SYLVATROP Editorial Staff Antonio M. Daño Editor-in-Chief Adreana Santos-Remo Veronica O. Sinohin Liberato A. Bacod Managing Editor Layout Artists Liberty E. Asis Gliceria B. De Guzman Adreana Santos-Remo Eduardo M. Tolentino Editors Circulation Assistant Marilou C. Villones Liberato A. Bacod Editorial Assistant Printing Coordinator January - December 2015 Vol. 25 Nos. 1&2 SYLVATROP, The Technical Journal of Philippine Ecosystems and Natural Resources is published by the Department of Environment and Natural Resources (DENR) through the Ecosystems Research and Development Bureau (ERDB), College, Laguna. Subscription rates: P75 for single issue copy (local); P150 for combined issues and US$15 per single issue copy (foreign) including airmail cost; US$30 for combined issues. Re-entered as Second Class Mail CY 2012 at the College, Laguna Post Office on 14 May 2013. Permit No. 2013-14. Address checks to The Circulation Officer and contributions or inquiries to The Editor-in-Chief at the following address: SYLVATROP, The Technical Journal of Philippine Ecosystems and Natural Resources Ecosystems Research and Development Bureau, DENR Tel. No. (049) 536-2229, 2269 Fax: (049) 536-2850 E-mail: [email protected] or [email protected] Cover Photo: Photo shows the watersheds of La Mesa and San Cristobal in Metro Manila and Sta. Rosa, Laguna, respectively. Cover Layout: Adreana Santos-Remo PREFACE Climate change has taken a huge impact in the research world. Several studies have been conducted to determine its effects in the environment. In the Philippines, while we have lower carbon emissions compared to other developing countries, we are considered to be one of the most vulnerable to the impacts of climate change. Because of the risks associated to climate change, Philippines has to push for developing strategies that could help us to either mitigate or to adapt to these impacts. Assessing the ecosystem’s vulnerability to hazards due to climate change forms an important decision tool towards better management of natural resources as well as minimized risk to environmental disasters. With the projected impacts of climate change, the streamflow and groundwater recharge in many water-stressed areas could further be decreased. This will vary depending on the vulnerability of the watershed. Thus, on 2009, the Ecosystems Research and Development Bureau implemented the study entitled “Vulnerability assessment (VA) of priority watersheds with coastal areas in the Philippines to climate change” to assess the vulnerability of different watersheds. This study employed an interdisciplinary approach in addressing a complex problem in aid of identifying the natural and social factors that magnify or intensify the effects of natural hazards. The study followed the framework formulated by ERDB in assessing the vulnerability of watersheds to hazards. In 2011, ERDB shifted its framework to include climate change as an important contributory to the vulnerability of watersheds. Four of the watersheds included in this VA project are featured in this Special Issue of Sylvatrop. This special issue contains results on the vulnerability of the watersheds, namely: 1) La Mesa Watershed in Metro Manila, 2) San Cristobal Watershed in Sta. Rosa, Laguna, 3) Kisloyan Watershed in Mindoro, Vulnerability framework used by ERDB in its vulnerability assessment studies to identify natural and anthropogenic hazards Vulnerability framework used by ERDB for vulnerability assessment studies from 2011 onwards (Adapted from the framework of Intergovernmental Panel on Climate Change (2011)) and the 4) Matutinao Watershed in Cebu. These VA results can therefore serve as input in the planning and preparation of watershed managers in managing the complexities of the watersheds under their jurisdiction. Emerging issues related to climate change are also incorporated in the discussion of the research results. Results of the four vulnerability assessment studies can be utilized in planning the sustainable development of a watershed and conserving its natural resources. With this, more responsive and integrated watershed management plans can be expected from our policy makers. We hope that this issue will inspire more researchers to conduct in- depth studies on vulnerability assessment using up-to-date and science based information. ANTONIO M. DAÑO Lead Author, VA Special Issue Sylvatrop, The Technical Journal of Philippine Ecosystems and Natural Resources 25 (1 & 2) 1-26 Vulnerability assessment of the La Mesa Watershed Reservation, Quezon City, Philippines Esmeralda P. Andres Rudolfo Espada, Jr. Supervising Science Research Specialist Planning Officer I Ecosystems Research and Development Service Email address: [email protected] DENR-National Capital Region North Avenue, Quezon City, Philippines Eduardo C. Calzeta Email address: [email protected] Forester II Email address: [email protected] Manuel S. Sabater Community Enviroment and Natural Riza C. Arjona Resources Officer Science Aide Email address: [email protected] Email address: [email protected] The vulnerability assessment of the La Mesa Watershed Reservation in Novaliches, Quezon City was conducted to provide the basis for the formulation of a sustainable watershed development and management plan. The guidelines on vulnerability assessment prepared by Daño (2006) of the Ecosystems Research and Development Bureau (ERDB) was also tested in the identification of vulnerable areas in the La Mesa Watershed. Four priority environmental hazards were assessed in the study area using a spatial analysis tool, the ArcGIS Model Builder. The composite map identified a total of 10.285 ha of very highly vulnerable areas distributed as follows: soil erosion (0.285 ha), landslide (0.014 ha), biodiversity loss (8.685 ha), and fire (1.141 ha). Keywords: Vulnerability assessment, La Mesa Watershed Reservation, ecological profiling and characterization, soil erosion vulnerability, landslide vulnerability, fire vulnerability, biodiversity loss vulnerability, Metro Manila, Philippines 2 E. Andres et al. THE SUSTAINABLE DEVELOPMENT AND MANAGEMENT OF ANY WATERSHED IS primarily dependent on the existing socioeconomic, political, institutional, ecological and physical resources. The status of these resources, both quantitatively and qualitatively, can be determined through a comprehensive ecological profiling and characterization of the watershed. These results of characterization are valuable inputs in assessing the area in terms of its vulnerability to geohazards. Knowing the geological hazards will help environmental managers in pinpointing priority conservation areas and formulating intervening actions to reduce environmental degradation and enhance the coping capacity of the watershed to potential environmental hazards. In Metro Manila, the remaining recharge is La Mesa Watershed Reservation (LMWR). The dam serves as a holding reservoir for the water coming from the transbasins of Umiray, Angat and Ipo Watersheds which are all declared as watershed reservations. The Proclamation of the La Mesa Watershed under Presidential Proclamation 1336 on July 25, 2007 completed the water system, thus, providing water security for Metro Manila. To date, LMWR is still considered as Unclassified Land of Public Domain, otherwise referred to as Public Forest per L. C. Map No. 639 issued on March 11, 1927. It is a titled property under the name of the Metropolitan Waterworks and Sewerage System (MWSS). Politically, it is under the jurisdiction of the Quezon City local government. This vulnerability assessment was conducted to determine the degree of vulnerability of the watershed in terms of soil erosion, landslide, fire and loss of biodiversity. The results of the study would provide baseline information for the preparation and implementation of the La Mesa Development and Management Plan. Review of literature Watersheds, considering the role they play, should always be given due conservation efforts. Vulnerability assessment of the watershed is one important tool to determine its risks and hazards. Different approaches can be used in the conduct of vulnerability assessment. One earlier study on vulnerability of watershed to climate change was conducted by Tiburan, Jr., et al. The author developed an approach that integrates geospatial-based model involving 21 indicators, classified into three major components: exposure, sensitivity and adaptive capacity. Each indicator was given a scale of 1 to 5 to signify the degree of vulnerability. Threshold level for each scale was determined using statistics and existing geospatial-based techniques. Subindices in the model was used to evaluate the extent of damage brought about by other pertinent issues associated Vulnerability assessment of the La Mesa Watershed Reservation 3 with climate change such as flood, drought, erosion, landslide, and biodiversity loss. It was emphasized in the paper that all these information played a significant role in the effective and efficient management of watersheds in the country, as well as in targeting policy interventions associated with climate change (Tiburan et al. 2010). Susceptibility assessment of areas prone to landslide remains one of the most useful approaches in landslide hazard analysis. The key point of such analysis is the correlation between the physical phenomenon and its triggering factors based on past observations. Many methods have been developed to capture and model this correlation, usually within a geographic information system (GIS) framework.