Aree

The tide is a periodic phenomenon of rising and falling of the sea surface due to the gravitational attraction exerted by the Moon, the Sun and other celestial bodies on the masses of water present on Earth and secondarily also due to meteorological disturbances. Data from the National Mareographic Network (ISPRA) were used to characterize the amplitude of the astronomical component of the tide signal along the Italian coasts. As is well known, the astronomical tide presents profound differences in the different Italian seas, reaching its maximum excursion in the Northern Adriatic and in the Venice Lagoon, being also strongly influenced by the configuration of the basin.

Continuous monitoring over time of the variations in the astronomical tidal amplitude allows us to highlight the hydrodynamic and therefore morphological changes within the Venice Lagoon, which owes its survival to the maintenance of very delicate environmental balances. The amplitude of the tide in the lagoon is compared with that characteristic of the Gulf of Venice, belonging to the same area from a geological point of view, but free from the anthropic intervention that characterizes the transition environment considered. The trend in tidal height is now substantially stable in almost the entire lagoon, after the strong variations observed as a consequence of profound changes introduced to the lagoon morphology during the first decade of the century.

Any solid material, manufactured or transformed by man, abandoned or lost in the marine and coastal environment, or which reaches the sea in any way, is defined as marine waste. Italy, with Legislative Decree no. 190/2010 transposing the Framework Directive on the Strategy for the Marine Environment, has been carrying out an intense monitoring program of marine waste since 2015, including beached waste. Twice a year, in spring and autumn, the coastal Regional Environmental Protection Agencies (ARPA) carry out solid waste monitoring in the sample areas of 69 reference beaches along the national coast. To evaluate the degree of beach cleanliness based on the density of waste in the monitored sample areas, the Clean Coast Index (CCI), an indicator developed and applied internationally, was calculated.

In 2024, the CCI was calculated for 66 beaches in spring and 69 in autumn. In spring, 80% of the beaches monitored were clean or very clean, compared to 8% dirty or very dirty. In autumn, 81% of beaches were clean or very clean, while 9% were dirty or very dirty. The rest of the beaches were quite clean. Compared to the previous year, the percentage of clean or very clean beaches increased in autumn (77% in 2023), while in spring it remained almost unchanged. In both spring and autumn there was a decrease in dirty and very dirty beaches, from 12% to 8% and from 12% to 9%, respectively.

The monitoring envisaged by the Marine Strategy Framework Directive 2008/56/EC for Descriptor 7 takes into consideration the significant and permanent alterations of the hydrographic conditions due to coastal and marine infrastructures subject to national EIA, built or in the process of being designed/built since 2012. Currently the reference indicator for the D7C1 is related to the extension of coastal marine water bodies of each Sub-Region, defined pursuant to the Directive 2000/60/EC, which presents impacts due to permanent changes in hydrological conditions attributable to the presence of new infrastructures built starting from 2012 and subject to national EIA. The objective for this indicator is not to exceed 5% of the extent of coastal marine water bodies. In 2024 the goal was achieved.

Progress towards achieving the good environmental status of marine waters depends on a series of key factors regulated in Directive 2008/56/EC (MSFD) and implemented in Italy through Legislative Decree 190/2010 (and subsequent amendments). One of the main factors is linked to contamination in waters and organisms and to the progressive elimination of pollution, ensuring that the presence of contaminants does not generate significant impacts or risks for the marine environment. Descriptor 8 of the Marine Strategy Framework Directive 2008/56/EC specifically requires the assessment of the presence of chemical contaminants (D8-C1) and their effects (D8-C2). This is accompanied by Descriptor 9 which provides for the evaluation of the level of contaminants in the edible tissues of fishery products compared to the limits established by Regulation (EU) 2023/915. In 2024, monitoring of the Marine Reporting Unit (MRU) West Mediterranean Sea (MWE). The data collected comes from the specific monitoring carried out by ISPRA and from the institutional monitoring of the experimental zooprophylactic institutes. The definitive evaluation, in relation to the judgement Good Environmental Status (GES), will be processed as soon as all the data produced by the regional agencies are available. With the data available to date, bioaccumulation has a problem linked to exceeding the regulated value of mercury, however from a health point of view a positive opinion is confirmed. This result is in line with what has already been highlighted in past years. For the sediment matrix there is a criticality linked to the presence of TBT and some metals.

Eutrophication is a process caused by the enrichment of nutrients, in particular nitrogen and phosphorus compounds, which determines an increase in primary production and algal biomass with consequent alteration of benthic communities and, in general, a decrease in water quality. The release of nitrogen and phosphorus into the marine and coastal environment can derive from diffuse sources (river loads, main collectors of agricultural activities and civil discharges) and from point sources (discharges deriving from wastewater treatment plants, industrial and deriving from aquaculture activities). 
The assessment of eutrophication of marine waters according to the Marine Strategy is carried out every six years using a combination of information on nutrient levels (concentrations in the marine environment), the primary effects of nutrient enrichment (chlorophyll 'a' concentration as an indicator of algal biomass) and the secondary effects of nutrient enrichment (impacts on organisms caused by hypoxia and/or anoxia phenomena in bottom waters) that are ecologically relevant.

The most recent assessment transmitted by Italy to the European Commission (October 2024) refers to the six-year period 2016-2021 and highlighted the achievement of Good Environmental Status. The analysis of 2022 monitoring data confirms this indication.

Since 2015, Italy, in implementation of the Marine Strategy Framework Directive (2008/56/EC), has implemented an extensive marine litter monitoring program, including microlitter present in the surface layer of the water column. The activity is conducted by the National System for Environmental Protection (SNPA), with the coordination of the Ministry of the Environment and Energy Security (MASE). Microwaste, particles of anthropic origin smaller than 5 mm, derive from both primary sources (industrial pellets, cosmetic microgranules, abrasives) and secondary sources (fragmentation of macrowaste). Their composition, quantity and distribution constitute a key parameter for assessing the good environmental status of marine waters. The processing of data collected from 2015 to 2024 highlights a stable median density of 0.04 microparticles/m² (approximately 40,000 microparticles/km²), with interannual and spatial variations linked to the different hydrodynamic conditions and anthropic pressures of the Italian marine subregions. In 2024 there is an increase in concentrations in the Adriatic Sea and a decrease in the Ionian Sea and the western Mediterranean. At Mediterranean level, the Barcelona Convention has defined a threshold value of 0.000845 microparticles/m² (845 microparticles/km²) for achieving good environmental status: the values ​​found in Italian seas, although stable in recent years, are still significantly higher.

Physical loss defines the seabed surface lost due to permanent changes to the substrate and/or morphology of the seabed induced by anthropogenic activities and/or works, such as coastal defense works, port infrastructures, wind farms, cables and pipelines, etc. It helps to define the level of integrity of the seabed (Descriptor 6), as defined pursuant to the Marine Strategy Framework Directive 2008/56/EC (MSFD) and Decision 2017/848/EC.

The "physical loss" indicator measures the extent and impact of the different types of works and/or activities on the seabed in total and by type of habitat. These data allow us to populate Criterion D6C1 (total physical loss) and Criterion D6C4 physical loss by habitat types ( Broad Habitat Types ), sensu MSFD.

In Italian seas the physical loss has values ​​between 19-34 km ², detected in the Ionian Sea and Central Mediterranean Sea MRU and in the Adriatic Sea MRU, respectively 19.9 km ² and 34 km ² in extension, and approximately 51 km ² observed in the MRU western Mediterranean Sea.

The Marine Strategy (Directive 2008/56/EC) represents an important governance tool for the sea system, promoting the adoption of strategies aimed at safeguarding the marine ecosystem aimed at achieving Good Environmental Status. Good Environmental Status is assessed on the basis of 11 qualitative descriptors and, among these, Descriptor 10 provides that the properties and quantities of marine waste do not cause damage to the coastal and marine environment. Since 2015, Italy has been implementing an extensive monitoring program for marine litter, including beached macro-litter. In 2024, the median of total marine waste stranded on Italian coasts was equal to 252 waste per 100 m, a value similar to that of the previous year (250 waste per 100 m). This is a density that confirms the decreasing trend of beached waste since monitoring was carried out, although still significantly higher than the threshold value of 20 waste per 100 m, established at European level as a requirement for achieving Good Environmental Status. As in previous years, single-use plastics are the most common beached waste, representing approximately 28% of the total, followed by smoking-related waste (mainly cigarette butts), equal to 9% of the waste recorded along the Italian coasts.

The indicator provides the percentage of groundwater monitoring stations divided into quality classes according to the average concentration of nitrates detected over a four-year monitoring period 2020-2023.

The classes typically represent conditions ranging from a low concentration of nitrates (good quality water) to high levels of contamination (at risk or polluted water). At a national level, 69.1% of monitoring stations have average nitrate concentration values ​​lower than 25 mg/l (good quality water); while 11.7% of the monitored stations recorded an average nitrate concentration greater than or equal to 50 mg/l (polluted water). Comparing the values ​​of the four-year period 2020-2023 with the previous one (2016-2019), a decrease in the average concentration is highlighted in 38.8% of the stations, an increase in 26.9% and stability in 34.4%.

The indicator provides the percentage of surface water monitoring stations divided into quality classes according to the average concentration of nitrates detected and in the four-year period 2020-2023, in order to provide an overview of the level of nitrate pollution. The classes typically represent conditions ranging from a low concentration of nitrates (good quality water) to high levels of contamination (at risk or polluted water). At a national level, 95.3% of monitoring stations have average nitrate concentration values ​​lower than 25 mg/l (good quality water); while 0.6% of the monitored stations recorded an average nitrate concentration greater than or equal to 50 mg/l (polluted water). Comparing the values ​​of the four-year period 2020-2023 with the previous one (2016-2019) shows a decrease in the average concentration in 22.4% of the stations, an increase in 20.6% and stability in 57% of the stations.

The indicator provides a national-level picture of the types of pressures acting on surface and groundwater bodies. This information derives from the reporting of the 3rd Water Management Plans drawn up by the District Basin Authorities in accordance with the provisions of the Water Framework Directive 2000/60/EC (WFD) which requires an examination of the impact of human activities on the state of the waters to be carried out. From the analysis of the data it is observed that the main type of pressure that impacts both categories of water, surface and underground, is that of the diffuse type for agricultural use. Subsequently, surface water bodies are impacted by hydromorphological pressure while underground water bodies are impacted by withdrawals.

Continuous monitoring over time of the variations in the propagation delay of the astronomical tide allows us to highlight the hydrodynamic and therefore morphological changes within the Venice Lagoon, which owes its survival to the maintenance of very delicate environmental balances. The tidal propagation delays within the lagoon are calculated with respect to the Gulf of Venice, belonging to the same area from a geological point of view, but free from the anthropic intervention that characterizes the lagoon environment considered. The tidal propagation delays are greater the greater the distance of the observation point from the port inlet from which it is fed. The tidal wave takes approximately 35/40 minutes to enter the lagoon through the narrowings of the three port inlets, while it takes approximately three hours to reach the more internal and remote areas.

Upwelling is a physical phenomenon due to the action of wind and currents which can generate a rising current, oriented offshore and orthogonal to the coast. 
This phenomenon has a notable impact on the local fish fauna and is therefore of great interest. The identification of the most favorable areas for the generation of this phenomenon was carried out using the wind speed and direction data provided by the National Mareographic Network (RMN) managed by ISPRA. These appropriately processed data allow us to identify the coastal areas that are most likely to be more exposed to the upwelling phenomenon such as, for example, the Carloforte area in Sardinia which is confirmed to be among the most favorable to the generation of this variable.

The indicator provides, for each month and for the entire year, the evaluation of the monthly and annual cumulative water height, expressed in mm, summarised to the surface of the national territory that is actually transferred to the atmosphere for evaporation phenomena from the liquid mirrors and the soil and perspiration of the vegetation and, therefore, does not contribute to the formation of renewable water resources.

In 2024, the estimated value of the total annual total real evapotranspiration was 540.3 mm, more than 9.5% at the average value for the period 1951–2024 estimated at 493.4 mm.

The quality of bathing water is essential for the protection of the health of citizens and plays an important role also in terms of the protection of the natural environment and the economic aspects in the tourism sector. For this reason, specific monitoring is carried out throughout the bathing season. With regard to the bathing season 2024, more than 31,600 samples of seawater and lake were collected and analyzed on a total of over 5,000 km of bathing coast. At municipal level the km of coast are divided into more or less extensive bathing waters, for a total of 5,506 bathing waters. The results of the analysis, in addition to guaranteeing the absence of hygienic health risks during the season, have also allowed to classify the waters. The classification was made using the results of the monitoring carried out during the 2024 bathing season and those of the previous three seasons (2023-2022-2021). At the national level, most of the waters are excellent in the classroom (91%), however, however, there are still critical issues due to the presence of water in the low class (1.1%) and not classifiable (1.1%), for which it is not possible to make a quality judgment because most are newly identified and have not completed the 4-year cycle of monitoring, necessary for classification. Even at the regional level, the percentage of water in the excellent and good classes is the highest.

The indicator provides, for each month and for the entire year, the evaluation of the monthly and annual cumulative water height, expressed in mm, in detail to the surface of the national territory, which infiltrates deep into the soil as a result of rainfall.

In 2024, the value of the annual total of the infiltration estimated at 226.8 mm, corresponding to 68.5 billion cubic meters, was slightly higher than the average of the period 1951, 2024 estimated at 216.1 mm, corresponding to 65.3 billion cubic meters.

The 12-month Standardized Precipitation Index (SPI) maps provide a nationwide and large-scale assessment of hydrological drought conditions, obtained using precipitation data collected and published by regional hydro-meteorological services and autonomous provinces and those of the suppressed National Hydrograph and Tire Service (SIMN, now merged into ISPRA) of the Department for National Technical Services. The 12-month aggregation timepiece chosen for the SPI assessment is the one that best describes the effects of drought (precipitation deficit) on the flow rate of rivers, recharging reservoirs and water availability in the aquifers.

In 2024, the 12-month SPI maps (SPI12) showed extreme and moderate drought conditions for the territories of central Italy and for the South and the major islands. The months from June to August 2024 were the most characterized by extreme drought conditions on the 12-month time scale (SPI12 –2.0), as a result of the precipitation deficit found in the second half of 2023 and then in 2024, particularly on southern Italy. The maximum extent reached by this condition was observed in June (16.1% of the Italian territory). From May 2024 until the end of the year, there was also an increase in areas characterized by severe or moderate drought on the 12-month time scale (–2.0 SPI12 –1.0). In this period, with the exception of October and December, the percentage of Italian territory subject to these conditions was always more than 20%, with a maximum in May (28.5%) and a minimum in September (21.6%).

The intensity and persistence of these conditions in 2024 had effects on the availability of water resources in different areas of Italy, resulting, consequently, in environmental and socio-economic impacts related to the use of water.

The indicator measures the increase in the average sea level in Venice, being of fundamental importance for the studies and conservation interventions of the city of Venice, as well as the lagoons and high Adriatic coastal areas at risk of flooding. In Venice, the average sea level has increased since the beginning of the recordings: in the period 1872-2024 the level increases by an average of 2.6 mm / year, with a trend not always constant and uniform over time. In this regard, it is considered appropriate to highlight the rate for the last thirty years (1993-2024), where the average sea level rise is almost doubled (4.8 mm/year).

The indicator derives from the application of the reference legislation for the determination of the ecological status of surface water within the meaning of Directive 2000/60/EC. From the data transmitted in the SoE WISE2 flow referring to 2023, it is noted that the EQB Fitoplankton was monitored at 151 stations and in 72% of them reached the "good or higher" ecological status. In the remaining 28% of the stations there is a state of lower quality than good.

The indicator derives from the application of the reference legislation for the determination of the ecological status of surface water within the meaning of Directive 2000/60/EC. For 2023, as part of the Soe WISE2 data stream, data on 694 monitoring stations for the EQB Macrobenthos were transmitted, which in 55% of them reached the "good or higher" ecological status. In the remaining 45% of the stations there is a state of lower quality than the good. For the EQB Diatomee in 2023, data from 591 monitoring stations were transmitted: in 74% of them there was a "good or higher" ecological status, the remaining 26% has an ecological status lower than the voucher.

The internal flow indicator provides the annual estimate, expressed in mm, of the amount of renewable water resource that is naturally produced in a given territory due to the effect of precipitation falling in the same territory. The indicator is calculated for each year from 1951 to 2024.

In 2024 the value of the indicator at national level was 522.8 mm, corresponding to 157.9 billion cubic meters. The average value of the indicator in the national territory of the last thirty years of climate 1991–2020 is 440.9 mm, corresponding to a volume of 133.5 billion cubic meters, while the long-term average 1951–2024 (so-called LTAA-Long-Term Annual Average) is 457.5 mm, corresponding to 138.2 billion cubic meters.

2024 was characterized by a positive anomaly compared to the long-term estimate (+14.3%), as well as compared to the last thirty years of the climatological period (+18.3%). This positive anomaly is attributable to the high rainfall in the North, while in the territories of Central and Southern Italy and the major islands a persistent drought has been observed. However, at the national level, the availability of renewable water resources continues to show, from 1951 to the present, a statistically significant negative trend.

The weather variables observed in the Venice Lagoon (the average annual atmospheric pressures, the total annual rainfall, the number of rainy days and thermal anomalies) allow to photograph the climate changes taking place. During 2024, in the presence of an average annual pressure of 1,0155.9 mbar (below 0.3 mbar compared to the average of the reference period), 1,127 mm of rain were recorded (+34% compared to the average) over a period of 96 rainy days, while temperatures continue to show themselves in trend and continuous increase.

The indicator shows the number of annual cases of tidal maximums, divided by height classes, detected at the station of Venice - Punta della Salute, representative of the historic city center. Monitoring the trend of the high and medium-high tide classes (above 80 cm compared to the ZMPS reference plane) allows you to control the pressure exerted both on the historic center of Venice (effects on the estate of the banks and buildings), and on the surrounding lagoon (environmental effects on the vegetation of the barenal habitats and on the greater erosion of the natural banks). In the last period, 2019 was an exceptional year as there were 28 cases of “high water”, i.e. exceeds of the threshold 110 cm on the ZMPS, record value of the entire historical series. As of 2020, the entry into operation of mobile barriers against flooding from high tide (model system "Mo.S.E.") has led to a differentiation in the number of cases of high water between the lagoon and the sea. 2024 recorded 12 cases of “high water” at sea and a single pass in Venice (on May 16, first case from 2021), thanks to the drive of the Mo.S.E. which defended the city.

Ostreopsis cf. ovate it is a potentially toxic Bentonic microalga, now present in most of the Italian coastal regions with blooms that can give rise to human intoxication phenomena and toxic effects on benting marine organisms (states of suffering or mortality). The continuous expansion along the Italian coasts of Ostreopsis cf. ovate , of its blooms and the health, environmental and economic problems associated with it, has led to establish a microalga surveillance monitoring program since 2007. This activity has been carried out annually in the summer season by the regional environment agencies (ARPA). The data provided so far by the ARPA, collected and processed by Ispra have clarified the distribution and performance of the blooms at national and regional level. To date, the microalga has been found at least once in the monitoring campaigns carried out so far in 12 coastal regions out of 15. In 2024, the Ostreopsis CF. Ovata is present in 11 coastal regions or in 147/196 stations (75%), while it is absent in all samples taken along the Coste of Emilia-Romagna, Marche, Molise and Veneto.

The indicator provides an assessment of the humidity conditions (surplus of precipitation compared to climatology) and drought (deficit of precipitation with respect to climatology) to which the national territory is subject, in terms of state and trend. For each month from 1952 to 2024, the percentage of Italian territory subject to a deficit and/or precipitation surplus is expressed through the Standardized Precipitation Index (SPI) relating to aggregate precipitation on the time scale of 3 and 12 months.

The 2024 was characterized, overall on a national scale, by a surplus of precipitation, to which the high volume of precipitation that poured into northern Italy contributed. Central Italy, South and the major islands have, on the other hand, continued to be characterized by a precipitation deficit.

This resulted in the highest percentage values of the national territory characterized by "extreme drought" (SPI -2.0) equal to 0.5% and 16.1%, respectively for cumulative precipitation over 3 months and the cumulative one over 12 months. The maximum percentage of national territory characterized by "severe or moderate drought" (?2.0 ? SPI ?1.0) was, instead, 24.1% on a time scale of 3 months and 28.5% on a 12-month time scale. On the other hand, on the 3-month time scale, the maximum values in the year of the percentage of the national territory characterized by "extreme humidity" (SPI ? 2.0) were 14.1%, while the maximum value relative to "severe or moderate humidity" (1.0 ? SPI ? 2.0) was equal to 42.1%. On a 12-month time scale, the percentage of the country affected by "extreme humidity" reached a maximum value of 20.8%, while the percentage with "severe or moderate humidity" reached a maximum of 28.4%.

The indicator provides, for each month of the year, the evaluation, by means of the Thornthwaite method, of the water height of per capitapiratospiration of monthly cumulated potential for the natural soil, expressed in mm, as follows to the surface of the national territory.

In 2024, the estimated value of the total potential annual subpostering on natural soil was 806,0 mm, deviating by +16% from the average value for the period 1951–2024, estimated at 695.4 mm.

The indicator provides the evaluation, expressed in mm, of the height of water, summarised to the surface of the national territory, which precipitates to the ground (both in liquid and solid form) for each month and for the entire year.

The indicator for 2024 shall be compared, for each month of the year, with the corresponding average values for the period 1951–2024 obtained by the same methodology. In 2024 the value of total annual rainfall in Italy was 1,055.5 mm (318.8 billion cubic meters), greater than 10% of the corresponding long-term average value (LTAA-Long-Term Annual Average) and about 8% compared to the annual average over the last thirty years of the climate 1991-2020.

Going down to the regional and district level, the situation is very diversified, with Northern Italy being affected in 2024 by quantities of precipitation higher than the long-term averages. On the other hand, the precipitation anomaly compared to the LTAA was negative in the Center and the South and the larger islands.

The indicator provides on an annual basis the assessment, expressed as a percentage, of the ratio between the annual volume of the runoff (surface preselling) and the annual volume of precipitation. This indicator aims to provide an assessment of the amount of water that is directly transformed into a surface runflow compared to total precipitation and to assess the trend over the long term, also in relation to the possible impact due to climate change. The annual values of the indicator shall also be compared with the corresponding average value calculated over the entire period 1951–2024.

In 2024, the value of the indicator was 26.1%, higher than the average value of 25.1% in the long term. This shows a trend reversal compared to 2023, in which there was a value of 23.7%, below the average. The comparison is even more marked with 2022, the year in which the indicator reached an all-time low of 18.5%.

The 12-month Standardized Precipitation-Evapotranspiration Index (SPEI) maps provide a nationwide and large-scale assessment of drought conditions and are obtained by analyzing the deviation of the hydro-climatic balance hydrological variable—defined as the difference between precipitation and potential evapotranspiration—from its reference climatology.

In 2024, the 12-month SPEI maps (SPEI12) highlight drought conditions, ranging from extreme to moderate, across central Italy, the South, and the major islands. The months from June to August 2024 were the most marked by extreme drought conditions on the 12-month timescale (SPEI12 ≤ –2.0), as a result of the precipitation deficit observed in the second half of 2023 and then in 2024, particularly in southern Italy, combined with the high temperatures that characterized all of 2024 (+1.33 °C anomaly in the average temperature compared to the 1991–2020 climatological mean).

The maximum extent of the hydro-climatic balance deficit was reached in June, with 33.5% of the Italian territory affected by extreme drought. Early in the year, the percentage of areas experiencing severe or moderate drought on the 12-month timescale (–2.0 < SPEI12 ≤ –1.0) was significant: 44.1% in January, 36.3% in February, and around 30% in March and April.

The intensity and persistence of these conditions in 2024 affected water resource availability in various areas of Italy, consequently causing environmental and socio-economic impacts related to water use.