Trend analyses for discharge-recharge of Tacin karstic spring (Kayseri, Turkey)

Abstract

Vast research is conducted around the world in order to determine the effects of climate change on water resources. Determining and preserving the rechanging characteristics of karstic springs has an important place in water resources management studies. In the present study, the variation trends of climate parameters, affecting the discharge trend of the Tacin karstic spring in Kayseri, Turkey and the spring discharge, were analyzed. For this purpose, the monthly mean discharge flow of the karstic spring between the years 1975 and 2017 and the monthly average temperatures and precipitation parameters belonging to the meteorological stations close to the spring (Kayseri, Pınarbaşı, Gemerek and Şarkışla) were adopted. In the trend analyses, the non-parametric Spearman Rho (SR), Mann Kendall (MK) and Şen-Innovative Trend analysis tests (Şen-ITA) were used in addition to the non-linear tests. Accordingly, a reduction was observed in the change trend of the precipitation parameter of Pınarbaşı and Kayseri stations and an increase in the respective measure of the Gemerek and Şarkışla stations while a noticeable decrease took place in the flow discharge of the Tacin karstic spring. The temperature parameter underwent a similar increase in all of the four stations meanwhile. Consequently, the decrease trend in the flow discharges of the Tacin karstic aquifer was inferred to stem from the reduction in the precipitation trend, observed in the southern part of the karstic aquifer.