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The Soils of Riley Park : An Argument for Science-Based Park Design Williams, Evan; McCallum, Marie; Simcoe- Metcalfe, Eli; Fung, Allison 2020

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      The Soils of Riley Park; An Argument for Science-Based Park Design Evan Williams, Marie McCallum, Eli Simcoe-Metcalfe, and Allison Fung  UBC ENVR 400 2019/20  IN PARTNERSHIP WITH LITTLE MOUNTAIN NEIGHBOURHOOD HOUSE  Acknowledgments  We would like to thank LMNH for the opportunity to work on this project. Thanks to Maayan Kreitzman for her support and insight throughout the project and to the rest of the teaching team, Tara Ivanochko and Michael Lipson, for facilitating a productive learning environment. We have the utmost gratitude for our community partner, Professor Emeritus, Arthur Bomke. Art provided invaluable guidance throughout the term, this project would not have been possible without his knowledge and insight. His passion for soils and the community inspired a deeper learning and connection to the project. Finally, we would like to thank Sharlene Singh and the students of Brock Elementary for allowing us to share our knowledge of Riley Park.   We would like to acknowledge that our project and data collection took place on the unceded, ancestral, and occupied, traditional lands of the xʷməθkʷəy̓əm (Musqueam), Səl̓ílwətaʔ (Tsleil-Watuth), Stó:lō, Shíshálh (Sechelt) and Skwxwú7mesh (Squamish) Nations of the Coast Salish peoples.                                    Executive Summary    Greenspaces are an essential part of city life, providing a retreat from daily life stressors, increasing self-esteem and promoting higher life satisfaction. It is important that urban parks are available to the public and usable throughout the year and all seasons. When designing a park, it is important to consider community objectives, and the underlying science of the park, such as soil type and distribution. Soils are key in understanding drainage capacity and promoting biodiversity by planting vegetation in the proper type of soil that best promotes growth.  Using Riley Park as a case study, this report highlights the benefits of high-resolution surface soil distribution mapping for urban park design. In addition, it builds upon the Vancouver Soil Map and describes the geological history of Riley Park.    Surface soil distribution maps were created from in field soil sampling (Figure E1). Samples were analyzed by texture and colour and were taken throughout the park along known soil boundaries. Four main soil types were classified: Glacial Marine soils, Glacial Till soils, Sunshine Sand, and Anthroposols. Compaction data was also recorded at each soil sampling location in order to make comparisons between soil type and compaction rate. Puddle observations were recorded using a GPS and visually compared to compaction data in order to infer trends. Percent coverage of impermeable surfaces was calculated by subtracting the total soil covered area from the total area using an aerial photograph.     Natural and human made (anthropic) soils were found throughout the park.  Glacial till, glacial marine and sunshine are naturally derived soils deposited by glaciers during the last glaciation. Glacial till soil is a more coarse-grained soil formed from the till left behind by glaciers on land and is considered to be well-drained. Meanwhile, glacial marine soil is a finer-grained soil formed from sediments that were released from glaciers over a marine environment. Glacial marine soil has a larger pore size distribution, allowing it to retain more water and drain less easily than glacial till soil. Lastly, sunshine sand, which has a similar texture to beach sand is characterized as a moderately well to well-drained soiled with a low to moderate water holding capacity. The presence of sunshine sand indicates that a shoreline once existed along the northwestern edge of Riley Park.    Anthroposols are human-made or altered soils. In Riley Park, the anthroposols originate from varying sources. The majority of the anthroposols deposited during the redevelopment of Riley Park are repurposed soils (mineral fill materials) transported from construction sites in the region. This soil is easily compacted and is the culprit of many of the drainage issues in the park. Other types of anthropic soils are found throughout the park including in the community garden which is composed of a much more nutrient rich soil in order to support plant growth. The anthroposols in the north quadrant of Riley Park are a major source of hydrological issues which is thereby negatively affecting park usability.    The hydrological and park usability issues in Riley Park showcase the importance of integrating science and community-based approaches to urban park design. Furthermore, understanding the history of the soils in the park is important not only for park design but it also serves as an educational tool for school groups and community members, creating a stronger connection to the land.       Figure E1. Map of Riley Park with delineated soil boundaries.     Based on our findings, we have developed several recommendations for urban planners to consider when developing new parks in order to promote environmentally sustainable and user-friendly greenspaces. The main takeaway from this study is that soils should be thoroughly investigated in order to determine how the park can meet community goals, promote biodiversity, and support natural drainage systems. Parks should be audited regularly to ensure design principles are met and that usability is not seasonally impacted due to poor drainage.        Our Team  Marie McCallum is a fourth year Environmental Science student in the Land, Air and Water concentration with a keen interest in sustainable soil science, sustainable watershed management and remote sensing. With experience working in a remote sensing laboratory as a work learn student at UBC, Marie has developed a passion for mapping. She also has experience with water quality management and soil sampling and analysis.   Eli Simcoe-Metcalfe is a fourth year Environmental Science student in the Land, Air and Water concentration with a keen interest in sustainable environmental design, restoration and water management. After two years working for BC Parks, Eli has developed a passion for developing spaces in which humans and nature can interact symbiotically. His dream job would be in the field of sustainable park design.   Allison Fung is a fourth year Environmental Science student in the Ecology and Conservation concentration with a keen interest in exploring different biological interactions within different ecosystems. Equipped with knowledge regarding ecology and plant science, she hopes that her contributions to the project can involve the community by educating them about the different soils found in the park.   Evan Williams is a fourth year Environmental Science student in the Land, Air, Water concentration with an interest in sustainable water management and conservation. Evan has developed his passion for conservation while working for Parks Canada in Jasper National Park and contributing to various different monitoring projects. He hopes to work in the in hydrological related field after graduation.                         Table of Contents EXECUTIVE SUMMARY .......................................................................................................................................... 2 OUR TEAM .................................................................................................................................................................. 4 1. INTRODUCTION .............................................................................................................................................. 7 2. PROJECT OBJECTIVES ................................................................................................................................. 7 3. BACKGROUND INFORMATION: THE NATURAL STATE OF RILEY PARK .................................... 8 3.1     HISTORY OF RILEY PARK .................................................................................................................................. 8 3.2 THE SOILS OF RILEY PARK .......................................................................................................................... 9 3.2.1 Glacial Marine Soils ............................................................................................................................ 11 3.2.2 Glacial Till Soils ................................................................................................................................... 11 3.2.3 Sunshine Sand ...................................................................................................................................... 11 3.2.4 Anthroposols ......................................................................................................................................... 11 3.3 THE VANCOUVER SOIL MAP ...................................................................................................................... 12 3.4 URBAN HYDROLOGY ................................................................................................................................. 13 3.5 WHAT DOES THIS PROJECT ENTAIL? ........................................................................................................... 14 4. METHODS ........................................................................................................................................................ 14 4.1     SOIL SAMPLING DESIGN .................................................................................................................................. 14 4.2 FIELD SAMPLING PROCEDURE .................................................................................................................... 15 4.2.1 Colour & Texture characterization ...................................................................................................... 15 4.2.2 Depth to Compaction ........................................................................................................................... 16 4.2.3 Water Drainage Approach ................................................................................................................... 16 4.3 MAPPING .................................................................................................................................................... 16 4.3.1 Soil Boundaries .................................................................................................................................... 16 4.4 SOIL TYPE & PAVED SURFACE PROPORTIONS ........................................................................................... 17 4.5 VISUALIZING DEPTH TO COMPACTION ...................................................................................................... 17 4.6 ANALYSIS OF WATER DRAINAGE .............................................................................................................. 17 4.7 COMPARISON AND VALIDATION ................................................................................................................ 17 5. RESULTS .......................................................................................................................................................... 17 5.1     SOIL DISTRIBUTION ......................................................................................................................................... 17 5.2 SOIL COMPACTION ..................................................................................................................................... 20 5.3 DRAINAGE ................................................................................................................................................. 22 6. DISCUSSION .................................................................................................................................................... 23 6.1    A STORY TOLD BY SOILS .................................................................................................................................. 23 6.2 PARK DESIGN: WHY A SCIENCE-BASED APPROACH? ................................................................................. 24 6.3 VARIABILITY IN SOIL COMPACTION .......................................................................................................... 25 6.4 EDUCATION: BROCK ELEMENTARY SCHOOL ............................................................................................. 25 7. CONCLUSION ................................................................................................................................................. 25 8. RECOMMENDATIONS FOR URBAN PARK PLANNERS ...................................................................... 26 REFERENCES ........................................................................................................................................................... 26 APPENDIX ................................................................................................................................................................. 28   Table of Figures Figure 1. a) Riley Park prior to the demolition of the Riley Park Community Centre and Percy Norman pool. b) Riley Park after the completion of its new design in 2016. ______________________________________________ 9 Figure 2. Soil samples collected in the field using a soil auger. The soil types are presented as follows: a) glacial till, b) glacial marine, c) sunshine sand, and d) anthroposol. __________________________________________ 10 Figure 3. The Vancouver Soil Map. The red, green, blue and purple colours represent the Langley-Cloverdale (marine sediments parent material), Whatcom-Scat (glacial marine parent material), Bose-Heron (glacial till parent material), and Delta-Tsawwassen (fluvial and marine parent materials) soil management groups, respectively. __________________________________________________________________________ 12 Figure 4. A close-up image of Riley Park from the Soil Map of Vancouver. The soils of Riley Park are entirely classified as part of the Bose-Heron (glacial till parent material) soil management group. ___________________ 13 Figure 5. A conceptual framework for urban park design that incorporates both science and community-based approaches. _________________________________________________________________________________ 14 Figure 6. Map showing hypothetical transition zones highlighted in yellow. 10m long transects are detailed by the red lines, the red “x” indicates a sampling location along the transects. This map was utilized as our preliminary sampling location guide. _______________________________________________________________________ 15 Figure 7. Example of vegetated plot (highlighted in blue) _____________________________________________ 15 Figure 8. An example of the soil boundary being drawn midway between a glacial till soil sampling point (red) and an anthropic soil sampling point (blue). ___________________________________________________________ 16 Figure 9. Map of Riley Park with delineated soil boundaries __________________________________________ 18 Figure 10. Percent distribution of soil types across the entire area of Riley Park. The park is composed of 43.9% natural soils (glacial marine, glacial till, and sunshine sand), 51.7% human-derived soils/surfaces (anthroposols and paved surfaces), and 4.4% unknown soils. ______________________________________________________ 19 Figure 11. Percent distribution of soil types in the north quadrant of Riley Park. The majority of the north quadrant of the park is composed of human-derived soils and surfaces (anthroposols and paved surfaces), totalling 81.3% cover. ______________________________________________________________________________________ 19 Figure 12. Percent distribution of soil types in the north quadrant of Riley Park. The majority of the south quadrant of the park is composed of natural soils, totalling 78.6% cover. ________________________________________ 20 Figure 13. Map of Riley Park with delineated soil boundaries, overlain with soil compaction points, ranging from high to low soil compaction. The lowest compaction measurement being 4 cm and the highest compaction measurement being >90 cm. ____________________________________________________________________ 21 Figure 14. Strip plot of soil depth to compaction for each soil type. Error bars and points show the distribution among compaction values for each soil type. No error bars displayed for sunshine sand as only one sample was found for this soil type. ________________________________________________________________________ 22 Figure 15. Map of Riley Park with delineated soil boundaries, overlain with soil compaction points and locations of observed areas of poor drainage (i.e. surface pooling of water). ________________________________________ 23  Table of Tables Table 1. Average depth to compaction calculated for each soil type throughout Riley Park with associated standard deviation. Only one sample of sunshine sand was found, therefore no mean or standard deviation was calculated. 20        1. Introduction  There is a growing realization that interactions with nature provide many desirable outcomes in terms of human well-being (Lin et al., 2014). For example, urban nature is connected with a greater capability to manage life stressors, higher life satisfaction and even increasing self-esteem (Sturm & Cohen, 2014). Urban dwellers now exceed 50% of the global population, and urban areas are predicted to absorb the majority of the continued population growth over the next four decades (UN, 2010). To ensure that urban dwellers continue to be close to nature, it is imperative that urban parks are maintained and that green spaces are expanding at the same rate as urban population growth.     Urban parks are also beneficial to the ecological environment of cities (Tse & Chau, 2012). They can help fight pollution, increase biodiversity in cities, and help regulate temperature and humidity (Smardon, 1988). Furthermore, urban parks have the ability to help mitigate surface runoff by draining excess water into soils (Kokkonen et al., 2018). This is especially important in cities such as Vancouver where the storm drainage system is increasingly stressed during the winter due to consistent rain events. In addition, cities are more susceptible to flooding as the proportion of land area covered by impermeable surfaces increases with increasing urbanization.    Urban park design is primarily dictated by its visual aesthetic quality and the activities it is hoping to offer (Tse & Chau, 2012). This can be seen in Riley Park which contains a variety of vegetation, terrain features and soccer and baseball fields. However, as this project report will show, a more science-based design approach may be imperative to practice more environmentally sustainable park design. An important first step to achieving this goal is the development of a comprehensive understanding of the surface soil distribution in an urban park. In this project, we build upon the Vancouver Soil Map which generalizes the soils of Riley Park as a singular soil type. The results of this project demonstrate the benefits of high-resolution soil mapping for soil management practices.    2. Project Objectives    I. To build a comprehensive map of surface soil distribution in Riley Park.    The surface soil distribution map enhances Little Mountain Neighbourhood House’s scientific understanding of Riley Park by providing it with an accurate and in-depth classification of the soil types present in the park at a local scale.    II. To identify trends between soil type, soil compaction and areas of poor drainage.    A secondary map was developed to visually identify connections between soil type, soil compaction and areas of poor drainage. To accomplish this, soil compaction measurements and georeferenced areas of poor drainage were overlaid onto the surface soil distribution map of Riley Park.    III. To aid in further assessment of park remediation efforts according to the key design principles put out by the Riley Park-Little Mountain Neighbourhood Community.    Using the secondary map, we highlight areas of poor drainage that exist in the redeveloped section of Riley Park. The key design principles did not include science-based goals, such as maximizing the drainage capability of the park. Areas of poor drainage in the redeveloped part of Riley Park affect park usability and demonstrate a missed opportunity to help mitigate surface overland flow thereby reducing stress on the Vancouver storm drainage system. This suggests that a science-based approach to park redesign is as important as a user experience-based approach.   3. Background Information: The Natural State of Riley Park    3.1     History of Riley Park  Riley Park is one of the two-hundred and forty public parks operated by the Vancouver Board of Parks and Recreation. In 1893, pioneers and loggers first reached the area that is now Riley Park while cutting trails around Little Mountain. By the early 1900s, a small community had established itself around Main Street (Riley Park, n.d.). In the 20th century, the Riley Park-Little Mountain Neighbourhood developed into a prominent community within the city of Vancouver. The growing population in the Riley Park-Little Mountain Neighbourhood resulted in the heavy urbanization of the area, leaving Riley Park as one of the few remaining green spaces in the community.     Riley Park was not always as green as it is today; the completion of the Hillcrest Centre for the 2010 Winter Olympic Games resulted in the demolition of the Riley Park Community Centre and the Percy Norman Pool in 2012. These buildings covered nearly the entire northern quadrant of Riley Park (Figure 1a). The demolition of the Riley Park Community Centre in 2012 allowed for a community garden to be established (Figure 1b). Construction of the newly designed Riley Park began in January 2016 and was completed in September 2016. Today, the park brings community members together, and is frequented by those who use the park for a variety of recreational activities. It is also home to the Riley Park Community Garden which supports neighbourhood organizations and charities with food grown from the garden.                                     Figure 1. a) Riley Park prior to the demolition of the Riley Park Community Centre and Percy Norman pool. b) Riley Park after the completion of its new design in 2016.    3.2 The Soils of Riley Park  Riley Park is primarily composed of three soils which are formed from different parent materials; glacial marine, glacial till and anthroposols. There is also a small area of the park that is composed of sunshine sand. The glacial marine, glacial till and sunshine sand that we observe today are the result of the most recent glacial period which occurred between 25 000 and 11 000 years ago (NOAA, n.d.).  In contrast, the anthroposols are recently deposited soils that have been modified or created as a result of human activities. Each soil type has a unique colour and texture which allows their parent material and soil development to be identified visually and texturally.     a) b)    Figure 2. Soil samples collected in the field using a soil auger. The soil types are presented as follows: a) glacial till, b) glacial marine, c) sunshine sand, and d) anthroposol.        a) b) c) d) 3.2.1 Glacial Marine Soils   Glacial marine soils are naturally occurring, derived from sedimentary materials that were released into the ocean as the ice sheets receded during the last glaciation period (Iverson et al., 2011). The materials embedded in the ice, including silts and clays sank through a marine environment where they were incorporated into the sediments and glacial till (Iverson et al., 2011). As the overlying pressure on land caused by the ice sheets decreased, the land eventually underwent isostatic rebound causing the glacial marine soils to be exposed to the atmosphere (Vancouver Soil Map, n.d.).     In Vancouver, glacial marine soils tend to be situated in elevations between 35 and 65m above sea level, accompanied with an undulating topography (Iverson et al., 2011). These soils have a silt loam to silty clay loam texture causing it to feel smooth to touch. In addition, variable amounts of larger stones and fragments are typically embedded in the finer matrix of the marine soils (Iverson et al., 2011) (Virtual Soil Science Learning Resources, 2011). Glacial marine has a medium to high available water-holding capacity due to the distribution of pore sizes. This soil is typically moderately to well-drained on slopes, but poorly drained in depressions. Lastly, glacial marine is susceptible to compaction (Iverson et al., 2011).     3.2.2 Glacial Till Soils   Glacial till soil is a naturally occurring soil derived from land-based deposits of rocks and other sedimentary material that were released as the ice sheets melting during the last glaciation period. The pressure induced by the ice sheets onto the deposited rocks caused them to be crushed into fine particles, forming deposits of soils (Iverson et al., 2011). In Vancouver, glacial till soils are normally situated at elevations greater than 65m above sea level, with a level topography. (Iverson et al., 2011). These soils have a gravelly sandy loam to loamy sand texture, causing it to feel coarser than glacial marine soils. Glacial till soils have a relatively high volume of pores, however they are not large enough to hold much water against the force of gravity (Art Bomke, Personal Communication, March 30th, 2020). Consequently, glacial till soils have low capillary pressure. Glacial till is considered moderately to well-drained on knolls and typically poorly drained in depressions (Iverson et al., 2011). Lastly, it is less susceptible to compaction relative to its glacial marine counterpart.     3.2.3 Sunshine Sand   Sunshine sand is a naturally occurring soil which was derived from glacio-fluvial deposits that were deposited by flowing water as the ice sheets receded during the most recent glaciation (Luttmerding, 1981). In Vancouver, sunshine sand is mostly situated at elevations between 20 and 150m above sea level. Their texture is characterized as sandy loam, varying occasionally to loamy sand or loam. Sunshine sand is a moderately well to well-drained soil which has a low to moderate water holding capacity (Vancouver-Langley book). Sunshine sand is commonly associated with the presence of glacial marine and glacial till soils (Vancouver-Langley book). The presence of sunshine sand is historically significant as it indicates that there once existed a shoreline along the northwestern edge of Riley Park.    3.2.4 Anthroposols   Anthroposols are azonal soils that have been modified or created as a result of human activities. Anthropic soils are commonly used for land reclamation after environmentally damaging human activities such as mining or construction (Naeth et al., 2011). In Vancouver, the city creates its own anthropic soil which is typically composed of residential compost-waste that is mixed with dredge sand (City of Vancouver, 2020). That being said, anthroposols can be derived from other sources as well. A natural soil can be classified as an anthroposol if its soil profile is significantly modified from its natural state (Naeth et al., 2011).    In Riley Park, the anthroposols originate from varying sources. The majority of the anthroposols deposited during the redevelopment of Riley Park are repurposed soils (mineral fill materials) transported from construction sites in the region (Arthur Bomke, Personal Communication, March 16th, 2020). These repurposed soils are characterized by their darker colour and gritty texture. Meanwhile, the raised beds in the community garden were constructed using a sandy loam mineral soil mixed with 25% spent mushroom compost, Super Soil, obtained from Surrey (Arthur Bomke, Personal Communication, March 16th, 2020).     3.3 The Vancouver Soil Map   The Vancouver Soil Map is a web-based tool that provides information about soil formation, urban agriculture, and soil types within the city of Vancouver (Vancouver Soil Map, n.d.). Currently, it is the highest resolution map of surface soil distribution in Vancouver. That being said, the Vancouver Soil Map is not completely accurate as the map is not ground-truthed at all locations (Vancouver Soil Map, n.d.).  As a result, soil management groups are generalized across larger areas than is actually true. For example, the Vancouver Soil Map classifies all the soils in Riley Park as Bose-Heron, i.e. glacial till. However, the high-resolution soil mapping of Riley Park performed in this project has shown that the park is composed of multiple soil types. This demonstrates that though the Vancouver Soil Map is useful, it is too general to use for the effective soil management of small areas such as Riley Park without ground-truthing    Figure 3. The Vancouver Soil Map. The red, green, blue and purple colours represent the Langley-Cloverdale (marine sediments parent material), Whatcom-Scat (glacial marine parent material), Bose-Heron (glacial till parent material), and Delta-Tsawwassen (fluvial and marine parent materials) soil management groups, respectively.      Figure 4. A close-up image of Riley Park from the Soil Map of Vancouver. The soils of Riley Park are entirely classified as part of the Bose-Heron (glacial till parent material) soil management group.    3.4 Urban Hydrology   The hydrology of Riley Park has been impacted by past construction in the park and the urbanization of the surrounding area (Arthur Bomke, Personal Communication, October 23, 2019). The urbanization of the Riley Park-Little Mountain neighbourhood resulted in the park being surrounded by impervious ground surfaces. The construction of the Community Centre/Percy Norman Pool as well as recent remediation efforts introduced anthropogenic soils to the park.     These human interventions in Riley Park caused the development of severely compacted soils in certain areas of the park (Art Bomke, Personal Communication, October 23, 2019). Consequently, this has affected the original drainage ability of Riley Park, and it is now more susceptible to overland flow (Arthur Bomke, Personal Communication, October 23, 2019). Considering that Riley Park contains mostly open areas, the fate of rainfall is largely decided by ground cover. In attempts to counteract excess water runoff, storm drains now exist throughout the park.    The current hydrological state of Riley Park is an example of a missed opportunity. Urban parks can act as important drainage areas for cities and reduce stress on the city drainage system (Kokkonen et al., 2018). A paper written by Zhang and Peralta (2018) found that directing runoff from roofs, sidewalks and streets to grass swales can significantly reduce runoff and infiltration. Interestingly, the north quadrant of Riley Park has the characteristics of a grass swale but has consistent pooling of water after rainfall events. The landscape design of the redeveloped north quadrant of the park relies on surface drains to remove excess water.   3.5 What does this project entail?  Riley Park is the first urban park to have its surface soil distribution mapped, in detail, in Vancouver. This project has now provided the city of Vancouver with a template for future mapping of soils in its urban parks. In addition, this report discusses how the methodology used for this project can be improved. Most importantly, the report highlights why understanding the surface soil distribution of a park leads to more environmentally sustainable park design.           Figure 5. A conceptual framework for urban park design that incorporates both science and community-based approaches. 4.  Methods   4.1     Soil Sampling Design  Initial soil sampling transects were based on the hypothesized permeable soil transition zones detailed by Dr. Bomke (Figure 6). Additional transects were then added to account for unsampled areas of the park and to build a more comprehensive soil characterization of Riley Park. Transect lengths varied based on the shape and length of the transition zones and vegetated plots in the park. A vegetated plot being defined as a vegetated area of the park that is bounded by impermeable surfaces (Figure 7). For each transect, soil samples and depth to compaction measurements were taken at even intervals. For example, a 10-metre-long transect had sampling points and depth to compaction measurements at 0m, 5m, and 10m. Soil type was assessed visually using texture and colour. Soil observations and depth to compaction values were recorded into a datasheet with associated GPS points.     During our fieldwork, the GPS had a measurement error ranging from 2 meters to 10 meters. As a result, the soil sampling transects were not accurately projected onto our initial map. To account for this discrepancy, the projected GPS points were ground-truthed using a field data sheet that detailed the location of the same transects (Appendix, A1).    However, the measurement errors introduced uncertainty into the mapping of the soil type boundaries. The smaller vegetated plots are the most sensitive to measurement error due to their smaller area. Therefore, the uncertainty of soil boundary locations is higher in smaller vegetated plots. In the future, GPS measurement error can be minimized by conducting fieldwork during clear skies allowing the GPS time to locate additional satellite units and by using a more accurate GPS unit such as a Trimble.       Figure 6. Map showing hypothetical transition zones highlighted in yellow. 10m long transects are detailed by the red lines, the red “x” indicates a sampling location along the transects. This map was utilized as our preliminary sampling location guide.       Figure 7. Example of vegetated plot (highlighted in blue)   4.2 Field Sampling procedure  4.2.1 Colour & Texture characterization  Soil samples were taken using an auger in the locations specified by the transects. Samples were collected from depths between 20-40 cm to analyze the B horizon. Soil type was determined using colour and texture. Colour was determined using the Munsell Colour Chart and texturization was performed following the techniques outlined in The Soil Management Guide for the Lower Fraser Valley (Bertrand et al., 1991). A photo was taken for each soil sample for future reference.     4.2.2 Depth to Compaction  For each soil sampling location, depth to compaction was measured using a cone penetrometer (Bertrand et al., 1991). The diameter of the penetrometer used was 30 mm and due to its length, the maximum depth that could be recorded was 90 cm (Agridry Rimik PTY Ltd., Toowoomba, QLD, Australia). Additional depth to compaction measurements were performed in areas of the park with sparse sampling sites. The cone penetrometer was pushed into the ground until it reached an impenetrable layer and depth of compaction was measured based on the length of penetrometer embedded in the ground. The measurements were recorded in a field notebook.    4.2.3 Water Drainage Approach  We visited Riley Park on two separate occasions after sustained rainfall events and conducted a visual assessment of the park to identify any regions where indicators of poor drainage are present. Indicators of poor drainage included pooling water, excessively muddy ground or observable excess overland flow. These areas were photographed and described in a field notebook and georeferenced with a GPS point. In an effort to record location data that is representative of the area affected, the coordinates were taken from the center of the region of interest (i.e. the middle of the puddle). This is the most representative approach as the contours of these areas are susceptible to change through time. By recording the centermost point, we provided the most probable location of repeated occurrences.    4.3 Mapping   4.3.1 Soil Boundaries  The GPS data was downloaded as a .csv and KML file using Garmin BaseCamp. The recorded depth to compaction and soil types were then added to the .csv. The KML file was uploaded to Google My Maps to project the sampling points onto Riley Park and perform preliminary soil boundary delineation. The locations of the projected transects were ground-truthed using the field map of the transects (Appendix, A1). Soil type boundaries were delineated using the polygon feature. In the areas where a soil type transition occurred, the soil boundary was drawn midway between the sampling points (Figure 8). Each polygon is colour coded to represent the different soil types.                         Figure 8. An example of the soil boundary being drawn midway between a glacial till soil sampling point (red) and an anthropic soil sampling point (blue).  4.4 Soil Type & Paved Surface Proportions   Area measurements for each soil type were calculated by the Google My Maps polygon feature while defining the soil boundaries. The area of Riley Park was calculated using the Google My Maps polygon feature where the outer sidewalks and streets defined the perimeter of the polygon. The area of all the polygons for each individual soil type were then summed and divided by the area of Riley Park to calculate the proportion of each soil type in Riley Park. The remaining proportion of the park was equivalent to the area of paved surfaces in Riley Park as the paved surfaces were unaccounted for with the polygon feature.   4.5 Visualizing Depth to Compaction   To visualize depth to compaction, the size of the associated GPS point was made to be proportional to the depth to compaction value, with larger circles representing less compact soil and smaller circles representing highly compact soil. This was accomplished by normalizing the depth to compaction values and using the ArcGIS proportional symbols renderer to scale the GPS points to size. The normalized data was on a scale from 0 to 1 with 0 representing the most compact data (4 cm) and 1 representing the least compact data (90 cm).    4.6 Analysis of Water Drainage   The georeferenced areas of poor drainage were overlaid onto the soil type polygons and weighted depth to compaction points. The map was then analyzed to visually identify trends between areas of poor drainage, soil type and levels of compaction.    4.7 Comparison and Validation  To compare and validate soil sampling results from the southern half of Riley Park, we used the 2016 PSAI soil sampling results provided by our community partner. The 2016 sampling results provide a chemical analysis of the soils in the southern half of Riley Park, including the percentage of total organic matter for each soil sampling location (Appendix, A2).    5. Results   5.1     Soil Distribution  Glacial marine, glacial till, anthroposols, and sunshine sand were found within the park boundaries. Glacial marine soils are situated in the southern section of the park while glacial till is mostly found alongside the north and northeastern edges of Riley Park (Figure 9). Anthroposols are found across the northern half of Riley Park as well as the southeastern edge of the park (Figure 9). A small area of sunshine sand was identified in the northwestern corner of Riley Park. Around forty-five percent of the park area is composed of natural, pre-existing soil, leaving around fifty-five percent of the park to be made up of human-made constituents (Figure 10). Additionally, the north quadrant is primarily composed of human-derived soils and surfaces while the south quadrant is mainly composed of natural soils (Figure 11 & Figure 12).     Figure 9. Map of Riley Park with delineated soil boundaries      Figure 10. Percent distribution of soil types across the entire area of Riley Park. The park is composed of 43.9% natural soils (glacial marine, glacial till, and sunshine sand), 51.7% human-derived soils/surfaces (anthroposols and paved surfaces), and 4.4% unknown soils.         Figure 11. Percent distribution of soil types in the north quadrant of Riley Park. The majority of the north quadrant of the park is composed of human-derived soils and surfaces (anthroposols and paved surfaces), totalling 81.3% cover.    Figure 12. Percent distribution of soil types in the north quadrant of Riley Park. The majority of the south quadrant of the park is composed of natural soils, totalling 78.6% cover.     5.2 Soil compaction    Soil compaction varies throughout the park with anthroposols having the lowest mean depth to compaction and glacial marine soils having the highest mean depth to compaction (Table 1). The standard deviation for depth to compaction is quite significant for all soil types with anthroposols having the highest standard deviation (Table 1). The high standard deviations indicate highly variable levels of soil compaction for all soil types. The standard deviation values for anthroposol, glacial marine and glacial till soils are all within 4 cm of each other (Table 1). Figure 13 shows a visual representation of the soil compaction data. Soil compaction values appear especially variable in the anthropic and glacial marine soils (Figure 13 & Figure 14). The highest degree of soil compaction was recorded in the coarse anthroposol area of Riley Park (Figure 13). In this area, soil compaction varied between 4 and 8 cm. The lowest level of soil compaction was recorded in the soccer field where compaction values exceeded the max length of 90 cm that could be recorded with the cone penetrometer.    Table 1. Average depth to compaction calculated for each soil type throughout Riley Park with associated standard deviation. Only one sample of sunshine sand was found, therefore no mean or standard deviation was calculated.  Soil Type  Mean Depth to Compaction (cm)  Standard Deviation (cm)  Anthroposol  29  20  Glacial Marine  40  18  Glacial Till  35  17  Sunshine Sand  NaN  NaN     Figure 13. Map of Riley Park with delineated soil boundaries, overlaid with soil compaction points, ranging from high to low soil compaction. The lowest compaction measurement being 4 cm and the highest compaction measurement being >90 cm.                    Figure 14. Strip plot of soil depth to compaction for each soil type. Error bars and points show the distribution among compaction values for each soil type. No error bars displayed for sunshine sand as only one sample was found for this soil type.     5.3 Drainage  Areas of consistent poor drainage are found on the northeastern edge of the soccer field (southern half of park, composed of glacial Marine soil) and on the southeastern side of the oval vegetated plot (Figure 15). The anthropic soils where poor drainage has high to medium compaction (Figure 15). By comparison, there are low levels of soil compaction in the glacial marine areas that have poor drainage. Therefore, the poor drainage in the glacial marine area is not associated with soil compaction and can be linked to other factors discussed in section 7.     Figure 15. Map of Riley Park with delineated soil boundaries, overlain with soil compaction points and locations of observed areas of poor drainage (i.e. surface pooling of water).    6. Discussion    6.1    A story told by soils  The presence of glacial marine, glacial till and sunshine sand in Riley Park is historically significant. These soils tell a story about the possible glacial, marine and land features that once existed in and around the park. The glacial marine soils in Riley Park indicate that the south quadrant was once submerged under the ocean. However, as the ice sheets receded and Riley Park experienced isostatic rebound, it exposed the soils in the southern quadrant of Riley Park to the atmosphere. Meanwhile, the glacial till soils in the north and northeastern sections of Riley Park indicate that the north quadrant was once covered by ice but was not submerged under the ocean. The presence of sunshine sand indicates that there once existed a shoreline along the northwestern edge of Riley Park (Soils of the Langley-Vancouver Map Area, 1981). The presence of anthroposols in Riley Park represents a turning point in the geological history of the park where human interference with the soils of Riley Park begins to take place.     6.2 Park Design: Why a science-based approach?  The results of this project highlight the importance of integrating a science-based approach to urban park design. The prioritization of community principles without scientific support has led to usability issues in Riley Park. Furthermore, the lack of soil management in the redeveloped north quadrant of Riley Park showcases a missed opportunity to help mitigate excessive surface overland water flow currently seen in Riley Park. The consistent poor drainage in the redeveloped north quadrant is a primary example of usability issues due to improper soil management in Riley Park (Figure 15).    For instance, the frequent pooling of water in the oval vegetation plot does not enable park-goers to sit and relax, as the park design principles intended (Figure 15). The oval vegetation plot is designed in such a way that the soils must saturate before water can make its way into storm drains (Dr. Bomke, Personal Communication, March 16th, 2020). Consequently, water pools on the surface of the grass before it flows towards the drain. To make matters worse, the saturation of the soil occurs quickly during a rain fall event due to the medium to high compaction of the anthropic soils (Figure 15).     The pooling of water confirms that soils and their hydrological characteristics should be considered prior to finalizing design initiatives in urban parks. In the case of Riley Park, it is possible that the surface drain dependent drainage system in the north quadrant might have been unnecessary with proper soil management. By using an anthropic soil with enhanced drainage capabilities and by minimizing compaction during and after construction it is likely that consistent overland flow might have been managed more effectively.     Furthermore, the importance of effective soil management is evidenced by Riley Park’s ability to accommodate the increased runoff caused by the internal paved surfaces. The north quadrant of Riley Park is covered by paved surfaces (30% of the surface area in that quadrant) and anthroposols (52% of the surface area in that quadrant). As a result, the relatively low draining capability of the anthroposols are further stressed by the increased runoff from the parking lot and wide concrete walkways. In comparison, only around 9% of the south quadrant is covered by paved surfaces. However, the north quadrant’s reduced drainage capability is also negatively affecting the south quadrant.   A chemical analysis was conducted on a dead tree that once stood by the northeastern edge of the soccer. Results of this analysis showed that there were chemical constituents of glacial till soil in the tree. Glacial till is situated in the northeastern part of Riley Park, indicating that there is subsurface flow moving from the northeast to the centre of Riley Park (Figure 9) (Dr. Bomke, Personal Communications, March 10th, 2020). The runoff from the parking lot is likely increasing the subsurface flow towards the southern half of the park. Consequently, soils such as the glacial marine in the northeast edge of the soccer field are being over-saturated, causing frequent pooling of water. It is unlikely that poor drainage is due to the glacial marine soil itself as it has low compaction and is considered a moderately to well-drained soil. Again, the poor drainage seen in the south quadrant of Riley Park demonstrates that more consideration for soil characteristics of the anthroposols should have been considered in the 2016 redevelopment.     6.3 Variability in Soil Compaction  Figures 13 and 14 show variable levels of soil compaction for each soil type, most notably with the glacial marine soils. The large variability of compaction found in the glacial marine soils can be explained by its physical characteristics and park-goer traffic in Riley Park. A saturated soil is more susceptible to compaction. That being said, glacial marine soils have more silt and clay in their matrix which have smaller pore sizes. These smaller pores fill with water more quickly but also do not drain as easily as large pores, which causes the soil to become saturated more easily.     Consequently, glacial marine soils are more frequently susceptible to compaction during the winter season in Vancouver (Dr. Bomke, Personal Communications, March 10th, 2020). The spatial variation in soil compaction is likely due to traffic by park goers, where areas of high traffic are more compacted, and areas of low traffic are less compacted. In comparison, glacial till soils are less susceptible to compaction due to their larger grain sizes. The increased grain size allows more room for water to flow freely through this soil. This results in well-drained soils, meaning that glacial till is less frequently saturated. Lastly, the glacial till soils are situated in areas with fairly low visitation by park users.    6.4 Education: Brock Elementary School   Once we had finished data collection and had a solid understanding of the soils that make up Riley Park, we spent a day teaching the history of the park and its soils to elementary school classes from Brock Elementary School. This hands-on, tactile learning experience is valuable for everyone involved. For the children, it allows them to participate in outdoor activities and learn a bit about what makes up their backyard. As experts in the field, it is important to develop methods that make your knowledge accessible to any audience in the hopes that the experience impacts their lives and changes the way that they think about something as simple as their local park. By telling a story of the history of soils, we can create a connection to the past and provide a deeper level of understanding.     7. Conclusion    Developing a comprehensive surface soil distribution map is an effective starting point and an essential tool in the designing of an environmentally sustainable urban park that supports community goals. This study of Riley park has demonstrated the importance of exploring the impacts that soils have on urban park hydrology and usability.  Proper soil management can help maximize park usability, mitigate surface overland flow and limit runoff input to city storm drainage systems. Overall, this project is a useful case study for future park design.     That being said, our analysis of the soil profile was limited to the B-horizon. When considering regional hydrological tendencies, it is important to consider what lies in the deeper soils and the soils in contiguous land as these are likely to have large effects on the movement of water in the area (Zhang, Wendroth, Matocha, Zhu, & Reyes, 2020). Furthermore, our fieldwork was introductory using rudimentary equipment and techniques. Although these techniques provide a baseline understanding, laboratory testing is essential to achieve accurate soil identification since colour and texture can be highly variable at a given level of soil saturation. Applying a random sampling method would also be beneficial in developing a stronger scientific argument and performing statistical analyses of soil characteristics in order to develop a more reproducible sampling method that could be applied to other urban parks.     8. Recommendations for Urban Park Planners    • Conduct a comprehensive assessment of Riley Park’s ability to meet the objectives of the park such as playfield use, green space, food production and native plantings. Use the assessment as a case study to help in the design of other parks in the City of Vancouver.     • For future urban park design, integrate an analysis of soil distribution to achieve the overarching goals of sustainable design.    • Focus on natural drainage systems which allow water to recharge aquifers thereby reducing the load on city infrastructure, rather than diverting run-off through culvert systems.   • Establish a team of auditors to evaluate the usability and accessibility of city greenspaces in an effort to identify and rectify design shortfalls leading to interrupted access or usability due to water management issues.         References  BC Treaty Commission. (2020). Interactive Map. [web resource] Retrieved from:             http://www.bctreaty.ca/map  City of Vancouver. (2020). Compost soil. [website] Retrieved from: https://vancouver.ca/home-property-development/compost-soil.aspx  Iverson, M. A., Holmes, E. P., & Bomke, A. A. (2012). Development and use of rapid reconnaissance soil inventories for reclamation of urban brownfields: A Vancouver, British Columbia, case study. Canadian Journal of Soil Science, 92(1), 191–201. doi: 10.4141/cjss2010-029  Kokkonen, T. V., Grimmond, C. S. B., Christen, A., Oke, T. R., & Järvi, L. (2018). Changes to the Water Balance Over a Century of Urban Development in Two Neighborhoods: Vancouver, Canada. Water Resources Research, 54(9), 6625-6642.    Lin, B. B., Fuller, R. A., Bush, R., Gaston, K. J., & Shanahan, D. F. (2014). Opportunity or orientation? Who uses urban parks and why. PLoS one, 9(1).    Luttmerding, H. A. (1981). Soils of the Langley-Vancouver Map Area (Vol #3). British-Columbia Ministry of Environment.   Miller, V. S., & Naeth, M. A. (2017). Amendments and substrates to develop anthroposols for northern mine reclamation. Canadian Journal of Soil Science, 97(2), 266–277. doi: 10.1139/cjss-2016-0145  Naeth, M. A., Archibald, H. A., Nemirsky, C. L., Leskiw, L. A., Brierley, J. A., Bock, M. D., ... Chanasyk, D. S. (2012). Proposed classification for human modified soils in Canada: Anthroposolic order. Canadian Journal of Soil Science, 92(1), 7–18. Doi: 10.4141/cjss2011-028   National Centers for Environmental Information. (2020). Glacial-Interglacial Cycles [website] Retrieved from: https://www.ncdc.noaa.gov/abrupt-climate-change/Glacial-Interglacial%20Cycles  Pawluk, S., & Bayrock, L. A. (1969). Some characteristics and physical properties of Alberta tills. Edmonton: Research Council of Alberta.  Rienzner, M., & Gandolfi, C. (2014). Investigation of spatial and temporal variability of saturated soil hydraulic conductivity at the field-scale. Soil and Tillage Research, 135, 28–40. doi: 10.1016/j.still.2013.08.012  Riley Park. City of Vancouver. (n.d.) Retrieved from https://bit.ly/33zm9tO     Smardon, R. C. (1988). Perception and aesthetics of the urban environment: Review of the role of vegetation. Landscape and Urban planning, 15(1-2), 85-106.    Sturm, R., & Cohen, D. (2014). Proximity to urban parks and mental health. The journal of mental health policy and economics, 17(1), 19.    Tse, M. S., Chau, C. K., Choy, Y. S., Tsui, W. K., Chan, C. N., & Tang, S. K. (2012). Perception of urban park soundscape. The Journal of the Acoustical Society of America, 131(4), 2762-2771.    Vancouver Soil Map. (n.d.). Retrieved from https://vancouversoils.ca/soil-formation/    Virtual Soil Science Learning Resources (Producer). (2011, December 7). Glacio-marine Parent Material [Video file]. Retrieved from: https://www.youtube.com/watch?V=dqjf3vs0xci                      Appendix  Figure A1. Map showing field sampling design for the first site visit. Transects are detailed by the red lines, and the “x” indicates sampling locations along the transects. This map served as a preliminary sampling guide for our first day of data collection.  Table 1A. 2016 soil test results provided by Arthur Bomke. Organic matter results are the primary focus for this report.        

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