Abstract:
The Cisadane watershed is one of the priority watersheds to be rehabilitated due to decreased productivity. Most of the upper watershed is included in Bogor District area, so its performance is much influenced by the dynamics of land use change in Bogor District. Bogor as a buffer of the nation’s capital, has a high pressure on land use changes. If these changes are not well planned, the carrying capacity of the land will be exceeded so that the aspects of sustainability in the development will not be achieved. This study aimed to examine the suitability of actual land use of upper Cisadane watershed with the spatial plan (RTRW) of Bogor District, and its impact on hydrological characteristic, especially on the surface runoff rates. Spatial analysis on GIS program was done to show the comparison between spatial plans as stated in RTRW 2005-2025 with the existing 2016 land use. Hydrological analyzes were also conducted by calculate the changes of surface runoff coefficients of both types of land use. The analysis shows that in 2016, the land use of Bogor District is dominated by dry land agriculture with 52% of the total area. The opposite is seen in the land use of RTRW, the allocation of dryland agriculture is only 2%, and the allocation for settlements is 33% or increase more than 3 times compared to actual settlements in 2016. For all land use class, suitability of the 2016’s land use is only 37% from RTRW map. Maximum efforts should be addressed to achieve ideal land use in 2025 as planned in the RTRW. The calculation result shows that surface runoff coefficient based on planned land use on RTRW is 0.49, while in actual 2016 land use the value is 0.46. Larger runoff coefficients, lead to increased surface flow is caused by the change of cultivation land use into build up area in the form of settlements or industrial estates. Rainwater harvesting and runoff control needs to be done, both with simple and cheap techniques on a household scale, to large-scale construction.
