Biophysical assessment of lasang watershed in davao del norte philippines

THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY SAINTLY GHIA A SARMIENTO TOPIC TITLE: BIOPHYSICAL ASSESSMENT OF LASANG WATERSHED IN DAVAO DEL NORTE PHILIPPINES BACHELOR THESIS Study Mode : Full-time Major : Environmental Science and Management Faculty : International Programs Office Batch : 2015-2018 Type : On-the-job-training (OJT) Thai Nguyen, 25/9/2018 Thai Nguyen University of Agriculture and Forestry Degree Program Bachelor of Environmental Science and Management Student Name Saintly Ghia A Sarmiento Student ID DTN1454290097 Thesis Title Biophysical Assessment of Lasang Watershed in Davao del Norte Philippines Supervisor(s) Hoang Hai Thanh Ph.D (TUAF) and Fe T Ociones (ERDB) Supervisor’s Signature(s) Abstract: In the Philippines, densely populated areas are mostly located in coastal areas that are either valley plains or floodplains Two of the most pressing and worsening environmental issues in these areas are flooding and pollution of rivers and waterways Lasang watershed is one of these areas experiencing these problems Flood modelling was conducted in the watershed using terrain analysis Terrain analysis involves geomorphological and spatial assessment of a watershed in terms of watershed shape, relief features, and channel morphology Parameters analyzed included circulatory and bifurcation ratios, stream densities and frequencies and watershed dimension Results show that Lasang watershed has medium flooding rate The critical parameter in the flood modelling is the stream frequency with very high rate Critical areas to flooding was also determined by spatially delineating low-lying areas ii Land uses and activities were also spatially studied to determine the relationship between the land use and activities to the type of pollution in drainage an waterway Lasang watershed is polluted with Chromium in terms of hard metal and sedimentation This related for having wide range of plantations like banana and the usage of air sprays There is a need for environmentally sensible usage measures in the area and protection with local ordinances Keywords: Watershed—Terrain Analysis—Water Analysis— Geomorphological Features—Hydrology—Water Pollution Number of pages: 43 Date of submission: September 25,2018 iii ACKNOWLEDGEMENT This study would not be a success without the help of the people around me I would like to thank my ERDB-UERD family, for making all of these possible, fun, meaningful, and for adding color to my college life All the memories and things you guys taught me will be forever treasured I would like to thank Ms Fe T Ociones, my adviser in ERDB for being my mentor, for treating me as a daughter and making this study a lot easier Thank you for the patience, kindness and guidance you gave me I also want to thank Dr Simplicia A Pasicolan, Division Chief of ERDB-UERD for whole-heartedly accepting me in the division Nevertheless, I am grateful to the Ms Hoang Hai Thanh, PhD, my supervisor in Vietnam for guiding me and helping me with open arms, despite the busy schedule she allotted and made sure she will have time for me I would like to thank my friends, special mention to Jerzynne Corpuz, Nicole de Castro, Kuya Imcon Abris, Ate Faith Arguelles, and Kuya Pierre Balite for being with me through this study I am most thankful for my family and Yamir Ortiz for the unconditional support and love throughout my ups and downs in making this study Special mention to my aunt Paula Alicante for helping me with the last-minute editing, grammar check and support; and to parents Ricardo S Sarmiento, Leilani V Amante and Ronel Virtucio for all the support that I needed To God be the glory iv TABLE OF CONTENTS List of Figures List of Tables List of Abbreviations CHAPTER I INTRODUCTION 1.1 Rationale 1.2 Objectives 1.3 Contents of work 1.4 Profile of the cooperating agency 1.5 Description of activities 1.6 Timeline CHAPTER II LITERATURE REVIEW 1.1 International literature review 1.2 National literature review 12 CHAPTER III STATUS OF THE CONSIDERED ISSUE AT THE TRAINING AGENCY 13 CHAPTER IV DISCUSSION AND LESSON LEARNED 37 1.1 Discussion 37 1.2 Lesson learned 37 CHAPTER V CONCLUSION .39 REFERENCES .40 APPENDICES .42 v LIST OF FIGURES Figure Page Figure 3.1 Location Map of Lasang watershed 16 Figure 3.2 Geologic Map of Lasang watershed 18 Figure 3.3 Soil Map of Lasang watershed 19 Figure 3.4 Land Classification of Lasang watershed 21 Figure 3.5 Slope Map of Lasang watershed 22 Figure 3.6 Land Use Map of Lasang watershed 24 Figure 3.7 Drainage Map of Lasang watershed 27 LIST OF TABLES Table Page Table 1.1 GANTT Chart of Activties Table 3.1 Number of streams in each stream order in Lasang watershed 28 Table 3.2 Lasang watershed parameters 29 Table 3.3 Ratings of the parameters used in the terrain analysis 30 Table 3.4 Vulnerability to flooding base on averaged values in terrain analysis 30 Table 3.5 Lasang watershed water wnalysis data 32 Table 3.6 NPCC Water quality criteria for wateruse 33 Table 3.7 Hard Metal Analysis in Lasang watershed 33 LIST OF ABBREVIATIONS CZFERD – Coastal Zone and Fresh Water Reasearch Division DAO – Decentralized Autonomous Organization Dd – Drainage Density DENR – Department of Environment and Natural Resources DO – Dissolve Oxygen ERDB – Ecosystems Research and Development Bureau ESRI – Environmental Systems Research Institute FERD – Forest Ecosystem Research Division GIS – Geographic Information System LESD – Laboratory and Experimental Division MGB – Mines and Geosciences Bureau NAMRIA – National Mapping and Researches Information Authority RDE – Real Driving Emissions Sf – Stream Frequency TDS – Total Dissolve Solid TTD – Technology Transfer Division UERD – Urban Ecosystem Research Division CHAPTER I INTRODUCTION 1.1 Rationale Populated urban areas in the Philippines, are mostly located in valley plains and floodplains These areas are also the most critical since agrarian, industrial and commercial societies are located here and practically most social and economic activities promoted by man are centered here Ironically, densely populated areas are also the most hazardous environments for habitation and settlement It is in the recent decades and with the advent of climate change that many environmental issues and problems have surfaced these areas vulnerable to hazards and depleted water and land resources available Two of the most pressing and worsening problems are flooding and pollution of rivers and waterways that usually drain in these areas These problems have put thousands of lives at risk either to flashfloods or water borne diseases due to water pollution The problem will grow each year as development and urbanization always slips ahead of land use planning and environmental protection There is a need therefore to address this lapse by putting forward recommendations and strategies for land and water resources management that will sustain and put forward logical land use plans for urban areas that will focus on environmental protection and conservation The inputs that will be needed are geo-morphological and hydrological assessments and modelling to spatially locate critical sites that need protection and rehabilitation Lastly, the study aims to recommend management strategies and policies for the protection, conservation and sustainable use of the land and water resources of highly urbanized areas The study therefore aimed to assess existing land use zoning and management of industrial, commercial and residential areas within critical urban areas to hazards of flooding, and water pollution 1.2 Objectives The main objective of the project was to develop a harmonized guideline incorporating environmental protection and land use management of a dense urban environment The specific objectives were: 1.2.1 To conduct bio-physical assessments of a watershed that served as inputs to terrain analysis, hydrology and water pollution studies and identification of critical areas 1.2.2 To generate thematic maps for Lasang watershed in Davao 1.2.3 To assist in the terrain analysis of watershed in Lasang watershed, this objective included the computation of geomorphological features that include stream densities and frequencies, watershed relief, bifurcation ratios and circulatory ratios 1.2.4 To assist in the field work in Davao City, this included conducting of focus group discussion of the Manobo Tribe in the historical lands of Davao, specifically in Barangay Baganihan 1.3 Contents of work The contents of work involved the characterization and the vulnerability assessment phases of the study Inputs for the vulnerability assessment came mostly from the characterization of the watershed Appendix 2, Equation 1.1, Lasang watershed has a result of 2.2 rating to a medium chance in vulnerability to flooding, meaning the watershed floods during extreme weather and misuse of the land use Table 3.2 Lasang watershed parameters Parameters Data Total Area (m²) 418359440.3 Length (meters) 49343.3396 Perimeter (meters) 183003.8995 Highest Elevation 2667.37 Lowest Elevation -1.88576 Average Bifurcation Ratio 5.012309231 Stream Frequency 9.15003E-06 Drainage Density 0.000117945 Elongation Ratio 0.467855155 Circularity Ratio 0.156898404 Relief Ratio 0.054095563 Roughness 0.314824959 29 Table 3.3 Ratings of the parameters used in the terrain analysis Rating Drainage Density (m/has) 1-20 20-40 40-60 60-80 80-100 Stream Frequency 0-.2 2-.4 4-.6 6-.8 8-1 Bifurcation Ratio 5-6 4-5 3-4 2-3 1-2 Circulatory Ratio 0-.2 2-.4 4-.6 6-.8 8-1 Relief Ratio 0-0.05 05-.10 1-.15 15-.2 2-3 Area (has) 025000 25000 to 50000 50000 to 75000 75000 to 100000 100000 and above Table 3.4 Vulnerability to flooding base on averaged values in terrain analysis Average value Vulnerability to Flooding 0-1 Very Low 1-2 Low 2-3 Medium 3-4 High 4-5 Very High 30 In-situ water analysis Water pollution of Lasang watershed Water pollution of drainage systems can be seen as synonymous to urbanization This is a global and national problem that has to be faced in fast urbanized areas and this problem will grow each year since urban planning is not proactive when it comes to pollution management The pollution is already worst before the conduct of cleanup is instituted Water is typically referred to as polluted when there is presence of anthropogenic contaminants As a result, it either cannot support its biotic community like fishes Monitoring of water quality was done in the Lasang watershed This is to identify the point and non-point sources of pollution and determine the type of pollution to the land use and land use activities Preliminary survey covering the areas of interest was done to identify and establish the water sampling stations The sampling stations for Lasang watershed are divided into three—the upstream, middle stream, and downstream (Appendix 1, Figure 1.2) However, not all the streams results are the same, the Lasang downstream got the highest pH, dissolve oxygen (DO) among two other streams, while the upstream has higher salinity, total dissolve solid (TDS), conductivity and temperature In terms of the phosphate and nitrate data gathered, highest is from Lasang downstream and midstream, respectively Data from the streams of Lasang watershed is shown in Table 3.5 Point sources included the direct measurements from ditches coming from the landfill in the city, the residential effluents and industrial effluents Parameters that we included were analyzed physic-chemical nitrates and phosphates and hard metals (Mercury, Chromium, Arsenic, Copper, and Lead) Analysis for physic-chemical 31 parameters and for nitrate and phosphates was done in in-situ and samples were brought to the CRL laboratories for the analysis for hard metals (Table 3.7) Standard used in the analysis and classification of the water As water moves along beneath the surface, it dissolves minerals and matter from decaying plants and animals and from rocks and soils themselves There, turbidity, TDS, Ph, dissolved gases and minerals are expected to be found in the river water Analysis of the headwaters will help to establish baseline information on the water quality of this undisturbed or unpolluted part of the river system, the guideline for the classification of the river water is the DAO # 34 series of 1990 system The standards and classifications are shown in Table 3.6 Table 3.5 Lasang watershed water analysis data Name Lasang Downstream Lasang Midstream Lasang Upstream Date Time pH 25/05/2018 8:50 AM 8.12 / 25/05/2018 9:45:00 AM 8.0 / 25/05/2018 10:30 AM 8.09 / Salinity (ppm) 95 111 127 147 / 148 166 / 165 187 / 189 213 233 274 55.8%/ 4.23 mg/L /4.3 ppm 4.25 PPm / 58% /4.15 mg/L 54.2% / 35˚C / 3.7 mg /L / 3.98 PPm 29.3 29.6 3.4 0.16 0.825 0.16 1 TDS (ppm / mg/L) Conductivity (µs) DO Temperature (˚C) Nitrate (ppm) Phosphate (ppm) 32 Table 3.6 NPCC water quality criteria for wateruse Units Parameters NPCC Water Quality Criteria Used DO ppm Min T ˚C Max Rise pH - 6.5-8.5 TDS mg/L - Alkalinity ppm - Turbidity FTU Not more than 30% Inc O-PO4 ppm 0.2 NH3-N ppm 0.5 Conductivity µs - Table 3.7 Hard metal analysis in Lasang watershed Date of collection: May 24-25, 2018 Lasang Streams Time of Arsenic Collection (mg/kg) Matrix: Sediment Chromium (mg/kg) Copper (mg/kg) Lead (kg/mg) Mercury (mg/kg) (D) 8:50 AM 2.0 75 39 - - (M) 9:45 AM - 14 14 - - 2.0 55 42 ND - 10:30 AM (U) (D)- downstream (M)-midstream (U)-Upstream 33 Focused group discussion with the Manobo Tribes Manobo, come from Mansuba from man (person or people) and suba (river), meaning river people The heads of the Manobo tribe are looking for the star-lit sky to control the season of planting, harvesting, fishing and hunting Each star can bring a dissimilar message and will direct the tribal group in their traditional way of living Nowadays only the members of the older generation of farmers are passing the knowledge to the present generation, to learn the old way of living, keep their culture and traditions alive and develop their consciousness about their own philosophy A Manobo community is mostly male subjugated, the man served as the head of the family and he is the one who will make the family choices Only a Royal, a Datu can practice polygamy, only with the agreement of the first wife and her parents The Manobo are both strong in mind and spirit, their cultural individuality is firmly rooted in the land and its nature The traditional way of life has not ended for most Manobos, they strive to uphold their values and traditions even while living in a modern society, faced with new truths, prepared to compete in the modern economic world instead of the world of nature The focused group discussion was held in Barangay Baganihan with the participation of the researcher and the Manobo Tribes, specifically with the Lumads The name Lumad grew out of the political developing among tribes during the martial law regime of President Ferdinand Marcos Main objective was to attain selfdetermination for their member-tribes or, put more concretely, self-governance within their ancestral area in accordance with their culture and normal laws No other Lumad organization had the rapid goal in the past During the discussion the Manobo Tribes 34 claimed that in before the place was urbanized the atmosphere was cool and the forest was rich in vegetation As the time goes by and due the illegal anthropogenic activities, the forest vanished before they not need to see a doctor because base on self-taught and generation practices, they well know that the medicines they need are found in the forest Therefore, now that these tribes are living in the modern times, they are forced to adapt on how urban people live The tribe despite of having scarce knowledge in the modern education, they know that the forest is very important, since it is also the main source of their livelihood, like planting of crops and making native, and self-made bracelets from Bagon that they gather from the forests, to sell in cities Despite of the outcomes of the modern age, these tribes are very well eager to help and bring back the lost beauty and richness of the forest The discussion group is shown in Appendix Figure 1.3 35 CHAPTER IV DISCUSSION AND LESSON LEARNED 4.1 Discussion The biophysical assessment of a watershed includes various advantages and disadvantages in various ways possible Using this study can give benefits not just for a small scale but in a larger scale, not just in local areas but also nationally and internationally, since we can easily know what the specific place has to offer, through this with the completion of all the things needed, like knowledge in ArcGIS, topographic maps, and time It can give people answers beyond their eyes and reach The study can easily show if a place is an ideal area for civilization, industrialization, or can be used for agricultural purposes Simple questions like, if it is a flood prone area or is it a dangerous place to build on buildings or to live in This study can easily inform, a person, a family, a community, a government or a nation through the maps produced This study will not limit only in the Philippines, but also in other countries around the world especially countries that are known to have a lot of mountains and high elevated places However, this study limits through the requirements needed to successfully pursue this kind of study, especially in the ArcGIS and watershed knowledge, which is a stepping stone for this study since not everyone has the opportunity to learn ArcGIS and watershed knowledge This also limits in having topographic maps, nationally and internationally, since not everyone has the access to specific agencies, companies and websites in order to get them 4.2 Lesson learned Objectives are met Skills learned in the internship are the understanding of watersheds, the knowledge for ArcGIS; lay outing, producing and interpreting maps, computing for the geomorphological features of watersheds, involving in a field work, 36 and conducting in-situ water analysis The experience in the internship serves as a sample of how things work in this study The challenges for this internship are the poor knowledge at first and the double time catch up to topics that are needed to be learned Both academic and personal goals are met, considering that this internship helped gain more knowledge and learn new things, and serves as an experience in a working place ad environment that requires an honest self towards co-workers, and higher authorities The results of this internship will be an assist for the future, that is valued to a very important part in starting an official job and work 37 CHAPTER V CONCLUSION There are many ecosystem services that watersheds can provide, including but not limited to the following: sedimentation control, nutrient cycling, carbon storage, increased biodiversity, soil formation, wildlife movement corridors, water storage, water filtration, flood control, timber and recreation, food, as well as decreased vulnerability to invasive species, the outcomes of climate change and other natural catastrophes These services are important to our environmental, economic, and social well-being Due to present advance technology like ArcMAP, it is possible to know if the area where the watershed is located has these ecosystem services or on the contrary, lacking of these that leads to issues and problems that can affect matter in the area The study conducted bio-physical assessment on Lasang watershed that helped with the terrain analysis, hydrology, and water pollution This study was able to generate thematic maps of the watershed From doing the terrain analysis the study obtained the geomorphological features of the watershed that included the stream densities and frequencies, watershed relief, bifurcation ratio and circulatory ratio Focused group discussion with the Manobo Tribes were done The study result showed that Lasang watershed has a medium rate of flooding The causes of flooding in this area is the extreme weather, the change in the land use, and the critical steep areas of the watershed As shown in the land classification and land use map for Lasang watershed, there are visible differences that explain the flooding in the area Since the watershed generally encompasses several types of land uses within a territorial influence, all positive or negative changes would affect the totality of the area and the people within and around it, hence watershed improvement and rehabilitation activities of each and every portion of the watershed needs careful planning 38 REFERENCES Batterbee,R.W and Binney H.A 2008 Natural Climate Variability and Global Warming: A Holocene Perspective Environmental Change Research Center University College London A John Wiley & Sons Ltd Publication Pp 244-264 Chettamart, Surachet.1985 A management plan for Khao Yai National Park Ph.D thesis proposal Univ of Wash., Seattle 62.p Harrison, R M 1992 Understanding Our Environment: An Introduction to Environmental Chemistry and Pollution 2nd edition Published by the Royal Society of Chemistry Thomas Graham House, Science Park, Cambridge Pp 60-62 Hawes, Robert A and Lawrence S Hamilton 1980 A method of watershed land classification and assessment for the tropics: a case study of Rio Guanare Venezuela Dept of Nat Res., N.Y State Col Of Agr And Life Sci Cornell Univ., Ithaca, New York 32 Pp March, W.M 2004 Landscape Planning Environmental Applications 2nd edition John Wiley & Sons, Inc pp 146-162 Mirza, M.Q and Ahmad, Q.K 2005 Climate Change and Water Resources in South Asia A.A Balkema Publishers Taylor & Francis Group London Pp 180-187 Ociones, F.T and Olvida, A.F 2004 A Technical Report on the Biophysical Characterization of the Dauin Watershed Ociones 2017 R&D for the Mangement and Improvement if Commercial and Industrial Zones at Highly Urbanized Areas in the Philippines 39 PAGASA (Philippine Storms and Typhoons and Climate Projections) Rice, W.E and Baird, R.B 2012 Standard Methods for the Examination of Water and Wastewater 2nd edition American Public Health Association and American Water Works Association Pp 1-100 Schroder, D 2015 Terrain Analysis for Flash Flood Risk Maps Hochschule fur Technik Stuttgart Schellingstr University of Applied Sciences Stuttgart.Pp 3-30 Wooldridge, D.D 1990 Manual on land use survey and capability classification for upland watersheds A publication of the ASEAN watershed project, College, Laguna, Philippines 3-21 pp WIKEPEDIA (Water Pollution) 40 APPENDICES Appendix Figure 1.1 Banana Plantation in Lasang watershed 41 Figure 1.2 Sampling Stations for Lasang Watershed Lasang Downstream above, Lasang Midstream in the bottom-left and Lasang Upstream on the bottom-right 42 Figure 1.3 Focused Discussion sites with the Manobo Tribes Appendix Eq 2.1 Computation for the vulnerability to flooding of Lasang watershed Circulatory Ratio Rating (0.2) + Bifurcation Ratio Rating (0.2) + Stream Frequency Rating (0.2) + Relief Ratio Rating (0.2) + Area Rating (0.2) = Vulnerability to Flooding Vulnerability to Flooding = 1(0.2) + 1(0.2) + 5(0.2) + 2(0.2) + 2(0.2) Vulnerability to Flooding = 0.2 + 0.2 + + 0.4 + 0.4 Vulnerability to Flooding = 2.2 or Medium Rate 43 ... ACTIVITIES 4 4 Introduction to Basics of Watersheds Introduction to ArcMap Training with GIS LAB employees Delineation of Lasang watershed Stream Ordering of Lasang watershed Computation of geomorphological... of latitude and between 125º0’0’’E and 125º50’0’’E east meridians of longitude Lasang watershed is in Davao City, one of the municipalities of Davao del Norte in Region I The watershed lies in. .. sets of data Delineating and ordering of streams and watershed boundary In order to start up the understanding for the watershed is to know how to delineate streams, ordering them and getting