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Abstract. The objective of the study is to provide global grids (0.5 • ) of revised annual coefficients for the Priestley-Taylor (P-T) and Hargreaves-Samani (H-S) evapotranspiration methods after calibration based on the ASCE (American Society of Civil Engineers)-standardized Penman-Monteith method (the ASCE method includes two reference crops: short-clipped grass and tall alfalfa). The analysis also includes the development of a global grid of revised annual coefficients for solar radiation (R s ) estimations using the respective R s formula of H-S. The analysis was based on global gridded climatic data of the period 1950-2000. The method for deriving annual coefficients of the P-T and H-S methods was based on partial weighted averages (PWAs) of their mean monthly values. This method estimates the annual values considering the amplitude of the parameter under investigation (ET o and R s ) giving more weight to the monthly coefficients of the months with higher ET o values (or R s values for the case of the H-S radiation formula). The method also eliminates the effect of unreasonably high or low monthly coefficients that may occur during periods where ET o and R s fall below a specific threshold. The new coefficients were validated based on data from 140 stations located in various climatic zones of the USA and Australia with expanded observations up to 2016. The validation procedure for ET o estimations of the short reference crop showed that the P-T and H-S methods with the new revised coefficients outperformed the standard methods reducing the estimated root mean square error (RMSE) in ET o values by 40 and 25 %, respectively. The estimations of R s using the H-S formula with revised coefficients reduced the RMSE by 28 % in comparison to the standard H-S formula. Finally, a raster database was built consisting of (a) global maps for the mean monthly ET o values estimated by ASCE-standardized method for both reference crops, (b) global maps for the revised annual coefficients of the P-T and H-S evapotranspiration methods for both reference crops and a global map for the revised annual coefficient of the H-S radiation formula and (c) global maps that indicate the optimum locations for using the standard P-T and H-S methods and their possible annual errors based on reference values. The database can support estimations of ET o and solar radiation for locations where climatic data are limited and it can support studies which require such estimations on larger scales (e.g. country, continent, world). The datasets produced in this study are archived in the PANGAEA database (https://doi.org/10.1594/PANGAEA.868808) and in the ESRN database

The landscape of river deltas and coastal wetlands is under a continuous alteration due the combined effects of human and natural factors. The aim of the study is to analyze the Land Use/Land Cover (LULC) changes and associated Ecosystem Services (ESs) of a protected wetland area in the Po river delta (Northern Italy). A combination of methodologies which take into account both the assessment of socio-economic benefits (approach of ESs) and the monitoring of ecosystems attributes (LULC change analysis using transition matrices TMs) were used by comparing the changes observed during two periods (1954–1976 and 1976–2008) described by different environmental protection governance. The period 1954–1976 is described by extensive land reclamations while the period 1976–2008 by significant efforts for applying environmental protection measures. The results highlighted an extensive loss of vegetated wetlands due to direct human interventions (croplands and urban areas expansion) during the first period. The direct human intervention was significantly reduced during the second period. However, vegetated wetlands losses did not follow an analogous reduction probably due to indirect human interventions and natural factors. TMs identified the exact LULC conversions while the ESs approach highlighted the significant economic impact of vegetated wetlands’ losses. Waste treatment was the most important ES of the specific system providing approximately 70 % of the estimated natural capital value. The proposed combination of the selected methods (TMs and ESs) provides a detailed description of landscape changes and their economic impact, which can be used as decision support tool for landscape conservation policies

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