Contribution to the Study of Forest Fires in Semi-Arid Regions with the Use of Canadian Fire Weather Index Application in Greece

Forest fires are of critical importance in the Mediterranean region. Fire weather indices are meteorological indices that produce information about the impact as well as the characteristics of a fire event in an ecosystem and have been developed for that reason. This study explores the spatiotemporal patterns of the FWI system within a study area defined by the boundaries of the Greek state. The FWI has been calculated and studied for current and future periods using data from the CFSR reanalysis model from the National Centers for Environmental Protection (NCEP) as well as data from NASA satellite programs and the European Commission for Medium-Range Weather Forecasts (ECWMF) in the form of netCDF files. The calculation and processing of the results were conducted in the Python programming language, and additional drought- and fire-related indices were calculated, such as the standardized precipitation index (SPI), number of consecutive 50-day dry periods (Dry50), the Fosberg fire weather index (FFWI), the days where the FWI exceeds values of 40 and 50 days (FWI > 40) and (days FWI > 50). Similar patterns can easily be noted for all indices that seem to have their higher values concentrated in the southeast of the country owing to the higher temperatures and more frequent drought events that affect the indices’ behavior in both the current and future periods

An Integrated Multicriteria Analysis Tool for Evaluating Water Resource Management Strategies

Water is involved, directly or indirectly, with many activities and needs that have to be met. The large scale and importance of water projects, the investments needed, the difficulty in predicting the results, and the irreversible character of the decisions have made decision making a complex scientific process. This paper presents a multicriteria analysis (MCA) tool for evaluating water resource management (WRM) strategies and selecting the most appropriate among them, using as an example a Greek area based on agricultural economy, which faces water scarcity problems. Seven alternative strategies were evaluated under hydrological and economic criteria. Four techniques were used—multi attribute utility theory (MAUT), analytic hierarchy process (AHP), elimination and choice expressing reality (ELECTRE), and technique for order of preference by similarity to ideal solution (TOPSIS)—based on the main MCA techniques (utility theory, analytical hierarchy, outranking theory, and classification theory, respectively), to compare their performance, and to reach the most appropriate and ‘fitting’ method for the examined problem. The weightings extracted from two samples, (i) a sample of decision makers/stakeholders and (ii) a group of WRM experts, were used to compare the results. The process was carried out for each questionnaire, and thus the model shows the uncertainty of each sample group and of each method, as well as the overall uncertainty. The results illustrate the reality of the WRM problems of the watershed, enlighten their roots, and have further strengthened our conviction that the cooperation between the scientific community and the authorities is vital for more sustainable and efficient WRM

Groundwater Nitrate Contamination Integrated Modeling for Climate and Water Resources Scenarios: The Case of Lake Karla Over-Exploited Aquifer

Groundwater quantity and quality degradation by agricultural practices is recorded as one of the most critical issues worldwide. This is explained by the fact that groundwater is an important component of the hydrological cycle, since it is a source of natural enrichment for rivers, lakes, and wetlands and constitutes the main source of potable water. The need of aquifers simulation, taking into account water resources components at watershed level, is imperative for the choice of appropriate restoration management practices. An integrated water resources modeling approach, using hydrological modeling tools, is presented for assessing the nitrate fate and transport on an over-exploited aquifer with intensive and extensive agricultural activity under various operational strategies and future climate change scenarios. The results indicate that climate change affects nitrates concentration in groundwater, which is likely to be increased due to the depletion of the groundwater table and the decrease of groundwater enrichment in the future water balance. Application of operational agricultural management practices with the construction and use of water storage infrastructure tend to compensate the groundwater resources degradation due to climate change impacts

Integrated Modeling of Agronomic and Water Resources Management Scenarios in a Degraded Coastal Watershed (Almyros Basin, Magnesia, Greece)

The scope of this study is to assess the effects of agronomic and water resources management scenarios on groundwater balance, seawater intrusion, and nitrate pollution and the comparison of the developed scenarios relative to the current crop production and water management regime in the coastal agricultural Almyros basin in the Thessaly region, Greece. Agronomic and water resources scenarios have been simulated and analyzed for a period of 28 years, from 1991 to 2018. The analysis has been conducted with the use of an Integrated Modeling System for agricultural coastal watersheds, which consists of coupled and interlinked simulation models of surface water hydrology (UTHBAL), reservoir operation (UTHRL), agronomic/nitrate leaching model (REPIC), and groundwater models for the simulation of groundwater flow (MODFLOW) and contaminant transport of nitrates (MT3DMS) and chlorides (SEAWAT). The pressure on water resources has been estimated with the Water Exploitation Index (WEI+) and the reservoirs’ operation with the Reliability index to cover the water demands. The indices of Crop Water Productivity, Nitrogen Use Efficiency, and Economic Water Productivity have been used to quantify the benefits and the feasibility of the alternative scenarios. The best results for the sustainability of water resources are achieved under the deficit irrigation and rain-fed scenario, while the best results for water resources and the local economy are achieved under deficit irrigation and reduced fertilization scenario

Modeling Flow and Nitrate Transport in an Over-Exploited Aquifer of Rural Basin Using an Integrated System: The Case of Lake Karla Watershed

The paper proposes an integrated modeling system consisting of a surface hydrology model, a water reservoir model, a Lake-Aquifer Interaction model, aground water model, and a transport and dispersion model to study ground water quality through two different operational management scenarios. The first scenario is examining the existing condition of groundwater quality without the reservoir operation while the second scenario is assessing the impact of the reconstruction of Lake Karla in the groundwater quality. The study highlights the importance of using an integrated hydrological modeling approach to investigate the groundwater quality in a region which is characterized by extensive agricultural activity

The Karla Aquifer (Central Greece), an Agricultural Region under Intensive Environmental Pressure Due to Agricultural Activities

The Agricultural Policy Environmental eXtender (APEX) model is used to study how different agricultural practices, such as fertilizing, irrigation, and tillage, would affect water quality and runoff in the Lake Karla watershed (Central Greece). The model was calibrated for the potential evapotranspiration with satisfactory results for the period 1980–2008 and for the yields of the main crops grown in the region (cotton, maize, and wheat) from 1980–2015

Quantitative Classification of Desertification Severity for Degraded Aquifer Based on Remotely Sensed Drought Assessment

Natural and anthropogenic causes jointly lead to land degradation and eventually to desertification, which occurs in arid, semiarid, and dry subhumid areas. Furthermore, extended drought periods may cause soil exposure and erosion, land degradation and, finally, desertification. Several climatic, geological, hydrological, physiographic, biological, as well as human factors contribute to desertification. This paper presents a methodological procedure for the quantitative classification of desertification severity over a watershed with degraded groundwater resources. It starts with drought assessment using Standardized Precipitation Index (SPI), based on gridded satellite-based precipitation data (taken from the CHIRPS database), then erosion potential is assessed through modeling. The groundwater levels are estimated with the use of a simulation model and the groundwater quality components of desertification, based on scattered data, are interpolated with the use of geostatistical tools. Finally, the combination of the desertification severity components leads to the final mapping of desertification severity classification