Abstract Groundwater regime in Bulgaria is influenced by climate variability. The impact is evident especially for karst water. A time series analysis of spring discharge for selected karst basins was performed. The impact of the 1982–1994 drought period on groundwater regime was detected. For springs that drain open and mountainous karst, the impact of climate variability is similar to that on surface waters. In fact, the difference in degree of influence of the drought period is related to the specific geological structure of the karst massifs and recharge conditions. Furthermore, the porous waters are characterized by a weaker reaction to such an effect. In general, groundwater use during the 1982–1994 drought period was impacted by climate variability due to limited resource availability.

Abstract Karst aquifers are some of the most important and well-used sources of water worldwide. The tapping of karst waters for use as drinking water has been important in the historical and economic development of many karst regions. Recent studies have found that karstified rocks and aquifer systems cover c. 15% of the Earth’s ice-free land. The greatest area of karst outcrops (>1 × 10 6 km 2 ) is in Russia, the USA, China and Canada. In the Mediterranean basin, groundwater is generally more abundant in karst than in other aquifers and has been extensively exploited. Karst groundwater is also widely used in the Middle East, China, North America, and northern and eastern Africa and is of crucial importance for the sustainable development of tourism and the economy. Karst aquifers currently supply c. 10% of the global population with drinking water and, in some zones, they are the only water resource available. However, the share of karst aquifers in the global supply of water will decrease with the predicted increase in population, concentrated in urban areas, and improvements in treatment technologies for water from other sources.

Abstract The development of past civilizations and the foundation of towns have always been strictly linked to the availability of water. In this paper, we analyse more than 2000 years of evolution of Yperia Krini spring in Thessaly (Greece), by investigating possible variations in terms of water discharge. In particular, the integrated analysis of geological, hydrological, hydrogeological and historical data relative to the spring, called by Sophocles a ‘gift of God and source of life’, allowed us to understand the role played by both climatic variations and anthropogenic activities on the behaviour and the characteristics of the local underground water resources within the Thessalian plain.

Abstract About two thirds of Jamaica is karst landscape, and karstic hazards affect much of the country and about half of the population, mostly in rural areas. The karst includes extensive areas of dolines and dry valleys, together with poljes and classical tropical tower and cockpit karst. With population and urbanization increases, and as infrastructure is developed, karstic hazards are becoming more prevalent and risks are increasing. One major natural hazard is seasonal drought, which disrupts water supplies, particularly in rural areas where groundwater resources are poorly developed and residents depend on rainwater and springs. Conversely, seasonal flooding, particularly that associated with tropical storms, causes property damage and human death, injury and displacement. Ground surface subsidence and collapse threatens developing infrastructure, dwellings and livestock, but the potential for catastrophic karstic failure of industrial facilities such as dams and retention ponds, including the storage facilities associated with bauxite mining and processing, appears to be relatively limited. Slope failure also occurs, but is not often recognized as a hazard and has not been studied in detail. Human impacts include quarrying, bauxite mining, groundwater abstraction, urbanization, agricultural development and tourism. Groundwater contamination is a serious anthropogenic hazard, particularly associated with the bauxite industry. Less than 10% of the karst area is within protected areas.