Improving Food and Water Security in Sumba, Indonesia

KG Evans, Monishka Narayan, Bijay Lamsal, Rozeeta Thapa, Norman Riwu Kaho, Sarah Elizabeth Hobgen, Bronwyn Myers, Penelope Wurm

    Research output: Working paper

    Abstract

    This 12-month project provides an outlook of the problems currently faced in Sumba, Indonesia relating to water management issues The research team consists of Engineers and Environmentalists from Charles Darwin University in Northern Australia and UNDANA University in Kupang, Indonesia. This project addresses the Engineering solutions to the saturated zone and ephemeral stream in Lambanapu and groundwater quality studies in Lambanapu and Mauliru regions. This integrated approach reflects the realities of living in and managing the water resources within irrigation developments, and proved highly productive and engagement for participants.
    Key findings are:

    • A better understanding of saturated zone which helped to design the field work plan accordingly such as taking drainage section measurements for quantitative analysis of the flow and the hydrodynamics of the primary irrigation channel.

    • A significant finding resulted from stable isotope analysis which verified and differentiated the water sources in the saturated zone. This analyses show that the major part of the water in the zone comes from the primary irrigation channel. This has confirmed what the farmers have long believed and that is that the primary irrigation channel is the reason for the inundation of the area. However, it is also to be noted that the groundwater table is also very shallow. This is the first time such a project was conducted in Lambanapu and this has helped clarify from the the source of the water.
    • The drainage line draining water from the saturated zone is not working effectively. Every year during the rainy season, it overflows, according to the local farmers, which makes the problem even more severe. This is due to the intersection of the ephemeral stream and the drain approximately halfway to the outlet. 
    • The primary irrigation channel is suffering from heavy losses of nearly 1.4 GL of water each year from the siphons that are installed across the channel. The flow rate at the distance 1500 m is nearly decreased by 50% due to the fact that there are numerous siphons, the growing vegetation that’s slowing down the flow rate because of the concrete cracks and seepage from the channel due to the loss of waterproofing.
    • Additionally, instead of simply suggesting an alternate design by the results generated from the field analysis and the results, an innovative approach to involve the community and taking their needs and requests into consideration has been implemented. This has resulted in a design that is appropriate to drain the saturated zone and also favoured by the local farmers at the same time. 
    • Extensive field studies in the ephemeral stream catchment delineated 5 land units each with variable erosion rates based on soil particle size distribution, confirmed the location of most of the main stream channel and provided a basis for partial calibration of the CAESAR-LisFlood landform evolution model. 
    • Possible drain design for ephemeral stream after further sensitivity studies are complete.
    • All physico-chemical parameters, cations and trace elements are under trigger values except for E.coli. Possible recommendations to treat E.coli are boiling and using water purification tablets.
    Key outputs of the project are:
    • Drain designs for saturated zone and ephemeral stream. 
    • Strategies to remove E.coli from drinking water from wells.
    • Strengthened existing partnerships and forged new partnerships among members of a multidisciplinary research team of engineers and environmentalists.
    Original languageEnglish
    Number of pages34
    Publication statusPublished - 1 Dec 2016

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