© Acta hydrotechnica 19/31 (2001), Ljubljana
ISSN 1581-0267
95
UDK / UDC : 556.51(497.4) Prejeto / Received: 3.12.2001
Predhodna objava / Preliminary scientific paper Sprejeto / Accepted: 8.1.2002
UPORABA ŠIFRANTA PADA VINSKIH OBMO ČIJ VODOTOKOV
REPUBLIKE SLOVENIJE ZA PRIPRA VO HIDROLOŠKIH MODELOV
THE APPLICATION OF THE WATERSHED CODING SYSTEM OF THE
REPUBLIC OF SLOVENIA FOR HYDROLOGICAL MODELLING
Mojca ŠRAJ
V prispevku je predstavljena uporabnost šifranta padavinskih obmo čij Republike Slovenije,
predvsem uporaba pri hidrološkem modeliranju, ki je podlaga za napovedovanje poplav, dolo čanje
poplavne ogroženosti in ukrepov varstva pred poplavami, ra čun vodne bilance itd. Kot primer je
predstavljen hidrološki model So če. Iz primera je razvidno, da se šifrant popolnoma ujema z
vhodno strukturo modela. Sistem šifriranja padavinskih obmo čij R Slovenije torej omogo ča
neposreden vnos v hidrološke modele.
Klju čne besede: hidrologija, padavinsko obmo čje, modeliranje, šifrant, reka So ča, padavine
The applicability of the watershed coding system of the Republic of Slovenia is represented in this
paper with the emphasis on the hydrological modelling which is the base for flood forecasting,
flood risk analyses and precautions against floods, water budget assessments, etc. The hydrological
model of the river So ča is represented as an example. The coding system completely tallies with the
model-input structure, as can be seen from the example. Therefore the coding system of the
Republic of Slovenia enables direct input in the hydrological models.
Key words: hydrology, watershed, modelling, coding system, the So ča river, precipitation
1. UVOD
Uporaba sodobne programske opreme za
upravljanje s prostorsko dolo čenimi bazami
podatkov zahteva po eni strani šifriranje, ki je
prilagojeno ra čunalniški obdelavi podatkov, po
drugi strani pa ponuja nove možnosti pri
urejanju podatkov in izdelavi modelov.
Na podlagi analize razli čnih sistemov
šifriranja v razli čnih državah je bil v Sloveniji
izdelan sodoben sistem šifriranja padavinskih
obmo čij (Brilly & Garantini, 1994; 1996; Šraj,
2000, 2001). Sistem je odprt in prilagojen
ra čunalniški obdelavi.
Šifrant padavinskih obmo čij omogo ča
urejanje podatkov o okolju, izdelavo
vodnogospodarskih na črtov in programov,
izdelavo sodobnih informacijskih sistemov za
potrebe varstva okolja ter izdelavo razli čnih
analiz in hidroloških modelov (Brilly et al.,
1993; Brilly & Šraj, 1998; WMO, 1994).
1. INTRODUCTION
The application of contemporary software
and hardware for managing spatially oriented
data requires a computer adapted coding
system and also offers new alternatives in data
management and model making.
A contemporary coding system for
Slovenian watersheds based on the analyses of
different coding systems in different countries
has been made (Brilly & Garantini, 1994;
1996; Šraj, 2000, 2001). The system is open
and applicable for computer data management.
The watershed coding system enables
environmental database management and
water management plans and programmes,
contemporary information systems for
environmental protection, as well as various
analyses and hydrological modelling (Brilly et
al., 1993; Brilly & Šraj, 1998; WMO, 1994).

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
96
V nadaljevanju je predstavljena uporaba
šifranta padavinskih obmo čij Republike
Slovenije za izdelavo hidroloških modelov, ki
so podlaga za napovedovanje poplav,
dolo čanje poplavne ogroženosti in ukrepov
varstva pred poplavami, ra čun vodne bilance
itd.
2. UPORABA ŠIFRANTA
PADA VINSKIH OBMO ČIJ
ZA HIDROLOŠKO
MODELIRANJE
2.1 UVOD
V okviru mednarodnega programa IHP
UNESCO se trenutno v Sloveniji izvajajo
hidrološke meritve in izra čuni na štirih
eksperimentalnih pore čjih: So če, Savinje,
Notranjske Reke in Dragonje (slika 1). Zato so
bila ta padavinska obmo čja pripravljena tudi
za vnos v hidrološki model HEC-1 (Šraj,
2000). S tem želim pokazati, da je sistem
šifriranja že sam po sebi strukturiran tako, da
omogo ča neposreden vnos v hidrološke
modele.
The application of the watershed coding
system of the Republic of Slovenia for
hydrological modelling, which is the base for
flood forecasting, flood risk analyses and
precautions against floods, water budget
assessments, etc., is represented in the present
work.
2. THE APPLICATION OF THE
WATERSHED CODING SYSTEM
FOR HYDROLOGICAL
MODELLING
2.1 INTRODUCTION
Within the international programme IHP
UNESCO, hydrological measurements and
calculations were carrying out on four
experimental watersheds in Slovenia: So ča,
Savinja, Notranjska Reka and Dragonja, at the
moment (Figure 1). For this reason, just those
watersheds have been prepared for
hydrological model HEC-1 (Šraj, 2000). I
want to indicate, that the structure of the
coding system alone, enables direct  input in
the hydrological models.
Slika 1. Eksperimentalna povodja v Sloveniji.
Figure 1. Experimental watersheds in Slovenia.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
97
2.2 TEMELJI RA ČUNALNIŠKEGA
PROGRAMA HEC-1 ZA HIDROLOŠKO
MODELIRANJE
Program HEC-1 je eden najstarejših in
najbolj znanih programov za simulacijo
površinskega odtoka. Razvili so ga v ZDA za
vojaške potrebe v Hidrološkem Inženirskem
Centru v Kaliforniji leta 1967. Leta 1984 so
razvili razli čico za osebni ra čunalnik in jo do
danes ve čkrat izpopolnili (Dodson &
Associates, 1995).
Ra čunalniški program HEC- 1  temelji na
matemati čnih odnosih, s katerimi predstavimo
posamezne meteorološke pojave ter hidrološke
in hidravli čne procese (Brilly, 1993).
Omogo ča transformacijo padavin v časovni
potek odtoka oziroma hidrogram. Strukturo
modela dobimo tako, da povodje razdelimo na
čim bolj homogena podpovodja, na katerih
izvajamo ra čunske operacije. HEC- 1 omogo ča
tri temeljne operacije:
1. S pomo čjo podatkov o padavinah in
infiltraciji ter enotnega hidrograma,
izra čuna hidrogram površinskega odtoka za
posamezno podpovodje.
2. Transformira podani hidrogram po re čni
strugi dolvodno ali skozi akumulacijo.
3. Sešteva hidrograme razli čnih podpovodij.
S pomo čjo omenjenih treh operacij
(izra čun, propagacija, seštevanje) je mogo če
modelirati tudi izredno kompleksna povodja.
Vsekakor pa mora biti vrstni red operacij
pravilno zastavljen, da ne pride do uporabe
napa čnih podatkov. Vrstni red operacij se
dolo ča samo s strukturo vhodnih podatkov.
2.3 EKSPERIMENTALNO PORE ČJE
SO ČE
Pore čje So če je po šifrantu padavinskih
obmo čij R Slovenije padavinsko obmo čje
prvega reda s šifro šest. Na drugi ravni je
celotno pore čje razdeljeno na štiri padavinska
obmo čja, na tretji ravni na 28, na četrti pa na
91 padavinskih obmo čij. Glede na
razpoložljive podatke je za hidrološki model
najprimernejša razdelitev na tretji ravni (slika
2). Iz ra čunske sheme v preglednici 1 je
2.2 BASIS OF THE COMPUTER
PROGRAM HEC-1 FOR
HYDROLOGICAL MODELLING
The HEC-1 computer program is one of the
most widely accepted methods for surface
runoff simulation. It was developed for
military use in the Hydrologic Engineering
Center in California, USA in 1967. In 1984, a
version of the program for the Personal
Computer was developed and improved
several times till today (Dodson & Associates,
1995).
The HEC-1 computer program is based on
mathematical relationships, which are intended
to represent individual meteorological,
hydrological and hydraulic processes (Brilly,
1993). It enables the transformation of the
precipitation into a basin runoff hydrograph.
With dividing the watershed into as
homogeneous sub-areas as possible we get the
structure of the model. HEC-1 model performs
three basic types of hydrograph operations:
1. By using precipitation information,
infiltration losses, and unit hydrograph
HEC-1 computes a runoff hydrograph for
each sub-basin.
2. Routes a given hydrograph through a
stream reach or reservoir.
3. Combines two or more hydrographs.
Even with only these three basic operations,
HEC-1 can model extremely complex
watersheds. However, the operations must be
performed in the correct sequence in order to
provide the intended results. The seqeunce of
computations is controlled only by the
organisation of the input data.
2.3 THE SO ČA RIVER EXPERIMENTAL
WATERSHED
 The So ča river watershed is one of the six
watersheds on the first level of the watershed
coding system of the Republic of Slovenia.
The whole watershed is divided on four sub-
watersheds on the second level, on 28 on the
third level and on 91 sub-watersheds on the
fourth level. The most appropriate for
hydrological model is the third level regarding
available data (Figure 2). As can be seen from

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
98
razvidno, da se šifrant popolnoma ujema z
vhodno strukturo modela. Sistem šifriranja
padavinskih obmo čij R Slovenije torej
omogo ča direkten vnos strukture v hidrološke
modele.
Prikaz strukture modela povodja So če je
podan na sliki 3, ra čunska shema pa v
preglednici 1.
2.4 HIDROLOŠKI MODEL
REKE SO ČE
Na podlagi ra čunske sheme (preglednica 1)
je bila izdelana vhodna datoteka hidrološkega
modela So če za program ProHEC- 1.
Modeliran je bil dogodek za november 1992,
ki je bil že predhodno modeliran in umerjen
(Šraj, 1995) in je dal zadovoljive rezultate.
Glavni vhodni podatek za izra čun odtoka so
padavine. Model predpostavlja enakomerno
razporeditev padavin znotraj padavinskega
obmo čja. Ob tem je velika težava v tem, da so
padavine na povodju So če zelo lokalnega
zna čaja. Težave pri modeliranju so nastale
predvsem zaradi premajhnega števila podatkov
in njihove nepopolnosti. Na povodju So če so
sicer štiri ombrografske postaje v Sloveniji
(Bovec, Knežke Ravne, Lokve in Podkraj) in
tri v Italiji (Capriva, Gradisca di Isonzo,
Fossalon do Grado), ki dajejo urne podatke o
padavinah, vendar so bili za november 1992
uporabni le podatki s treh postaj: Lokve,
Podkraj in Capriva. Po celotnem padavinskem
obmo čju So če pa je enakomerno razporejenih
tudi 50 ombrometrskih postaj (slika 4), ki
dajejo dnevne podatke o padavinah. S
pomo čjo teh podatkov so bile za vsako
padavinsko obmo čje posebej izra čunane
povpre čne dnevne padavine. Padavinska
simulacija na posameznih obmo čjih pa je bila
simulirana tako, da so bile dnevne koli čine
padavin linearno reducirane po padavinskem
vzorcu najbljižjega ombrografa. Tu so verjetno
nastale manjše ali ve čje napake, saj je bil
najbližji ombrograf v časih precej oddaljen ali
pa na popolnoma druga čni nadmorski višini.
the sequence of computations in Table 1, the
coding system completely tallies with the
model-input structure. Therefore the coding
system of the Republic of Slovenia enables
direct input in the hydrological models.
The model input structure for the So ča
watershed is in the Figure 3 and the sequence
of computations in Table 1.
2.4 THE SO ČA RIVER
HYDROLOGICAL MODEL
The ProHEC- 1 input file for the So ča
hydrological model was made based on the
sequence of computations in Table 1. The
event for november 1992 was modelled. The
same one was modelled and moderated before
(Šraj, 1995) and it was given satisfactory
results.
Precipitation is the main input datum for
runoff computation. Evenly precipitation
distribution was adopted inside each
watershed. The fact that the precipitation in the
So ča watershed has a very local character
caused a large problem, because of
insufficiency of the data. In the So ča river
watershed there are four automatic rainfall
gauging stations in Slovenia (Bovec, Knežke
Ravne, Lokve and Podkraj) and three in Italy
(Capriva, Gradisca di Isonzo, Fossalon do
Grado), which are giving hourly data, but for
november 1992 only data from three stations:
Lokve, Podkraj and Capriva were applicable.
There are also 50 rainfall-gauging stations
with daily data, regularly arranged over the
watershed (Figure 4). An average daily
precipitation was calculated for each
watershed with those data. Hourly
precipitation simulation of each watershed was
then linearly reduced upon the nearest station
with daily data.  Here probably some smaller
or larger mistakes occurred, because the
nearest station with the hourly data was
sometimes rather faraway or on completely
different sea level.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
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Slika 2. Šifrant padavinskih obmo čij So če.
Figure 2. Watershed coding system of the So ča River.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
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Slika 3. Struktura hidrološkega modela So če.
Figure 3. The structure of the So ča river hydrological model.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
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Preglednica 1. Ra čunska shema pore čja So če.
KO-
RAK
ŠT. NA
KUPU
OPERACIJA RA ČUNSKA SHEMA PORE ČJA SO ČE
11 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 1 – Trentarska
So ča (611)
22 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 2 – Koritnica
(612)
3 1 seštevanje sešteje dva hidrograma iz korakov 1 in 2 v soto čju So če in Koritnice
4 1 propagacija propagira val iz koraka 3 do soto čja So če in U čje
52 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 3 – Bovška So ča
(613)
63 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 4 – U čja (614)
7 1 seštevanje sešteje tri hidrograme iz korakov 4, 5 in 6 v soto čju So če in U čje
8 1 propagacija propagira val iz koraka 7 do soto čja So če in Tolminke
92 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 5 – Tolminska
So ča (615)
10 3 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 6 – Tolminka
(616)
11 1 seštevanje sešteje tri hidrograme iz korakov 8, 9 in 10 v soto čju So če in Tolminke
12 1 propagacija propagira val iz koraka 11 do soto čja So če in Idrijce
13 2 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 7 – So ča-Modrej
(617)
14 1 seštevanje sešteje dva hidrograma iz korakov 12 in 13 v soto čju So če in Idrijce
15 2 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 8 – Idrijska
Idrijca (621)
16 3 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 9 – Kanomljica
(622)
17 2 seštevanje sešteje dva hidrograma iz korakov 15 in 16 v soto čju Idrijce in Kanomljice
18 2 propagacija propagira val iz koraka 17 do soto čja Idrijce in Cerknice
19 3 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 10 – Masorska
Idrijca (623)
20 4 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 11 – Cerknica
(624)
21 2 seštevanje sešteje tri hidrograme iz korakov 18, 19 in 20 v soto čju Idrijce in Cerknice
22 2 propagacija propagira val iz koraka 2 1 do soto čja Idrijce in Trebuš čice
23 3 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 12 – Stopniška
Idrijca (625)
.
.
.
.
.
.
.
.
.
.
.
.
50 3 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 24 – Dobravska
Vipava (645)
51 4 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 25 – Branica
(646)
52 2 seštevanje sešteje tri hidrograme iz korakov 49, 50 in 5 1 v soto čju Vipave in Branice
53 2 propagacija propagira val iz koraka 52 do soto čja Vipave in Lijaka
54 3 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 26 – Prvaška
Vipava (647)
55 4 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 27 – Lijak (648)
56 2 seštevanje sešteje tri hidrograme iz korakov 53, 54 in 55 v soto čju Vipave in Lijaka
57 2 propagacija propagira val iz koraka 56 do soto čja So če in Vipave
58 3 izra čun izra čuna hidrogram površinskega odtoka s padavinskega obmo čja 28 – Mirenska
Vipava (649)
59 1 seštevanje sešteje tri hidrograme iz korakov 4 1, 57 in 58 v soto čju So če in Vipave

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
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Table 1. The sequence of computations for the So ča watershed.
STEP
NO. ON
THE
STACK
OPERA-
TION
SEQUENCE OF COMPUTATIONS FOR THE SO ČA WATERSHED
1 1 compute compute runoff hydrograph from watershed 1 – Trentarska So ča (611)
2 2 compute compute runoff hydrograph from watershed 2 – Koritnica (612)
31c o m b i n e combine two hydrographs from steps 1 and 2 in the confluence of the So ča and
Koritnica streams
4 1 route route hydrograph from step 3 to the confluence of the So ča and U čja streams
5 2 compute compute runoff hydrograph from watershed 3 – Bovška So ča (613)
6 3 compute compute runoff hydrograph from watershed 4 – U čja (614)
71c o m b i n e combine three hydrographs from steps 4, 5 and 6 in the confluence of the So ča and
U čja streams
8 1 route route hydrograph from step 7 to the confluence of the So ča and Tolminka streams
9 2 compute compute runoff hydrograph from watershed 5 – Tolminska So ča (615)
10 3 compute compute runoff hydrograph from watershed 6 – Tolminka (616)
11 1 combine combine three hydrographs from steps 8, 9 and 10 in the confluence of the So ča
and Tolminka streams
12 1 route route hydrograph from step 11 to the confluence of the So ča and Idrijca streams
13 2 compute compute runoff hydrograph from watershed 7 – So ča-Modrej (617)
14 1 combine combine two hydrographs from steps 12 in 13 in the confluence of the So ča and
Idrijca streams
15 2 compute compute runoff hydrograph from watershed 8 – Idrijska Idrijca (621)
16 3 compute compute runoff hydrograph from watershed 9 – Kanomljica (622)
17 2 combine combine two hydrographs from steps 15 and 16 in the confluence of the Idrijca in
Kanomljica streams
18 2 route route hydrograph from step 17 to the confluence of the Idrijca and Cerknica streams
19 3 compute compute runoff hydrograph from watershed 10 – Masorska Idrijca (623)
20 4 compute compute runoff hydrograph from watershed 11 – Cerknica (624)
21 2 combine combine three hydrographs from steps 18, 19 in 20 in the confluence of the Idrijca
and Cerknica streams
22 2 route route hydrograph from step 2 1 to the confluence of the Idrijca ans Trebuš čica
streams
23 3 compute compute runoff hydrograph from watershed 12 – Stopniška Idrijca (625)
.
.
.
.
.
.
.
.
.
.
.
.
50 3 compute compute runoff hydrograph from watershed 24 – Dobravska Vipava (645)
51 4 compute compute runoff hydrograph from watershed 25 – Branica (646)
52 2 combine combine three hydrographs from steps 49, 50 in 51 in the confluence of the Vipava
and Branica streams
53 2 route route hydrograph from step 52 to the confluence of the Vipava and Lijak streams
54 3 compute compute runoff hydrograph from watershed 26 – Prvaška Vipava (647)
55 4 compute compute runoff hydrograph from watershed 27 – Lijak (648)
56 2 combine combine three hydrographs from steps 53, 54 in 55 in the confluence of the Vipava
and Lijak streams
57 2 route route hydrograph from step 56 to the confluence of the So ča and Vipava streams
58 3 compute compute runoff hydrograph from watershed 28 – Mirenska Vipava (649)
59 1 combine combine three hydrographs from steps 4 1, 57 in 58 in the confluence of the So ča
and Vipava streams

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
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Slika 4. Razporeditev padavinskih in limnigrafskih  postaj na padavinskem obmo čju So če.
Figure 4. Locations of the rainfall and water level gauging stations in the So ča watershed.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
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Lastnosti padavinskih obmo čij so dolo čene
na podlagi hidrografskih, geometrijskih,
geoloških in pedoloških kriterijev (Šraj, 1995).
Geometrijske lastnosti padavinskih obmo čij
(preglednica 2) so bile dolo čene s pomo čjo
programa AutoCAD Map na podlagi
digitaliziranih topografskih kart v merilu
1:25000. Hidrografski in geološki kriteriji
(preglednica 3) pa so bili dolo čeni s pomo čjo
karte talnih zna čilnosti in karte hidrogeologije,
ki sta bili podigitalizirani v merilu 1:250 000.
Vsako padavinsko obmo čje je vezano na svoj
enotni hidrogram, ki ni odvisen od naliva.
HEC- 1 omogo ča sintetiziranje enotnega
hidrograma po treh metodah. Najboljše
rezultate je dala SCS metoda. Pravilna oblika
enotnega hidrograma je poleg pravilne
padavinske situacije najpomembnejša pri
analizi površinskega odtoka.
Hidrološki model je bil umerjen za štiri
dogodke s pomo čjo merjenih hidrogramov na
devetih postajah vzdolž So če in njenih
pritokov (Šraj, 1995). Pri merjenih
hidrogramih je bil dolo čen delež baznega
odtoka in odštet od celotne vrednosti pretoka.
Problem predstavlja položaj limnigrafov, ki se
vedno ne ujema z mejami padavinskih obmo čij
(slika 4) in je umerjanje lahko samo približno.
Model je bil umerjen tako, da odstopanja v
volumnih odtoka niso bila ve čja od 10% in da
so se konice merjenih in izra čunanih
hidrogramov čim bolje ujemale, tako po višini
kot po času (slika 5, preglednica 4).
Model je dal, glede na pomankljive
padavinske podatke, dobre rezultate. Razlike v
volumnih poplavnih valov so minimalne.
Konice so se časovno dobro ujele. Malo slabši
so rezultati na padavinskih obmo čjih Ba če in
Vipave. Kot je razvidno iz rezultatov, ve čji del
pretoka prispeva padavinsko obmo čje Idrijce.
 Characteristics of the watersheds were
defined, based on hydrographic, geometric,
geological and pedological properties (Šraj,
1995). Geometric characteristics of the
watersheds (Table 2) were defined with
computer program AutoCAD Map, based on
digitised topographic maps 1:25 000. Maps of
soil characteristics and hydrogeology digitised
in scale 1:250 000 have been the base for
defining hydrographic and geological
characteristics (Table 3). Each watershed has
its own unit hydrograph, independent from the
storm. HEC-1 enables a syntetization of the
unit hydrograph with three methods. SCS
method has given the best results in our
example. The right shape of the unit
hydrograph is beside the right precipitation
situation the most important thing by the
runoff analyses.
Hydrological model was moderated for four
events with measured hydrographs on nine
stations along the So ča river and its tributaries
(Šraj, 1995). The base runoff was defined from
measured hydrographs and subtracted from the
whole one.  There was another problem
because the location of the gauging stations
wasn’t always in accordance with the
watershed boundaries (Figure 4), so the
moderating has been approximate. The model
was moderated thus that deviation of the
volumes wasn’t exceeded 10% and that the
peaks of the measured and calculated
hydrographs overlaid the best by high and time
(Figure 5, Table 4).
Model has given good results according to
insufficiency of the data. The differences in
volumes of hydrographs have been minimal
and peaks have been good time corresponded.
Only the results for Ba ča and Vipava
watersheds were a little bit worse. The major
part of the runoff was contributed by Idrijca
watershed, as can be seen from the results.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
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Preglednica 2. Geometrijski podatki za posamezna padavinska obmo čja So če (Šraj, 2000).
Table 2. Geometric data for individual So ča sub-watersheds (Šraj, 2000).
Šifra /
Code
Št. HEC/
HEC No.
Površina /
Area
Dolžina /
Length
Težiš če /
Centre of
gravity
Padec /
Slope
A [km
2
] L [km] Lca [km] I [%]
611 1 178,6 21,5 10,8 1,8
612 2 86,7 14,0 7,6 1,8
613 3 75,8 8,5 4,2 0,7
614* 4 51,0 13,8 6,7 1,8
615 5 176,9 28,4 15,1 1,0
616 6 63,6 11,0 8,0 0,5
617 7 13,0 3,6 2,5 0,4
621 8 160,8 22,2 9,8 0,5
622 9 45,4 11,7 5,2 0,65
623 10 42,2 11,8 5,7 0,5
624 11 45,2 13,2 6,9 0,5
625 12 70,3 13,6 8,5 0,5
626 13 101,5 14,4 6,5 0,2
627 14 30,8 8,5 4,2 0,55
628 15 144,5 21,8 10,3 0,55
629 16 3,1 2,3 1,4 0,55
631 17 149,1 22,6 14,1 0,3
633 18 176,3 8,9 1,8 0,2
635* 19 64,2 12,5 8,5 0,08
641 20 131,3 1,5 1,5 0,2
642 21 50,4 12,6 6,9 0,2
643 22 16,8 4,9 3,2 0,2
644 23 88,5 9,3 5,0 0,2
645 24 70,4 14,0 5,8 0,15
646 25 80,3 29,6 13,6 0,2
647 26 23,8 10,5 4,4 0,09
648 27 57,9 9,0 6,2 0,1
649* 28 46,8 17,0 7,9 0,09
* padavinsko obmo čje sega tudi izven meja Slovenije
* watershed outside of the Slovenia national border

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
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Preglednica 3. Parametri posameznih padavinskih obmo čij So če
za dogodek November 1992 (Šraj, 2000).
Table 3. Model parameters for individual So ča sub-watersheds
for november 1992 event (Šraj, 2000).
Padavinsko
obmo čje /
Watershed
T
p 
[h] IA [mm] CN K [h] X
1 7 15 29
2 6 35 29
3 6 35 29 0,8 0,15
4 5 21 48
5 6 24 30 2,6 0,15
6 6 21 40
7 5 25 36 0,3 0,3
8 4 15 55
9 2 20 68
10 4 9 60 1,1 0,1
11 5 10 75
12 7 25 40 1,3 0,09
13 6 29 68
14 6 25 40 0,8 015
15 3 10 37
16 3 12 70 0,2 0,5
17 5 8 80 2,1 0,05
18 8 25 40 0,8 0,15
19 9 22 50 1,7 0,06
20 3 10 40
21 7 10 65
22 3 15 70 0,7 0,15
23 8 15 40
24 7 10 75 1,9 0,06
25 8 10 70
26 7 7 70 1,4 0,08
27 5 2 70
28 5 2 60 2,4 0,05
Tp čas zakasnitve povodja v urah / watershed lag value in hours
IA za četne izgube na nezasneženi površini v mm / initial rainfall abstraction in mm
for snow free-ground
CN SCS koeficient za dolo čanje padavinskih izgub / SCS curve number for rainfall
losses on snow-free ground
K Muskingumov koeficient propagacije v urah / Muskingum coefficient for routing
X Muskingumov utežni koeficient propagacije / Muskingum weighted coefficient for
routing

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
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Slika 5. Primerjava merjenih (tanka črta) in izra čunanih (poudarjema črta)
hidrogramov (Šraj, 2000).
Figure 5. Comparation of the measured (thin line) and calculated (bold line)
hydrographs (Šraj, 2000).

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
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Preglednica 4. Analiza rezultatov hidrološkega modela So če (Šraj, 2000).
Table 4. Analyses of the So ča hydrological model results (Šraj, 2000).
model november 92
VOLUMEN /
VOLUME
razlika /
difference
Qmax
razlika /
difference
Tp
razlika /
difference
[10
6
 m
3
] [%] [m
3
/s] [%] [h] [h]
KRŠOVEC 1,2 24,10 0,5
ra čunani / computed 15,98 182 28,5
merjeni / measured 16,18 146 28
LOG ČEZSOŠKI 6,8 38,00 1
ra čunani / computed 27,44 350 29
merjeni / measured 25,70 254 28
ŽAGA 0,0 3,50 5,5
ra čunani / computed 4,98 79 25,5
merjeni 4,98 77 20
KOBARID 3,0 23,20 5,5
ra čunani / computed 43,75 528 30,5
merjeni / measured 42,48 428 25
HOTEŠ ČEK 8,6 25,50 4,5
ra čunani / computed 68,81 929 28,5
merjeni / measured 63,33 740 24
BA ČA 0,7 42,90 8,5
ra čunani / computed 12,69 201 30,5
merjeni / measured 12,77 141 22
SOLKAN 3,6 18,80 5
ra čunani / computed 174,90 2066 32
merjeni / measured 168,78 1740 27
DORNBERK 3,2 42,20 5,5
ra čunani / computed 25,14 247 36,5
merjeni / measured 25,97 174 42
MIREN 8,8 19,90 3
ra čunani / computed 36,97 322 38
merjeni / measured 40,52 268 41

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
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2.5 AVTOMATSKA IZDELAVA
VHODNE STRUKTURE
HIDROLOŠKEGA MODELA S
POMO ČJO ŠIFRANTA
Ker se šifrant popolnoma ujema z vhodnimi
strukturami hidroloških modelov in je
prilagojen ra čunalniški obdelavi, ga lahko s
pomo čjo GIS-ov uporabimo tudi za
avtomatsko izdelavo vhodne strukture
hidrološkega modela.
V bazi šifer padavinskih obmo čij poiš čemo
na želeni ravni vse šifre oziroma padavinska
obmo čja, ki sestavljajo pore čje našega
hidrološkega modela (slika 6). To storimo
tako, da definiramo najmanjšo in najve čjo
iskano šifro. Pri tem uporabimo tekstovni
na čin razvrš čanja, ki nam pravilno razvrsti
šifre, tudi če kombiniramo ve č ravni hkrati.
Razvrš čenim šifram avtomatsko dodelimo
števila od ena naprej in jih preko GIS-ov
(Autodesk, 1998) vnesemo še v grafi čni del
baze. Tako s pomo čjo šifranta padavinskih
obmo čij in GIS-ov avtomatsko izdelamo
vhodno strukturo hidrološkega modela.
2.5 THE APPLICATION OF THE
WATERSHED CODING SYSTEM FOR
AUTOMATIC MAKING THE
HYDROLOGICAL MODEL INPUT
STRUCTURE
Because the coding system completely
tallies with the model input structure and it is
computer adapted, it can be used for automatic
construction of the hydrological model input
structure with GIS.
All codes composed our hydrological
model watershed on the desired level had been
searched in the watershed’s code database
(Figure 6). We do that with defining the
maximum and minimum code using text type
of arrangement. So we can get the correct
arrangement also by combining more levels at
the same time. Numbers from one up were
automatically assigned to arrange codes and
entered also in the graphical part of the base
by GIS (Autodesk, 1998). So hydrological
model input structure was made automatically
with help of the watershed coding system and
GIS.
3. DRUGI PRIMERI UPORABE
ŠIFRANTA
Ker je sistem šifriranja prilagojen
ra čunalniški obdelavi, je njegova uporabnost v
GIS-ih (slika 7) zelo velika. Šifrant lahko
prekrivamo z drugimi digitalnimi bazami, npr.
s karto pokrovnosti, s karto hidrogeoloških
zna čilnosti, z digitalnim modelom reliefa itd.,
delamo statisti čne analize, izdelujemo
poljubne tematske karte (slika 8) itd. Na
podlagi šifranta se dolo čijo tudi
administrativne meje obmo čnih vodnih
skupnosti.
3. OTHER EXAMPLES OF THE
CODING SYSTEM APPLICATION
Because the coding system is computer
adapted its applicability in GIS (Figure 7) is
great. The coding system could be overlaid
with other digital maps such as map of land
cover, hydrogeological map, digital model of
relief and so on. We can do statistical analyses,
make optional thematic maps (Figure 8) etc.
Administrative boundaries of regional water
communities could also be defined on base of
the coding system.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
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Slika 6. Avtomatska izdelava vhodne strukture hidrološkega modela So če v GIS-ih.
Figure 6. Automatic making of the hydrological model input structure with GIS.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
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Slika 7. Šifrant padavinskih obmo čij Republike Slovenije v GIS-ih.
Figure 7. The coding system of the Republic of Slovenia in GIS.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
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Slika 8. Prikaz glavnih padavinskih obmo čij R Slovenije s šifrantom na četrti ravni.
Figure 8. Review of the main watersheds of the Republic of Slovenia with the coding system on the fourth level.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
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Slika  9. Padavinsko obmo čje So če, prekrito z mrežo modela ALADIN-SI.
Figure 9. The So ča river watershed overlaid with the ALADIN-SI model net.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
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Še en primer uporabe šifranta padavinskih
obmo čij: padavinska obmo čja, prekrita z
mrežo modela ALADIN-SI, ki nam daje
napoved padavin za 48 ur vnaprej.
Napovedane padavine, ki pripadajo
posameznemu kvadratu mreže, se
procentualno porazdelijo na posamezno
padavinsko obmo čje. Tako dobimo vhodne
podatke za hidrološke modele pri
napovedovanju poplavnih valov (slika 9)
(Brilly in ostali, 2000).
Naslednji korak je dolo čitev karakteristik
posameznih padavinskih obmo čij in njihova
vklju čitev v GIS. Tak sistem je bistvenega
pomena za sodoben razvoj vodnega
gospodarstva, u činkovito zaš čito okolja,
napovedovanje poplav itd.
One another example of the application of
the coding system: watersheds overlaid with
ALADIN-SI model net. The model
ALDADIN-SI gives us precipitation forecast
for 48 hours beforehand. Forecasted
precipitation within individual square of the
model net had been distributed to the
individual watershed by percentage. Thus we
get input data for hydrological models by
flood forecasting (Figure 9) (Brilly et al.,
2000).
The next step is defining the characteristics
of the individual watersheds and their
incorporating in GIS. Such as system is
significant for contemporary development of
the water management, effectively
environment protection, flood forecasting etc.
4. ZAKLJU ČKI
Pomen šifranta padavinskih obmo čij R
Slovenije je izjemen, saj si je tudi Evropska
agencija za okolje za eno od prvih nalog
zadala izdelavo katastra in šifranta vodotokov
držav Evropske unije (Morris, 1994).
Sistem šifriranja padavinskih obmo čij je
strukturiran tako, da omogo ča preprosto
programiranje in neposreden vnos v hidrološke
modele. Tudi kombiniranje razli čnih ravni
šifranta se popolnoma ujema z vhodno
strukturo modela.
Šifrant padavinskih obmo čij predstavlja
temelj sodobnega informacijskega sistema za
potrebe varstva okolja, urejanje podatkov o
okolju, njihovo obdelavo in statisti čno analizo,
za izdelavo vodnogospodarskih na črtov,
programov, strokovnih podlag, katastra
vodnogospodarskih objektov in ostalih
prostorsko dolo čenih podatkov.
4. CONCLUSIONS
Making the river coding system of the
European Union was one of the first tasks of
European Environmental Agency also (Morris,
1994). The coding system of the Republic of
Slovenia is therefore significant.
The structure of the watershed coding
system enables simple computer programming
and direct hydrological modelling.  Also
combining different levels of the coding
system completely tallies with model input
structure.
The coding system of the Republic of
Slovenia represents the basis of contemporary
information system for environment
protection, environmental data management,
data handling and statistical analyses, water
management plans and programmes, cadastre
of hydraulic structures and other space related
data.

Šraj, M.: Uporaba šifranta padavinskih obmo čij vodotokov Republike Slovenije za pripravo hidroloških modelov -
The Application of the Watershed Coding System of the Republic of Slovenia for Hydrological Modelling
© Acta hydrotechnica 19/31 (2001), 95-115, Ljubljana
115
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Naslov avtorja - Author's Address
mag. Mojca ŠRAJ
Univerza v Ljubljani – University of Ljubljana
Fakulteta za gradbeništvo in geodezijo – Faculty of Civil and Geodetic Engineering
Katedra za splošno hidrotehniko – Chair of Hydrology and Hydraulic Engineering
Jamova 2, 1000 Ljubljana, Slovenia
E-mail: msraj@fgg.uni-lj.si