Delineation of groundwater potential zones in the Comoro watershed, Timor Leste using GIS, remote sensing and analytic hierarchy process (AHP) technique

TLDR

Groundwater is essential for the socio‑economic development of the Comoro watershed in Timor Leste, yet its management has been inadequate. The study aims to delineate groundwater potential zones in the watershed using GIS, remote sensing, and the analytic hierarchy process. Groundwater potential was classified into five zones and validated against recorded bore‑well yield data. The resulting map shows the northwest alluvial plain as very high potential (5.4 % of the watershed), the eastern and foothill areas as high (4.8 %), moderate zones covering 2 %, and the remaining 87.8 % as poor or very poor, with southern and central hilly terrain particularly poor due to steep slopes and low‑permeability conglomerate soils, offering a useful tool for future resource planning.

Abstract

Groundwater plays an important role for socio-economic development of Comoro watershed in Timor Leste. Despite the significance of groundwater for sustainable development, it has not always been properly managed in the watershed. Therefore, this study seeks to identify groundwater potential zones in the Comoro watershed, using geographical information systems and remote sensing and analytic hierarchy process technique. The groundwater potential zones thus obtained were divided into five classes and validated with the recorded bore well yield data. It was found that the alluvial plain in the northwest along the Comoro River has very high groundwater potential zone which covers about 5.4 % (13.5 km2) area of the watershed. The high groundwater potential zone was found in the eastern part and along the foothills and covers about 4.8 % (12 km2) of the area; moderate zone covers about 2.0 % (5 km2) of the area and found in the higher elevation of the alluvial plain. The poor and very poor groundwater potential zone covers about 87.8 % (219.5 km2) of the watershed. The hilly terrain located in the southern and central parts of the study area has a poor groundwater potential zone due to higher degree of slope and low permeability of conglomerate soil type. The demarcation of groundwater potential zones in the Comoro watershed will be helpful for future planning, development and management of the groundwater resources.