The Effect of Climate Change on the Discharge and Characteristics of Karst Springs in Kermanshah Province

Mountainous regions of Folded Zagros (karst basin of Alvand) and High Zagros in Kermanshah have various karst aquifers which are discharged by karst springs. The aforesaid aquifers are considered as the main source providing drinking water of human communities, the ecosystems of the basins, and basic current of Alvand and Qaresou Rivers. Moreover, they have a vital role in the sustainability, continuity, and formation of urbanization in the studying area. The present study aims to investigate the effects of climatic changes on quantitative features and not only the present but the future discharge diet of the springs. In the present research, hydrodynamic method (Mangin method and time series) and hydro-chemical method (graphic method, ionic and saturation ratios) are used to evaluate karst system feature of the index aquifers. The findings show that karst geomorphology in High Zagros is more developed than the zone of Folded Zagros. Besides, the findings from hydrodynamic and hydro-chemical methods of the aquifers prove different development of karst systems and different hydrodynamic and hydro-chemical behavior of the aquifers. Comparing the findings from hydrodynamic and hydro-chemical methods and surface karst developments, it turns out that karst geomorphology has a firm effect on qualitative and quantitative features of the studying aquifers. Furthermore, studying the precipitation process of the region during the last decades reveals a decreasing process of precipitation and the occurrence of numerous droughts during last two decades leading to a decreasing process of discharge process of the springs. Predicting climatic changes of the regions in future indicates that there is a decreasing process of precipitation and changes affecting discharge diet of karst springs. Moreover, predicting annual discharge of the studying springs during next decade shows a considerable decrease of the spring discharge. The output of climatic models demonstrates that not only the discharge decrease, but also the periodic movement of over-hydration to cold season and the decrease of base discharge in hot period of year are regarded as the other climatic factors on the studying karst springs. Moreover, the difference of surface karst morphology and the rate of development of karst system lead to different hydrodynamic behavior of aquifers against precipitation fluctuations and climatic changes. Besides, qualitative features of the studying water have a significant relationship with the input water volume entering the aquifer and has no relationship with precipitation fluctuations.
Extended Abstract
1-Introduction
Nowadays, the need for providing water to facilitate human needs and natural ecosystems has increasingly attracted the attention worldwide. Karst regions and springs are of underground water sources which are distinguished from other grounds due to their unique and complex features. Karst water sources are considered as strategic sources. They play an important role in environmental sustainability and providing the needing water of communities worldwide due to the features like suitable quality, easy extraction, and high renewal. They are specially very important in arid and semi-arid regions like Iran, specifically Zagros Regions. Karst aquifer are sensitive to input fluctuation (precipitation) like rate, intensity, type,…regarding the rate of  karst system development. Therefore, climatic changes and following precipitation fluctuations affect the watering diet of karst aquifers. In fact, climatic changes of past two decades has intrigued water crises in Zagros regions and unsustainability of the environment of the region like .. of acorn jungles and erosion in Kermanshah, Ilam and Lorestan. The present study aims to investigate the effects of the changes on karst springs of Kermanshah Province.
2- Materials and Methods
Therefore, a mixture of data and statistical methodologies were used. The data include precipitation data, thermal parameters, relative moisture and the discharge of 11 stations of Ministry of Power and Meteorological Organization during a shared 18-year period, long-term data of network precipitation on GPCC Center during a period from 1986-2014. Moreover, different statistical tests, like self-correlation test, Men Kendall, SPI statistics, were applied to study the climatic changes and their effects on the behavior of karst springs in the region. At first, graphic Men Kendall test was used to find the process and the changes of the selected stations and springs discharge and precipitation. As the next step, using SPI test, the occurred droughts during the period were calculated. As rain gauge stations did not have appropriate and same statistical period, in the present study, the data of Kermanshah stations were used for High Zagros and Sarpol-e-Zahab stations for Folded Zagros. Besides, network data (GPCC) near the springs, during a period from 1986-2014, were also used. Self-correlation method was used to recognize the features of discharge and cyclic changes. At the end, mixing the data, the effect of climate change on the watering of karst spring was analyzed.
3- Results and Discussion
Based on the previous studies about the effect of droughts and climate changes on watering diet of karst springs, there are two general factors on the way of watering diet of the springs are affected. The studied area has faced several droughts, precipitation decrease, snow coefficient decrease, moisture decrease, temperature increase,… from late 70s to early 90s. However, the reflection of the changes in watering diet of the springs in Folded and High Zagros was affected by the amount of karst system development. The influence of water diet and process of folded Zagros springs from climate fluctuation and drought are affected by hydrodynamic, morphometric, the extent features of aquifers and local climate. The influences of watering diet and process of High Zagros springs from climate fluctuations and drought are different according to the kind of karst system and they are mostly effected by hydrodynamic features and local climate. In this zone, the springs of High Zagros zone show more reaction to droughts and short-term changes of precipitation which is mostly due to the development of karst system and low volume of dynamic savings of aquifers. 
5- Conclusion
The findings from self-correlation of the springs show that except for Yavari spring, the discharge of other springs in High Zagros is highly dependent on precipitation. In contrast, except for Marab and Rijab, the other springs of Folded Zagros are less dependent on precipitation. Climatic condition of representative stations reveal that the climate of the region has had considerable changes from 1986-2014 which had an intensive dry condition. In fact, the data from precipitation of the stations and selected network data show precipitation decrease and the increase of continuous and periodic drought in both zones. In contrast, thermal condition has had increasing condition. The most moisture decrease and temperature increase of the region is reported at the end of the 90s. quantitative and qualitative analysis shows considerable changes related to climatic changes, for the watering of the springs during the past two decades has had a decreasing process following negative process of precipitation. Severe droughts and precipitation decrease without temporal delay lead to watering decrease of karst springs of the region. Besides, qualitative features of the water have changed which are affected by the volume of input water to the aquifer; as a matter of fact, it has no significant relationship with precipitation fluctuation.