Thomas Triadi Putranto

Developing a groundwater conservation zone in Jepara groundwater basin

Jepara groundwater basin has an area of about 545 km2. An increase in the number of residents accelerated the need for clean water. One circumstance to meet the needs of clean water is to utilize groundwater. Increasing groundwater utilization can result in damage to groundwater conditions and the environment. Therefore, it is necessary to conserve groundwater. The objective of this research was to prepare utilization and conservation zones and to conduct hydrogeological conditions and groundwater quality research in the area for recommendations of groundwater use. The methods were geological, and hydrogeological mapping included measurement of groundwater levels and groundwater sampling. Groundwater levels were measured via 150 dug wells, six springs and 16 artesian wells. The results determined the type of lithology in the form of tufa units, volcanic breccia, andesite and alluvium. Groundwater levels showed the direction of groundwater flow was from the southeast to the northwest. The pH value of artesian wells ranged between 6.70-9.19. There are four conservation zones in a confined aquifer, i.e. secured, vulnerable, critical and damaged.Jepara groundwater basin has an area of about 545 km2. An increase in the number of residents accelerated the need for clean water. One circumstance to meet the needs of clean water is to utilize groundwater. Increasing groundwater utilization can result in damage to groundwater conditions and the environment. Therefore, it is necessary to conserve groundwater. The objective of this research was to prepare utilization and conservation zones and to conduct hydrogeological conditions and groundwater quality research in the area for recommendations of groundwater use. The methods were geological, and hydrogeological mapping included measurement of groundwater levels and groundwater sampling. Groundwater levels were measured via 150 dug wells, six springs and 16 artesian wells. The results determined the type of lithology in the form of tufa units, volcanic breccia, andesite and alluvium. Groundwater levels showed the direction of groundwater flow was from the southeast to the northwest. The pH value of artes...

Application of Aquifer Vulnerability Index (AVI) method to assess groundwater vulnerability to contamination in Semarang urban area

An approach to assess groundwater to contamination is developing groundwater vulnerability map. Groundwater vulnerability is formulated as an intrinsic relative, the dimensionless property of a groundwater system that depends on its sensitivity to unfavourable human and natural impacts. Thus, to assess groundwater vulnerability to contamination in Semarang urban area is the objective of this research by using Aquifer Vulnerability Index (AVI). This method considered of two parameters related to the unsaturated zone, i.e. thickness (d) of each sedimentary layer in the unsaturated zone and Estimated hydraulic conductivity (K) of these sedimentary layers. There are five levels of groundwater vulnerability by using AVI method, i.e. extremely low, low, moderate/medium, high, and extremely high. The thinner the layer covers the aquifer, and the higher the value of the hydraulic conductivity of sediment layers will be increasingly vulnerable to pollution.