Non-structural measures
The non-structural measures are expected to prevent further catchment degrada- tion (soil conservation) and include local community participation (e.g., bio-pores, land terracing, gully plugs, regreening and/or reforestation)
Bio-pores (biopori)
Bio-pores (biopori) is a water absorption method which is used to reduce the sur- face run-off and inundation effect by increasing the water infiltration capacity into the ground. Bio-pores are an appropriate and environmentally friendly technology to deal with flooding and reduce inundation problems by increasing water absorp- tion, converting organic waste to compost, utilizing soil organisms and roots and overcoming the health problems caused by inundation such as dengue and ma- laria. This method was chosen because it is easy and cheap, so in future the local people can implement it by themselves. The recommended numbers of bio-pore holes were calculated using the equation (http://biopori.com/jumlah.php):
Total bio-pore holes = rainfall intensity (mm/hour) x impervious area (m2)/ vol- ume of water flowing per hole (litres/hour)
Location of the boreholes: Dusun Cukal, , Dadapan Wetan and Dusun Dadapan Kulon; each sub-village (or dusun) had 50 holes each.
Land terracing
The land terracing activity is aimed at rehabilitation of the terraces. A terrace is a levelled section of a steep cultivated area, designed as a method of soil conser- vation to slow or prevent rapid surface run-off. A terrace is a soil conservation structure constructed by digging and filling to form a tillable surface, end bund and drainage ditch which follows the contour line. It is complemented with other structures such as waterways and drop structures perpendicular to the contour line. Once the terracing is complete, it is further strengthened by the planting of
elephant grass. The terracing is in two locations in Dusun Cukal with a total area of 10 ha.
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