Urban land suitability could be evaluated from the aspects such as the imbalance of the existing land-use structure and function distribution, along with the scarcity of land resources, so as to provide people with more a rational use of land service space.
1. Introduction
The advancement in the economy and technological dependence has led to the increasing demand for urban residential area in various countries around the world. Various serious issues have been raised due to the rapid increase in the urbanization rate such as air pollution, imbalanced land-use structure, lack of traffic management, and many more
[1][2]. This situation has raised the social economic burden on the management and environment for optimization of urban residential land, requiring the help of various urban planning agencies. This raises the need for a reliable and quantified urban residential environment for building a more improved understanding of the process of urbanization. In order to analyze this viewpoint, various factors should be kept in mind to understand the complete scenario of a land-use factor.
Figure 1 depicts the land-use factors which generally affect the urban land distribution.
Figure 1. Land-use factors affecting the urban land distribution.
In recent years, the population has continued to grow, and cities have developed rapidly. The range of activities people need is constantly increasing. Therefore, people’s demand for urban land is becoming stronger and stronger. The random development of urban land resources does not only damage the urban ecosystem but also leads to uncoordinated land use due to the imbalance in land-use structure and its function distribution. This urbanization process also wastes precious land resources and leads to the low utilization rate of land
[3]. Therefore, reasonable urban expansion is very important for the sustainable use of land. To better understand the laws of urban land use, the dynamic changes of urban land expansion are studied. It is of great significance to the scientific planning of land expansion and the sustainable development of land.
GIS ideas and methods are comprehensively applied in this work based on the ideas of system theory and cybernetics, according to the different functions and characteristics of the city. Based on this scientific hypothesis, the appropriate mathematical models are selected to reflect these functions and characteristics. Achieving the quantification of the analysis process is key to embodying quantitative planning in the evaluation of urban land use
[4]. Realizing the quantification, standardization, systemization, and information acquisition of urban land evaluation will become an important subject for scientifically evaluating the suitability of urban land. Based on the analysis and summary of the relevant theories of urban land suitability evaluation, the comprehensive evaluation method of urban land suitability based on GIS technology is explored
[5].
There are several land suitability methods defined in the literature for assessing crops using the qualitative and quantitative approaches. Some of these approaches use Boolean algebra
[6], weighted linear combination methods
[7], and various multiple regression approaches
[8] for analyzing the statistics. Among the various traditional approaches, the categorical data for the qualitative approach are depicted in
Table 1.
Table 1. Descriptive analysis of various land suitability methods.
Research |
Crop |
Methods |
Bagherzadeh and Gholizadeh | [9] |
Alfalfa |
Artificial Neural Network (ANN) |
Bagherzadeh et al. | [10] |
Soyabean |
Fuzzy approach |
Danvi et al. | [11] |
Rice |
Machine Learning (ML) |
Deng et al. | [12] |
Rice |
ANN + Genetic Algorithm (GA) |
Estes et al. | [13] |
Maize |
Machine Learning (ML) |
Lopez-Blanco et al. | [14] |
Several Crops |
Fuzzy approach + ML |
Raza et al. | [15] |
Several Crops |
Fuzzy approach |
The literature presented in this table depicts various approaches utilized by food and agricultural organization for land suitability frameworks. Most of the identified tractional methods indicates that the socioeconomic data are minimal, and this is very critical in the case of conducting the assessment for crop suitability
[16][17]. Some of the approaches also pointed out the limitations of using the ordinal linear combinations for addressing the problems which are needed to practice the non-linearity. It was also revealed that the suitability and vulnerability of the transcending approaches is more in the cases of qualitative and quantitative analyses.
2. Evaluation of Suitability of Urban Land Using GIS Technology, Take Yan'an as an Example
2.1. Analysis on the Evaluation Results of Land-Use Suitability in the New Planning Area
The suitability level and degree of impact of subdivided construction land need to consider the characteristics and distribution of the current topography of the planning new area
[18][19]. The northern New Area of Yan’an has many mountain structures and complex topography, which poses certain limitations to the construction of urban land. Combining the four major influencing factors mentioned above and analyzing through the GIS system, the suitability construction distribution map is obtained. According to the above calculation method, the degree of influence of each evaluation factor is obtained. Then, through the ArcGIS weighted synthesis tool, the weight of the construction land is obtained.
Figure 26 shows the resulting weight map. According to the result of the superposition analysis, the suitability construction level of the planning new area is divided into three types: suitable construction area, generally suitable construction area, and unsuitable construction area. Finally,
Figure 37 shows the most suitable construction land area, which is about 80% of the total planning area. The banned construction area occupies the smallest land area, about 4% of the total planning area.
Figure 26. Index weights of the evaluation system for the suitability of construction land.