Hydrogeological relationships on the north-eastern edge of the Zagreb aquifer : master’s thesis

Zadatak ovog diplomskog rada bio je detaljnije opisati hidrogeološke odnose na sjeveroistočnom rubu zagrebačkog vodonosnika. Na istraživanom području izvedena su četiri nova zdenca: IW-1, IW-2, PW-1 i PW-2. Krajem 2014. te početkom 2015. godine izvedena su pokusna crpljenja na spomenuta četiri zdenca. Na temelju rezultata pokusnih crpljenja određeni su hidrogeološki parametri vodonosnika i hidraulički parametri zdenaca. Za istraživano područje utvrđene su sljedeće prosječne vrijednosti hidrogeoloških parametara: transmisivnost T = 3,62x10-2 m2/s, koeficijent uskladištenja S = 3,71x10-5 i hidraulička vodljivost K = 4,47x10-3 m/s. Jednadžbe sniženja u zdencima glase: s = 20,504 Q + 93,501 Q2 (IW-2); s = 25,915 Q + 69,289 Q2 (IW-1); s = 18,803 Q + 462,74 Q2 (PW-1); s = 20,657 Q + 112,1 Q2 (PW-2). Kemijske analize uzoraka vode iz svih zdenaca ukazale su na povišene koncentracije željeza, odnosno u svim uzorcima koncentracija je premašila maksimalnu dozvoljenu koncentraciju (MDK) za pitku vodu. Pretpostavlja se da se radi o prirodno povišenom sadržaju željeza, svojstvenom vodonosnicima taloženim u reduktivnim uvjetima. Visoke koncentracije željeza te smještaj zdenaca na istraživanom području ukazuju da je zahvaćen drugi vodonosni sloj građen od dominantno jezersko–barskih naslaga.Abstract: The aim of this thesis was to provide a detailed description of the hydrogeological relationships on the north-eastern edge of the Zagreb aquifer. Four new wells were drilled in the investigated area: IW-1, IW-2, PW-1 and PW-2. Pumping tests on these four wells were performed at the end of 2014 and the beginning of 2015. Based on the results of the pumping tests, the hydrogeological parameters of the aquifer and the hydraulic parameters of wells were determined. The following average values of hydrogeological parameters were defined for the investigated area: transmissivity T = 3,62x10-2 m2/s, storage coefficient S = 3,71x10-5 and hydraulic conductivity K = 4,47x10-3 m/s. Drawdown equations in the wells are as follows: s = 20,504 Q + 93,501 Q2 (IW-2); s = 25,915 Q + 69,289 Q2 (IW-1); s = 18,803 Q + 462,74 Q2 (PW-1); s = 20,657 Q + 112,1 Q2 (PW-2). The chemical analyses of water samples from all wells have shown the elevated iron concentration, i.e. iron concentration exceeds the maximum permissible concentration (MPC) for drinking water in all samples. It is assumed that the elevated iron content is due to natural causes, which is typical for sediments deposited in reductive conditions. High iron concentration and the location of the wells in the investigated area indicate that these wells were drilled in the second aquifer, with the predominantly lacustrine–marshy deposits