ACTA GEOGRAPHICA 
GEOGRAFSKI ZBORNIK 


SLOVENICA 

2020 
60 
1 
ACTA GEOGRAPHICA SLOVENICA GEOGRAFSKI ZBORNIK 60-1 • 2020 
Contents 
Mojca POKLAR
Comparison of the sonar recording method and the aerial photography methodfor mapping seagrass meadows 7 

Vanja PAVLUKOVIĆ, Uglješa STANKOV, Daniela ARSENOVIĆ 
Social impacts of music festivals: A comparative study of Sziget (Hungary) and Exit (Serbia) 21 
Péter János KISS, Csaba TÖLGYESI, Imola BÓNI, László ERDŐS, András VOJTKÓ,István Elek MAÁK, Zoltán BÁTORI 
The effects of intensive logging on the capacity of karst dolines to provide potential microrefugia for cool-adapted plants 37 

Radu SĂGEATĂ 
Commercial services and urban space reconversion in Romania (1990–2017) 49 

Kristina IVANČIČ, Jernej JEŽ, Blaž MILANIČ, Špela KUMELJ, Andrej ŠMUC
Application of a mass movement susceptibility model in the heterogeneous Miocene clastic successions of the Slovenj Gradec Basin, northeast Slovenia  1 

Andrej GOSAR 
Measurements of tectonic micro-displacements within the Idrija fault zone in the Učjavalley (W Slovenia) 79 

Piotr RAŹNIAK, Sławomir DOROCKI, Anna WINIARCZYK-RAŹNIAK 
Economic resilienceofthe command andcontrolfunctionof citiesin Centraland EasternEurope 95 

Mateja FERK, Rok CIGLIČ, Blaž KOMAC, Dénes LÓCZY 
Management of small retention ponds and their impact on flood hazard prevention in the Slovenske Gorice Hills 107 
Gregor KOVAČIČ
Sediment production in flysch badlands: A case study from Slovenian Istria 127 

Vesna LUKIĆ, Aleksandar TOMAŠEVIĆ 
Immigrant integration regimes in Europe: Incorporating the Western Balkan countries 143 

Mitja DURNIK 
Community development: LocalImmigrationPartnershipsin Canadaand implications forSlovenia 155 
ISSN 1581-6613 
9 771581 661010 


MANAGEMENT OF SMALL RETENTION PONDS AND THEIR IMPACT ON FLOOD HAZARD PREVENTION IN THE SLOVENSkE GORICE HILLS 
Mateja Ferk, Rok Ciglič, Blaž Komac, Dénes Lóczy 

Retention pond at the former Benedictine monastery at Jareninski Dvor. 
DOI: https://doi.org/10.3986/AGS.7675 UDC: 911:556.18(497.41) 627.13:556.166(497.41) COBISS: 1.01 
Mateja Ferk1, Rok Ciglič1, Blaž Komac1, Dénes Lóczy2 

Management of small retention ponds and their impact on flood hazard prevention in the Slovenske Gorice Hills 
ABSTRACT: One of the methods of water resource management is to construct small retention ponds. Within the framework of the »Possible ecological control of flood hazard in the hilly regions of Hungary and Slovenia» project the management of small ponds and their impact on flood prevention were studied in selectedcatchments.Dataonpondmanagementweregatheredfrominterviewswithpondowners.Inapilot study, we conducted aninventarisation and classification of all retention ponds. Primarily they were con­structed for more specific use: fishing, irrigation, watering livestock. These functions have been gradually replaced by leisure-time activities, aesthetics, and tourism. Spring, stream and rainfall-fed ponds prevail in the pilot area and reduce the flood risk. Due to the increased variability of precipitation patternsponds are also becoming an important measure to limit drought consequences at a local level. 
KEYWORDS:hydrogeography,naturalhazards,floods,watermanagement,dams,detentionponds,Slovenia 

Upravljanje malih vodnih zadrževalnikov in njihov vpliv na poplavno varnost Slovenskih goric 
POVZETEK: Eden od načinov gospodarjenja z vodnimi viri je izgradnja majhnih zadrževalnih ribnikov. Vokviruprojekta»PrimerniekološkiukrepinapodročjupoplavnenevarnostivhribovitemobmočjuMadžarske inSlovenije«smopreučiliupravljanjemajhnihribnikovinnjihovvplivnapreprečevanjepoplavvizbranih porečjih.Podatkeoupravljanjuribnikasmozbralispomočjointervjujevzlastnikiribnikov.Vpilotništudi­jismoizvedliinventarizacijoinrazvrščanjezadrževalnihribnikov.Vglavnemsobilizgrajenizanamensko uporabo, kot je ribolov, namakanje, napajanje živine. Te funkcije so postopoma nadomestile prosti čas, estetika in turizem. Na pilotnem območju prevladujejo zadrževalniki, ki jih polnijo izviri, vodotoki in padavine,inzmanjšujejopoplavnoogroženost.Zaradivečjevariabilnostipadavinpostajajoribnikinalokalni ravni tudi pomemben ukrep za omejevanje posledic suše. 
KLJUČNE BESEDE: hidrogeografija, naravnenesreče, poplave, upravljanje voda, pregrade, vodna zajetja, Slovenija 
The paper was submitted for publication on November 12th, 2019. Uredništvo je prejelo prispevek 12. novembra 2019. 
1 Research Centre of the Slovenian Academy of Sciences and Arts, Anton Melik Geographical Institute, Ljubljana, Slovenia mateja.ferk@zrc-sazu.si, rok.ciglic@zrc-sazu.si, blaz.komac@zrc-sazu.si 
2 University of Pécs, Institute of Geography and Earth Sciences, Pécs, Hungary loczyd@gamma.ttk.pte.hu 

1 Introduction 
Inthepast,watermanagementfocusedonbuildingandmanagingwatersupplyinfrastructure.Thisapproach brought into use large-scale centralized water storage infrastructure systems for irrigation, sewage, and energyproductionwhichwerealsousedforfloodcontrol.AccordingtothedataoftheWorldCommission on Dams (World register…2020) there were more than 50,000 dams globally in 2019. In Slovenia, there are47largedams(KomacandZorn2016).Thisso-calledhardpathwatermanagementhasimprovedhuman watersecurityworldwide.However,thediminishingcapacityofthehardpathtosolveemergingwaterprob­lemsledwatermanagerstoseeknewapproaches.Softpathsolutionsfocusoninstitutionalreforms,small-scale interventions,theintroductionofwater-efficienttechnologies,andthemanagementofagricultural,indus­trial, and residential water use. They can better address future water scarcity where hard path approaches havenotbeensuccessful(Wutichetal.2014).Retentionpondsonfluvialsystemsareausefulsoftpathapproach andcontributetowaterresourcemanagementbyinfluencingwaterdischargeandsedimenttransportdynam­ics (Verstraeten and Poesen 2001; Koskiaho 2003), and water chemistry (Fairchild and Velinsky 2009). 
Retention ponds can be divided by their size into two categories. Large ponds or reservoirs are flood retentiondams,floodcontroldams,waterretentionobjects,andsedimenttraps,whilesmallretentionponds are fishing ponds, watering holes, and pools. The dams of large retention ponds are mostly of concrete or combined construction, while small retention ponds involve simpler earthworks (Steinman and Banovec 2008; Table 1). In Slovenia, large ponds were mostly built for energy production, drinking and techno-logicalwaterstorage,floodanddroughtmanagement,andirrigationforfoodproduction(Širca2010).Small retention ponds, on the other hand, provide water for irrigation and support secondary uses, such as fish-ingand tourism. With large retention ponds, the detention time is from one to several years, while it lasts from one to several days in the small ones. 
InSlovenia,waterinfrastructuremanagementisbeyondindividualinterestsandisapublicutilityser­viceconcessedbytheSlovenianEnvironmentAgency.However,theListoftheexistingwaterinfrastructure excludes sediment retention objects, their inflow and outflow channels, and irrigation and drainage sys­tems, while only the barriers and dams are included (Seznam obstoječe…2006). The Waters Act (Zakon 
o vodah 2002) lists 40 dams as water infrastructure (Globevnik 2012) while the Rules to determine water infrastructure (Pravilnik o določitvi…2005) declare the formal status of water infrastructure, especially relatedtomaintenance.WaterinfrastructureispartofgeodeticdataandgovernedintheEUbytheINSPIRE Directive (Infrastructure for…2017). 
In Slovenia, the water infrastructure is governed by the National water management program, water management plans, remediation programs, and other water management programs. The National water management programdetermines watermanagementpolicy,aswell asthegoals,directives,and priorities 
Table 1: Types of water ponds according to the construction and type of distribution of water pressure (Steinman and Banovec 2008). 

for water use, protection, and management. At the catchment level, the period 2016–2021 is regulated by the Adriatic Sea Watershed Management Plan (Načrt upravljanja voda na vodnem območju Jadranskega…2016; Uredba o načrtih upravljanja 2016) and the Danube River Catchment Management Plan (Načrt upravljanja voda na vodnem območju Donave…2016; Uredba o načrtih upravljanja 2016). 
Water infrastructure objects are documented in the Water Register, the official record of the SlovenianWaterAgency(E-vode2019).Itencompasses55databasesonwater,includinghydrology,water typology, water areas, nature protection areas and flood hazard maps (Pravilnik o vodnem…2017). Although new data regarding hydrology and use of the water areas are available they lack coherence as they were created through desktop work, without any field research (Barborič et al. 2017). Significant differenceswereindicatedbetweentheofficialdocumentationonwaterinfrastructureandtheactualstate innature(Sodnik,KogovšekandMikoš2014).Thisespeciallyappliestosmallwaterinfrastructureobjects, such as ponds. 
Two regulations on retention ponds exist in Slovenia, but they originally support the management of large retention ponds and they are only applied to hydroelectricity dams. These are the Rules on the tech­nical monitoring of high water dams(Pravilnik o tehničnem…1966) and the Rules on the monitoring of seismicity in the area of large dams (Pravilnik o opazovanju…1999). The Instructions for preparing riskassessments for dam barrier failures (Lenart, Rajar and Širca 2017) were never passed in the Republic of Slovenia,sotoday’spracticeisbasedonanalmosthalf-a-century-oldYugoslavregulation(Uputstvo…1975). AttheEuropeanlevel,thecoredocumentregulatingretentionpondsistheManifestoonDamsandReservoirs (Manifesto…2015),whiletheKyotoProtocol(Worlddeclaration…2012)governstheissueatgloballevel. 
In general, the situation is rather bad as regards the comprehensive approach to planning, construc­tion, operation and safety rules for water dams in Slovenia. The rules are scattered across constructionandotherlegislation,welackorderlinessandevenacomprehensiveoverviewofthesituation(Širca,Ravnikar TurkandZadnik2010).Largeretentionponds(hydroelectricitydamsareexcluded)arepoorlymaintained andnotregularlyexamined.Pastconstantchangesandscatteredorganizationofretentionpondmanagement causedbadmanagementpractices.Archivaldatawereoftenlostandsometimeseventheconstructiondataare missing (Širca, Ravnikar Turk and Zadnik 2010). Many so-called sediment trap objects are not regu­larlycleanedandnolongerretainsediments(Papež2010),leadingtoerosion(Kračun2010)andincreasing flash flood hazard (Komac and Zorn 2011). Since their construction, the barriers have not been adjusted to the current hydrological, climate, and land use conditions (Zemeljske…2016), exposing the regions to combined and cascade disasters (Komac 2015). 
Therefore,thehazardintheSlovenskeGoriceHillsshouldnotbeignoredalthoughtheregionhaslower dams than other regions in Slovenia. Their less cohesive building material and structure need to be con-sidered.Asevenlargeretentionfacilitiesfaceseveralworryingissues,itisevenmorechallengingtoenforcelegislationforsmallretentionponds(Širca2010).Furthermore,incompleterecordsonsmallretentionponds and bodies of water are an important, even pressingissue, urgently calling for their comprehensive analy­sisandmanagement.Themanagementoflargedamsfacesnumerousissuesandhasbeenputtotheagendas ofdifferentnationalandinternationalorganizations.Smallretentionpondmanagement,ontheotherhand, encounters several challenges that have not been properly addressed yet. An important issue is the rapid fillingofthepondswithsedimentwhichincreasesmaintenancecosts(VerstraetenandPoesen1999;2000). Also, the improved accessibility of water in the last century for people and their livestock decreased the need for ponds in rural areas, consequently they are increasingly abandoned (Mioduszewski 2012). 
TheprojectentitledPossibleecologicalcontroloffloodhazardinthehillyregionsofHungaryandSlovenia is one of the attempts to address this question in the Pannonian Basin. It studies the suitability of ecolog­ical measures for decreasing floods hazard in the hilly regions of Eastern Slovenia. Namely, while sustainable reduction of flood risk can be achieved by large scale spatial planning and land use adapta­tioninthedownstreamrivervalleys,waterretentionareasinsmallbasinscaneffectivelylowerthefrequency offloods (Hooijer et al. 2004; Richert et al. 2011; Kijowska-Strugała and Bucała-Hrabia 2019). It has been establishedthatsmallretentionpondsareespeciallyeffectiveinpeakflowreductiononalocalscale(Chrétien etal.2016).Furthermore,studieshaveshowntheyhaveabeneficialimpactonlimitingerosion(Verstraeten and Poesen 1999; Koskiaho 2003), as well as improving runoff quality (Chrétien et al. 2016) and are an added ecological value of the environment (Mioduszewski 2012). 
In the research, we focused on ponds that are defined as small artificial structures to retain freshwa-ter.WeinvestigatedthemanagementofsuchpondsinthePesnicaRivercatchment(partofSlovenskeGorice 
Hills).Thedetailedanalysisoftheretentionpondsintworepresentativelower-rankedcatchments–Jarenina and Vukovje creeks consisted of spatial analysis and in-depth interviews. The aim of the paper is to pre­sent a comprehensive assessment of management practices of small ponds, and their impact on flood prevention in the Slovenske Gorice Hills. 

2 Hydrological features of the Slovenske Gorice Hills 
The Slovenske Gorice Hills are a hilly region in north-east Slovenia (Perko 1998). The area is located in the west of the Pannonian Basin between the Drava River to the south and the Mura River to the north. The hills are composed of Neogene marine sediments: mostly clays, sandy marl, sandstone, and con­glomerates, with local outcrops of limestone (Belec 1998; Kert 1998). According to the calculations using a version of the Gavrilović equation according to Pintar, Mikoš and Verbovšek (1986), the annual sedi­ment production in Slovenske Gorice Hills is 1031.6m3/km2 or 16.5t/ha and the annual sediment yield is 639.7m3/km2 or 10.2t/ha (Hrvatin et al. 2019). Water flows quickly from the impermeable bedrock to the lowlands and the Slovenske Gorice Hills have a dense stream network (2.1km/km2). Relatively high precipitation and high temperatures contribute to high evapotranspiration during summer when many smallwatercoursesdryup.Specificrunoffanddischargecoefficientsarebelowaverageinthearea(Kolbezen 1998;Frantar2008a;2008b).Inrecentyears,asmallershareofsnowprecipitationhasincreasedwaterrunoffduring winter (Žiberna 2017). The share of forest below the Slovenian average covering about a third of thearea(Kert1998)decreaseswaterretentioninsourceareas.However,inthelasthundredyears,theland-scape has changed considerably: the share of forests has increased, replacing orchards and vineyards on steep slopes (Ciglič and Nagy 2019; Deriaz et al. 2019). In addition, modernization of agriculture led to terrace abandonment in viticulture (Pipan and Kokalj 2017). Small amount of precipitation, high evapo-transpiration,quickrunoff,andpoorretentioncapacityincreasethefrequencyofdroughts(Frantar2008a;2008b; Kozjek, Dolinar and Skok 2017; Žiberna 2017). 
The valley floors had often been flooded before the regulation of watercourses in the second half of the 20th century. These measures have decreased flood hazard in the valleys but as the streams have been changed by man, water runs off faster. Water discharge varies significantly; it rises during downpours and snowmeltsandlowersduringdroughtswhenthestreamsevendesiccate(Kert1998).Torrentialfloodsare common and occur during local downpours in summer and autumn (Trobec 2016). As noted elsewhere (Frantar and Hrvatin 2005; Kovačič 2016; Hrvatin and Zorn 2017), the precipitation trend in the period1961–2016ispositiveintheautumnandwintermonths(Žiberna2017).Theincreaseofprecipitationdur­ing the colder months with limited evapotranspiration poses a threat to flood security and increases the importance of maintaining small retention ponds for the future. 
Duetosignificantvariabilityofprecipitationandwaterdischarge,theareaoftheSlovenskeGoriceHills issubjecttohighuncertaintyofwatersupplymanagement:ononehand,itreceivesshort-lived,heavydown-pours and torrential floods with a quick water discharge, while on the other hand, long periods with very scarce and low amounts of precipitation occur leading to water shortages. This is why innovative man­agementpracticesareneededinordertoincreasewaterretentionduringdroughtsandpreventhighwater runoff. One of the measures for water retention in the periods of drought and for preventing runoff dur­ing the period of more abundant precipitation is ensuring proper land use (for example, by afforestation) andwaterinfrastructuremanagement.Thelatterinvolvesriverbanksmaintenanceandexcavatingorbuild­ing small and large water retention ponds. 
2.1 The Pesnica River Valley 
ThePesnicaRiverValleyislocatedinthecentralpartoftheSlovenskeGoriceHills.Itrunsfromthenorth-west to the southeast collecting most of the waters in the area. The catchment is of asymmetrical shape withtheleft,north-easternbankmorehydrologicallydeveloped.Thevalleyfloorisafew100mwideabove ZgornjaKungota,anditswidthextendstoabout3kminthelowerreachesnearPtuj.Thevalleywasdevel­opedinMioceneclasticsediments,mainlysandstoneandmarl.Theflatvalleybottomisfilledwithfluvial deposits and was shaped by the river’s frequent floods in a wetland environment. In the past, a very low stream gradient –1.7‰ (Kobold 2012) caused the meandering of the river. This can be clearly observed on the Josephine Military Map (e.g. Zorn 2007) or on the map of the Franciscean Cadastre (Natek 1992; Gabrovec, Bičík and Komac 2019; Kladnik et al. 2019). The meandering river channel was channelized in the 1960s in order to support agriculture. Of its approximately 69km course (65km on the Slovenianter­ritory), about 50km were regulated. In order to prevent flash floods about 90km of the tributaries were alsoregulated(Juvanetal.1997).Intotal,13%ofthestreamnetworksurfacehasbeenmeliorated(Leitinger 2012) and only the headwaters of some small tributaries and small narrow valleys remained undisturbed. With channelization the wetland was converted to farmland, on the other hand, channelization increas­es flood hazard (Lóczy, Kis and Schweitzer 2009; Lóczy and Dezső 2013). The flood hazard prevention measures in the Pesnica River Valley included the building of several large retention ponds. The largest retentionpondalongthePesnicaRiveristhePernicaaccumulationlake(Figure1).Itconsistsoftwoparts; the Pernica 1 and Pernica 2 retention ponds, divided by a dam and afloodgate. The Jarenina and Vukovje creeksflowintothePernica1retentionpond.ThePesnicaRivercontributeswaterintothePernica2reten­tion pond. Also the Pristava retention pond lies on the Pesnica River, while all other retention ponds are located on its tributaries (Figure 2). 

Figure 1: Pernica accumulation lake in 2006 and 2016. 

2.2 Spatial analysis of the Jarenina Creek and Vukovje Creek catchments 
The catchments of Jarenina and Vukovje Creeks are similar by their average elevation (306m and 318m, respectively)whichisabout50mhigherthantheaverageelevationoftheSlovenskeGoriceHills.Theval­ley floors lie at an altitude of 250m, while the highest peaks of the hills exceed 400m in the north-western part of the JareninaCreek catchment. Slope gradients, which were calculated with a 5m resolution, range between 13° and 14°, with a maximum of about 50°. Landslide susceptibility level on a scale from 0 to 5 (after the landslide index method; Zorn and Komac 2008) is around 3, while areas with the highest pos­sible level of landslide susceptibility (scale level 5) can be found in both catchments. 
AccordingtotheSlovenianEnvironmentAgency,theaveragetemperaturewas–1.1°CinJanuaryand 20.1°C in July in the period from 1981 to 2010. The area gets about 980mm of precipitation on average, withjustunder4200MJ/m2ofinsolation.Annualsnowcoverspansfrom42to56days.Theaverageevap­otranspiration is just over 630mm and, on average, about 350mm of water drains from the area. The net groundwater recharge is about 80mm on average but it can vary significantly. The variation coefficient of groundwater recharge is 82% in the Jarenina Creek catchment and 52% in the Vukovje Creek catch-ment.Partsofthepilotareaexperiencesoilwatershortage(over80%)upto20daysormore.Bothcatchments have watercourses of the first, second, and third order (Figure 6). 
Land use is similar in both catchments. About one-third of the area is covered by meadows, followed by forests and arable fields. The percentage of the forested area is lower in the Jarenina Creek catchment than in the Vukovje Creek catchment, while the percentage of arable land is somewhat higher. The fourth categoryisbuilt-upareas,whileotherareasincludevineyards,permanentcrops,andovergrownareas.There are only a few tenths of a percent of water surfaces and wetlands. 
The catchments considered have identical natural geographical features. However, it was confirmed that the Jarenina Creek catchment has been more reshaped by human activity. This is confirmed by the higher share of built-up areas and agricultural land use. However, today there is more forest than in the firsthalfofthe19th centuryandfewerfieldsandvineyards(Deriazetal.2019;GabrovecandKumer2019). 


3 Methods 
WeselectedsevensmallretentionpondsinthePesnica Rivercatchmentto conductdetailedanalyses using geoinformationtools andstructuredinterviewswiththewaterpondowners(Figure2). Astructuredinter-view(ŠmidHribarandLedinekLozej2013;PipanandKokalj2017)isatechniqueforthesystematicgathering ofverbalinformation.Itwasusedtorecordopinionsanddeterminetheinterviewee’sposition(Nared2007) on the selected examples of anthropogenic bodies of water in order to analyze their common features. We studied theseexamplesto determine themain characteristicsof themanagementsystemofsmallretention ponds,theirversatility,andchallenges.Theinterviewswerestructuredwiththefollowingsequenceofquestions: 
• 
Who is the landowner? 

• 
Who manages the water body? 

• 
What year was the pond established? 

• 
What was it primarily used for? 

• 
What is its current purpose? 

• 
What is the depth of the water? 

• 
What is the speed of sediment accumulation and how often does it have to be removed?

• 
Do the pond banks have to be maintained? 

• 
Has the pond ever been (over)flooded? The results enabled us to evaluate the sustainability of the ponds from the management perspective 


(i.e. maintenance efforts, the quantity of sediment input, primary purpose, frequency of flooding). 
Basedonfieldobservationsandtheinformationgainedfromtheinterviews,apilotstudywasdesigned tomapandclassifyalltheretentionpondsinthecatchmentsofthetwoPesnicaRivertributaries:theJarenina and Vukovje Creeks which both contribute to the Pernica 1 retention pond (Figures 1 and 2). 
Alltheretentionpondsinthepilotareaweremappedinthegeographicinformationsystemandapond inventory was created. The collected data included: 
• 
Catchment name; 

• 
Location (coordinates); 

• 
ID number and name of the pond; 

• 
Pond surface area (m2); 

• 
Description of the hinterland – inflow; 

• 
Description of the area of the water reservoir – outflow. 


Wecalculatedthepercentageofsmallretentionpondsthatareconstructedonthemainwatercourseand influence water discharge and sediment yield anda percentage of ponds that work with a bypass channel. 

4 Results and discussion 
4.1 Interviews with the pond owners 
The structured interviews with the owners of the small retention ponds served as an insight into the com­mon challenges regarding their management observed in previous studies: from legislation issues (Širca 2010) to costs related to maintenance (Verstraeten and Poesen 1999; 2000; 2001) and the motivation to maintain or abandon the ponds (Mioduszewski 2012). The results show that in the Pesnica River catch­ment the ponds are usually privately owned and the owners manage them by themselves. Although they are responsible for the operative as well as financial aspects of management they mostly lack experience with any possible authorities responsible for water-related topics. Understandably, since also the review oflegislationaboutsmallretentionpondsinSloveniashowedtherearenospecificandclearlawsandrules (they apply only for large retention ponds). In most cases, the uncertainties and confusion of the legisla­tion do not create problems for individual landowners to establish private ponds. In only one case, the interviewee reported an issue with acquiring a permit to remove sediments from his retention pond in the Vukovje Creek catchment. Consequently, the pond was abandoned and is currently empty. 

Figure 2: Location of small retention ponds included in the interviews with the pond owners and the pilot study area. 
Based on their primary function when they were created and also their current function the ponds canbedividedintotwomaingroups:fishingponds(commercialandnon-commercial)andirrigationponds. Some retention ponds have existed for hundreds of years. They were made for aesthetic reasons and for fish farming near castles (e.g. Hrastovec Castle; Figure 3), countryside mansions (e.g. former Rittersberg in Spodnji Jakobski Dol), or monasteries (e.g. the Benedictine Monastery at Jareninski Dvor; Figure 4). They can be distinguished from most other ponds by their larger size, which is a consequence also of the favorable environmental conditions: they were created in natural stream valleys, at large natural springs, and in lower basins with permanently high groundwater levels. Through time and the changes in own­ership, their function was adapted to the owners’ needs. However, the ornamental and fishing ponds have mostly preserved their original function to this day. 
Decades ago, fish cultivation was an additional source of income for farmers in the Slovenske Gorice Hills.Nowadays,thefinancialimpactisminimal,leadingmanyoftheownerstoabandonthefishingponds. According to the interviewees, the lower income from fish sales in the past decade is most likely a conse­quenceofthedominatinglow-pricedproductsbymajormanufacturersonthemarket.Theirobservations are in line with the findings at the European Union level where the economic performance of fish farm­ing was linked to the heavy global competition but also to market requirements for the constant supply and quality with guaranteed environmentally-friendly production chains (Review of the EU…2009). Competingwithsuchrequirementsisimpossibleforindividual,non-alignedfarmers.Furtherfactorsneg­ativelyinfluencingaquaculturedevelopmentarewateruserconflictsandincreasinglycomplexregulations (ReviewoftheEU…2009).Consequently,commercialfishfarmingwillbecomeeconomicallybeneficialonly if it is integrated into national strategic development plans, providing the farmers with economic stimula­tionsandlegaladvice,andconnectingthemintolocalproductionchains(Adámek,MosserandHauber2019). 
Theothergroupofretentionpondsisintendedforirrigationtomaximizeorstabilizecropyields.They were constructed in the 1990s when state subventions were made available. The irrigation water is used in orchards, vineyards and private gardens. The interviews revealed that the pond maintenance costs for the owners are comparable with the gains of irrigation. Therefore, the owners are looking for additional possibilities to use the existing ponds, otherwise, the ponds will be abandoned. Consequently, the trend of retention pond use is shifting towards an increasingly multi-functional role: irrigation, watering live­stock, tourism with non-commercial sports fishing, and the aesthetic function is gaining in importance. Also, other research has shown that public awareness of the benefits of multi-functional ponds encour­ages local people to properly maintain them (Oda et al. 2019). Due to increased climate variability and 

Figure 3: The tradition of fishing in the castle ponds at Hrastovec Castle has been maintained for several centuries. 
change in precipitation patterns (see chapter 2) the need for irrigation ponds will most likely increase in thefuture.Furthermore,smallon-farmpondsareamoresustainablewatersource,comparedtolargescale groundwater extraction for irrigation (Sanfo et al. 2017; Vico, Tamburino and Rigby 2020). 
Usually,retentionpondsareconstructedinareasoflocalspringsandstreams.Consequently,constructing them requires simply digging out or deepening a small basin in the valley floor, with minimal construc­tion of barriers or dams. Simple dams are constructed by piling up clay sediment and fortified in places withwoodenstakes.Someinterviewedpondownersstatedthepondswereconstructedmanydecadesago by previous landowners. In such cases, the knowledge about motivation and reasons for constructing the ponds at a specific location in a specific way is lost. 
ThebedrockoftheSlovenskeGoriceHillsispronetoquickweatheringanderosion.Furthermore,despite the fact that these shallow retention ponds are no more than 5m deep, they do not need to be frequently cleaned as the accumulation of sediment is still slow. The owners remove the sediment from the ponds onlyonceinevery10to30years.Thereareseveralreasonsforthat,demonstratingthedeepunderstanding and knowledge of local people about their environment: 
• 
The retention ponds are usually located in areas with low inclination slopes, where the torrential char­acter of the watercourses is decreased. 

• 
Low sediment accumulation occurs also because the retention ponds were generally created above the main watercourses and are not subject to flooding. 

• 
Many ponds are built on springs or small tributaries transporting low amounts of bedload. 

• 
When the ponds are built next to the streams, to minimize pond sedimentation, the main watercourse iscommonlydivertedtobypassthepond(Figure5).Theinundationofpondsiscontrolledbywaterchan­neled from the main watercourse which transports significantly less bedload material. In this way, the owners avoided possible damage during floods and high sediment flow along the main streams. 



Figure 4: Fishing pond (marked with red rectangle) at the Benedictine Monastery at Jareninski Dvor as shown on the Franciscean Cadastre from the early 19th century (Franciscejski kataster 1824). 
These adaptation methods helping the owners to more efficiently manage and maintain the ponds, influence also the effect of the ponds as possible natural ecological measures for preventing floods. For this reason, we analyzed the percentage of retention ponds in the pilot areas that are located directly on thestreamnetworkandthenumberofpondsthatarephysicallyseparatedfromthewatercoursesandonly filled with groundwater or precipitation (chapter 4.2). 
Sincetheissueofpondsedimentationwasfrequentlyalreadylimitedbycreatingspecificresilientpond types, some interviewed pond owners reported the removal of aquatic weeds from the retention ponds as themosttimeandcostconsumingmanagementissue.Overgrowthbyvegetationcausesproblemsbecause italterstheecologicalconditionsinthepondsveryquicklybyinducingeutrophication,overgrowthofthe surface with algae, leading to low visibility and low oxygen level (Vanacker et al. 2016). Such changes in water properties are harmful to fish populations and, consequently, need to be avoided especially in fish-ingponds(Vanackeretal.2016;Adámek,MosserandHauber2019).Thisiswhythevegetationintheretention ponds, and especially on their banks, has to be regularly removed every few years (Figure 5). 

4.2 Pond inventarisation in the catchments of Jarenina and Vukovje Creeks 
Atotalof41artificialstructurestoretainfreshwater(i.e.retentionponds)weredetectedduringfieldmap-ping in the Jarenina Creek and Vukovje Creek catchments (Figure 6, Table 2). The identified ponds cover a total area of 15,014.73m2 and the average pond size is 366.21m2. Despite the comparable size of both catchments, there are significantly fewer ponds in the Jarenina Creek catchment (15 ponds) than in the Vukovje Creek catchment (26 ponds). However, the largest pond of all (JC1 – 5,125m2) and the average pondsizeintheJareninaCreekcatchment(642.81m2)considerablyexceedthepondsintheVukovjeCreek catchment (average size is 206.64m2). Also, the total area of ponds in the Jarenina Creek catchment (9,642.10m2) is larger than in the Vukovje Creek catchment (5,372.63m2). 

Figure 5: Vegetation is removed from the banks of the retention ponds every few years. White arrow is indicating the location of the diversion channel which diverts the excess water and bedload around the pond. 
Ponds differ according to the material and method of construction, their source of water, and the way in which water can be drained from the pond (Fish pond…2005). Additionally, the possible influence of ponds to decrease flood hazard was evaluated. 

Figure 6: The catchment of Jarenina and Vukovje creeks with the location of small retention ponds classified according to their influence on flood hazard reduction. The figure is showing also the drainage basin network with the order classification (Strahler 1957). The data on the stream network was acquired from the Surveying and Mapping Authority of the Republic of Slovenia. 
All identified ponds in both catchments were built using local natural material (i.e. gravel, sand, clay, soil,andwood)andcanbedefinedassimpleearthenponds.Noconcreteormetalconstructionswereused. Accordingtotheconstructionmethods,thepondsareeitherdug-outpondsorcut-and-fillponds(Table 3). The dug-out ponds (also sunken ponds) are constructed in flat areas by excavating bedrock material to formaholeintheground(Fishpond…2005).Theexcavatedmaterialcanbeusedtoadditionallystrength-enorrisepondwallsabovethesurroundingsurface.Inbothcatchments15ponds(37%)aredug-outponds: 5 ponds (33,3%) in the Jarenina Creek catchment, and 10 ponds (38,5%) in the Vukovje Creek catchment. The cut-and-fill ponds (also barrage ponds) are constructed on slopes by the excavation of the bedrock material and using it to embank the pond on the downslope side (Fish pond…2005). In this way, a bar-rierordamisbuilttoretainthewater.Inbothcatchments,26ponds(63%)arecut-and-fillponds:10ponds (66,6%) in the Jarenina Creek catchment, and 16 ponds (61,5%) in the Vukovje Creek catchment. 
Accordingtothesourceofwaterrecharge,thepondscanbefedbygroundwaterorsurfacewater(Fish pond…2005). The groundwater can flow to the pond as seepage from the matrix porosity of the bedrock (the level of water will vary with the groundwater-table) or from a spring in or close to the pond (the level of water will vary according to the wet/dry seasons). The surface water can be supplied by rainfall or from surface run-off (e.g. surface stream) both dependent on the wet/dry seasonality. All identified ponds are fed by a combination of water sources (e.g. rainfall and seepage affect all ponds). However, for analytical reasons, the main source of water for each pond was considered in the study (Table 3). 
The most common source of water in all identified ponds is groundwater (73%): 67% of ponds in the Jarenina Creek catchment and 77% of ponds in the Vukovje Creek catchment. Approximately two-thirds of the groundwater and 46% of all the water in both catchments comes from springs. Only three ponds in each catchment are supplied by surface water coming from a stream (15% of all water supply). 12% of the ponds are mainly supplied by rainfall. Like it was discussed through the interviews with pond own­ers (see chapter 4.1), also the pond inventarisation confirmed that the pond location (from the aspect of water supply) is well adjusted to the environmental conditions of the Slovenske Gorice Hills. Ponds fed byseepageandspringwatertransportaninsignificantamountofbedloadandneedlessmaintenance.From theaspectofsustainability,pondsfedbygroundwater(seepageorsprings)havealoweramplitudeofwater-table variability and are less affected byprecipitation seasonality. In rural areas, the reliability of the water sources was especially important before the construction of the water distribution system and remained important for livestock and plantation farmers until the present. Moreover, the importance of sustainable small ponds is increasing due to the current climate variability (Sanfo et al. 2017; Vico, Tamburino and Rigby 2020). 
Another method (used also by some interviewed pond owners) to prevent flooding and/or filling of ponds with bedload transported by streams is to construct diversion channels to divert excess water and bedload around the pond (Fish pond…2005). Out of 6 ponds fed by a surface stream, 4 ponds (2 in each 
Table 2: Pond inventory of Jarenina (JC) and Vukovje Creek (VC) catchments showing the area of the identified ponds. 
ID  area (m2)  ID  area (m2)  ID  area (m2)  
JC1  5125.00  VC1  929.00  VC16  312.00  
JC2  801.00  VC2  117.00  VC17  346.00  
JC3  1103.00  VC3  91.20  VC18  113.00  
JC4  125.00  VC4  301.00  VC19  204.00  
JC5  39.00  VC5  64.90  VC20  440.00  
JC6  31.40  VC6  120.00  VC21  263.00  
JC7  250.00  VC7  33.00  VC22  138.00  
JC8  837.00  VC8  6.23  VC23  118.00  
JC9  271.00  VC9  150.00  VC24  83.80  
JC10  557.00  VC10  129.00  VC25  141.00  
JC11  109.00  VC11  267.00  VC26  532.00  
JC12  98.40  VC12  54.50  
JC13  88.60  VC13  166.00  
JC14  124.00  VC14  106.00  
JC15  82.70  VC15  147.00  

Table 3: Pond classification by construction method, water supply, and water outlet. The table shows the ID values of identified ponds in the Jarenina Creek catchment (JC1, JC2,…JC15) and Vukovje Creek catchment(VC1, VC2,…VC26). 








GROUNDWATER SURFACE WATER 
Seepage Spring Rainfall Surface stream Surface channel Underground Pumped Undrainable channel 

DUG-OUT POND 8, 9, 13 / 5, 12 / 
/ 8, 9 5, 12 13 
CUT-AND-FILL POND 2 6, 7, 10, 11, 14, 15 / 1, 3, 4 
3, 4, 14, 15 1, 2, 6, 7, 10, 11 / / 

DUG-OUT POND 4, 5, 6, 9, 24, / 2, 8, 13 / 
6 4, 9, 26 2, 8, 13 5, 24, 25 
25, 26 
CUT-AND-FILL POND / 1, 7, 11, 12, 15, / 3, 10, 14 
3, 14, 19 1, 7, 10, 11, 12, 18 / 
16, 17, 18, 19, 
15, 16, 17, 20, 
20, 21, 22, 23 
21, 22, 23 
catchment;JC3andJC4,andVC3andVC14)haveadiversionchannel.BothpondsintheVukovjeCreek catchmentarecurrentlyoutofoperation(surroundedbymeadowsandpartlyovergrownbybush).Weassume they are several decades old and that the diversion channels played a greater role in the past when they wereusedaswateringholesforlivestock.BothpondsintheJareninaCreekcatchmentwerebuiltinthelast twodecadesandhavecurrentlyanaestheticandtourismfunction.Thediversionchannelsforbothponds are regularly cleaned and maintained. Land use changes (afforestation reflecting the changes in farming economy)alteredthefunctionofthemajorityofponds.Theirmaintenancestronglydependsontheaware­nessofpondownersofthepossiblebenefitsofmulti-functionalponds:irrigation,tourism,andaesthetics. 
Considering the supply of water, the surface stream-fed ponds have the most direct impact on water and sediment discharge (Koskiaho 2003; Muendo et al. 2014; Chrétien et al. 2016) by slowing down the run-off and consequently on flood reduction. This effect is lessened by the diversion channels, especial­ly for the bedload which can be transported around the ponds. For water retention in the source area of the catchments also rainfall and spring-fed ponds are important as both types are correlated to precipi­tation patterns; some excess water is stored in the source area during peak flows decreasing fast drainage towardslowervalleys(Koskiaho2003;Chrétienetal.2016).Stream,rainfall,andspring-fedpondsarebecom­ing more and more important also for limiting on the impacts of drought at individual and local levels due to increased variability of precipitation patterns (Oda et al. 2019; Vico, Tamburino and Rigby 2020). Ponds fed through seepage do not influence water discharge (i.e. movement of groundwater). Moreover, during floods, these ponds can be completely submerged and are not impacting the extent of floods or sediment transport. On the other hand, because they are excavated below the water-table they represent vulnerablelocationsforchemicalorbiologicalcontaminationofthegroundwater(LóczyandDezső2013). 
For sustainable management of ponds also the outlet of water is important which can be drainable or undrainable (Table 3). Drainable outlets can be driven by gravitation (surface streams and underground channels) or the water can be mechanically pumped from the pond. Gravitational outlets are typical for cut-and-fill ponds supplied by springs and surface streams. Mostly they have controlled outlets because they were built by embankment (e.g. barrier or dam) through which a surface or underground channel enablesthedrainageofexcesswater.IntheJareninaCreekcatchment12outof15pondshaveacontrolled surface (4 ponds) or an underground (8 ponds) outlet channel. In the Vukovje Creek catchment, 19 out of26pondshaveacontrolledsurface(4ponds)oranunderground(15ponds)outletchannel.Thesetypes ofoutletsdirectlyinfluencedrainagedownstream(e.g.discharge,bedloadandsuspendedsediment,aswell as water quality). Therefore, their proper management reduces flood and drought risks. All ponds fed by rainfall (5 ponds in both catchments) were excavated on higher ground above the valley floor but have nosurfaceorundergroundoutlet.However,theycanbeemptiedbypumpingoutwater,ifneeded.Ofaspe­cialtypearepondsfedbyseepage,whicharedeepenedbelowthesurroundingsurfaceandcannotbedrained (watertabledictatesthewaterlevelofthepond).Asmentionedbefore,theyhavethelowestimpactonflood reduction but are the most vulnerable point for water pollution, e.g with increased nutrient presence (Ilić and Panjan 2018). 


5 Conclusion 
The paper discusses small water ponds in north-eastern Slovenia on the example of the Slovenske Gorice Hills. The main conclusion is that small retention ponds, unlike large ponds, are not included in the regional, national and international legislation and the management is left to the landowners. Poor and uncoordinated management strategies and low investments contribute to the state of the water ponds and furtherminimizetheirpossibleuseinfloodprotection.Wealsonotedthatthelong-termlandscapechanges, especially land use changes, considerably alter the functioning of the small ponds as an important part of the hydrological system. Inthe last decades, afforestation, related to the changes in the farming economy, lowered the sediment input and shifted the prevailing use of water ponds from commercial fishing, irri­gationandwateringlivestocktootherfunctions,suchastourism,non-commercialfishing,andaesthetics. 
More than half of the retention ponds in the catchments of Jarenina and Vukovje creeks are supplied bygroundwater(throughseepageorsprings)whichincreasesthesustainabilityofpondsbecauselesseffort is needed to maintain them (low sedimentation rates, reliable source of water). Only 15% of the ponds are suppliedbysurfacestreamsand12%byrainfall.Thepondsconstructedonsurfacestreamslargelyimpact 
the water discharge and sediment transport and reduce the flood hazard. However, their maintenance is moredemandingthanthatofotherpondtypes.Tocopewithsedimentinfillingandavoidpeakflowdam­agestoponds,diversionchannelswerebuiltontwo-thirdsofsuchponds,divertingthemajorityofbedload and excess water around the ponds. This technique lowers the maintenance efforts and increases pond sustainability, however, it lowers the pond impact on flood hazard reduction. 
Forwaterretentioninthesourceareaofthecatchmentsbothrainfallandspring-fedpondsareimpor­tant as both types are correlated to precipitation patterns; some excess water is stored in the source area during peak flows decreasing fast drainage towards lower valley sections. Stream, rainfall, and spring-fed ponds are due to increased variability of precipitation patterns becoming more and more important also for limiting drought consequences at an individual and local level. Ponds fed by seepage have an egligi­ble impact on flood risk reduction . Nevertheless, they are vulnerable locations for chemical or biological contamination of the groundwater because they are deepened below the local water-table level. 
Since the owners’ investments to maintain the retention ponds are relatively high compared to their economic benefits, the owners often choose to abandon retention ponds. Although retention ponds do not prevent floods, their future abandonment would destabilize the hydrological and agriculture system and increase flood risk and drought impact in the area. 
ACKNOWLEDGEMENTS: The authors acknowledge the study was performed in the frame of the pro­ject Possible ecological control of flood hazard in the hilly regions of Hungary and Slovenia. The project was financially supported by the Slovenian Research Agency (ARRS, N6-0070) and the Hungarian National Research, Development and Innovation Office (NKFIH, SNN 125727 and the programme Excellence in Higher Education, Theme II. 3. »Innovation for sustainable life and environment«). The study was per­formed also in the frame of a research programme Geography of Slovenia (ARRS, P6-0101). 

6 References 
Adámek, Z., Mösser, M., Hauber, M. 2019: Current principles and issues affecting organic carp (Cyprinus carpio) pond farming. Aquaculture 512. DOI: https://doi.org/10.1016/j.aquaculture.2019.734261 Barborič,B.,TriglavČekada,M.,Bric,V.,Kete,P.,DežmanKete,V.2017:Novepodatkovnepodlagezaboljše 
upravljanje z vodami. Naravne nesreče 4. Ljubljana. Belec, B. 1998: Panonski svet. Slovenija, pokrajine in ljudje. Ljubljana. Chrétien, F., Gagnon, P., Thériault, G., Guillou, M. 2016: Performance analysis of a wet-retention pond 
in a small agricultural catchment. Journal of Environmental Engineering 142-4. DOI: https://doi.org/ 10.1061/(ASCE)EE.1943-7870.0001081 Ciglič,R.,Nagy,G.2019:Naturalnessleveloflanduseinahillyregioninnorth-easternSlovenia.Geografski vestnik 91-1. DOI: https://doi.org/10.3986/GV91101 
Deriaz, J., Ciglič, R., Ferk, M., Loczy, D. 2019: The influence of different levels of data detail on land use changeanalyses:acasestudyofFranciscanCadastreforapartofthePannonianHills,Slovenia.European countryside 11-3. DOI: https://doi.org/10.2478/euco-2019-0019 
E-vode, 2019. Medmrežje: http://www.evode.gov.si/index.php?id=1 (4.11.2019). Fairchild,G.W.,Velinsky,D.J.2009:Effectsofsmallpondsonstreamwaterchemistry.LakeandReservoir 
Management 22-4. DOI: https://doi.org/10.1080/07438140609354366 Fish pond construction and management, 2005. A field guide and extension manual. FranciscejskikatasterzaŠtajersko,k.o.Vajgen[Weigen],listB03.ArhivRepublikeSlovenije.Ljubljana,1824. Frantar, P. 2008a: Odtočni količniki. Vodna bilanca Slovenije 1971–2000. Ljubljana. Frantar, P. 2008b: Specifični odtoki 1971–2000. Vodna bilanca Slovenije 1971–2000. Ljubljana. Frantar,P.,Hrvatin,M. 2005:PretočnirežimivSlovenijimedletoma1971in2000. Geografskivestnik 77-2. Gabrovec,M.,Bičík,I.,Komac,B.2019:Landregistersasasourceofstudyinglong-termland-usechanges. 
Acta geographica Slovenica 59-2. DOI: https://doi.org/10.3986/AGS.7349 Gabrovec, M., Kumer, P. 2019: Land-use changes in Slovenia from the Franciscean Cadaster until today. Acta geographica Slovenica 59-1. DOI: https://doi.org/10.3986/AGS.4892 Globevnik, L. 2012. Vzdrževanje vodne infrastrukture in vodotokov – pomen, realnost in perspektive. 
1. kongres o vodah Slovenije, 22. marec 2012. Ljubljana. 
Hooijer, A., Klijn, F., Pedroli, G. B. M., Van Os, A. G. 2004: Towards sustainable flood risk management in the Rhine and Meuse river basins: synopsis of the findings of IRMA-SPONGE. River Research and Applications 20. DOI: https://doi.org/10.1002/rra.781 
Hrvatin, M., Ciglič, R., Lóczy, D., Zorn, M. 2019: Določanje erozije v gričevjih severovzhodne Slovenije z Gavrilovićevo enačbo. Geografski vestnik 91-2. DOI: https://doi.org/10.3986/GV91206 
Hrvatin,M.,Zorn,M.2017:TrendipretokovrekvslovenskihAlpahmedletoma1961in2010.Geografski vestnik 89-2. DOI: https://doi.org/10.3986/GV89201 
Ilić, D., Panjan, J. 2018: Nitrogen and phosphorus pollution in Goričko Nature Park. Acta geographica Slovenica 58-1. DOI: https://doi.org/10.3986/AGS.727 
InfrastructureforSPatialInfoRmationinEurope–INSPIRE.Brussels,2017.Internet:https://inspire.ec.europa.eu/ about-inspire/563 (21.10.1019). 
Juvan,S.,Hojnik,T.,Kaligarič,S.,Trop,M. 1997:PresojavplivovnačrtovanegapotekaACpopesniškidolini na vodni režim in vodno okolje. Mišičev vodarski dan, zbornik referatov. Maribor. 
Kert, B. 1998: Slovenske gorice. Slovenija, pokrajine in ljudje. Ljubljana. 
Kijowska-Strugała,M.,Bucała-Hrabia,A.2019:Floodtypesinamountaincatchment:TheOchotnicaRiver, Poland. Acta geographica Slovenica 59-1. DOI: https://doi.org/10.3986/AGS.2250 
Kladnik,D.,Geršič,M.,Pipan,P.,VolkBahun,M.2019:Land-usechangesinSlovenianterracedlandscapes. Acta geographica Slovenica 59-2. DOI: https://doi.org/10.3986/AGS.6988 
Kobold, M. (ur.) 2012: Hidrološki letopis Slovenije 2009. Ljubljana. 
Kolbezen, M. 1998: Kopenske vode. Geografski atlas Slovenije. Ljubljana. 
Komac, B. 2015: Modeliranje obpotresnih pobočnih procesov v Sloveniji. Geografski vestnik 87-1. DOI: 
https://doi.org/10.3986/GV87107 Komac, B., Zorn, M. 2011: Vloga zavarovanih območij pri blažitvi naravnih nesreč. Razvoj zavarovanih območij v Sloveniji. Regionalni razvoj 3. Ljubljana. Komac, B., Zorn, M. 2016: Naravne in umetne pregrade ter z njimi povezani hidro-geomorfni procesi. Geografski vestnik 88-2. DOI: https://doi.org/10.3986/GV88204 Koskiaho, J. 2003: Flow velocity retardation and sediment retention in two constructed wetland–ponds. Ecological Engineering 19-5. DOI: https://doi.org/10.1016/S0925-8574(02)00119-2 Kovačič, G. 2016: Discharge trends of the Adriatic Sea basin rivers in Slovenia, excluding the Soča river basin. Geografski vestnik 88-2. DOI: https://doi.org/10.3986/GV88201 Kozjek, K., Dolinar, M., Skok, G. 2017: Objective climate classification of Slovenia. International journal of climatology 37-S1. DOI: https://doi.org/10.1002/joc.5042 Kračun, M. 2010: Analiza zamuljevanja akumulacije Pernica z vidika njenega namena. Varnost pregrad vSloveniji.12.posvetovanjeSlovenskeganacionalnegakomitejazavelikepregrade(SLOCOLD).Krško. Leitinger,V.2012:HidrografskeznačilnostiporečjarekePesnicespoudarkomnavodnogospodarskihure­ditvah. Diplomsko delo, Fakulteta za humanistične študije Univerze na Primorskem. Koper. Lenart, S., Rajar, R., Širca, A. 2017: Prispevek projekta VODPREG 2 k oceni porušitev vodnih pregrad. Trajnostni razvoj mest in naravne nesreče. Naravne nesreče 4. Ljubljana. Lóczy,D.,Dezső,J.2013:Groundwaterfloodinghazardinrivervalleysofhillregions:exampleoftheKapos River, Southwest-Hungary. Hungarian Geographical Bulletin 62-2. Lóczy, D., Kis, E., Schweitzer, F. 2009: Local flood hazards assessed from channel morphometry along the Tisza River in Hungary. Geomorphology 113. DOI: https://doi.org/10.1016/j.geomorph.2009.03.013 
Manifesto: Dams & Reservoirs 2015. Issue 1. European ICOLD Club. October 2015. 
Mioduszewski, W. 2012: Small water reservoirs – their function and construction. Journal of Water and Land Development 17-VII-XII. 
Muendo, P. N., Verdegem, M. C. J., Stoorvogel, J. J., Milstein, A., Gamal, E., Minh Duc, P., Verreth, J. A. J. 2014: Sediment accumulation in fish ponds; Its potential for agricultural use. International Journal of Fisheries and Aquatic Studies 1-5. 
NačrtupravljanjavodanavodnemobmočjuDonavezaobdobje2016–2021,2016.Internet:https://www.gov.si/ assets/ministrstva/MOP/Dokumenti/Voda/NUV/63dbe4066b/NUV_VOD.pdf (5.10.2019). 
Načrt upravljanja voda na vodnem območju Jadranskega morja za obdobje 2016–2021, 2016. Internet: https://www.gov.si/assets/ministrstva/MOP/Dokumenti/Voda/NUV/4195091b63/NUV_VOJM.pdf (28.2.2020). 
Nared, J. 2007: Prostorski vplivi slovenske regionalne politike. Geografija Slovenije 16. Ljubljana. 
Natek, K. 1992: Franciscejski kataster in geografski informacijski sistem. Traditiones 21. 
Oda,T.,Moriwaki,K.,Tanigaki,K.,Nomura,Y.,Sumi,T.2019:Irrigationpondsinthepast,present,andfuture: A case study of the Higashi Harima Region, Hyogo Prefecture, Japan. Journal of Hydro-environment Research 26. DOI: https://doi.org/10.1016/j.jher.2018.11.004 
Papež, J. 2010: Obseg in pomen rednega urejanja voda. Varnost pregrad v Sloveniji. 12. posvetovanje Slovenskega nacionalnega komiteja za velike pregrade (SLOCOLD). Krško. 
Perko, D. 1998: The regionalization of Slovenia. Acta geographica 38. 
Pintar, J., Mikoš, M., Verbovšek, V. 1986: Elementi okolju prilagojenega urejanja vodotokov: alternativa utesnjevanju živih naravnih procesov v toge objekte. Drugi kongres o vodama Jugoslavije. Beograd. Pipan, P. Kokalj, Ž. 2017: Transformation of the Jeruzalem Hills cultural landscape with modern vineyard terraces. Acta geographica Slovenica 57-2. DOI: https://doi.org/10.3986/AGS.4629 
Pravilnik o določitvi vodne infrastrukture. Uradni list Republike Slovenije 46/2005. Ljubljana. 
Pravilnikoopazovanjuseizmičnostinaobmočjuvelikepregrade.UradnilistRepublikeSlovenije92/1999, 44/2003 in 58/2016. Ljubljana. Pravilnikotehničnemopazovanjuvisokihjezov.UradnilistSocialističnefederativnerepublikeJugoslavije 7/1966. Beograd. 
Pravilnik o vodnem katastru. Uradni list Republike Slovenije 30/2017. Ljubljana. 
Review of the EU aquaculture sector and results of costs and earnings survey 2009. Definition of data col­lection needs for aquaculture, Final report. 
Richert, E., Bianchin, S., Heilmeier, H., Merta, M., Seidler, C. 2011: A method for linking results from an evaluation of land use scenarios from the viewpoint of flood prevention and nature conservation. Landscape and Urban Planning 103. DOI: https://doi.org/10.1016/j.landurbplan.2011.07.001 
Sanfo, S., Barbier, B., Dabiré, I. W. P., Vlek, P. L. G., Fonta, W. M., Ibrahim, B., Barry, B. 2017: Rainfall vari­ability adaptation strategies: An ex-ante assessment of supplemental irrigation from farm ponds in southern Burkina Faso. Agricultural Systems 152. DOI: https://doi.org/10.1016/j.agsy.2016.12.011 
Seznam obstoječe vodne infrastrukture. Uradni list Republike Slovenije 63/2006, 96/2006. Medmrežje: http://www.pisrs.si/Pis.web/pregledPredpisa?id=DRUG2548 Sodnik, J., Kogovšek, B., Mikoš, M. 2014: Vodna infrastruktura v Sloveniji: kako do ocene realnega stan­ja? Naravne nesreče 3. Ljubljana. 
Steinman, F., Banovec, P. 2008: Hidrotehnika, Vodne zgradbe I. Univerza v Ljubljana, Fakulteta za grad-beništvo in geodezijo. Ljubljana. Medmrežje: http://fgg-web.fgg.uni-lj.si/kmte/documents/academic/ skripta/Hidrotehnika_sept.2008.pdf 
Strahler, A. N. 1957: Quantitative analysis of watershed geomorphology. Transactions of the American Geophysical Union 38-6. DOI: https://doi.org/10.1029/tr038i006p00913Širca,A.2010:Slovenskevelikepregrade:stanje,perspektiveinovire.VarnostpregradvSloveniji.12.posve­tovanje Slovenskega nacionalnega komiteja za velike pregrade (SLOCOLD). Krško.
Širca, A., Ravnikar Turk, M., Zadnik, B. 2010: Vloga strokovnih združenj pri izboljševanju varnosti pre­grad.VarnostpregradvSloveniji.12.posvetovanjeSlovenskeganacionalnegakomitejazavelikepregrade (SLOCOLD). Krško.
ŠmidHribar,M.,LedinekLozej,Š.2013:Theroleofidentifyingandmanagingculturalvaluesinruraldevel­opment. Acta geographica Slovenica 53-4. DOI: https://doi.org/10.3986/AGS53402 Trobec,T.2016:Prostorsko-časovnarazporeditevhudourniškihpoplavvSloveniji.Dela46.DOI:https://doi.org/ 10.4312/dela.46.5-39 Uputstvo o izradi dokumentacije za određivanje posledica usled iznenadnog rušenja ili prelivanja visokih brana. Savezni komitet za poljoprivredu, 1975. Beograd. UredbaonačrtihupravljanjavodanavodnihobmočjihDonaveinJadranskegamorja.UradnilistRepublike Slovenije 67/2016. Ljubljana. 
Vanacker, M., Wezel, A., Arthaud, F., Guérin, M., Robin, J. 2016: Determination of tipping points for aquatic plantsandwaterqualityparametersinfishpondsystems:Amulti-yearapproach.EcologicalIndicators64. DOI: https://doi.org/10.1016/j.ecolind.2015.12.033 
Verstraeten,G.,Poesen,J.1999:Thenatureofsmall-scaleflooding,muddyfloodsandretentionpondsed­imentation in central Belgium. Geomorphology 29. Verstraeten, G., Poesen, J. 2000: Estimating trap efficiency of small reservoirs and ponds: methods and implications for the assessment of sediment yield. Progress in Physical Geography 24-2. 
Verstraeten,G.,Poesen,J.2001:Variabilityofdrysedimentbulkdensitybetweenandwithinretentionponds anditsimpactonthecalculationofsedimentyields.EarthSurfaceProcessesandLandforms26-4.DOI: https://doi.org/10.1002/esp.186 
Vico, G., Tamburino, L., Rigby, J. R. 2020: Designing on-farm irrigation ponds for high and stable yield fordifferentclimatesandrisk-copingattitudes.JournalofHydrology584.DOI:https://doi.org/10.1016/ j.jhydrol.2020.124634 
World declaration on water storage for sustainable development. 24th Congress of the International Commission on Large Dams, 5.6.2012. Internet: https://www.icold-cigb.org/userfiles/files/World% 20declaration/World%20Declaration-ENG.pdf (15.2.2020). 
Worldregisterofdams.InternationalCommissiononLargeDams,September2019.Internet:https://www.icold­cigb.org/ (24.2.2020). 
Wutich, A., White, A. C., White, D. D., Larson, K. L., Brewis, A., Roberts, C. 2014: Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions. Hydrology and Earth System Sciences 18. DOI: https://doi.org/10.5194/hess-18-109-2014 
Zakon o vodah. Uradni list Republike Slovenije 67/2002, 2/2004, 41/2004, 57/2008, 57/2012, 100/2013, 40/2014 in 56/2015. Ljubljana. 
ZemeljskeinbetonskevodnepregradestrateškegapomenavRepublikiSloveniji,VODPREG2,2016.Razvojno raziskovalni projekt, Končno poročilo. Zavod za gradbeništvo, IBE d.d., Fakulteta za gradbeništvo in geodezijo, Ljubljana, Hidrotehnik d.d. Ljubljana. 
Zorn, M. 2007: Jožefinski vojaški zemljevid kot geografski vir. Geografski vestnik 79-2. 
Zorn, M., Komac, B. 2008: Zemeljski plazovi v Sloveniji. Georitem 8. Ljubljana.
Žiberna,I.2017:TrendivodnebilancevseverovzhodniSlovenijivobdobju1961-2016.GeografijaPodravja. Maribor.