Study on Soil and water in a changing environment Final Report, June 2014 mmmll A great deal of additional information on the European Union is available on the Internet. It can be accessed through the Europa server (http://ec.europa.eu). Luxembourg: Office for Official Publications of the European Communities, 2014 ISBN 978-92-79-38794-4 DOI: 10.2779/20608 No of catalogue: KH-02-14-745-EN-N © European Union, 2014 Reproduction is authorised provided the source is acknowledged. Soil and water in a changing environment FINAL REPORT European Commission (DG ENV) 27 June 2014 Document information CLIENT European Commission (DG ENV) CONTRACT NUMBER 07.0307/2012/635531/ETU/B.1 REPORT TITLE Final Report PROJECT NAME Soil and water in a changing environment PROJECT TEAM BIO Intelligence Service, HydroLogic PROJECT OFFICERS Mr. Luca Marmo Mr. Thomas Strassburger Ms. Alia Atitar de la Fuente DATE 27 June 2014 AUTHORS Shailendra Mudgal, BIO Intelligence Service Sarah Lockwood, BIO Intelligence Service Helen Ding, BIO Intelligence Service Slavco Velickov, HydroLogic Tom Commandeur, HydroLogic Michael Siek, HydroLogic KEY CONTACTS Shailendra Mudgal [email protected] Or Sarah Lockwood [email protected] ACKNOWLEDGEMENTS We are grateful for comments given on an earlier version of the manuscript by Prof. Sjoerd van der Zee (Wageningen University, NL), Dr. Dagmar Haase (Helmholtz Centre for Environmental Research, DE) and Dr. Csilla Farkas (Research Institute for Soil Science and Agricultural Chemistry, HU). We would also like to thank Carlo Lavalle, Claudia Baranzelli and Ana Luisa Barbosa from the JRC for providing us with a scenario of reference and relevant datasets for the future projections of the soil water holding capacity. We would also like to thank Sandra Berman for her review of intermediary versions as well as Claire-Marie Gherardi, Amandine De Schaetzen, Isabelle Ma, Guillaume Furet and Elsa Ouvrard for their help in collecting information. 2 | Soil and water in a changing environment DISCLAIMER This report contains the results of research by the authors and is not to be perceived as the opinion of the European Commission. The project team does not accept any liability for any direct or indirect damage resulting from the use of this report or its content. Please cite this publication as: BIO Intelligence Service (2014), Soil and water in a changing environment, Final Report prepared for European Commission (DG ENV), with support from HydroLogic Photo credit: cover @ Per Ola Wiberg ©BIO Intelligence Service 2014 Soil and water in a changing environment | 3 This page is left intentionally blank. 4 | Soil and water in a changing environment Table of Contents EXECUTIVE SUMMARY 11 LIST OF ABBREVIATIONS 23 GLOSSARY 25 INTRODUCTION 29 CHAPTER 1 “SOIL WATER RETENTION CAPACITY” OR HOW SOILS CAPTURE, STORE AND RELEASE WATER 33 1.1 Soil water retention in the water cycle 33 1.2 Mechanisms of soil water retention 34 1.2.1 Introduction 34 1.2.2 Description of mechanisms 36 1.3 Ecosystem services dependent on soil water retention capacity 38 1.3.1 Provisioning services 40 1.3.2 Regulation services 41 1.3.3 Supporting services 43 1.4 Synthesis 45 CHAPTER 2 PARAMETERS INFLUENCING SOIL WATER RETENTION CAPACITY 47 2.1 Properties of the soil matrix and related parameters 48 2.1.1 Soil structure 48 2.1.2 Soil texture 50 2.1.3 Soil organic matter 51 2.1.4 Soil biodiversity 52 2.2 Soil cover 53 2.2.1 Overview 53 2.2.2 Impacts of different land covers 54 2.3 Soil water content 56 2.4 Climate parameters 57 2.5 Synthesis and discussion 58 CHAPTER 3 KEY DRIVERS INFLUENCING SOIL WATER RETENTION AND IMPACTS ON ASSOCIATED ECOSYSTEM SERVICES 63 3.1 Land use trends 63 Soil and water in a changing environment | 5 3.1.1 Context 63 3.1.2 Land use changes between forests, grassland, arable land and urban areas 64 3.2 Management practices in agriculture, and opportunities for improving soil water retention capacity 73 3.2.1 Farming systems in the EU 73 3.2.2 Choice of plant species 76 3.2.3 Soil management 78 3.2.4 Water management 83 3.2.5 Landscape management 84 3.2.6 Discussion 85 3.3 Urbanisation patterns and opportunities for better SWR capacity 86 3.3.1 Density of development 86 3.3.2 Capacity of infiltration within the cities: green infrastructures, permeable materials and urban drainage capacity 89 3.4 Climate change 91 3.5 Synthesis and discussion 92 CHAPTER 4 TRENDS IN SOIL WATER RETENTION CAPACITY 97 4.1 Trends in the capacity of soil to hold water 98 4.1.1 Trends due to land use changes and agricultural practices 98 4.1.2 Impact of urbanisation 104 4.2 Trends in the risk of SWR related flooding and droughts in a changing climate 108 4.2.1 Risk of flooding (increased runoff) 108 4.2.2 Risk of droughts 112 4.3 Effects of SWR capacity’s evolution on water use 116 4.4 Discussion and Conclusions 118 CHAPTER 5 ECONOMIC IMPLICATIONS OF THE DISRUPTION OF SOIL WATER RETENTION CAPACITY 121 5.1 Impacts of floods 122 5.1.1 Arable land 123 5.1.2 Grassland 125 5.1.3 Forest land 126 5.1.4 Urban land 127 5.2 Impacts of droughts 128 5.2.1 Arable land 129 5.2.2 Forest land 131 6 | Soil and water in a changing environment 5.3 Synthesis and discussion 133 CONCLUDING REMARKS 135 REFERENCES 139 ANNEX 1 OVERVIEW OF THE CASE STUDIES INVESTIGATED ANNEX 2 FURTHER ANALYSIS OF SOME PARAMETERS AND DRIVERS OF SOIL WATER RETENTION CAPACITY ANNEX 3 DETAILED METHODOLOGY FOR THE ESTIMATION OF PAST, CURRENT AND FUTURE TRENDS IN SWR ANNEX 4 ESTIMATING ECONOMIC IMPACTS OF CHANGES IN SWR ANNEX 5 EXPERTS’ CONSULTATION Soil and water in a changing environment | 7 List of Tables Table 1: Major parameters governing soil water retention capacity ............................................. 12 Table 2: SWR capacity of different land use types ....................................................................... 13 Table 3: Impact of land cover changes on maximum soil water content ...................................... 14 Table 4: Impact of different farming practices on SWR capacity .................................................. 17 Table 5: Summary of the key parameters influencing SWR capacity ........................................... 60 Table 6: Impact of land use changes on bulk density (BD) and organic carbon (OC) .................... 67 Table 7: Impact of agricultural practices on bulk density (BD) and organic matter (OM) .............. 75 Table 8: Main drivers influencing soil water retention capacity .................................................... 92 Table 9: Estimated economic impacts derived from yield losses during the flood event ............ 124 Table 10: Economic impacts of flood on recreational forest service in selected MS ................... 126 Table 11: Economic damages due to floods in urban areas ........................................................ 128 Table 12: Estimated economic impacts of drought on arable lands ........................................... 130 Table 13: Estimated economic impacts of drought on forest for selected MS ............................ 132 List of Figures Figure 1: The water cycle – water content and residence time ..................................................... 33 Figure 2: Soil water retention in the water cycle .......................................................................... 34 Figure 3: Schematic illustration of soil water retention ................................................................ 34 Figure 4: Dynamics of soil water retention .................................................................................. 35 Figure 5: Four components of soil – example of a typical agricultural soil .................................... 35 Figure 6: Illustration of saturated and unsaturated zones ............................................................ 36 Figure 7: Different states of water in the soil ............................................................................... 38 Figure 8: Ecosystem services provided by soil water retention capacity ...................................... 39 Figure 9: Prague 2002 - overview of flooded city ......................................................................... 42 Figure 10: Access to soil water and rooting depth ........................................................................ 43 Figure 11: Parameters affecting soil water retention capacity ..................................................... 47 8 | Soil and water in a changing environment Figure 12: Key soil dwellers, intervening on SWR capacity as physical and chemical engineers or biological regulators ................................................................................................................ 52 Figure 13: Influence of forest on runoff vs. infiltration .................................................................. 54 Figure 14: Water balance components in built-up areas as a function of sealed surfaces ............. 55 Figure 15: Flash flooding in Malborghetto-Valbruna (Northern Italy) in August 2003 ................... 57 Figure 16: Land cover land use changes for the period 2000-2006 ............................................... 65 Figure 17: Urbanisation trend for the period 2000-2006 .............................................................. 66 Figure 18: Map of flood regulating ecosystem services supply-demand budget for the Etropole area in Bulgaria ............................................................................................................................ 70 Figure 19: Flooded areas in Dresden in 2002 ...............................................................................