Abilities of Network Analysis
Network Analysis is a feature of ArcGIS which is geographic information system program. This system has many features and uses. Extensions of Network Analysis include Survey Editor and Survey Analyst which give the system even further capabilities. The diverse functionality of the system allows it to perform multiple analyses quickly and efficiently by merely inputting the necessary data and mathematical forumalas. When used in conjunction with various methodologies for collecting data, it can be an invaluable tool in the area of parks and conservation. Abilities of Network Analysis • Multiple point routing • Time calculation
• Allocation of networks • Expandable maps • Auto generation of maps Since Network Analyst has the ability to import and export files, it can utilize the files to create and generate locations, directions, the nearest facilities, cost, routes and service areas. It can update different fields, band collection statistics, calculate probability, calculate likelihood and block and filter statistics. It can virtually build an entire network of ATV trails. (ESRI, 1995-2008) Network Analysis is able to store sizeable quantities of thematic subject matter to be saved for separate and distinct geographical features.
Survey Analyst and Survey Editor are survey functions which are an extension of ArcGIS. Survey Editor is a tool that enables the saving of survey data obtained from such sources as field notes, survey equipment, and to input survey data gathered by individuals. Survey Analyst allows surveyors and GIS professionals to work in collaboration in order to incorporate value to vital GIS functions. Various GIS Functions • Integration of survey data in a geo-database. • Ameliorate the quality of mapped items. • Map new items. • Arrange survey data for specific ventures. • Maintain collected data and provide a report of reliability. (ESRI, 1995-2008)
Network Analysis and GIS can be an extremely useful tool when planning to build new ATV trails. Before expanding on the use of Network Analysis and GIS we must first understand the considerations that are taken into account before building ATV trails. Planning and development must be carefully considered in order to meet with the standards of government agencies and to achieve positive reviews by resource professionals. Four Areas of Consideration • Property limitations – Some of the limitations may include privately owned property and areas restricted by state or federal government such as wildlife, fishing, and wetland areas.
• Possible effects on the environment – Implementing new trails with already existing trails may either minimize or increase negative effects on the environment and may have the same effect on trail maintenance. • Durability of underlying soils – ATV’s wears away vegetation over time to reveal the underlying soil. Therefore, it must be determined whether the soil is durable or whether it will degrade with use which would require armoring in order to create a stable surface. (Wisconsin Department of Natural Resources, 2005) Fine loam or clay loam that’s sufficiently drained is the preferred soil for trails.
Soils made up of clay, silt and sand have a greater degree of erosion and compact more easily making them undesirable. (Snyder, 2008) • Effects on wildlife- The effects of ATV trails on wildlife habitat and endangered species need to be considered. GIS maps, topographic maps, and photographs can help identify vegetation, wildlife habitat, archeological corridors, wetlands, and stream crossings. Other areas of concern include safety. One consideration is trail condition. Natural features such as steep areas, rocky terrain, or unstable surfaces would create possible hazards to ATV users. Trails should not cross any busy road.
Social issues are also an area of concern. If there is any public controversy in the area then perhaps alternative areas should be considered. Whether or not the trails will be used by various groups and during what seasons they will be used should also be considered. Cooperation with partners is another issue of concern. Information such as whether or not any clubs will contribute to the building and maintenance of the trails, whether or not nearby community’s support the ATV trails, and whether volunteers will be available to patrol the trails on a regular basis are details that should be addressed in advance or the construction.
Management and administration concerns might include such issues as whether or not there is a sponsor and whether there will be staff designated to manage the trails. (Wisconsin Department of Natural Resources, 2005) As previously mentioned, Network Analysis is a diverse GIS system. It can be a valuable too not only in the building of new trails, but also in maintaining existing trails. The following is an example of the use of Network Analysis and GIS software for existing ATV trails. The Glenallen District of the Bureau of Land Management in Alaska used Network Analysis and GIS software to evaluate ATV trail conditions.
The reason an analysis of the trails was necessary was because many had deteriorated to the degree of becoming unusable. When the trails were abandoned in the deteriorated areas, new trails were forged next to the abandoned trails. The cycle continued until the deteriorated trails covered many acres of land. Deteriorated and abandoned trails are detrimental to the environment. They have a negative impact on vegetation, soils, hydrology, and aesthetic resources. With the input of the proper data into Network Analysis, trails could be rated and solutions to the problem could be found.
There are various methodologies for gathering data that are used in conjunction with Network Analysis and GIS. Some of these include helicopter observation, digital video, photographs, historic railroad maps, and county soil maps. The purpose of this was to provide visual evidence of trail conditions and a source of review preceding field work. Other forms of technologies used included a mapping-grade GPS receiver, a TSCI data logger, Trimble Pathfinder Pro XA, and Trimble Asset Surveyor. Network Analysis and GSI was utilized to perform several tasks in order to evaluate the ATV trails.
Tasks Performed with the Aid of Network Analysis and GSI • Trail segment types – This means to determine whether a specific trail is a single track or double track. Double tracks would determine an ATV trail and are identified by parallel lines of destroyed vegetation. A single trail would indicate a foot path or a game trail. They also wanted to determine the proximity of deteriorated trails to other trails and whether or not they were an extension of another abandoned trail. • Trail type – There are five different descriptions of trail types.
A main trail is a primary portion of trail. Trails described as secondary-active are a portion of a main trail although they are not used quite as often. Abandoned trails are portions of trail that are no longer used, but still identifiable. Access trails are used to access main trails. Cutoff portions are basically short-cuts to other areas of trails. Spur trails lead to areas of interest and other trails. • Trail slope – The slope of the trails is the altitude which is measured and calculated using GPS. The measurements are then exported and stored in the GSI system.
• Trail rating – ATV trails develop s deep tracks over a period of time. These tracks are referred to as ruts. Trails are rated according to the degree of vegetation stripping and the depth of ruts created by the ATV’s. • Track width- The width of the track is determined by the area that is actually used by the ATV’s. Width’s are estimated and sometimes manually measured. • Mud index – Rutting and drainage of water impact the trails. The mud index is a measurement of to what degree it’s impacted. Mud holes are areas of water accumulation that are also muddy.
They are created by trails being rutted to the point of reaching the ground water. The index can be rated from no mud holes to various counts including multiple mud holes. • Trail drainage – This assessment is made based upon the observation of both the soil and terrain and is determined by the amount of water on the trail ranging from no water to running water. • Trail Characteristics – Composition of the trails changes over time, according to the use of the trails and climatic influences. The characteristic ratings include native mineral, native organic, gravel and others.
• Vegetation destruction – Usage of the trails often strip away the vegetation. Sometimes vegetation is stripped only in the tracks and other times it occurs across the entire width of the trails. Other trail features were also recorded. They included features such as stream crossings and their conditions, points of interest such as campsites, cabins and scenic views. Points of reference that often mark the trails including mileposts, trail junctions, trailheads and survey markers were also noted. Photographs and digital videos were taken of points of interest along with the compass reading.
All of the documented data was saved and merged with the GIS. The purpose of the trail survey was twofold, not only to collect the data, but also to integrate the data into a management tool (Network Analysis and GIS) in order to prioritize and expedite trail maintenance, in order to plan maintenance projects, and in order to establish funding needs. The goals were achieved by developing a scoring system that listed trail conditions that reflected the impact of individual trail characteristics on the need for trail maintenance. The total sum of the scores would determine the ranking of the trails.
Besides the ranking scores, categories of maintenance needs were also established. Network Analysis is an effective management tool. (Bruehler, 2004) Network Analysis has the ability to depict detailed situations such as networks of ATV trails. Users are able to model data based on points of coincidence such as trail markers, structures, and natural features. It can help in planning new trails in an existing network and modeling access. It can generate the best routes for ATV trails and calculate optimal routes for emergency vehicles and the amount of time it would take them to reach various segments of the trails.
These are all areas of consideration, but one of the major issues in regard to ATV trails, as mentioned previously, is the affect they have on soil, water, fish, wildlife and vegetation. This includes the abandonment of trails as well as the building of new trails. Despite the negative impact it needn’t be long-term if routine maintenance is applied. Vegetation is greatly impacted by ATV use. Trails are often stripped of natural vegetation and invaded by aggressive vegetation and weeds. Restoration and rehabilitation efforts are usually needed so the eco-balance will not be negatively affected.
It is unhealthy for the environment for the trails to become invaded by weeds, but a balance between weeds and more sensitive vegetation are needed in order to maintain a healthy environment. Healthy vegetation also requires a healthy underlying soil. If the federal government owns the trails there is usually a greater degree of protection offered for the vegetation. Rehabilitation efforts may have a negative impact on the vegetation in the short-term, but once health is restored and if routine maintenance is performed, the vegetation would maintain its health.
Ultimately, healthy vegetation would have a positive effect on soil, air and water quality and the overall ecosystem including wildlife habitat. It’s also necessary to maintain healthy soil and water quality in order to continue to have healthy vegetation. Healthy vegetation is also important to ATV riders. They have indicated that they prefer trails with scenic views and have indicated preferences in vegetation for viewing as they ride as well as other points of interest along the trails. Network Analysis can identify aesthetic points of interest along the trails and calculate the time and distance between the points of interest.
(Colorado Canyons NCA, 2004) California used GIS to monitor wildland vegetation. Since the landscape does change over time due to natural and human interactions, agencies were commissioned to map, monitor and access these changes. It was first necessary to establish a baseline for the vegetation in order to monitor the changes and to determine the effects of these changes on the environment. It’s vital that the baseline information be consistent so that evaluations will be accurate. The field data collected was slope angle, elevation, slope aspect and the predominant species of vegetation in the monitored areas.
Various vegetation layers were then created with Network Analyst. These layers included the predominant vegetation in different areas, the density of the vegetation and the percentages of other vegetations. Data collected in the field and pre-existing data enables Network Analyst to create models that can predict the probability of what species of vegetation will recur. Besides vegetation data, such variables as terrain, elevation, soil and land composition, climate and precipitation were also factors in creating these models.
A matrix table was then developed using mapped data on one axis and observed features on the other axis. The more frequent the matches, less errors there are. This proved the accuracy of the map. Creating a log of the vegetation allowed for strategic planning and to aid in long-term monitoring. Factors that were monitored included such things as growth, mortality and species. Ground inventory logs were plotted which makes it possible to estimate the population of various species of vegetation. The changes were detected, interpreted and finally a map is created depicting the change classes.
The classes included small amounts of vegetation, no vegetation, and increase in vegetation and decreases in vegetation. The changes were processed by means of image segmentation. Through image segmentation, specific regions were created and texture bands were created. Various effects identified green vegetation, canopy cover, and the moisture of the soil. Images, photographs, vegetation and topographic maps, and GIS coverage are used to measure the degrees of change. The changes are then labeled and logged. (Ralph Warbington, 2007)
Duck Mountain Provincial Park in Saskatachewan, Canada is park is in a forest setting. The terrain has many hills and lakes. It’s rich with vegetation and surrounded by prairie. The park is in use every season of the year. Camping facilities includes, a lodge, cabins and townhouses. It also has wilderness camping. Large groups can rent out the recreation hall or amphitheatre. The lakes are rich with pike, walleye, perch, and rainbow and tiger trout. The park hosts a wide variety of activities including ATV trails. (Government of Saskatchewan, 2008)
ATV trails have been invaded by aggressive vegetation. When ATV trails are built, vegetation, stumps, roots, and loose stones are all removed from the trail. Sometimes there is further clearing along side the trails to provide more scenic views and wildlife openings, to restore native vegetation and to manage water drainage. It’s also usually necessary for trails to be graded. The top soil is cleared and moved to the side of the trails. This is done in order to create a more stable surface and one that fit the topography of the trail.
Sometimes a sub-soil is used to replace the topsoil, but sometimes gravel or crushed stone is used. All of these things have an impact on the vegetation. Network Analysis would be a helpful tool in determining the connection between the ATV trails and the invasion of aggressive vegetation. In order to determine the connection they must use various methodologies to collect data in regards to the ATV trails. Some of the methods they could use might be aerial observation, digital images, photographs, topography maps, and soil maps.
The data they would need to collect would include trail use, soil quality, air quality and drainage. Once all the data is gathered they could import it into Network Analysis and use it to find out why the ATV trails were being invaded with aggressive weed. Once they determine the probable cause they could then use Network Analysis to create a rehabilitation and maintenance program. Using the GIS coordinates, digital images, and evaluation of indicator variables and other data to determine the impact of ATV use over time, the situation can be monitored and updated in Network Analyst.
Soil, water, and air quality should be checked on a routine basis and updated in Network Analyst. The data can also be used in conjunction with Network Analyst to determine how often trail maintenance should occur and prioritize the trails according to need. There are several areas of maintenance that are necessary to prevent any future problems. General Maintenance • Pruning vegetation • Picking up litter • Patrolling and observing trails for any potential problems Trail Tread Maintenance • Observing and logging soil and trail condition
• Logging any hazards of potential hazards • Routine grooming of the trails to slow down deterioration of trails • Restore of track trails to their previous natural state • Picking up litter on trails and around trail heads Clearing Maintenance • Prune trees of dead or broken limbs • Remove debris and logs • Position logs, cuttings, and debris strategically in order to discourage off-trail use (Unknown, 2007) Maintenance practices such as management of exotic and noxious weeds, restoration of native vegetation, and growing healthy perennial plants all benefit the environment.
In areas such as Duck Mountain Park where ATV trails are over run by aggressive weeds, it would be a great benefit to get them under control. Such remedies as non-native plants and chemical treatments may be used to control the undesirable vegetation. Since Network Analyst has mapping techniques that enable you to compare a given data cell with other data cells, methods on one trail could be compared to methods on another trail to determine which method is most effective. (James R. Srittholt, 2006) Ridding the trails of the weeds would vastly improve plant diversity which would also be good for the environment.
A healthy environment provides a better experience for visitors. References Cited Bruehler, G. (2004). GIS/GPS Trail Condition Inventories: A Virtual Toolbox for Trail Managers. Eagle River: Clarus Technologies/Integrated Concepts and Research Corporation. Colorado Canyons NCA. (2004, July). Proposed Colorado Canyons NCA RMP. Retrieved December 17, 2008r, from blm. gov/pgdata/etc/medialib/blm/co/… /PRMP_chapter4_envcon_cd. pdf ESRI. (1995-2008). ArcView Network Analyst.
Retrieved December 17, 2008, from ESRI GIS and Mapping Software: http://www. esri.com/software/arcview/extensions/networkanalyst/ Government of Saskatchewan. (2008). Duck Mountain Provincial Park. Retrieved December 17, 2008, from Tourism, Parks, Culture and Sport: http://www. tpcs. gov. sk. ca/DuckMountain James R. Srittholt, R. N. (2006). Mapping Undisturbed Landscapes in Alaska an Overview Report. D. C. : Word Resources Institute. Manitoba Conservation. (2002, May). Duck Mountain Provincial Park Management Planning Program. Retrieved December 19, 2008, from http://gov. mb. ca/… /parks/public_consult/duck-mtn/newsletter_july_2008. pdf Ralph Warbington, L. L. (2007).
Monitoring Wildland and Vegetation in California On a 5-Year Coordinated Schedule Using Remote Sensing, GIS and Ground Based Sampling. Sacramento: California Department of Forestry. Snyder, S. (2008). Appied Geography. St. Paul: Elsevier, LTD. Lewis County. (2007). Lewis County Proposed Recreational Trails Plan For ATVs. Lowville: Lewis County. Wisconsin Department of Natural Resources. (2005). So You Want to Buid an All Terrain Vechicle Trail – A Practical Guide to Evaluating Trai Potential for Trail Grant Sponsors. Washington, D. C. : Department of Interior.Sample Essay of AssignmentExpert.com