Water availability and demand in Sri Lanka show a highly spatial variability and temporal variability. Sri Lankan economy depends on agricultural production. It is important to consider these factors very precisely with inputs from different scientific experts and field observation. Several scientific communities have already reported the importance of different hydrogeological factors, viz., geomorphology, geology, land use/land cover, slope, soil cover, drainage density, surface temperature, etc., controlling groundwater potential of any areas, however, the extent to which they affect it may differ from place and time (Sener et al. This method that has a significant potential to monitor the information about various phenomenon and changes on the earth surface, such as soil type, geomorphology, land use/land cover, elevation, slope, etc., based on spectral reflectance on earth surface is widely accepted (Avtar et al. On the other hand, the integrated use of remote sensing, GIS, and satellite data is time and cost effective means to assess and manage groundwater resources (Adiat et al.
Although best methods to estimate aquifer thickness and preferable location of borehole are groundwater pumping test/drilling test and stratigraphy analysis, they are cost and time intensive as well as often require skilled manpower (Moss and Moss 1990 Fetter 1994 Madan et al. Human activities cause changes in groundwater by change in land use/land cover, soil cover, and reduction in groundwater recharge. The arid and semi-arid areas characterized by short periods of heavy rainfall and prolonged dry periods, the continual replenishment of groundwater storage and its sustainable utilization is indispensable to address the water needs of the community. It is one of the most significant natural resources which support both human needs and economic development. Water is one of the most essential commodities for mankind and the largest available source of fresh water lays underground. The hydrogeomorphological units, such as alluvial plain, low slope area, and land occupied by forest, are prospective zones for groundwater occurrence in the study area. The final map of the area was demarcated by four different zones of groundwater prospects, viz., good (5.32 % of the area), moderate (61.90 % of the area) poor (26.61 % of the area), and very poor (6.17 % of area).
Five different themes of information, such as geomorphology, geology, soil type (extracted from existing topo sheet) slope and land use/land cover (extracted from digital processing of AVNIR satellite data) were integrated with weighted overlay in GIS to generate groundwater potential zonation map of the area. This work strives to generate groundwater potential zonation map using integrated use of remote sensing and geographic information system (GIS) for Killinochi area, Northern Sri Lanka.
The development of a reasonable model for groundwater potential is need for the present time. However, the decreasing trend in the rainfall regime of the dry zones and the increase in population size (temporary inflow) and, hence, the demand for water for irrigation and other livelihood requirements, calls for a sustainable exploitation of the groundwater resources in the region. Dry zone of Killinochi basin in Northern Sri Lanka, which was devastated by civil war for last 25 years, is again being revitalized by human settlement and urbanization in last couple of years. There is now a strong consensus that climate change poses a fundamental challenge to the well-being of all countries, with potential of being the harshest on countries already suffering from water scarcity.
Groundwater is a vital natural capital for the consistent and economic provision of potable water supply for both rural and urban environments.