Designing of dry detention area along the Mura River in Gabrje, the municipality of Lendava

V magistrski nalogi smo obravnavali vpliv umestitve suhega zadrževalnika ob reki Muri na območju Gaberja v občini Lendava, ki je poplavno zelo ogrožena. V programskem orodju HEC-RAS 5.0.5 smo na obravnavanem območju, ki se nahaja na levem bregu reke Mure na odseku med naselji Kot do naselja Kolonija Petišovci, pripravili 1D model vodotoka znotraj visokovodnih nasipov ter 2D model poplavnih površin na suhi strani levo brežnih visokovodnih nasipov. Modela sta bila združena v kombinirani 1D-2D hidravlični model. Za predvideno območje suhega zadrževalnika smo izdelali volumensko analizo, na podlagi katere je bila pripravljena modelirana geometrija prelivnega objekta, za dotok vode v suhi zadrževalnik. Na območju vtoka v suhi zadrževalnik smo čez visokovodni nasip modelirali povezavo z elementom bočnega preliva. Na podlagi rezultatov hidravličnega modela, smo prikazali postopek dimenzioniranja prelivnega objekta s podslapjem, ter vpliv umestitve suhega zadrževalnika na iztočni hidrogram in znižanje gladine, na celotnem obravnavanem območju. Ugotovili smo, da s suhim zadrževalnikom dosežemo ugoden vpliv na konico visokovodnega vala s povratno dobo sto let ter časom trajanja štirih dni, saj se gladine vode ob visokovodnih nasipih obravnavanega območja znižajo v povprečju za cca. 25 cm, na določenih mestih do cca. 40 cm, pri tem pa se na območje suhega zadrževalnika akumulira 6% celotnega volumna visokovodnega vala (16,78 mio m3), z ojezeritvijo površine 661 ha.In the master\u27s thesis, we studied the influence of locating the dry detention area along the Mura River in the Gaberje area in the municipality of Lendava, which is exposed to high flood risk. In the HEC-RAS 5.0.5 hydraulic software we concentrated on the area positioned next to the left bank of the Mura River on the section between settlements Kot and Kolonija Petišovci. We prepared a 1D model of the river channel within high-water levees and a 2D model of floodplains on the dry side of the left bank levees. The models were joined in a coupled 1D-2D hydraulic model. For the planned dry detention area, a volume analysis was performed and sizing of the lateral structure (weir) was conducted in order to control the inflow of water into the detention area during the floods. In the area of the inflow into the dry detention area, a connection with the lateral structure was modeled over the high-water levees. Based on the results of the hydraulic model, we demonstrated the process of dimensioning the lateral weir with a stilling basin. We analyzed the influence of the dry detention area operation on the outflow hydrograph shape and considered lowering of flood water levels along the studied section. Results of our calculations show that the impact of the dry detention area has a beneficial effect on lowering the peak of a high-water hydrograph with a 100-years return period and a duration of four days, since the water levels along the high-water embankments of the studied area decreased on average by approximately 25 cm, in certain places up to about 40 cm. We estimated that 6% of the total volume of a high-water wave (16.78 million m3) could be accumulated in the dry detention area, the maximum size of the flooded detention area would be 661 ha