Watershed Management Learning Packet 1 PDF

Learning Packet 1: Introduction, definitions, concepts and principles of Watershed Management Lessons to Learn: After reading the lessons on the introduction of watershed, watershed and its resources, World’s and Philippine forests, and watershed management concepts, you should be...

Learning Packet 1: Introduction, definitions, concepts and principles of Watershed Management Lessons to Learn: After reading the lessons on the introduction of watershed, watershed and its resources, World’s and Philippine forests, and watershed management concepts, you should be able to: 1. Enumerate examples of watersheds in Benguet. 2. Identify the over harvested and abused watershed resources in your place. 3. Explain the relation of Philippine population to forests. 4. Explain the triangular concept of watershed management. 5. Understand the types of streams found in a watershed. WATERSHED MANAGEMENT I. Introduction WATERSHED is land bounded by a topographic divide which intercepts stores and directs/drains rainwater to a stream or river system down to a common outlet known as a mouth either a lake, sea, or ocean, (Plates 1 and 2). Topographic divide refers to surface divide (top of mountains) while phreatic is refers to underground divide or rock formations. Watersheds provide water for agricultural, industrial and domestic purposes, they are essential to the socio-economic progress and economic stability of the country. In addition, watershed provides timber, forage, wildlife and also services like protective and aesthetic values. However, because of the various destructive activities of man associated with his quest for his basic needs, many of the country’s watersheds have been devastated. The country nowadays is encountering different man-made calamities that include siltation and sedimentation due to soil erosion. Such calamities occur because of logging and firewood cutting, kaingin making, improper farming practices, forest fires, grassland burning, improper range management and many others. Watershed managers are presently encountering problems due to increasing population of watershed farmers. In this pressing situation, there is a need to come up with a better watershed management strategy that will satisfy the upland farmers’ need for food, fuel, shelter and livelihood but at the same time that is compatible with the ecological requirements of the site. Plate. 1 Watershed Plate. 2 Watershed Watershed Resources A watershed is composed of the following resources: water, soil, vegetation, rock, minerals, flora and fauna, human and improvements. The following are the five 7 Largest basins in the Philippines Rank Basins Region Drainage Area (ha) 1. Cagayan Cagayan Valley 2,569,648 2. Mindanao S. Mindanao 2,315,900 3. Agusan N. Mindanao 1,092,100 4. Pampanga C. Luzon 975,900 5. Agno Luzon 595,200 6. Abra Ilocos 512,500 7. Pasig Laguna 467,800 Note: The head water of Agno river basin in Mt. Data, traverse towards the municipalities of Kabayan to Ambuclao dam in Bokod to Binga Dam in Itogon, Benguet and continue traversing to San Roque dam in San Manuel and San Nicolas in Pangasisnan; (The whole stretched is known as the Upper Agno river basin) and from San Roque dam to Carmen Bridge in Rosales to Urdaneta and exits to Lingayen Gulf in Pangasinan. (Lower Agno River Basin) The head water of the river basin in Mt Data in Benguet to its mouth or outlet in Lingayen Gulf in Pangasinan is known as the Agno River Basin. Types of Streams Found in the Watershed 1. Ephemeral stream – Stream that has water just after rainfall 2. Intermittent stream – Stream that has water only during the rainy season 3. 3. Perennial stream – Stream that has water all through-out the year Plate. 3 Types of streams World’s forest: The world has only 30% forest cover; 40% relatively undisturbed (frontier forest); 39% of frontier forest threatened; 11 countries including Finland, Sweden, Vietnam, Guatemala, and Thailand are on the verge of losing their frontier forest. 76 countries already lost their frontier forests; 56 countries have less than10% forest cover and half of the original forest cover was lost during the last 30 years (Source: FAO 2000) There are more than one billion people who lack access to a steady supply of clean water and there are 2.4 billion people – more than 1/3 of the world’s population, who do not have access to proper sanitation. More than 2.2 million people, mostly in developing countries, die each year from diseases associated with poor water quality and poor sanitary conditions. (Arias, P. R. (2003) Table shows 1 shows the country’s population and remaining forest. Of the reported 7.2 million hectares’ forest in 2004, 6.5 million are within alienable and disposable (A & D) land. Table 1 Philippine Forest and population WATERSHEDS: 83% of the 114 watersheds of NIA with total area of 3,968,805 ha are in critical conditions; Of the 4.7 million hectares (total area) NIA watersheds, only 31% of it is covered with forest, the rest are grassland (31%), cultivated (37%), and built areas (1%). SOIL DEGRADATION: The estimated annual rate of soil loss in the country is 74-81 million tons. Between 63-77% of the country’s land area are affected by soil erosion; 13 out of 73 provinces have over half of their land area being moderately to severely eroded (WRDP-WMIC-FMB-DENR-COWI, 1998). Human can survive in two months with water without food but may die after a week without water (From LWTD Poster, Undated) Status/trend of river: 29 river systems in Luzon are reported dead or dying. 10 reported dead by EMB (as cited by Bengwayan, 2000): Watershed Management ✓ Implies the control or manipulation of watershed to carry out planned activity aimed at attaining, specific objectives. ✓ Refers to the management of all-natural resources of a drainage basin to protect, maintain and improve water yield. ria g 4. Activity 1 1. Enumerate 3 examples of watersheds found in CAR region. (3 points) 2. Explain the relationship of Philippine population to its forests found in table 1. (2 points) 3. Enumerate examples of over harvested and abused watershed resources in your place (3 points). 4. What type of stream is Balili river? Explain why. (2 points) River Basins In the Philippines 3 important multiple-use forestry components to be considered in managing watershed. 1. Production - water, agricultural crops and other watershed resources 2. Protection - Protection against draught, climatic changes and typhoons etc. 3. Amenity (accessory benefits) Recreation and aesthetic values a. Recreation values Under recreational are: fishing, swimming, Boating, climbing, picnicking, and hunting b. Aesthetic Values Aesthetic refers to scenic value like biodiversity, landscapes, waterfalls and other eco-tourism sites. Learning Packet 2: Lessons to Learn: After reading the lessons, on watershed problems, benefits from successfully manage watersheds, and principles governing watershed management and development you should be able to: 1. Identify the causes of problems in a watershed and able to recommend its mitigating measures. 2. Explain the benefits from successfully manage watersheds. 3. Explain or discuss the principles governing watershed management and development. Watershed Problems 1. Soil Erosion-worst problem -74-81 million tons of soil are lost annually from upland 2. Loss of biodiversity-species and habitat loss 3. Declining land/site productivity of upland farm because of soil fertility decline. 4. Microclimate deterioration - Increasing temperature locally 5. Low water quality and quantity Benefits from Successfully Manage Watershed 1.Economic Benefits a.) Water supply – hydro-electric power production and for domestic use b) Forestry- Production of forest products c) Agriculture- crops and livestock production d) Fishery- aquaculture in reservoir and watershed stream/rivers e) Mining- quarrying for construction purposes 2. Social services a) Ecotourism- scenic landscape b) Recreation-mountain climbing, fishing, etc. c) Historical- protection of historical monuments d) Cultural- protection of indigenous cultures. e) Health- Watershed control of water borne diseases that affects human 3. Environmental Services a) Biodiversity- flora/fauna conservation b) Soil conservation- erosion control c) Water conservation- retention/storage; quality control Figure 13. Effects of watershed condition to run-off and erosion d) Oxygen generation- plants releases oxygen to atmosphere e) Microclimate amelioration- amelioration of temperature extreme Principles Governing Watershed Management /Development 1. Holistic and Balance Framework Holistic in Ecology, views man and environment as a single system. Watershed is an ecosystem, with numerous physical, biological and social components that are intricately related to one another. Its properties and behaviors are the products or the interactions between its components as influenced by other systems and factors around it. It is largely affected by human activities and climate. In return, its properties and behaviors affect human activities and climate. It is a complex natural system, which easily responds to the alteration of almost any of its compartments. To manage its sustainability, it is therefore essential to treat all compartments with equal importance. Watershed has many uses. They are ecologically, environmentally and socio-economically important being intimately attached to climate and socioeconomic systems. Figure 14. Showing Interrelationship of biotic and abiotic components in an ecosystem.  2. Sustainable Management and Development Sustainable development is meeting the needs of the present generations without compromising the ability of the future generations to meet their own needs. (World Commission on Environment and Development. 1987, cited in the Philippine Agenda 21). 3. Participatory Approach and Equitability Watershed is a common property with many stakeholders. The benefits derived from a watershed should be equitably shared among all stakeholders who are willing to participate and invest in the management of watershed resources. Some of the major watershed stakeholders include the state, the forest communities, the local government units, water users, and the forest-based industry sector. Sustainable participation of major stakeholder is essential due to the complex nature of watershed ecosystem and the magnitude of tasks needed to be performed. The path to sustainability of watershed resources is replete with roadblocks that will become less formidable only with the concerted efforts of stakeholders. 4. Efficiency and Effectiveness Economics financial resources are usually associated with watershed management for so many years, money is always a constraint. It is therefore important that needs are properly identified and prioritized within the context of a sound management plan to meet whatever money is available that can be spent on project that are truly worthwhile and can most effectively address the prioritized needs. It is also important to ensure that land, water, timber and other watershed resources are allotted and used efficiently. That is, environmental and economic benefits derived from resource use are maximized and the associated costs minimized. 5. Multi- sectoral and Interdisciplinary Approach *All the agencies involved, including the community organizations/people. *Field of experts Activity 2 1. Identify the 3 causes of, and recommend mitigating measures to, the declining productivity of upland agricultural farms. (3 points) 2. Discuss or explain the effects of watershed condition to, rainfall run-off and erosion in figure 13. (4 points) 3. Under the principles governing watershed management and development the number 1 principle “Holistic in ecology, views man and environment as a single system”. What are these referred to as physical, biological, and social components that are intricately related to one another? (3 points) Name: _____________________ Section: __________ Answer Sheet for Activity 2 Note: Follow the format provided below in answering the questions. 3 causes of declining productivity Recommended mitigating measure of agricultural Land 1 2 3 4-6. Ground cover Effect to Run-off Effect to Erosion Good ground cover 4 Fair ground cover 5 Poor 6-7 8-10 Components of Ecosystem Referred to as Physical 8 Biological 9 Social 10 Learning Packet 3: Lessons to Learn: After reading the lessons on evaporation, condensation, transpiration and precipitation of the hydrologic cycle you should be to: 1. Explain how rainfall is formed. 2. Differentiate cold front and warm front, convective, orographic, and cyclonic precipitations II. The Hydrologic Cycle -The hydrologic cycle is a continuous process by which water is transported from the oceans to the atmosphere to the land and back to the sea. (Hydrology Vessmen 1986) Earth’s Water -The ocean contains 96.5 water and 3.5% on land approximately 1% of the earth’s water as fresh water. Hydrologic cycle is expressed as P=RO+E+T+I+S where: P=precipitation T= transpiration RO=run-off I=interception E=evaporation S=soil moisture/storage A) EVAPORATION- Solar radiation heats liquid from bodies of water causing gradually change into a gas or water vapor. Bodies of water Evaporation (water vapor) Condensation (reduction of temperature) Clouds (small water droplets 5to75 micrometers) Coalescence (formation of bigger droplets) Rain (>0.5mm diameter) Factors Affecting Evaporation a. Solar radiation b. Temperature/ Relative Humility c. Volume of available water d. Vegetation/Soil Cover e. Soil B) Condensation- Results of the reduction of temperature by the removal of latent heat of evaporation resulting to liquid product known as condensate. C) Clouds- condensed form of atmospheric moisture of consisting of small water droplets or tiny ice crystals. (Clouds range in size from about 5-75 micrometers or 0.0002to 0.003in) D) Transpiration –evaporation of water particles from plant opening or from stomata of leaves. E) Precipitation- all forms of water deposited on the earth surface and derived from atmospheric vapor. Watch how rainfall is formed? https://youtu.be/nP02YF8_c2E Measurement of rainfall (rain gauges) 1.) Non recording rain gauges 2.) Recording/ automatic rain gauge a.) Weighing recording type rain gauge b.) Tipping bucket Plate 3. Tipping Bucket Plate 4. Weighing recording rain gauge TYPES OF PRECIPITATION 1.) Convective precipitation- results from excessive heating of the earth’s surface, causing water vapor to rise up condense, coalesce and increase in diameter before they fall as raindrop. 2.) Orographic precipitation- wind from the sea or ocean blows the condensed nuclei, towards the seashore, the condensation nuclei, coalesce and increase in diameter before they come across physical barriers usually fall as rain the windward direction. 3.) Cyclonic precipitation- precipitation resulting from movements of air masses due to differences in barometer pressure. Watched how typhoons are formed? 1. https://youtu.be/uzxgYaNm7dc 2. https://youtu.be/W2UDbDXXYGE  Figure 2 Types of precipitation Watch the warm front and cold front https://youtu.be/huKYKykjcm0 2 Types of cyclonic precipitation a.) Non-frontal- low pressure area is –lifted by air masses, followed by cooling and raindrop formation. b.) Frontal –opposite air masses with different temperature meet precipitation occurs at the boundaries of the masses. 4. Clouding seedling- silver iodide plus dry ice (solid carbon dioxide) is sprayed into the clouds which attract several small water droplets to come together to form raindrops. Learning packet 5 Lessons to Learn: After reading the lessons on subsurface flow, percolation, and streamflow of the hydrologic cycle you should be able to: 1. Explain the importance of subsurface flow, percolation and streamflow in sustaining and recharging the water table in rivers; 2. Discuss the relationships of percolation to artesian wells, geysers, and aquifers; 3. Enumerate the importance of measuring stream flow; 4. Compute for streamflow discharge; and 5. Interpret a hydrograph. I.) Subsurface Flow – inters the ground water aquifer and then slowly finds its way to streams. (above water table) J.) Percolation – water that percolate to a great depth and then appears after long time intervals often as distant points as springs, artesian wells, and geysers (below water table) Factors Affecting Percolate 1.) water content of soil 2.) vegetation 3.) depth of soil K.) Stream-flow – movement of water under the force of gravity through a defined semi-permanent channel. - Stream flow hydrograph – graphical representation of a stream-flow discharge - Common units of stream-flow discharge in the Standard International (SI) is expressed in cubic meter per second. Watershed Characteristics that Affects Stream-flow a.) Size of watershed b.) b.) Shape of watershed c.) c.) Channel slope d.) Drainage density and network e.) Presence of bodies of water within the watershed Variables that Affect Stream-flow a.) intensity of rainfall b.) duration of rainfall c.) amount d.) land use  e.) condition of watershed f.) type of vegetation Importance of Stream-flow 1.) Planning for flood control 2.) Estimating the dependability of water supply 3.) Designing reservoir storage Parts of Stream-flow Hydrograph 1.) Rising limb – refers to abrupt or gradual increase in water level in rivers depending on the condition of watershed or intensity of rainfall. 2.) Falling limb/recession - refers to either abrupt or gradual decrease in water level in rivers depending on the condition of watershed or intensity of rainfall. 3.) Peak flow –refers to the highest water level in the river or stream. Hydrograph Quantity (water) 15 Peak flow 10 Rising limb (the graph shows abrupt increase of water level) 5 Falling limb (the graph shows abrupt decrease of water level) 0 5 10 15 Time Figure 3 Stream-flow hydrograph - Hydrograph – graphical representation on the rise and fall of water volume or discharge in a river for certain period of time expressed in cubic meter per second. Measurement of Velocity 1.) Floatation method 2.) Current meter Sedimentation 1.) Sediment – refers to soil particles that are transported by stream flow 2.) Sedimentation - process of deposition of transported soil particles, gravels and cobbles 3.) Sediment yield – total sediment outflow from the watershed 4.) Suspended load – portion of the sediment discharge consist of fie soil particles, such as silt and clay which are transported in suspension. 5.) Bed load – portion of the sediment discharge consist of sand gobbles and gravels 6.) Total sediment load –b bed loads and suspended loads Mode of Transport 1.) Suspension - sediments are suspended in water 2.) Saltation – bouncing sediments 3.) Bed load - sediments that move constantly in contact with the steam bed. Stream-flow ___________________________________________________________________ Suspension (silts or clay) Bed load …………………………………………………………………………………………………………………………….. Water surface Saltation Figure 4. Sediments transported by water current Figure 5 hydrograph of a forested and denuded watershed Learning Packet 4 Lessons to Learn: After reading the lessons on interception, infiltration, and Surface run-off, you should be able to: 1. Explain the importance of interception to watershed management. 2. Discuss the relationships of infiltration to soil erosion and flooding. 3. Enumerate at least three importance of infiltration to watershed. F.) Interception- refers to rainfall caught by vegetation or crown of trees. Kindly watch this video on how to measure interception. https://youtu.be/VZGioyqIbgU Factors in Influencing Interception A.) Rainfall intensity, duration, and distribution B.) Vegetation characteristics Importance 1.) Influences soil moisture distribution 2.) Reduces the type and quantity of precipitation to be converted to overland flow. TYPES 1.) Through fall- precipitation which is initially or not all intercepted by vegetation then falling directly to the ground. 2.) Stem-flow - precipitation that is initially intercepted and flows through the stem. 3. Interception loss via evaporation – precipitation which is initially intercepted, then converted to water vapor. Methods of Measurement 1.) Direct method -using rainfall gauges over and under the vegetation, the difference between the two represents the intercepted precipitation. 2.) Indirect method - by the use of regression equation, given several dependent factors the interception is estimated. G.) Infiltration –refers to the vertical entry of water from the surface into the soil. Kindly click the you tube link and watch the video of infiltration and Surface Run-off. https://youtu.be/cz-FZ-ADQjE Importance: Major process that recharges the water table. Factors Affecting Infiltration Capacity 1.) Thickness of saturated layer 2.) Soil moisture 3.) Compaction caused by rain 4.) In wash of fine materials 5.) Entrapped air 6.) Microbial activities 7.) Soil porosity 8.) Land uses – logging, road construction, kaingin, grazing Measurement of Infiltration a.) areal measurement – analysis of rainfall run- off data from a watershed. b.) Point measurement eg.Ring infiltrometer -sinle ring -double ring Kindly watch the you tube videos on how to measure infiltration. Single ring infiltration measurement: https://youtu.be/9KSdTFHA_E4 Double ring infiltration Measurement: https://youtu.be/W3YzCxOf5LE Range of Soil Infiltration Values (mm/hr) 250 very rapid H.) Surface Run-Off – refers to water flowing on soil surface as a result of soil saturation SRO occurs when rate of precipitation exceeds the rates of which water infiltrates. Factors Affecting Run-Off 1.) Climate factors a.) Type of precipitation b.) Rainfall intensity c.) Duration of rainfall d.) Distribution of rainfall on basin 2.) Physiographic factors a.) Land use b.) Area c.) Shape d.) Elevation e.) Slope d.) Orientation Methods of Measuring SRO 1.) Use of run-off plots 2.) Weirs or Flumes Activity 4 1. Explain the importance of interception to watershed management. (2 points) 2. Discuss the relationships of infiltration to soil erosion and flooding. (2 points) 3. Enumerate at least three importance of infiltration to watershed. (3 points) 4. Interception loss via evaporation is a type of precipitation that reaches the ground. Do Agree or disagree, Why? 5. How much is the amount of intercepted rainwater if the rain-gauges above and below the tree collected 100 ml, and 70 ml respectively? Learning Packet 6 Lessons to Learn: After studying and reading the hydrologic cycle illustrations of a denuded and forested watersheds, and reading the lessons on water augmentation respectively, you should be able to: 1. Differentiate the hydrologic cycle undergoing in forested and denuded watershed. 2. Enumerate water augmentation practices in your places. Hydrologic Cycle in Forested and Denuded Watershed The two illustrations of forested and denuded watersheds (Fig. 6) summarizes the differences of the hydrologic processes involve in the hydrologic cycle. See the illustrations and note the differences. A. Forested Watershed B. Denuded Watershed Figure 6 Denuded and Forested Watershed A Activity 5 Note: Use 1 page only 1. Enumerate at least 4 hydrologic processes missing or that changes in a denuded watershed compared to the forested watershed. (4 points) 2. Enumerate and show picture of at least 3 water augmentation practices of farmers or residents in your home town or other municipalities in Benguet. (6 points).