Assessing Urban Land use Change in New Braunfels, Texas from 2013 to 2020

Urban cities are the major drivers of economic growth and development. Economic growth and development however results in considerable land cover land use dynamics. This study assessed the dynamics in land cover land use that have occurred in New Braunfels, Texas in the last 7 years (2013 2020) to observe areas in the city that had experienced considerable shifts in land cover and land use. A 30-meter resolution Landsat images were used to examine possible changes in land cover land use. New Braunfels was observed to have experienced significant changes in land use especially in developed areas. This change can be attributed to the influx of people into the city, contributing to the need for increased urban development. Analysis of this study shows that about 16% (about 553 hectares) of forest land cover class and 28% (about 1,139 hectares) of grassland class in time 1 (August 31, 2013) changed to built-up land use class in time 2 (November 5, 2020). A limitation to this study was that of the spatial resolution of images used. Higher spatial resolution images could impact the producers, users, and overall accuracy assessment. Results from this study can aid in supporting better decisionmaking for sustainable urban development and climate change mitigation.


Introduction
Urban land use change is a significant process resulting from global environmental dynamics [1,2]. The formation and operation of an ecosystem is greatly affected by urban land uses [3]. The challenges associated with urban land use change include overcrowding, crime, pollution, increased energy utilization, and a loss of viable farming land [3,4]. Remote sensing aids the precise procurement of urban land-use information for developing urban districts; however, inadequate remote sensing information limits the acquisition of urban land use data [5].
Remote sensing can also be used in explaining the spatial distribution between various land uses in urban districts [6].
New Braunfels is a city that falls inside Comal and Guadalupe counties in the U.S. [7] The city spans across 44.9 square miles (116 km 2 ) and had a total population of about 90,209 people in 2019 [8]. New Braunfels is considered a suburb just north of San Antonio, and part of the Greater San Antonio metropolitan area [10]. New Braunfels is one of the cities in the US experiencing a massive population influx. It was ranked by the US Census Bureau, the second fastest growing city in the US between July 1, 2016 and July 1, 2017, having an 8% increase and a total population of 79,152 people [10]. This population growth is projected to continue. The city is located in the southeastern part of Comal County, about 48 miles (77 kilometers) southwest of Austin, right between the cities of San Marcos and San Antonio with the Interstate highway 35 (IH-35) cutting through it [9].
New Braunfels has experienced a 158% population growth since the year 1990. New

Objectives
This study performs a change detection analysis to uncover those changes in land use that have occurred in the city of New Braunfels, Texas in the last seven years (2013 -2020). In this study, we examine those parts of New Braunfels that have had considerable changes in land usage. The specific objectives of this study are as follows: c.
Conduct an accuracy assessment to assess classification results. d.
Post-classify the classified images to observe for land cover changes in both years (2013 and 2020)

Data and Methodology
For this study, the dates of August 31, 2013 and November 5, 2020 were chosen. These dates were specifically selected based on availability of data having significantly less cloud cover (0.13% and 0.19% cloud cover respectively

Grassland
Grasses, shrubs and scrubs.  conducted. An overall accuracy of 68.33% and 73.33% was generated respectively for 2013 and  Overall Classification Accuracy = 73.33%

Discussion and conclusion
This study examined the city of New Braunfels to assess for any observable land In the accuracy assessment process, we used 60 and 80 points (2 scenarios) distributed around the 4 land cover classes using both stratified random and random sampling methods.
However, we observed, after 3 trials, that the water land cover class had got only a few points compared to the 3 other classes (grassland, built-up and forest) on both images. This may have produced a fairly biased result and impacted on both the users and producer's accuracy values.
This limitation was in part due to the water class having a limited number of pixels (only a very small part in both images had water). Perhaps, it would be helpful if one could manually place the reference points on the images instead of depending on the randomly generated points but again, this could even aggravate user bias. Another solution to this could be to increase the number of randomly generated points. Another limitation to this study was that of the spatial resolution of the images used in this study. Perhaps, higher spatial resolution images could have impacted on the producers, users and overall accuracy assessment [14,15].
Results from this study can aid the appropriate bodies in planning properly for the city of New Braunfels and other cities as regards resource allocation and distribution. As noted by [16] in their land use land cover change study of Changchun, most cities place their emphasis on economic development which often lead to increased pressure on urban land, as such, urban planners should explore strategies to promote urban sustainable development. Cities can also apply land use change methods in determining areas where growth and development need to be promoted as well as where they need to be controlled.

Funding
This work received no funding.