Strategi Keberhasilan Rehabilitasi Hutan dan Lahan Pada DAS Cidurian

Abstract

Cidurian Watershed is one of the watersheds in Java Island that is classified as a watershed to be rehabilitated. The performance of Cidurian Watershed, from upstream to downstream, is classified as poor. Agriculture land dominates the land cover in Cidurian Watershed. It potentially causes land degradation. It is showed by the increase of degraded land in Cidurian Watershed. It increased b 24,21% (20.744, 29 ha) from 2013 to 2018 which lead to frequent flash flood disasters in Cidurian Watershed occurred in March 2017 and April 2018, respectively. Land and forest rehabilitation strategy need to be applied to optimize the land and forest rehabilitation program sustainably. This research aims to 1) assess the hydrological characteristics of Cidurian Watershed using the SWAT (Soil and Water Assessment Tool) hydrological model; 2) assess the hydrological performance based on the prepared simulation scenarios; and 3) formulate successful strategies for Land and Forest Rehabilitation in Cidurian Watershed based on the best scenario. Various land use and management scenarios were simulated using SWAT to estimate their impact on the hydrological characteristics of the Cidurian Watershed. The applied scenarios are as follows: 1) Implementation of Spatial Planning of Banten and West Java Province; 2) Implementation of Forest and Land Rehabilitation and; 3) Implementation of Forest and Land Rehabilitation, combined with Soil and Water Conservation measures. The calibration and validation of the model showed a satisfactory category with NSE values of 0.53 and 0.50, respectively. All scenarios result in a better improvement on hydrological responses compared to the existing conditions in 2020. The surface runoff and sediment yield decreased and the lateral flow and base flow increased. The scenarios reduced the value of the Annual Flow Coefficient and Flow Regime Coefficient. Implementation of Forest and Land Rehabilitation and Soil and Water Conservation is the best scenario with Annual Runoff Coefficient and Flow Regime Coefficient values 0,27 and 22.40. The strategy of forest and land rehabilitation in Cidurian Watershed can be applied through the good Environmental Governance concept. Watershed management will be conducted in a synergistic, integrated, and effective matter among the stakeholders and society. The funding of Cidurian Watershed management can be conducted to follow the money follow program concept. It will be funded based on the program that fits the management target in synergistic of the stakeholder.