Forest Fire Risk Z ones Mapping and Fire Infrastructions in San D iego, CA Introduction
Accessibility
Wild fire in San Diego is a big issue we need to pay primary attention to. The cost on firefighting in a single year of 2007 reaches $80 million. Therefore, by doing this research, we’d like to answer the following 3 questions. 1. Where are the places with the highest possibility of wild fire? 2. How is the accessibility to these locations from the fire stations? 3. In what way can we improve the condition? Our research covers two parts. The first part is a fire risk analysis with multiple geological features including elevation, slope, aspect, land use, distance to road and distance to settlement. Each is with a standard scoring rule and a specific weight. Thus, we can get a map on overall score evaluation of each cell. Next, with the high-risk value areas generated from the map and the location of the existing fire stations, we will conduct a network analysis on the fire infrastructures. By building the service area for the fire stations and calculating the distance from the high-risk areas to the closest fire stations, we can answer the second and third questions.
The result indicates that for 75% regions with high possibility of fire, the accessibility of fire services is less than 6 minute. 90% regions could be reached in 10 minutes. However, some of the regions have relatively low fire-saving accessibility. Some of them could be as long as 20 minutes. For thouse regions, the service of fire station is in need of change.
Hot Spot Analysis
The data analysis is focused on hot spot analysis of target hazard regions. Unising ArcScene, we redefined the region average fire hazard score in hot spot areas. Combine with the street network, it is clear that most hazard zones are located in low-density street area. In hot spot, most of the value that determines whether it is easy to cause fire is relatively high. The demand fire instucted area is the combination of two hazard area-one is areas lack of fire-saving infrastures while the other has higher possibility of fire-issues. Most of the high-demand fire instructed areas are outside the central city while some of them are located in further suburbs. This indicates the suffiency of fire infrastructures in different small areas. Reference:
Intelligent GIS system of forest fire alarm and it’s controlling strategy design Duan, Y. X. ; Cao, J. Z. ; Luo, Z. L. 2011 International Conference on Machine Learning and Cybernetics, July 2011, Vol.4, pp.1809-1814 GIS-Based Forest Fire Risk Assessment and Mapping Gai, Chengcheng ; Weng, Wenguo ; Yuan, Hongyong 2011 Fourth International Joint Conference on Computational Sciences and Optimization, April 2011,
The maps above show the accessibility to the fire stations from the fire stations. The green cross represents hazard regions within 10-minute service area. The orange cross represents hazard regions out of the service area. They are generally located in the south-east part of San Diego where there are fewer fire stations, and fewer roads. The red cross represents the hazard region not accessible by current network, for which we need to build more roads for the fire stations to reach.
Methodology Our model consists of 2 parts. First, we will conduct a multiple-layer suitability analysis about
reclassify
feture analysis
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landuse type forest,argricluture, urban, barren, river,
the possibility of catching wild fire in different areas. By analyzing features and reclassification, we can get the evaluation score of each geological factor (elevation, slope, aspect, landcover, distance to road and distance to settlement), and by assigning different weight in raster calculation, we can get the overall evaluation map. Then, we extract out the areas with high risk and transform into polygon and centroid points. By using the network we built with the road data, we can get the 10-minute service area of the fire stations and the time it takes to each hazard location.
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E valuation map
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road distance 50,100,200, 300,400
distance value 0,1,2,3,4,5
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firestation accessible network net work analysis
Intermediate Results 1. DEM and the result of reclassification. The class division is set at 500, 1000 and 1500. Higher
elevation is easier to catch fire. 2. Slope and the result of reclassification. The class division is set at 5,10,25, 35. Higher elevation is easier to catch fire. 3. Aspect and the result of reclassification. South facing region is the easiest to catch fire. North facing region is the hardest. 4. Distance to settlement and the result of reclassification. The further away to residential area, the lower the risk is. 5. Land cover and the result of reclassification. The order from risk from highest to lowest is nature, agriculture, human landscape, urban and barren land. 6. Distance to road and the result of reclassification. The further away to road, the lower the risk is. 7. The total evaluation score. The risk of the east region is higher than the west, but the high risk regions still scatters in the whole San Diego region.
Living in Parks Stormrm Water Design and Learn frm Savannah The design is based on a flooding issue place. Based on a thorough investigation of Savannah wards and cells, a design strategy of using community parkes beome the solution of storm water problems. The combination of urban design ideas and lanscape architecture design solution offers the place new energy as well as walkable community and public places. Site area:40 acres Contribution: Individual Work Length: 8 weeks Type: Urban Design and Landscape architecutre design
2) Water dynamics and dimensioning on the basis of the assumption that stormwater management requires dimensioning skills from the designer for the calculation of storage volumes and infiltration capacity (see Backhaus et al. 2012; Geldof & Kluck 2008); 0
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3) Stormwater accentuation on the basis of the assumption that landscape-based stormwater management projects are often characterized by explicit stormwater accentuation (see Dreiseitl et al. 2001; Hoyer et al. 2011);
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Solutions for Storm Water Management
One of the main accomplishments of the conceptual plan is to increase the street connectivity from a few entrance to many intersections, extending street grid from Downtown. Also, we remain the two buildings and a symbolic tree with square, as a way of respecting its history. These remnant buildings can serve as a community space. Taken motif from here, we conceit of similar scale fenced public squares in terms of junction among mixed neighborhood. less than 40 feet in width between buildings, are as much a part of a cityâ&#x20AC;&#x2122;s street network as larger streets. While they may not carr heavy loads of through traffic, they provide access to properties and are often integral parts of the non-motorized street network.
There are three types of park. One is to slow the water down, the second is to let the storm water going throug. The third is to detain the water when the big raining. All the related pavements, and types of trees are serving for the stormwater purpose. While they also serve for differn activities and strong connection to the neighborhood.
The street design with various of trees and pavement. They have different lanes for vehicles, pedestrians, street ast well as leading places. The elements that make up city streets, from sidewalks to travel lanes to transit stops, all vie for space within a limited right-of-way.Very small streets, less than 40 feet in width between buildings, are as much a part of a cityâ&#x20AC;&#x2122;s street network as larger streets. While they may not carr heavy loads of through traffic, they provide access to properties and are often integral parts of the non-motorized street network.
impact topography on urban form
Take Atalanta as an Example Urbanization Density Atlanta is located along the low foothills of the Appalachian Mountains, which makes it a fairly hilly region. The north and west suburbs have significantly higher elevations as compared to the other regions, with the average elevation being around 1000ft. Apart from elevation, relief features play a major role with how a city’s population is distributed. Studies show that human population is mainly concentrated in areas with a flatter topography. However, that is in contrast to what we see in Atlanta.
Overview of the Geography As shown in the DEM map, the center of the city has higher elevation, while low elevation area concentrate around river valley in north and southeast of the Atlanta. Another feature is the existence of multiple rivers and branches, which pose threat of flooding and require special attention. Building Footprint in High Slope Area This map identifies building footprints in areas of slope higher than 15 and 30 degree, which are considered area of high slope. As shown in the map, most of the buildings in area of slope larger than 30 are in the downtown and midtown area, and that in 15 to 30 degree ae around creeks. Moderate slopes. Gentle grades of less than about 10% (a one foot rise over 10 feet) are the easiest to build on. Between 15% and 20%, you should plan to spend more on grading and the foundation, which will need to be higher or stepped down on the low side. This is a good slope for walk-out basement. Steep slopes. Much above about 20%, you may have to do more extensive earth moving and soil stabilization to create workable grades and prevent erosion. Cut and fill operations can get costly, especially if you have to truck in additional fill. The cost of fill varies greatly depending on what is nearby and accessible, so don’t make assumptions here — get estimates.
The density in the city mostly follows the elevation pattern, with higher elevated areas having higher density. The slope/aspect however does not seem to have had much effect on distribution. We also see When going into further detail, we can see that residential areas are mostly concentrated in the central, highly elevated regions, so they’re not in danger of being flooded. The other buildings, which include commercial, residential, institutional, etc, are spread throughout the region, so the ones on the periphery come directly under the FEMA flood zone (need to confirm this).
Footprint within Flood Zone Since most of the buildings were built before the regulation on floodplain came out, there are plenty of constructions within flood zone, mainly around creeks in the north and middle-to south, as shown in the zoomed-in maps. Households within flood zones are required to have flood insurance. To put it simple, floodplain is not a suitable site for buildings. According to the Floodplain Management in Georgia, the floodplain shall perform its natural function – if possible, keep it as open space. Other compatible uses: recreational areas, playgrounds, reforestation, parking, gardens, pasture, and created wetlands.
The major factor in deciding Atlanta’s layout was transportation, as we can see from the city spreading outwards from where the railway lines are. The suburbs came later along with the automobiles. Topography does not seem to have played a major role with density but we still see a relationship between the two.