Full Technical Report: Climate-proof Irrigation Strategies

Full Technical Report: Climate-proof Irrigation Strategies Author name: Stefano Bagli Author organization: GECOsistema srl (Italy) Full Technical Report: Climate-proof Irrigation Strategies

Summary Using the Copernicus Climate Change Service (C3S), GECOsistema, has supported Romagna Land Reclamation and Irrigation Authority to make projections on the future supply of the water available to crops in Italy s Castiglione District (Forlì-Cesena Province). Predicting irrigation needs and planning better rotation and spatial distribution of crops can help irrigation managers to mitigate the threats posed by climate change. Water is a vital resource for agriculture and a change in supply directly affects a crop s success. The Castiglione District covers an area of 2062 hectares. The Romagna Land Reclamation and Irrigation Authority is responsible for meeting irrigation demand in this area. With climate scenarios generated from C3S Sectorial Information System (SIS) for Water data for 2020, 2050 and 2080 it was possible to quantify for six different crops: kiwi, seed chard, persimmon, peach, horticultural crop and corn, the deficit or surplus of water for each crop, the capacity of existing irrigation systems to meet requirements, and the potential yield and economic losses at harvest. Irrigation authorities are required to improve or build new infrastructures. They save money if they can more accurately predict future water supply through understanding climate change. "[C3S] will help us to protect crops and ultimately safeguard agriculture through irrigation strategies that anticipate the water shortages that could come with climate change." Solution Copernicus wetness indicators give the difference between expected precipitation and evaporation and represents a proxy for assessing crop irrigation needs or harvest yield losses due to water stress. Within this project, GECOsistema in Italy developed an online tool (www.climate-tools.com) that uses these indicators to help the Romagna irrigation managers to assess the suitability of any existing irrigation network under the climate change scenario. The tool helped them to quantify the potential deficit or surplus of irrigation water and therefore evaluate investments in new infrastructures, improvement and adaptation technologies and practices. Through C3S SIS for water, the Romagna authority can also assess and identify more sustainable crop practices; quantify potential damage to crops and harvest under the current crop scheme and irrigation capability; and adapt irrigation of especially thirsty crops. C3S SIS for water was the sole source of this type of data. No other climate change specific data or studies were available from other data providers or national agencies. Results The data were used to calculate water demand under different climate change scenarios. The irrigation system in the Castiglione District was found to be inadequate in the face of long-term climate change for several crop practices. Full Technical Report: Climate-proof Irrigation Strategies

The Romagna Authority was advised to develop a new crop scheme based on Copernicus projections; consider improved irrigation systems; and find new irrigation technologies to conserve water supplies in the Castiglione District. "C3S has highlighted the risks associated with climate change and this will help us to validate new and existing irrigation proposals." commented Daniele Domenichini, C.P. Eng. at Romagna Land Reclamation and Irrigation Authority. Conclusion Climate services represent an effective tool to assist irrigation managers in infrastructure planning and mitigation implementation. In addition, climate services and indicators are useful to raise awareness on the challenges that climate change pose. Particularly, for organizations that have not taken climate change into consideration yet as an important variable in the decision-making process. The Romagna Land Reclamation and Irrigation Authority has an online tool based on C3S SIS water data that enables them to develop irrigation strategies that can resist adverse conditions caused by climate change. Up to now, the information and tools to do this were not available. The main message of this case study is: new tools and data give irrigation managers the possibility to evaluate climate risks and support irrigation risk management in the context of climate change. Press Release https://climate.copernicus.eu/gecosistema-climate-proof-irrigation-strategies-italy-saves-crops https://climate.copernicus.eu/news-and-media/press-room/press-releases/climate-proof-irrigationstrategies-save-crops-italy http://www.greenreport.it/news/clima/salvare-lagricoltura-italiana-dai-cambiamenti-climaticinuove-strategie-irrigazione/ Full Technical Report: Climate-proof Irrigation Strategies

Contents Introduction... 1 Step 1: SWICCA Indicator - Wetness1... 2 Description:... 2 Results:... 2 Step 2: Spatial downscaling to a resolution of 1 or 2 km suitable for the case study... 4 Description:... 4 Results:... 4 Step 3: Mapping Wetness1 with a temporal timeframe of 10 days in the study area... 8 Description:... 8 Results:... 8 Step 4: Mapping climate risk for agriculture and identification of areas where adaptation and/or mitigation measures should be adopted... 10 Description:... 10 Results:... 10 Step 5: Climate Risk Assessment: Evaluate the risk and economic damages on agriculture... 11 Description:... 11 Results:... 12 Step 6: Climate Risk Management: CLIMATE SMART AGRICULTURE SEASONAL FORECAST... 31 Description:... 31 Results:... 31 Conclusion of Full Technical Report... 34 Full Technical Report: Climate-proof Irrigation Strategies

Introduction The Romagna Land Reclamation and Irrigation Authority is in charge to maintain and develop the irrigation network in order to meet irrigation demand and minimize agricultural damages in a small agricultural district in the Province of Forlì-Cesena, Rimini and Ravenna (Italy). In order to plan adaptation/mitigation options or new investments in irrigation network and assess the economic damages and risk posed by climate change to irrigated crops, the irrigation manager needs information about how soil water balance and irrigation demand might change in climate change scenario. Through a bottom-up approach to better fulfill the customer's needs and tackle some of its decisionmaking challenge, a simplified soil water balance indicator has been developed (Wetness 1) and combined with crops water demand and irrigation availability in order to assess the agricultural economic damages for the study area. Wetness 1 data provided by portal at decadal values has been validated and downscaled to 2 km of spatial resolution, the indicator provides high-resolution information useful for predicting the spatial variation of soil water content (Wetness1 indicator) and consequently the water irrigation needs under climate change scenarios In particular, the cumulative sum of decadal values representative for each irrigation district can be efficiently adopted by irrigation managers in order to assess the following aspects: quantify the variation, in terms of duration (number of decadal), of negative values of the Wetness1 cumulative sum; identify and locate the most critical irrigation districts in terms of soil water availability and increases in irrigation demand; evaluate if the existing irrigation network can respond to new water irrigation demands; quantify yield losses and identify the best adaptation and mitigation options. The present document describes the planned tasks that are necessary to perform the climate indicator for the case study of interest. Figure 1 - Workflow Climate-proof Irrigation Strategies Full Technical Report: Climate-proof Irrigation Strategies 1

Step 1: C3S SIS Water Indicator - Wetness1 Description: The selected indicator (Wetness1), able to spatially predict the water irrigation needs and the climate risk for crops, has been identified in the soil hydro-climatic balance (BIC) and evaluated as a net balance between rainfall and PET every 10 days. This indicator is available in the portal interface as Wetness1 and has been downloaded at spatial resolution of 5 km and also at E-HYPE sub-basins resolution. Wetness1 decadal values are provided, for each climate change scenario, as relative percentage and absolute variation. Results: At the resolution of 5 km, the user is unable to plan and evaluate any decisions concerning irrigation adaptation strategies. Nevertheless, from the climate scenario of Wetness1, provided by the interface, it is possible to evaluate how, in the region of interest (see Figure 2), positive and negative variations can significantly affect irrigation network performance and spatial cropping distribution in the future with respect to relevant economic consequences in terms of new investments and value of crops. Figure 2 - Wetness1 at 5 k and EHYPE Catchment spatial resolution - 2020 Climate Change scenarios only refer to wetness1 indicator variation, because socioeconomic indicators, particularly Landuse, show no future variations, as reported in Figure 3. Full Technical Report: Climate-proof Irrigation Strategies 2

Figure 3- variation of landuse in Castiglione district Full Technical Report: Climate-proof Irrigation Strategies 3

Step 2: Spatial downscaling to a resolution of 1 or 2 km suitable for the case study Description: Step 2 is required in order to map climate scenarios of hydro-climatic balance indicator (Wetness1) at a higher spatial resolution (from 5km to 2 km). The final maps plotting the climate scenarios of Wetness1 (absolute or cumulative sum) are manipulated by the user in order to identify which agricultural area will potentially be affected by water stress, to understand which branches of the irrigation network will be overexploited, and finally to predict the spatial evolution of cropping patterns. Two different downscaling procedures were applied, depending on the type of climate data provided: Relative Variation rescaling factor applied to decadal Wetness1 values as registered by the meteorological stations located in the study area. The rescaling factor consists in the percent variation as provided by the Wetness1 indicator available in the interface; Absolute Variation the predicted variation is added to values as registered by the meteorological stations located in the study area. The downscaling procedure consists in applying the relative or absolute variation to each available meteorological station present in the study area. The historical long-term mean decadal values of Wetness1 have been corrected with the variation provided by the climate change scenario in the demonstrator. Results: The new downscaled Wetness1 data and maps were uploaded in a dedicated web mapping service available at http://www.climate-tools.com/swicca/view/index/index.html. The web interface allows the user to generate interactive web charts of absolute sum, cumulative sum, relative variation, number of negative decadal values and the ensemble cumulative sum of Wetness1 indicator (Figure 4 to Figure 9). Full Technical Report: Climate-proof Irrigation Strategies 4

Figure 4 - Web Mapping App and visualization of the SWICCA Irrigation case study. Figure 5 - Downscaled Wetness1 decadal values Castiglione Station Full Technical Report: Climate-proof Irrigation Strategies 5

Figure 6 - Downscaled Wetness1 cumulative sum decadal values Castiglione Station. To consider the amount of water available for each decadal value in the irrigation network and the real value of PET for a specific crop, the user has the possibility to define specific decadal values of irrigation (mm/decadal) and of the kc coefficient for PET. Figure 7 - Downscaled Wetness1 cumulative sum decadal values S. Pietro in Vincoli Station, no Irrigation Figure 8 - Actual Water Irrigation Capacity (mm/decadal) S. Pietro in Vincoli Station Full Technical Report: Climate-proof Irrigation Strategies 6

Figure 9 - Downscaled Wetness1 cumulative sum decadal values S. Pietro in Vincoli Station, with Irrigation. Figure 10 - Downscaled Wetness1 statistical ensemble cumulative sum decadal values Castiglione Station, with Irrigation. By analysing the cumulative sum of the Wetness1 indicator, computed with and without irrigation, the user can evaluate at the end of the irrigation period (October) the water deficit for a specific crop and subsequently can assess the agricultural damages or the mitigation/adaptation options available in order to fill the water gap. Full Technical Report: Climate-proof Irrigation Strategies 7

Step 3: Mapping Wetness1 with a temporal timeframe of 10 days in the study area Description: To produce climate maps of Wetness1 values, the downscaled values computed for each meteorological station available in the area of interest has been interpolated (ordinary kriging from the R package automap: https://cran.r-project.org/web/packages/automap/index.html). The maps were produced at 2 km spatial resolution. Results: The user-friendly web mapping interface allows the user to generate high-resolution maps of the Wetness1 indicator through the selection of a Hydrological Model (E-HYPE, LISFLOOD or VIC421), the time frame (2020, 2050, 2080) and the climate change scenario. The user can request maps for the following Wetness1 values: Absolute values for a specific decadal single and ensemble climate scenario; Cumulative sum of absolute values for all decadal single and ensemble climate scenario; Relative changes for a specific decadal; Number of decadal with negative cumulative sum of absolute values; Figure 11 C3S SIS water web-service map generation options. A B C Full Technical Report: Climate-proof Irrigation Strategies 8

Figure 12 - Maps of downscaled BIC/wetness1 indicator using the E-HYPE model RCP26 scenario 2020 (A), scenario 2050 (B), and scenario 2080 (C). Figure 13 - Maps of downscaled cumulative sum of the Wetness1 indicator using the LISFLOOD model scenario e- CSC_REMO2009_MPI-ESM-LR_rcp85, year of reference 2080. Full Technical Report: Climate-proof Irrigation Strategies 9

Step 4: Mapping climate risk for agriculture and identification of areas where adaptation and/or mitigation measures should be adopted Description: The spatial analysis of the evolution of the Wetness1 indicator, under different climate change scenarios considering the characteristics of the actual irrigation network (extension and operational area) and crop pattern water demand, supports the user in identifying areas that could benefit from adaptation and/or mitigation measures in terms of improvements in the irrigation network and water conservation. The possibility to map the cumulative sum of absolute values of the Wetness1 indicator and the number of decadal with negative cumulative sum values support the irrigation manager in: evaluating the amount of irrigation water needed to sustain specific crops under a specific climate change scenario; identifying the agricultural area and crops at risk; quantifying the potential agricultural losses; selecting the best mitigation and/or adaptation options: water-saving technologies and best practices; appropriate sustainable agriculture techniques. Results: Figure 14 reports on the number of decadal with negative cumulated sum values of the Wetness1 indicator. An increase in the number of negative decadal correspond to high water irrigation demand, representing a risk for the irrigation systems in place and for the existing crop patterns. By analysing the spatial distribution, it is possible to identify the major agricultural areas at risk. Figure 14 - Map of the number of decadal with negative values of the cumulative sum of Wetness1 indicator using the E- HYPE model scenario e-e-smhi_rca4_ec-earth_rcp85, year of reference 2080. Full Technical Report: Climate-proof Irrigation Strategies 10

Step 5: Climate Risk Assessment: Evaluate the risk and economic damages on agriculture Description: For this step of the workflow we developed a simple case study concerning the assessment of climate risk on a small irrigation district, named Castiglione (2062.21 ha, Figure 15), characterised by the presence of an existing water irrigation system that sustains different crops practices. The irrigation manager s main challenge consists in evaluating, under a climate change scenario, if the existing irrigation system is able to satisfy the water demand for the on-going agricultural practices; and, subsequently assess the climate risk in terms of harvest losses and economic damages. Figure 15 - Castiglione District case study. Table 1 reports the list of cultivated crops in the Castiglione District and the relative value of the kc crop seasonal evaporation coefficient. Crop kc earlyseason [Mar-Apr] kc midseason [May-Aug] kc lateseason [Sep-Oct] Actinidia (kiwi) 0.40 1.05 1.05 Onion 0.7 1.00 0.75 Strawberry 0.85 0.75 0.20 Seed chard 0.35 1.20 0.70 Persimmon 0.85 0.75 0.2 Peach 0.55 0.9 0.65 Horticultural crops 0.5 1.05 0.9 Corn 1 1.15 1.05 Table 1: List of crops for the Castiglione District and associated kc coefficient values. Irrigation practices in this District usually start in March and finish by October, the mean season is considered to extend from May to July. Full Technical Report: Climate-proof Irrigation Strategies 11

The existing irrigation system s maximum capacity is able to provide an irrigation flow rate of 0.478 m 3 /s for the entire area of the Castiglione District. Under the hypothesis of exploiting the irrigation system at maximum rate for 24 h during irrigation periods, the amount of water provided evenly per unit of area is equal to 20 mm every 10 days. Under the hypothesis of maintaining the actual unitary irrigation flow rate (20 mm/decadal) and the actual scheme of crop cultivation, with their specific kc values, the case study evaluates if the actual irrigation system is capable of meeting crop requirements under a climate change scenario and quantifies potential economic losses. Results: Through the web mapping user interface of the dedicated climate service, the irrigation manager can evaluate for each crop in the area, the cumulative Wetness1 trend by specifying a value for the kc and the provided irrigation. By analysing the cumulative trend of Wetness1 at the end of the irrigation period, the manager can easily quantify the deficit or surplus of water for each crop. Figure 16 reports, for actinidia (kiwi) and strawberry, the yearly trend of kc and on the unitary amount of irrigation. Figure 16 - Unitary amount of irrigation and kc values for 2 crops in the Castiglione District Figure 17 displays the trends of cumulative sum for the Wetness1 indicator for each crop, taking into account the present case and a climate change scenario. Reported evaluations are obtained using the E-Hype model and considering as the climate impact scenario for 2020, 2050 and 2080 the RCA4_HadGEM2-ES_rcp85, SMHI_RCA4_EC-EARTH_rcp85. Full Technical Report: Climate-proof Irrigation Strategies 12

Figure 17 - Cumulative sum of the Wetness1 indicator in the Castiglione District using the E-HYPE model climate change scenario RCA4_HadGEM2-ES_rcp85, SMHI_RCA4_EC-EARTH_rcp85, for the years of reference 2020, 2050 and 2080. The plots in Figure 17 support the irrigation manager in evaluating if at the end of the irrigation period (October), under the hypothesis of using the irrigation network at maximum capacity (maximum rate for 24h), a specific crop has enough water available in order to maintain production and avoid damaging water deficits. In this case study, a deficit in terms of water availability for all crops is expected for the 2080 RCA4_HadGEM2-ES_rcp85 scenario and for the 2050 E-SMHI_RCA4_EC-EARTH_rcp85 scenario. In order to evaluate importance of crop scheme as adaptation measure, Castiglione District case study has been completed by calculating the reduction of economic profit due to water deficit condition. Different crops show various behavior because of distinct kc crop seasonal evaporation coefficient (Table 1), so in the same district situations of economic loss can stand beside safe situations, depending on crop characteristic. Using the climate tool (http://www.climate-tools.com/swicca/view/index/index.html) we calculated for each crop cumulative value of Wetness1 indicator, finding a threshold value of -40 mm; this value is the one below which cultivation yield shows a reduction of about 30%. Threshold value has been fixed considering medium soil texture in study area, soil moisture residual conditions and medium root length for crops; once Wetness1 indicator falls below this value, crops feel water deficit and yield (and profit) reduces. Considering specific crops profit in wet and in dry conditions, profit reduction for specific cultivation among the whole district can be easily calculated. Full Technical Report: Climate-proof Irrigation Strategies 13

The Climate tool lets also to consider 2020, 2050 and 2080 temporal scenarios, giving all the elements to evaluate probability of future profit reduction for different crops, showing most economic hazardous crops for district, depending on irrigation flow rate and Climate Change conditions. Potential of irrigation system takes in account full water availability, with only limitation due to technological reasons, but in future scenarios, also water availability at the source can be reduced, leading to hydrological drought condition (differing from technological drought which is related to system technological limitation). Actually in Castiglione district, water for irrigation comes from Po river through a Channel, the Canale Emiliano Romagnolo CER, and Climate Change conditions can also affect global availability of this water source. To account a future technological limitation of the irrigation system and potential reduction of water availability, we can consider an hypothetical reduction of 25% in total potentiality of irrigation system, that equals to an amount of water provided per unit of area of 15.02 mm every 10 days. Next graphs taken from the climate tool show for each decade, cumulative distribution function (CDF) of cumulative sum of the Wetness1 indicator for the ensemble of the combinations of every model and every climate change scenario. The tool can estimate loss probability, meaning the possibility among all the combinations to have, for each crop, Wetness1 indicator below threshold value of -40 mm and face cultivation yield reduction. Economic evaluation has been developed for Castiglione District and for 6 different crops: kiwi, seed chard, persimmon, peach, horticultural crop and corn. For every crop, specific gross production [ /ha] is reported in optimal condition and in water deficit condition; knowing total cultivated area [ha] inside district for each crop, it is possible to compute total possible economic damage due to future climate change conditions. For selected crops, climate change conditions illustrate potential economic damages for all kind of cultivations. Kiwi and horticultural crop will have 0.15-0.20 of probability to be in water deficit condition in 2020, with yearly economic loss of about 4600 for kiwi and about 75000 for horticultural crop. Seed chard shows possible deficit condition in 2050 (up to 0.5 of probability), with annual loss of about 70000, while corn will be in water deficit condition even since 2020 in every scenario, leading to annual economic loss of about 36000. Fruit cultivation will be in water deficit condition in 2080, with yearly economic loss of about 7700 for persimmon (probability of about 0.1) and about 18000 for peach (probability of about 0.15). The main outcomes from this case study are: the irrigation system is probably not suitable to face long-term climate change (2020, 2050 and 2080 horizon), according to the scenarios analysed; significant economic damages in terms of crop yield losses have been evaluated and quantified for several crops located in the Castiglione district with a total economic damage close to 200 keuro per year. adaptation measures should be evaluated for the Castiglione District, particularly: a new crop scheme should be evaluated for this District and the tool can provide all the necessary support for this task; investments in improving the irrigation systems should be considered; economical evaluation alternative measures should be considered (e.g.: water-saving technologies) new irrigation technologies Full Technical Report: Climate-proof Irrigation Strategies 14

Kiwi (Actinidia) Area [ha] 0.99 Gross production [ /ha] 15640 Gross production [ ] 15483.60 Reduced Gross production (-30%) [ /ha] 10948 Reduced Gross production (-30%) [ ] 10838.52 Loss [ ] 4645.08 Figure 18 - kiwi cultivated area in Castiglione district Figure 18 shows kiwi cultivated area in Castiglione district. Actual total gross production is 15 483.60, but Climate Change ensemble scenarios show, in condition of irrigation reduction, possibility of water deficit condition (a probability of about 15% in 2020 and up to about 50% in 2080), leading to a possible economic loss of 4 645.08 every year. Full Technical Report: Climate-proof Irrigation Strategies 15

Figure 19 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, kiwi cultivation, year 2020, irrigation reduction of 25%. Figure 20 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, kiwi cultivation, year 2050, irrigation reduction of 25%. Figure 21 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, kiwi cultivation, year 2080, irrigation reduction of 25%. Full Technical Report: Climate-proof Irrigation Strategies 16

Seed chard Area [ha] 33.75 Gross production [ /ha] 6900 Gross production [ ] 232859.82 Reduced Gross production (-30%) [ /ha] 4830 Reduced Gross production (-30%) [ ] 163001.87 Loss [ ] 69857.95 Figure 22 - seed chard cultivated area in Castiglione district Figure 22 shows seed chard cultivated area in Castiglione district. Actual total gross production is 232 859.82, Climate Change ensemble scenarios show, in condition of irrigation reduction, possibility of water deficit condition (a probability of about 50% in 2020 and up to about 75% in 2080), leading to a possible economic loss of 69 857.95 every year. Full Technical Report: Climate-proof Irrigation Strategies 17

Figure 23 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, seed chard cultivation, year 2020, irrigation reduction of 25%. Figure 24 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, seed chard cultivation, year 2050, irrigation reduction of 25%. Figure 25 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, seed chard cultivation, year 2080, irrigation reduction of 25%. Full Technical Report: Climate-proof Irrigation Strategies 18

Kaki (persimmon) Area [ha] 1.44 Gross production [ /ha] 17680 Gross production [ ] 25459.20 Reduced Gross production (-30%) [ /ha] 12376 Reduced Gross production (-30%) [ ] 17821.44 Loss [ ] 7637.76 Figure 26 - Persimmon cultivated area in Castiglione district Figure 26 shows persimmon cultivated area in Castiglione district. Actual total gross production is 25 459.20, future Climate Change ensemble scenarios show, in condition of irrigation reduction, possible water deficit condition in 2080 (probability of about 10%), with a possible economic loss of 7637.76 every year. Full Technical Report: Climate-proof Irrigation Strategies 19

Figure 27 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, persimmon cultivation, year 2020, irrigation reduction of 25%. Figure 28 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, persimmon cultivation, year 2050, irrigation reduction of 25%. Figure 29 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, persimmon cultivation, year 2080, irrigation reduction of 25%. Full Technical Report: Climate-proof Irrigation Strategies 20

Peach Area [ha] 5.12 Gross production [ /ha] 11750 Gross production [ ] 60160.00 Reduced Gross production (-30%) [ /ha] 8225 Reduced Gross production (-30%) [ ] 42112.00 Loss [ ] 18048.00 Figure 30 - Peach cultivated area in Castiglione district Figure 30 shows peach cultivated area in Castiglione district. Actual total gross production is 60 160.00, future Climate Change ensemble scenarios show, in condition of irrigation reduction, possible water deficit condition in 2080 (probability of about 15%), with a possible economic loss of 18048.00 every year. Full Technical Report: Climate-proof Irrigation Strategies 21

Figure 31 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, peach cultivation, year 2020, irrigation reduction of 25%. Figure 32 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, peach cultivation, year 2050, irrigation reduction of 25%. Figure 33 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, peach cultivation, year 2080, irrigation reduction of 25%. Full Technical Report: Climate-proof Irrigation Strategies 22

Horticultural crops Area [ha] 36.35 Gross production [ /ha] 6900 Gross production [ ] 250815.00 Reduced Gross production (-30%) [ /ha] 4830 Reduced Gross production (-30%) [ ] 175570.50 Loss [ ] 75244.50 Figure 34 Horticultural crop cultivated area in Castiglione district Figure 34 shows horticultural crops cultivated area in Castiglione district. Actual total gross production is 250 815.00 (considering tomato specific gross production), Climate Change ensemble scenarios show, in condition of irrigation reduction, possibility of water deficit condition (a probability of about 20% in 2020 and up to about 50% in 2080), leading to a possible economic loss of 75 244.50 every year. Full Technical Report: Climate-proof Irrigation Strategies 23

Figure 35 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2020, irrigation reduction of 25%. Figure 36 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2050, irrigation reduction of 25%. Figure 37 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2080, irrigation reduction of 25%. Full Technical Report: Climate-proof Irrigation Strategies 24

Mais (corn) Area [ha] 60.28 Gross production [ /ha] 2000 Gross production [ ] 120560.00 Reduced Gross production (-30%) [ /ha] 1400 Reduced Gross production (-30%) [ ] 84392.00 Loss [ ] 36168.00 Figure 38 - Corn cultivated area in Castiglione district Figure 38 shows corn cultivated area in Castiglione district. Actual total gross production is 120 560.00, future Climate Change ensemble scenarios show, in condition of irrigation reduction, clear water deficit condition even since 2020, leading to a possible economic loss of 36 168.00 every year. Full Technical Report: Climate-proof Irrigation Strategies 25

Figure 39 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, corn cultivation, year 2020, irrigation reduction of 25%. Figure 40 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, corn cultivation, year 2050, irrigation reduction of 25%. Figure 41 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, corn cultivation, year 2080, irrigation reduction of 25%. Full Technical Report: Climate-proof Irrigation Strategies 26

Previous graphs take in account maximum efficiency of irrigation systems; this hypothesis is not completely correct, because for estimating real water availability for cultivations it s relevant to consider type and efficiency of the irrigation systems. Considering for example horticultural crop, actual system is usually sprinkling, with an efficiency of 65-70%; with this system, real water availability for crop is 10.514 mm per unit of area every 10 days. A reduction of water consumption could be reached by an improving of application efficiency, like for example drip irrigation, that could reach 90-95% efficiency (equals to 13.518 mm per unit of area every 10 days), or sub-irrigation, that could reach up to 100% efficiency (equals to 15.02 mm per unit of area every 10 days). Graphs of Figure 42 Figure 47 show Wetness1 indicator for horticultural crop in Castiglione district, depending on irrigation system efficiency. Actual efficiency (70%) brings in CC scenarios to deficit condition and to economic losses, while an increase of efficiency (to 90% or even to 100%) can reduce economic losses. Table 2 quotes median value of CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble for different efficiency of irrigation systems. Red values are the ones that fall below threshold value of -40 mm (value below which cultivation yield shows a reduction of about 30%). efficiency 70% 90% 100% 2020-102.88-48.702-21.702 2050-110.107-55.927-28.927 2080-134.22-80.042-53.042 Table 2: median value of CDF of cumulative sum of the Wetness1 indicator in different efficiency scenarios (values in mm) For horticultural crop in Castiglione district, only 100% efficiency irrigation system can assure absence of economic losses in 2020 and 2050 scenarios. Considering the whole territory of irrigation authority, the area with horticultural crop in 2016 is about 929 ha. Cultivation yield reduction of about 30% means a potential annual loss (considering tomato specific gross production) of about 1 920 000; the increase of irrigation systems efficiency can avoid a relevant loss or, in other words, bring to relevant gain in economic term. Total investment cost for upgrading irrigation technology can return in yearly avoided economic losses, due to future yield cultivation reduction. Area [ha] 929 Gross production [ /ha] 6900 Gross production [ ] 6407467 Reduced Gross production (-30%) [ /ha] 4830 Reduced Gross production (-30%) [ ] 4485227 Loss [ ] 1922240 Table 3: calculation of total economic losses for horticultural crops in the irrigation authority territory Full Technical Report: Climate-proof Irrigation Strategies 27

Figure 42 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2020, irrigation reduction of 25%, 70% efficiency Figure 43 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2050, irrigation reduction of 25%, 70% efficiency Figure 44 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2080, irrigation reduction of 25%, 70% efficiency Full Technical Report: Climate-proof Irrigation Strategies 28

Figure 45 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2020, irrigation reduction of 25%, 90% efficiency Figure 46 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2050, irrigation reduction of 25%, 90% efficiency Figure 47 - CDF of cumulative sum of the Wetness1 indicator in the Castiglione District for model ensemble, horticultural crop cultivation, year 2080, irrigation reduction of 25%, 90% efficiency Full Technical Report: Climate-proof Irrigation Strategies 29

Improving irrigation system efficiency is one of the first strategy for water saving, both in actual and CC conditions. Generally, adaptation and mitigation strategies could be divided into 2 big groups: field measures and governance measures. Field measures are the ones that could be achieved by users, typically referring to replacement of high water consuming crops (for example corn) with crops with lower water requirements (for example winter cereals, forage crops, sorghum, barley). Governance measures are the ones that could be implemented by water manager, in this case Romagna Land Reclamation and Irrigation Authority, referred both to adaptation or mitigation. For adaptation strategy, irrigation authority could for example schedule an irrigation program, in order to split resource among all the user, reducing total water supply. For mitigation strategy, irrigation authority could for example improve conveyance system, from open channel net to pipeline directly connected to water source (for Castiglione district, water source is Canale Emiliano Romagnolo CER ), or using digital irrigation, to automate and optimize water management. Economical resources for these investments (both infrastructural and digital ones) could be found in global reduction of water consumption, bringing to an enhancement of net gross production of cultivation (Table 3) and to an increased availability of water that can be provided by irrigation authority. Full Technical Report: Climate-proof Irrigation Strategies 30

Step 6: Climate Risk Management: CLIMATE SMART AGRICULTURE SEASONAL FORECAST Description: This step of the workflow is focused on assessing and evaluating the best adaptation and mitigation options in order to minimize the climate risk and economical losses and move toward a stronger climate smart agriculture for the study area. Case study developed with climate tool showed possibility of evaluating long-term planning scenarios. Client can assess crop sustainability for each district, or otherwise estimate potential economic losses for every cultivation. For short-term planning scenarios, seasonal forecast provided by the interface can help to directly adapt irrigation strategies to meteorological trend over 8 months period. A simple case study has been developed for Castiglione district, using monthly forecast of rain and temperature provided by the portal interface at E-Hype basin resolution to calculate Wetness1 indicator for 2 crops with early plantation, onion and seed chard. Ensemble of forecast scenarios during the period September 2017-April 2018 can show high possibility of water deficit condition since the beginning of next year crop season. Results: crop Kc Table 4 shows monthly values of Kc sep oct nov dec jan feb mar apr coefficient used for case study. Autumn and winter Onion 1 1 1 1 1 1 1 0.7 months are supposed with no cultivation Seed chard 1 1 1 1 1 1 0.35 0.35 for simplicity. Table 4: monthly Kc values used for Castiglione seasonal Case study Wetness1 indicator at the end of august 2017 has been estimated in -75.43 mm, a critical drought situation, as by data of water availability provided by ARPAER CRITERIA model (https://www.arpae.it/dettaglio_documento.asp?id=708&idlivello=64) for Castiglione district. Soil hydro-climatic balance (BIC) yearly trend for study area, can be estimated, using precipitation and potential evapotranspiration data provided by ARPAER, in value of about -502 mm. Adding positive provision by irrigation rate for Castiglione district during irrigation period (20.027 mm/each decadal per unit of area), Wetness1 indicator can be valued in -75.43 mm. Full Technical Report: Climate-proof Irrigation Strategies 31

Figure 48 and Figure 49 show percentiles of cumulative sum of the Wetness1 indicator for models forecast ensemble in Castiglione District for Onion and Seed chard. Starting point is estimated Wetness1 indicator at the end of August, seasonal forecasts are referred to 51 members provided by ECMWF. Figure 48 - percentiles of cumulative sum of the Wetness1 indicator in the Castiglione District for model forecast ensemble, onion cultivation Full Technical Report: Climate-proof Irrigation Strategies 32

Figure 49 - percentiles of cumulative sum of the Wetness1 indicator in the Castiglione District for model forecast ensemble, seed chard cultivation Previous graphs show that at the beginning of cultivation season (months of March and April), wetness1 indicator results in high probability (0.33 for seed chard, 0.7 for onion) of negative values; this situation is potentially critical, needing irrigation since early beginning of crop season, while March and April are usual characterized by high positive values of Wetness1 indicator. This evaluation could be detailed by irrigation authority for all districts and provided to user in periodical bulletin, helping farmers to plan cultivation and water management operation since winter season. Full Technical Report: Climate-proof Irrigation Strategies 33

Conclusion of Full Technical Report All workflow objectives have been achieved. New tools and data give irrigation managers the possibility to evaluate climate risks and support irrigation risk management in the context of climate change. The selection and design of climate impact indicators has been made through a bottom-up approach characterized by a full involvement of the client. During the years of 2015 and 2017, the client has been directly involved in eight formal on-site meetings and was kept in permanent liaison (through email and telephone) in order to obtain useful feedbacks and problem-solving suggestions. Considering the entire workflow, the main successful factor in the suggested implementation of indicators are: the AGILE approach and the flexibility of implementing climate change information (by downscaling provided data to irrigation districts resolution) inside the currently used and updated Soil Water Balance Indicator (BIC), clearly a saving time option for both the Authority and the Purveyor, The online demonstrator interface that is quite easy to use and to take data from for the area of interest. The dedicated web mapping climate service developed for this case study and available at http://www.climate-tools.com/swicca/view/index/index.html The main outcomes from this case study are: the irrigation system is probably not suitable to face long-term climate change (2020, 2050 and 2080 horizon), according to the scenarios analysed; significant economic damages in terms of crop yield losses have been evaluated and quantified for several crops located in the Castiglione district with a total economic damage close to 200 keuro per year. adaptation measures should be evaluated for the Castiglione District, particularly: a new crop scheme should be evaluated for this District and the tool can provide all the necessary support for this task; investments in improving the irrigation systems should be considered; economical evaluation alternative measures should be considered (e.g.: water-saving technologies) new irrigation technologies Economical resources for adaptation and mitigation investments (both infrastructural or digital ones) could be found in global reduction of water consumption, bringing to an enhancement of net gross production of cultivation and to an increased availability of water that can be provided by irrigation authority. Seasonal forecast evaluations could be detailed by irrigation authority for all districts and provided to user in periodical bulletin, helping farmers to plan cultivation and water management operation since winter season. Full Technical Report: Climate-proof Irrigation Strategies 34