Source: SEAMEO BIOTROP's Research Grant | 2016
Abstract:
Ciliwung Watershed has very important roles as a buffer zone area of
Jakarta. To overcome flood problem in Jakarta related and caused
by Ciliwung River, there is a need alternatives policy to control Ciliwung River
discharge effectively, either using
mechanical technique, vegetative
technique, soil conservation technique or their combination. Conditon of Ciliwung Hulu
Watershed in 2014 becomes worst and so very sensitive from high rainfall since has no capacity to absorp, keep and save
water from rainfall, especially high rainfall. Scenario of the building of the two big dams Ciawi Dam
and Sukamahi Dam is considered the most effective in controlling Ciliwung River
Upstream discharge since it will be able to decline drastically ratio of
maximum-minimum discharge from 399,15 (under actual condition) to 28,77 as
compared to agroforestry scenario that will reduce ratio of maximum-minimum
discharge to 80,40 and zero runoff scenario (combinatiof of agroforestry and
soil conservation techniques to produce zero runoff) that will reduce ratio of maximum-minimum discharge
to 29,33. The two dams, Dam
Ciawi dan Dam Sukamahi requires protection from sedimentation threat and shortage of water
supply from upstream area of so that the two dams can still work optimally and
effectively and thier life period will not be shortened. The common way to
safeguard the upstream area from intensive soil erosion and declining soil infiltration can be done by preventing of
tree cutting, coversion of vegetative land to non-vegetative land, and
implementation of combination of vegetative and soil conservation techniques to
minimize overland flow and soil erosion.
SWAT Model and
HEC-Geo-HMS Model can be used as a tool or instrument to predict or estimate or
assess the effect or impact of land management practices to water and sedimentation
in a watershed that consist of several types of
soil, land uses and its management in a certain period.