Identification of Spatiotemporal Patterns of Rainfall Erosivity as Decision Support to Erosion Control in Switzerland

Abstract

Rainfall has direct impacts on soil mobilization by rapid wetting or splash and runoff effects and is one of the main driving forces of water erosion. A combination of rainfall amount and intensity is expressed as rainfall erosivity (R-factor) which is one of the five soil erosion risk factors (rainfall erosivity, soil erodibility, slope steepness and length, cover management, and support practices) in the Revised Universal Soil Loss Equation (RUSLE) (Renard et al., 1997; Foster et al., 2008). As Switzerland has a high spatial and seasonal variation of climate parameters, the correlated rainfall erosivity can be expected to have a regional characteristic and seasonal dynamic throughout the year. The study of these spatiotemporal patterns is decisive in combination with the dynamics of the vegetation cover (C-factor) in order to allow for an accurate soil erosion risk assessment and thus a target-oriented management of agricultural practices and hazard controls. The intra-annual variation of the R-factor was mapped by a monthly modeling approach to assess simultaneously spatial and monthly patterns of rainfall erosivity (Schmidt et al., 2016). We used a network of 87 precipitation gauging stations with a 10 min temporal resolution to extract the long-term (19.5 years) monthly mean rainfall erosivity (R mo). Subsequently, the spatial and temporal pattern of R mo were explained based on a stepwise generalized linear regression (GLM) and significant spatial covariates like snow depth, a combination product of hourly precipitation measurements and radar observations (CombiPrecip), daily Alpine precipitation (EURO4M-APGD), monthly precipitation sums (RhiresM), and topographic parameters (elevation, slope, aspect derived from SwissAlti3D). The monthly R-factor for each month is mapped by summarizing the predicted R-factors of the regression equation and the corresponding residues which are interpolated by ordinary kriging (regression-kriging). Furthermore, we investigated the cumulative percentage of the daily R-factor within a year to assess the annual time period in which rainfall erosivity has its highest proportion. Monthly rainfall erosivity maps of Switzerland confirm the high seasonality of rainfall erosivity with lowest national means in January (10.5 MJ mm ha-1 h-1 month-1) and highest in August (263,5 MJ mm ha-1 h-1 month-1). Likewise, a high spatial variability can be observed for Switzerland. The cumulative daily rainfall erosivity revealed on a national scale a share of 62% of the total annual rainfall erosivity within the period from June to September. Within the canton Ticino, even 70% was reached within the same period. The high percentage of rainfall erosivity within a short period of time (4 months) is likely to have a large impact on the soil erosion susceptibility since it may coincide with the lowest (after harvesting or grass cutting/ pasturing) and/or most unstable vegetation cover (after late sowing) (Hartwig and Ammon, 2002; Wellinger et al., 2006; Torriani et al., 2007; Prasuhn, 2011). Our research highlight that rainfall erosivity in Switzerland has a very high variability within months and regions. The findings are of relevance for soil conservation planning and might be a basis for selective erosion control measures, such as a change in crop or crop rotation to weaken the rainfalls impact on soils and vegetation by increasing soil cover or stabilizing topsoil during these susceptible months.

Full text

BGS JAHRESTAGUNG – 9./10. FEBRUAR 2017 – UNIVERSITÄT B E R N
BODENWISSENSCHAFT UND
BODENSCHUTZ: EINE
GRENZÜBERSCHREITENDE
HERAUSFORDERUNG
SSP CONGRÈS ANNUEL – LES 9/10 FÉVRIER 2017 – UNIVERSI T É D E B E R N E
LA SCIENCE ET LA PROTECTION DU SOL:
UN DÉFI À TRAVERS LES FRONTIÈRES
SSP CONGRESSO ANNUALE – 9/10 FEBBRAIO 2017 – UNIVERSITÀ DI BERNA
SCIENZA E PROTEZIONE DEL SUOLO:
UNA SFIDA SENZA CONFINI
SSSS ANNUAL MEETING – FEBRUARY 9th/10th 2017 – UNI V ERSITY OF BERN
SOIL SCIENCE AND SOIL PROTECTION:
A CHALLENGE ACROSS BOUNDARIES

1
IMPRESSUM
BGS Vorstand | SSP Comité
Präsident | Président
Matias Laustela
Vizepräsidentin | Vice-présidente
Dr. Sophie Campiche
Sekretär | Secrétaire
Prof. Markus Egli
Kassierin / Caissière
Dorothéa Noll
Beisitzende | Assesseurs
Prof. Stéphane Burgos
Dr. Reto Meuli
Prof. Moritz Müller
Prof. Rolf Krebs
François Füllemann
Tagungsort | Lieu du congrès
Universität Bern
Uni Tobler
Länggassstrasse 49
3012 Bern
Tagungsband | Volume des résumés
Ausgabe | Édition 1 / 2017
Auflage | Tirage 200
Druck | Imprimé ZHAW, 8820 Wädenswil
Herausgeber | Éditeur
Bodenkundliche Gesellschaft der Schweiz BGS
Société Suisse de Pédologie SSP
Redaktion | Rédaction
BGS Geschäftsstelle | SSP bureau exécutif
Dr. Beatrice Kulli & Simon Amrein
c/o ZHAW
Schloss
8820 Wädenswil
+41 (0)58 934 53 55
bgs.gs@soil.ch
Organisiert durch | Organisé par
Prof. Sandra Spielvogel
Referierende | Conférenciers
Abiven Samuel
Alaoui Abdallah
Bigalke Moritz
Boivin Pascal
Breidenbach Andreas
Bünemann-König Else
Burgos Stéphane
Ebneter Laura
Frossard Aline
Germann Peter
González Domínguez Beatriz
Gosheva Sia
Grüter Roman
Gschwend Florian
Guggenberger Georg
Heger Thierry
Herschbach Jennifer
Herzog Chantal
Huang Jen-How
Huifang Ma
Jarosch Klaus
Karlsson Anneli S.
Keller Thomas
Kögel-Knabner Ingrid
Leifeld Jens
Luster Jörg
Mäder Paul
Magalì Matteodo
Mayer Jochen
Mestrot Adrien
Meuli Reto Giulio
Mosimann Thomas
Noll Dorothea
Nunan Naoise
Razavi Bahar S.
Schmidt Simon
Schwilch Gudrun
Shi Pu
Steffens Markus
Tatti Dylan
Van der Voort Tessa Sophia
Wächter Daniel
Wiggenhauser Matthias

36
Identification of spatiotemporal patterns of rainfall erosivity as decision support to erosion control
in Switzerland
Simon Schmidt1, Christine Alewell1, Panos Panagos2 & Katrin Meusburger1
1 Environmental Geosciences, University Basel, Bernoullistrasse 30, 4056 Basel, Switzerland, si.schmidt@unibas.ch
2 Joint Research Centre of the European Commission, Institute for Environment and Sustainability, Via E. Fermi 2749, 21027 Ispra, Italy
Rainfall has direct impacts on soil mobilization by rapid wetting or splash and runoff effects and is one of the main
driving forces of water erosion. A combination of rainfall amount and intensity is expressed as rainfall erosivity (R-
factor) which is one of the five soil erosion risk factors (rainfall erosivity, soil erodibility, slope steepness and length,
cover management, and support practices) in the Revised Universal Soil Loss Equation (RUSLE) (Renard et al.,
1997; Foster et al., 2008).
As Switzerland has a high spatial and seasonal variation of climate parameters, the correlated rainfall erosivity can
be expected to have a regional characteristic and seasonal dynamic throughout the year. The study of these spatio-
temporal patterns is decisive in combination with the dynamics of the vegetation cover (C-factor) in order to allow for
an accurate soil erosion risk assessment and thus a target-oriented management of agricultural practices and haz-
ard controls.
The intra-annual variation of the R-factor was mapped by a monthly modeling approach to assess simultaneously
spatial and monthly patterns of rainfall erosivity (Schmidt et al., 2016). We used a network of 87 precipitation gaug-
ing stations with a 10 min temporal resolution to extract the long-term (19.5 years) monthly mean rainfall erosivity
(Rmo). Subsequently, the spatial and temporal pattern of Rmo were explained based on a stepwise generalized linear
regression (GLM) and significant spatial covariates like snow depth, a combination product of hourly precipitation
measurements and radar observations (CombiPrecip), daily Alpine precipitation (EURO4M-APGD), monthly precipi-
tation sums (RhiresM), and topographic parameters (elevation, slope, aspect derived from SwissAlti3D). The month-
ly R-factor for each month is mapped by summarizing the predicted R-factors of the regression equation and the
corresponding residues which are interpolated by ordinary kriging (regression-kriging). Furthermore, we investigated
the cumulative percentage of the daily R-factor within a year to assess the annual time period in which rainfall ero-
sivity has its highest proportion.
Monthly rainfall erosivity maps of Switzerland confirm the high seasonality of rainfall erosivity with lowest national
means in January (10.5 MJ mm ha-1 h-1 month-1) and highest in August (263,5 MJ mm ha-1 h-1 month-1). Likewise, a
high spatial variability can be observed for Switzerland. The cumulative daily rainfall erosivity revealed on a national
scale a share of 62% of the total annual rainfall erosivity within the period from June to September. Within the canton
Ticino, even 70% was reached within the same period. The high percentage of rainfall erosivity within a short period
of time (4 months) is likely to have a large impact on the soil erosion susceptibility since it may coincide with the
lowest (after harvesting or grass cutting/ pasturing) and/or most unstable vegetation cover (after late sowing) (Hart-
wig and Ammon, 2002; Wellinger et al., 2006; Torriani et al., 2007; Prasuhn, 2011).
Our research highlight that rainfall erosivity in Switzerland has a very high variability within months and regions. The
findings are of relevance for soil conservation planning and might be a basis for selective erosion control measures,
such as a change in crop or crop rotation to weaken the rainfalls impact on soils and vegetation by increasing soil
cover or stabilizing topsoil during these susceptible months.

65
TEILNEHMERLI S T E | LISTE DES PARTICIPANTS | LISTA DI PARTICIPANTI
AbächerliAnnaoekoͲbag
AbivenSamuelUniversitätZürich
AchermannMatthiasUmweltundEnergieLU
AlaouiAbdallahUniversitätBern
AllemannLukasFachstelleBodenschutzZH
AmreinSimonBGSGeschäftsstelle
AmstutzRenéProNatura
BaumgartnerͲHägiKarinForstl.Ing.ͲBüroBaumgartnerͲHägi
BergerRomanZHAW
BigalkeMoritzUniversitätBern
BöhlertRalphTERREAG
BoivinPascalHESͲSOGenève
BonoRolandAmtfürUmweltschutzundEnergie
BorerFranz 
BreidenbachAndreasGeorgͲAugustͲUniversitätGöttingen
BüelerFranziskaETHZürich
BullingerGéraldineHEIAͲFR
BünemannͲKönigElseFiBL
BurgosStéphaneHAFL
CampicheSophiecentreecotox
CarizzoniMarcoBABUGmbH
ChervetAndreasAmtf.LandwirtschaftundNaturBE
ClémentArnoldElisabethKadima
ClémentJeanͲPierre Kadima
CottetPeggyCSDIngénieursSA
DakhelNathailePronaSA
deCastroPortesRaquelUniversitätZürich
DerungsNicolasUniversitédeNeuchâtel
DiblasiAntonioSANU
DietrichFabienneUniversitédeLausanne
DiriwächterThomasLandwirtschaftAargau(LWAG)
DubathMarcͲAndréBasler&HofmannSA
EbneterLauraUniversitätBern
EgliMarkusUniversitätZürich
EscherJeanͲRobertfuagͲforumumweltag
FankhauserOphélieNaturaBiologieappliquéeSàrl
FedierMelanieCSDIngenieureAG
FelderStefanSolGeoAG
ForrerIrèneImpergeologieAG
FortisJoëlHEIAͲFR
FreyBeatEidg.ForschungsanstaltWSL
FrossardAlineEidg.ForschungsanstaltWSL
FullemannFrancoisDGEͲSolsVD
GermannPeterUniversitätBern
GigandetͲBerdatNatachaNaturaBiologieappliquéeSàrl
GivordLéonie 
GonzálezDomínguezBeatrizUniversitätZürich
GoshevaSiaEidg.ForschungsanstaltWSL
GrandStephanieUniversitédeLausanne
GrobUrsNABO
GrüterRomanETHZürich
GschwendFlorianAgroscope
GsponerRolfFachstelleBodenschutzZH
GublerAndreasNABO
GutSamuelGEOTESTAG
HagedornFrankEidg.ForschungsanstaltWSL
HänziPeterLandwirtschaftAG
HartmannMartinEidg.ForschungsanstaltWSL
HasingerGerhardbioͲconseil.chsàrl
HavlicekElenaOfficefédéraldel'Environnement
HegerThierryCHANGINS
HeimAlexanderKlausBüchelAnstalt
HeinzelmannLionel 
HerschbachJenniferUniversitätBern
HerzogChantalAgroscopeReckenholz
HösliDorisFSKB
HuangJenͲHowUniversitätBasel
HuberMartinBSB+PartnerAG
ImsengMartinUniversitätBern
JacquetClémentineServicedel'agricultureNE
JaroschKlausUniversitätBern
JiYingETHZürich
KarlssonAnneliS.UniversitätBern
KayserAchimAmtfürUmweltThurgau
KellerPatrickFachstelleBodenschutzZH
KellerThomasAgroscope
KellermannLivHAFL
KnechtMarianneAmbio
KnechtenhoferLarsFRIEDLIPARTNERAG
KögelͲKnabnerIngridTechnischeUniversitätMünchen
KöhlerSandraInfraconsultAG
KrebsRolfZHAW
KulliBeatriceZHAW
KündigClaude 
KusterEmmanuelTERREAG
LangCorsinBundesamtfürUmweltBAFU
LaustelaMatiasBasler&HofmannAG
LeBayonClaireUniversitédeNeuchâtel
LeifeldJensAgroscope
LemannTatendaUniversitätBern
LeopizziSaskiaHESͲSOGenève
LevasseurClémentInstitutAgricoledeGrangeneuve
LüscherClaudearcoplan
LüscherPeter 
LusterJörgEidg.ForschungsanstaltWSL
MaHuifangETHZürich
MacKevettKarinUniversitätBasel
MäderPaulFiBL
MagaliMateodoUniversitédeLausanne
MaîtreVéroniquebureaupEaudSol
MargrethMichaelSoilComGmbH
MargrethStephanAmtfürUmweltSO
MatileLuziusZHAW
MaurerAngelaFRIEDLIPARTNERAG
MaurerClaudiaFachstelleBodenschutz
MayerJochenAgroscope
MeierChristianKissling+ZbindenAG
MestrotAdrienUniversitätBern
MeuliRetoGiulioNABO
MeusburgerKatrinUniversitätBasel
MeyerChristineFRIEDLIPARTNERAG
MoroDanieleLombardiSA
MosimannThomas 
MössingerEvaGEOTESTAG

66
MuheimLuisETHZürich
MüllerDominikA.AbteilungfürUmweltAG
MüllerMoritzHAFL
NiggliLauraFachstelleBodenschutzBE
NiksereshtFahime 
NollDorothéaCHANGINS
NussbaumMadleneETHZürich
ObersonAstridETHZürich
OechslinStefan 
OehlFritzAgroscope
ParratValérieSANU
PaulSonjaUniversitätBasel
PerruchoudAndréͲLaurent 
PetrilloMartaUniversitätZürich
PfenningerTobiasFachstelleBodenschutzZH
PfisterHansPfisterTerraGmbH
PlotzkiAnna 
PrasuhnVolkerAgroscope
RandevosonFinaritraUniversitédeLausanne
RauschenThomas 
RazaviBaharS.GöttingenUniversity
ReutimannAdrianPermakulturͲLandwirtschaft
RiverRobertToggenburgerAG
RossiMarcoStudiod'agronomia
RowleyMikeUniversitédeLausanne
RüdyMurielleAmtfürWasserundAbfallBE
RupflinChristinemyxGmbH
SägesserJanineInterkantonalesLabor
SchaubDanielAbteilungfürUmweltAG
SchellenbergerAndreasBundesamtfürUmwelt
SchirmerSvenNiutecAG
SchlatterFrédéricDROSERASA
SchmidGuidoAmtfürUmweltundEnergieSG
SchmidhauserAninaGascheͲBodengutachten
SchmidigerCorinneFachstelleBodenschutzZH
SchmidlinNicoleFachstelleBodenschutzBE
SchmidtSimonUniversitätBasel
SchmutzDanielAmtfürUmweltschutzu.EnergieBL
SchniderFrançoisSchniderBodenberatung
SchomburgAndreasUniversitätNeuchâtel
SchulinRainerETHZürich
SchumacherSophie 
SchwabLorenz
SchwarzMartinFachstelleBodenschutzZH
SchwilchGudrunUniversitätBern
SeitzBenjaminAgroscope
ShiPuETHZürich
SiegristJuliaSoilComGmbH
SommerSarahZHAW
SpielvogelSandraUniversitätBern
StähliRuediBundesamtfürUmwelt
StammlerNadjaGrunerAG
SteffensMarkusTechnischeUniversitätMünchen
StegerMarkusFachstelleBodenschutzZH
StokarMarianneBodenfachstelleAG
StrickerBenjaminDr.RolandWyssGmbH
TandySusanETHZürich
TattiDylanHAFL
TreschSimonFiBL/UniNe
UrianekPetr 
UtzingerFionaFachstelleBodenschutzZH
VadiGaëlleHEIAͲFR
vanderVoortTessaSophiaETHZürich
VeghMarina 
VerasaniAdrianSRPIngenieurAG
VoegelinAndreasEawag
VögeliAlbisserChristianeAmtfürWasserundAbfallBE
vonKänelChristophGEOTESTAG
vonRohrGabyAmtfürUmweltSO
WächterDanielNABO
WalkerPatriciaBABUGmbH
WannerCécileFachstelleBodenschutzZH
WegelinThomasFachstelleBodenschutzZH
WegmannFabioBundesamtfürUmwelt
WernliMichaelSoilComGmbH
WiggenhauserMatthiasETHZürich
WüthrichRaimundSwissSteelAG
ZihlmannUrsAgroscope
ZimmermannMichaelBundesamtfürLandwirtschaft
ZimmermannStephanEidg.ForschungsanstaltWSL

LOCATION | TAGUNGSORT | LIEU | LOCALITÀ
Universität Bern
Uni Tobler
Länggassstrasse 49
3012 Bern
Hörräume F 021 und F 022
Die Buchung einer Unterkunft ist
Sache der Teilnehmenden.
La réservation de l‘hébergement
est à la charge du participant.
La riservazione in albergo
è a carico del partecipante.
The booking of an accommodation
is the responsibility of the participants.
DI NN E R | A B EN D ES S EN | S OU PER | C EN A
Restaurant zum Äusseren Stand
Zeughausstrasse 17
3011 Bern
Das Mittagessen und die Zwischen-
verpflegung sind inbegriffen. Das
Abendessen wird von den Teilnehmern
mit der zugesandten Rechnung bezahlt.
Le repas de midi et les pauses-café sont
inclus, le repas du soir est à la charge des
participants.
Inclusi pranzo e spuntini durante le pause.
La cena è a carico dei singoli partecipanti.
Lunch and coffee are included in the
congress fee. Dinner is additionally is paid
by the participants with the invoice.
CO NT A CT | K ON T AK T | CO N TA CT | C ON T AT T O
BGS Geschäftsstelle
Beatrice Kulli und Simon Amrein
c/o Zürcher Hochschule für angewandte Wissenschaften
Postfach
8820 Wädenswil
+41 (0)58 934 53 55
bgs.gs@soil.ch