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A method for supporting an operational regional risk and vulnerability analysis for hydrological hazards is suggested and applied in the Island of Cyprus. The method aggregates the output of a hydrological flow model forced by observed temperatures and precipitations, with observed discharge data. A scheme supported by observed discharge is applied for model calibration. A comparison of different calibration schemes indicated that the same model parameters can be used for the entire country. In addition, it was demonstrated that, for operational purposes, it is sufficient to rely on a few stations. Model parameters were adjusted to account for land use and thus for vulnerability of elements at risk by comparing observed and simulated flow patterns, using all components of the hydrological model. The results can be used for regional risk and vulnerability analysis in order to increase the resilience of the affected population.

Estimation of drought in a certain temporal and spatial scale is crucial in climate change studies. The current study targets on three agricultural areas widespread in Greece, Ardas River Basin in Northeastern Greece, Sperchios River Basin in Central Greece, and Geropotamos River Basin in Crete Island in South Greece that are characterized by diverse climates as they are located in various regions. The objective is to assess the spatiotemporal variation of drought conditions prevailing in these areas. The Standardized Precipitation Index (SPI) was used to identify and assess the present and future drought conditions. Future simulated data were derived from a number of Regional Climatic Models (RCMs) from the ENSEMBLES European Project. The analysis was performed for the future periods of 2021-2050 and 2071-2100, implementing A1B and B1 scenarios. The spatial analysis of the drought conditions was performed using a combined downscaling technique and the Ordinary Kriging. The Mann-Kendall test was implemented for trend investigation. During both periods and scenarios, drought conditions will tend to be more severe in the upcoming years. The decrease of the SPI values in the Sperchios River Basin is expected to be the strongest, as it is the only study area that will show a negative balance (in SPI values), regarding the drought conditions. For the Ardas and the Geropotamos River Basins, a great increase of the drought conditions will occur during the 2021-2050 period, while for 2071-2100 period, the decrease will continue but it will be tempered. Nevertheless, the situation in all study areas according to the SPI classification is characterized as 'Near-normal', in terms of drought conditions. [ABSTRACT FROM AUTHOR]

Focusing on flood risk and the information associated with it, developing risk management plans is often overlooking public perception of the threat. The perception of risk varies in many different ways, especially between the authorities and the affected public. It is because of this disconnection that many risk management plans concerning floods have failed in the past. This paper examines the private adaptation capacity and willingness with respect to flooding in two different catchments in Greece. The catchments of Evros and East Attica show recent flood events in the past 20 years. Two case studies were undertaken, comprised of a survey questionnaire focusing on 155 and 157 individuals, from a rural (Evros) and a peri-urban (East Attica) area, respectively, and they focused on those vulnerable to periodical (rural area) and flash floods (peri-urban area). Based on the comparisons drawn from these responses, and identifying key issues to be addressed when flood risk management plans are implemented, improvements are being recommended for the social dimension surrounding such implementation. [ABSTRACT FROM AUTHOR]

This research effort describes the design, development and testing of a Decision support system that performs torrential risk estimation of mountainous watersheds. The system applies an innovative model of Fuzzy logic. The application of the system was done in one of the most risky watersheds of Greece river "Kosynthos" which is located in the North-Eastern part of the country. The system was tested successfully in the 32 most important subwatersheds of "Kosynthos". Its main advantage is that it offers the chance to evaluate the torrential risk of the mountainous watersheds based on a small number of parameters that are easy to measure. The final target is the classification of the watersheds based on their risk. [ABSTRACT FROM AUTHOR]

Soil moisture monitoring at a global or regional scale is nowadays achieved through remotelysensed observations which are considered as a reliable source of information for soilmoisture. Due to the coarse spatial resolution of the available remotely sensed products, thereis need for a downscaling approach which is usually based on other finer scale remotelysensed information along with in situ soil moisture measurements. The objective ofthe downscaling approach is to produce fine resolution soil moisture estimates byexamining the possible relationships between optical / thermal remotely senseddata and commonly monitored in situ meteorological information. In this study adownscaling approach for remotely sensed land surface soil moisture observations fromNASA’s Soil Moisture Active Passive (SMAP) mission was developed. In our workwe used daily global observations acquired by the L-band (1.4 GHz) operatingmicrowave radiometer at a spatial resolution of ∼ 40 km, while the daily in situsoil moisture observations along with other meteorological parameters, like airtemperature and precipitation, were retrieved from a six-stations network located in NorthGreece. The aim of our study was to integrate SMAP passive soil moisture observationsand remotely sensed environmental information in the form of the NormalizedDifference Vegetation Index (NDVI) along with daily in situ measurements in order todevelop a downscaling approach. In consonance with the preliminary conducteddiagnostic tests, SMAP passive soil moisture retrievals, Moderated Resolution ImagingSpectroradiometer (MODIS) NDVI data, daily precipitation and daily mean air temperaturewere found to be possible predictors for soil moisture estimates at a daily time stepwith a resolution of 1 km. Thus, a multilinear regression model was established byintegrating SMAP passive Level 3 soil moisture data, Moderated Resolution ImagingSpectroradiometer (MODIS) 16-day NDVI values, daily precipitation and daily mean airtemperature values. During further examination of the developed regression equation, theperformance of our methodology was enhanced as land use information was added to theprocess. Pursuant to the initial results of the developed approach using in situ measurements for atime period of 20 months, it is argued that SMAP passive soil moisture downscaling can beeffective with the utilization of supplementary environmental information. The accuracy ofour results was ascertained by examining some fundamental statistical parameters, such asthe Residual Standard Error (RSE) and the Multiple R squared (R2). Our resultsindicated an R2value of 0.56 and a low RSE value of 0.04 m3⋅m−3 demonstratingthus the potential of our methodology to achieve soil moisture estimates at a fineresolution. The above described downscaling procedure was conducted with freely available remotesensing data, whilst data processing was executed within the R statistical computingenvironment. [ABSTRACT FROM AUTHOR]