High Resolution of Water Availability for Emilia-Romagna Region over 1961–2015

F Cervi,M M Nistor

doi:10.1155/2018/2489758

Abstract

In this study, monthly time series of precipitations and temperatures from 1024 controlled and homogeneous meteorological stations located in the Emilia-Romagna region (northern Italy) are processed in order to assess potential climate changes that occurred during the period 1961–2015. Normal period as baseline between 1961 and 1990 (1990s) and recent period between 1991 and 2015 (2010s) were adopted in this study to analyse the possible effect of climate change on water availability during long-term period. Based on monthly and annual temperature (TT), precipitation (PP), and potential (ET0), the actual evapotranspiration (AET0) and water availability (WA) were computed at high spatial resolution. Between the two analysed periods, during the 2010s, it was found an increase in the maximum mean annual temperature by 1.08°C while the maximum mean annual precipitation saw a slight decrease (from 2222 mm to 2086 mm). The precipitation decrease is more intense in the South and West sectors of area (8%) and mainly depends on negative changes taking place during the winter and the beginning of spring (from December to March). The maximum mean annual ET0 and AET0 reached values of 663 mm and 565 mm during the 1990s, while during the 2010s, the found values were 668 mm and 572 mm, respectively. Because of the decrease in precipitation and increase in the ET0 and AET0, the WA (the proportion of precipitation that is available at the soil surface for subsequent infiltration and runoff processes) shows a reduction (about 10–20%) in the whole region, with exception of the North-East part of the Emilia-Romagna region. The decrease in the mean annual water availability induces severe issues concerning the water resources management across the whole Emilia-Romagna region.

Highlights

Surface water and groundwater are precious resources that are exploited worldwide for drinking, agricultural, industrial, and energetic purposes
Being directly recharged by solid and liquid precipitations, both surface water and groundwater are dependent on climate changes. e latter can cause variability in inter- and intra-annual discharges of springs and rivers because of changes in the total amount and pattern of rainfall and/or snowfall occurring in the corresponding recharge areas and catchments
Data of maximum and minimum air temperatures and precipitation from 1024 controlled and homogeneous meteorological stations from the Emilia-Romagna region [19] (Supplementary material 2) were used to assess the climate change effect on water availability at spatial scale over 1961–2015. ese data are available at high spatial resolution (5 km2) and are suitable for climatic studies, including both the computation of climatic indices based on daily values and analyses in which averaged values over a sufficiently large time scale are needed

Summary

Introduction

Surface water and groundwater are precious resources that are exploited worldwide for drinking, agricultural, industrial, and energetic purposes. Several authors have highlighted a precipitation reduction in the last century [1,2,3] that has mainly affected the winter and spring seasons [4] This decrement was not uniform across the area, it has been found to be more intense since the 1990s [2, 5, 6]. As evidenced in [15], the reduction in runoff into the river network induces negative changes to the recharge of these porous aquifers; the latter can be affected by reduction in water availability in the mountainous areas [16]. Low flows reflect the minimum peak of precipitation occurring in summer and in the beginning of autumn (August, September, and October) when evapotranspiration and water demand for agricultural purposes are the highest. Water supply depends on spring flow rates and may encounter problems during the summer season, when people staying in their holiday homes double the residential population [8]

Materials and Methods

Results

Annual Trends of Climate Variables