and availability

A methodological framework for an easy and reliable estimation of the full cost of irrigation water

The requirements of the Water Framework Directive (WFD) 2000/60 for the full water cost recovery have brought reactions and difficulties to their implementation, especially for irrigation water. We propose a systematic and objective methodology for the estimation of the cost of irrigation water. The application is made in a degraded Greek watershed, considering surface and groundwater resources. The main novelties of this study are: (i) the attempt to combine different approaches for the estimation of the ‘resource cost’ of irrigation water, and (ii) the investigation of the potential interaction between resource and environmental cost in order to avoid the overestimation of the full cost of water. The analysis shows that both resource and environmental costs can be high in degraded areas, and water policy is likely to affect these costs. Therefore, further analysis is needed on possible water pricing policies for recovering the full cost of irrigation water. © 2020 CIWE