Assessing the long-term sustainability of the groundwater resources in the Bacchiglione basin (Veneto, Italy) with the Mann-Kendall test: suggestions for higher reliability

Submitted: 15 February 2021
Accepted: 16 March 2021
Published: 29 March 2021
Abstract Views: 1246
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The social, economic, and ecological importance of the aquifer system within the Bacchiglione basin (Veneto, IT) is noteworthy, and there is considerable disagreement among previous studies over its sustainable use. Investigating the long-term quantitative sustainability of the groundwater system, this study presents a statistical methodology that can be applied to similar cases. Using a combination of robust and widely used techniques, we apply the seasonal Mann-Kendall test and the Sen's slope estimator to the recorded groundwater level timeseries. The analysis is carried out on a large and heterogeneous proprietary dataset gathering hourly groundwater level timeseries at 79 control points, acquired during the period 2005-2019. The test identifies significant decreasing trends for most of the available records, unlike previous studies on the quantitative status of the same resource which covered the domain investigated here for a slightly different period: 2000-2014. The present study questions the reason for such diverging results by focusing on the method's accuracy. After carrying out a Fourier analysis on the longest available timeseries, for studies of groundwater status assessment this work suggests applying the Mann-Kendall test to timeseries longer than 20 years (because otherwise the analysis would be affected by interannual periodicities of the water cycle). A further analysis of two 60-year-long monthly timeseries between 1960 and 2020 supports the actual sustainable use of the groundwater resource, the past deployment of the groundwater resources notwithstanding. Results thus prove more reliable, and meaningful inferences on the longterm sustainability of the groundwater system are possible.

Aguilar JB, Orban P, Dassargues A, Brouyére S (2007) Identification of groundwater quality trends in a chalk aquifer threatened by intensive agriculture in Belgium. Hydrogeology Journal, 15, 1615.
Altissimo L, Dal Prà A, Scaltriti G (1999) Osservatorio interprovinciale per la tutela delle falde acquifere. Relazione conclusiva. Amministrazione Provinciale di Vicenza.
ARPAV (2016) Stato quantitativo dei corpi idrici sotterranei - ALLEGATOA alla Dgr n. 552 del 26 aprile 2016. Regione del Veneto.
Bras LR, Rodriguez-Iturbe I (1994) Random functions and hydrology. Dover Publications.
Consorzio di Bonifica Brenta (2021, febbraio 04) Dati Freatimetrici. Retrieved from Consorzio di Bonifica Brenta:
Dal Prà A, Bellatti R, Antonelli A, Costacurta R, Sbettega G (1977) Distribuzione dei materiali limoso-argillosi nel sottosuolo della pianura veneta. Quaderni IRSA e del Consiglio Nazionale delle Ricerche, IRSA, Rome.
Dal Prà A, Bellatti R, Costacurta R, Sbettega G (1976) Distribuzione delle ghiaie nel sottosuolo della pianura veneta. Quaderni IRSA e del Consiglio Nazionale delle Ricerche, IRSA, Rome.
Daughney CJ, Reeves RR (2006) Analysis of temporal trends in New Zeland's groundwater quality based on data from the National Groundwater Monitoring Programme. Journal of Hydrology (New Zealand), 41-62.
Douglas EM, Vogel RM, Kroll CN (2000) Trends in floods and low flows in the United States: impact of spatial correlation. Journal of Hydrology, 240, 90-105.
Drápela K, Drápelová I (2011) Application of Mann-Kendall test and the Sen's slope estimates for trend detection in deposition data from Bilỳ Křı́ž (Beskydy Mts., the Czech Republic) 1997-2010. Beskydy, 4, 133-146.
Du Bui D, Kawamura A, Tong TN, Amaguchi H, Nakagawa N (2012) Spatio-temporal analysis of recent groundwater-level trends in the Red River Delta, Vietnam. Hydrogeology Journal, 20, 1635-1650.
Gan TY (1995) Trends in air temperature and precipitation for Canada and north-eastern USA. International Journal of Climatology, 15, 1115-1134.
Gavrilov MB, Lazić L, Pešic A, Milutinović M, Marković D, Stanković A, Gavrilov MM (2010) Influence of hail suppression on the hail trend in Serbia. Physical Geography, 31, 441-454.
Gocic M, Trajkovic S (2013) Analysis of changes in meteorological variables using Mann-Kendall and Sen's slope estimator statistical tests in Serbia. Global and Planetary Change, 100, 172-182.
Hamed KH (2008) Trend detection in hydrologic data: the Mann-Kendall trend test under the scaling hypothesis. Journal of Hydrology, 349, 350-363.
Heath RC (1976) Design of Ground-Water Level Observation--Well Programs. Groundwater, 71-77.
Helsel DR, Hirsch RM (2002) Statistical methods in water resources (Vol. 323). US Geological Survey Reston, VA.
Hirsch RM, Slack JR, Smith RA (1982) Techniques of trend analysis for monthly water quality data. Water Resources Research, 18, 107-121.
Hrnjak I, Lukić T, Gavrilov MB, Marković SB, Unkašević M, Tošić I (2014) Aridity in Vojvodina, Serbia. Theoretical and Applied Climatology, 115, 323-332.
Kahya E, Kalaycı S (2004) Trend analysis of streamflow in Turkey. Journal of Hydrology, 289, 128-144.
Kendall MG (1948) Rank correlation methods. Griffin.
Koutsoyiannis D (2003) Climate change, the Hurst phenomenon, and hydrological statistics. Hydrological Sciences Journal, 48, 3-24.
Mann HB (1945) Nonparametric tests against trend. Econometrica: Journal of the Econometric Society, 245-259.
Mondal A, Kundu S, Mukhopadhyay A (2012) Rainfall trend analysis by Mann-Kendall test: A case study of north-eastern part of Cuttack district, Orissa. International Journal of Geology, Earth and Environmental Sciences, 2, 70-78.
Panda DK, Mishra A, Jena SK, James BK, Kumar A (2007) The influence of drought and anthropogenic effects on groundwater levels in Orissa, India. Journal of Hydrology, 343, 140-153.
Passadore G, Monego M, Altissimo L, Sottani A, Putti M, Rinaldo A (2012) Alternative conceptual models and the robustness of groundwater management scenarios in the multi-aquifer system of the Central Veneto Basin, Italy. Hydrogeology Journal.
Patle GT, Singh DK, Sarangi A, Rai A, Khanna M, Sahoo RN (2015) Time series analysis of groundwater levels and projection of future trend. Journal of the Geological Society of India, 85, 232-242.
Pettenuzzo G (1999) Analisi delle variazioni nel tempo di alcuni parametri del bilancio idrologico nell'alta pianura alluvionale vicentina e padovana. Università degli Studi di Padova, Inedito.
Polemio M, Casarano D (2008) Climate change, drought and groundwater availability in southern Italy. Geological Society, London, Special Publications, 288, 39-51.
Rahman AU, Dawood M (2017) Spatio-statistical analysis of temperature fluctuation using Mann-Kendall and Sen's slope approach. Climate Dynamics, 48, 783-797.
Ribeiro L, Macedo ME (1995) Application of multivariate statistics, trend-and cluster analysis to groundwater quality in the Tejo and Sado aquifer. IAHS Publications-Series of Proceedings and Reports-Intern Assoc Hydrological Sciences, 225, 39-48.
Ribeiro L, Kretschmer N, Nascimento J, Buxo A, Rötting T, Soto G, Señoret M, Oyarzún J, Maturana M, Oyarzún R (2015) Evaluating piezometric trends using the Mann-Kendall test on the alluvial aquifers of the Elqui River basin, Chile. Hydrological Sciences Journal, 60, 1840-1852.
Sen PK (1968) Estimates of the regression coefficient based on Kendall's tau. Journal of the American Statistical Association, 63, 1379-1389.
Shadmani M, Marofi S, Roknian M (2012) Trend analysis in reference evapotranspiration using Mann-Kendall and Spearman's Rho tests in arid regions of Iran. Water Resources Management, 26, 211-224.
Some'e BS, Ezani A, Tabari H (2013) Spatiotemporal trends of aridity index in arid and semi-arid regions of Iran. Theoretical and Applied Climatology, 111, 149-160.
Svensson C, Kundzewicz WZ, Maurer T (2005) Trend detection in river flow series: 2. Flood and low-flow index series/Détection de tendance dans des séries de débit fluvial: 2. Séries d'indices de crue et d'étiage. Hydrological Sciences Journal, 50.
Tabari H, Marofi S, Aeini A, Talaee PH, Mohammadi K (2011) Trend analysis of reference evapotranspiration in the western half of Iran. Agricultural and Forest Meteorology, 151, 128-136.
Tabari H, Nikbakht J, Some'e BS (2012) Investigation of groundwater level fluctuations in the north of Iran. Environmental Earth Sciences, 66, 231-243.
Van Lanen HA (1998) Monitoring for groundwater management in (semi)-arid regions. Unesco.
Vousoughi FD, Dinpashoh Y, Aalami MT, Jhajharia D (2013) Trend analysis of groundwater using non-parametric methods (case study: Ardabil plain). Stochastic Environmental Research and Risk Assessment, 27, 547-559.
Wahlin K, Grimvall A (2010) Roadmap for assessing regional trends in groundwater quality. Environmental Monitoring and Assessment, 165, 217-231.
Waldner P, Marchetto A, Thimonier A, Schmitt M, Rogora M, Granke O, et al. (2014) Detection of temporal trends in atmospheric deposition of inorganic nitrogen and sulphate to forests in Europe. Atmospheric Environment, 95, 363-374.
Wibig J, Glowicki B (2002) Trends of minimum and maximum temperature in Poland. Climate Research, 20, 123-133.
WMO (1994) Guide to Hydrological Practices. World Meteorological Organization.
Yue S, Pilon P, Cavadias G (2002) Power of the Mann-Kendall and Spearman's rho tests for detecting monotonic trends in hydrological series. Journal of Hydrology, 259, 254-271.
Zhang Q, Xu CY, Zhang Z (2009) Observed changes of drought/wetness episodes in the Pearl River basin, China, using the standardized precipitation index and aridity index. Theoretical and Applied Climatology, 98, 89-99.
Meggiorin, M., Passadore, G., Bertoldo, S., Sottani, A., & Rinaldo, A. (2021). Assessing the long-term sustainability of the groundwater resources in the Bacchiglione basin (Veneto, Italy) with the Mann-Kendall test: suggestions for higher reliability. Acque Sotterranee - Italian Journal of Groundwater, 10(1).


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