**4. Data characteristics**

**Source Technique Factors Suitability**

texture, moisture, organic C,

Residential, extractive industry,

NDVI, LUC, climate data set,

Distance from river, LUC,

crop pattern, distance from residential areas, roads, proximity to interested

EC, electrical conductivity; GDD, growing degree days; NDVI, normalized difference vegetation index.

According to **Table 1**, even if the suitability target is same, there might be small differences between factors. Some of the important essential factors are the same in agricultural suitability studies, such as soil depth, slope, and soil texture. However, there are different factors: erosion rate, soil nutrients, and crop productivity. Data accessibility, database availability, and method can be affected factors despite the same purpose. Also, these factors may be changed with respect to regional differences. If there is flood risk in an area, we have to assess flood risk rate

Van City is located in eastern Turkey, and it is the most crowded city of the Eastern Anatolian Region of Turkey (**Figure 2**). Van Province's population was 1,096,397 in 2015, and almost 472,000 of them lived in Van central city area. Population has increased almost 5.5% during the last 5 years [23]. The main incomes in the region are animal production, agriculture, border trading, and tourism. Mainly continental climate is dominant, but alpine and sub-alpine climate effects are observed in high regions. Van central city's area climate is warmer than in those around it because of Van Lake. This lake is the biggest lake in Turkey and its water

Slope, soil depth,

pH, EC, primary nutrients (N, P, K)

marine industry, recreation subfactors

DEM, economic and

social data

urban areas,

areas

**Table 1.** Sample techniques and factors used in land-use suitability studies.

[37] RS integrated GIS, expertbased weighting using AHP

210 Sustainable Urbanization

[30] GIS-MCE-

[38] RS integrated

AHP

[39] Fuzzy logic, AHP-GIS-WLC

fuzzy AHP

GIS-based MCE,

in land-use suitability analyses.

**3. Study area**

**field**

Urban land suitability

Eco-city evaluation

Waste water disposal area suitability

Agriculture 2015

**Year**

2015

2015

2016

The research data set contains (i) satellite images and LUC data, (ii) digital elevation model (DEM) data, (iii) LUA data, (iv) distance from road and urban built-up area data, and (v) restrictive areas or constrained areas (**Figure 3**).

#### **4.1. Satellite images**

Landsat 5 TM and Landsat 8 OLI data sets were used to detect urban area change between 2002 and 2015 in Van central city area. Landsat imageries have a great potential for monitoring the land-use/cover change because of large time series database and available spatial (30 m) and spectral (VIS, NIR, SWIR, and TIR) resolutions [24]. Two Landsat images were used for LUC and change detection. An earlier image was taken on August 2002, and the later one was recorded on August 2015.

**Figure 3.** Input data set (criteria or factors) used in the urban sprawl suitability of Van City.

#### **4.2. DEM data**

Elevation data were obtained from ASTER Global DEM data set in 30 m spatial resolution. Slope and hillshade images were produced from DEM data in GIS interface. Additionally, DEM data were used as ancillary data in LUC classification stage to detect the LUC change based on elevation. Also, such data sets may be improved for the accuracy of the LUC classi‐ fication [2].

#### **4.3. LUA data**

The LUA of Turkey was mapped by Soil Survey Staff of Turkey. This map shows capable lands and capability degrees in eight categories (1 refers to very capable and 8 refers to not capable) based on slope, soil depth, soil type, geological type, etc. Highly available lands can be used for agriculture, urban built-up, and industrial facilities. However, land-use suitabili‐ ty is variable according to the scenarios. For example, agricultural areas are important be‐ cause available lands are limited so, in ecological or sustainable scenarios, highly available lands must be protected for agriculture.

### **4.4. Distance images**

Distance from roads and urban built-up areas are produced from road maps and urban area maps, which are produced from classified LUC map. Road and settlement distance is signif‐ icant to evaluate the infrastructure and superstructure availability of a land for urban sprawl.

#### **4.5. Restrictive areas**

Urban cannot sprawl to regions, such as water bodies, existing built-up areas, security areas, and historical protection areas. Also, restrictive areas are modified according to the scenarios. Some wetlands are closed for urban sprawl in the ecological scenario.
