The ecological environment is the material carrier for meeting human survival and social sustainable development needs, usually including the water resource environment, land resource environment, biological resource environment and climate resource environment. With the accelerating process of social industrialization, people’s daily life and production activities have caused varying degrees of impact on the ecological environment, some of which are irreversible. For example, the irrational exploitation of resources has caused the phenomena of soil erosion and land desertification, and the global warming caused by industrial wastes and automobile exhaust emissions. In recent years, the national government has attached great importance to the restoration and protection of the ecological environment. It has repeatedly proposed the development of the concept of harmonious coexistence between humans and nature, with the approach that lucid waters and lush mountains are invaluable assets and building an ecological civilization is the key to development. Therefore, for the construction and development of ecological civilization, the regional ecological environment needs to be immediately and comprehensively restored and protected, and the ecological security assessment of land resources and the environment is an essential part of that whole ecological restoration and protection system.

At present, research on the ecological security evaluation of land resources mainly focuses on two aspects. One is the ecological security level and health degree of the land resources themselves, and the other is the degree of support for the land resources for human development and utilization (Lu et al., 2016). Foreign scholars Karr et al. conducted relevant research on land ecological environmental quality from the perspective of the sensitivity of ecological environmental system, and finally concluded that although the sensitivity of the ecological environment system can reflect the damage and impact of human production activities and natural disasters on land resources and the environment, it cannot accurately measure the magnitude of the damage or the bearing limit of the environment (Karr, 1981). The Pressure-State-Response (PSR) (Atici, 2010; Ye et al., 2011) developed by the Organization for Economic Cooperation and Development (OECD) has solved precisely this problem. The PSR can intuitively express the causes, results and countermeasures regarding the degradation of ecological environmental quality, and can accurately reflect the internal relations of the land ecosystem. At the same time, the Driving force-State-Response (DSR) (Pang et al., 2014) that the United Nations Commission on Sustainable Development (UNCSD) published was widely used at that time. On the basis of PSR and DSR, the European Environment Agency, European Statistical Office and Food and Agriculture Organization (FAO) put forward the Driving force-Pressure- State-Impact-Response (DPSIR) (Singh et al., 2012) and Driving force-Pressure-State-Exposure-Response (DPSER) (FAO, 1997), respectively. These two sets of framework models can not only reflect the internal relationships between multiple elements and the land ecosystem from multiple fields, but they can also reflect the internal relationships among various factors. They are also very intuitive for the display of evaluation results, and so they are the two sets of evaluation models most widely adopted thus far. The commonly used land resources ecological security assessment methods in China mainly include the comprehensive index method (Fu et al., 2020), principal component analysis method (Chen et al., 2021), grey correlation method, matter element model method (Guo et al., 2020), ecological footprint method and several others. Although many scholars have carried out a lot of research work based on the above evaluation models and methods, there are still several problems. 1) The evaluation index factor data mainly come from social and economic development status and statistical data, which are too simplistic. 2) The evaluation models rarely take into account the influence of native land resources and natural geographical factors on land ecological security, and so they fail to fully reflect the relationships and influences between various factors and the land resource ecosystem. 3) The calculation method of index weights is too simplistic, and there are many subjective factors affecting the weight results, which further affect the accuracy of the evaluation results. With the continuous development of 3S (RS, GIS, GPS) Technology, choosing the multi-source data fusion with the combination of RS (Remote Sensing) and GIS (Geographic Information System) technologies, using the raster data structure for storage, and selecting a specific research area of the land resource ecological security to evaluate, can not only comprehensively reflect the effects of multiple factors on land resource ecological security condition (Gao et al., 2019), but also has the advantages of simple superposition operation, easy data acquisition, wide coverage area, strong timeliness and easy visual expression (Li et al., 2012).

As the region with the most abundant water resources in Xinjiang, Altay has always been honored as the “water tower” in northern Xinjiang. Altay is also one of the country’s six forest areas, and the quality of its woodland resources and water resources is high, but the arable land area is relatively limited (Sun et al., 2020). The contradiction between humans and land caused by the continuous growth of the population has become a major barrier to the development of the social economy and industry in the Altay region. Therefore, in order to evaluate the ecological security of land resources in Altay region quickly and effectively, it is particularly necessary to choose scientific and reasonable methods. This paper combined DPSIR (Driving force- Pressure-State-Impact-Response) and EES (Environment- Economic-Society), based on an RS and GIS technology platform, selected multi-source data, and used the analytic hierarchy process, entropy value method, and linear weighted sum function method to build the Altay regional land resource ecological security evaluation index system. It then used this system to evaluate and grade the ecological security of regional land resources, in order to diagnose the current situation due to the unreasonable development and utilization of various land constraints and the existing land resource ecological security problems, and to determine the land restriction factors and existing ecological security problems of land resources caused by unreasonable exploitation and utilization (Zhang et al., 2017). Based on the powerful spatial analysis function of GIS, this paper analyzed the spatial differentiation of the characteristics of the ecological security of land resources in Altay region, and put forward reasonable countermeasures and suggestions for protection and restoration. These assessments were carried out in order to solve the contradiction between man and land in Altay region, to accelerate the pace of sustainable development of the regional economy, to provide decision-making basis and support, and to better achieve the harmonious coexistence of man and nature coordinated and unified development.

On the basis of collecting and studying the achievements of previous studies, this paper systematically analyzed the geological, geographical, human, social and economic data and statistics of Altay area. Combining the DPSIR framework model and EES framework model, and supported by 3S Technology, the target layer, criterion layer, element layer and indicator layer of the research were determined. Twenty-seven index factors were selected from the three aspects of environment, economy and society, and used to carry out ecological security evaluation. The ecological security of land resources in the whole region was evaluated and classified, and the impact of ecological security on the three representative elements of mining activities, geological hazards and land use types were separately considered. The main index factors influencing regional ecological security were obtained, which better reflected the close relationship between the subsystems of the ecological environment. This study selected multi-source data, and then used the analytic hierarchy process, the entropy value method, and the linear weighted summation function method to construct the land resources ecological security evaluation index system for the Altay region. The errors caused by subjective and objective factors were effectively reduced, so this method greatly improved the accuracy of the evaluation results. In addition, the evaluation index data were easy to obtain, the index factor selection was more comprehensive, and it had a strong operability and a certain reference.

According to the above research methods, the status of ecological security in Altay region was finally obtained. The results clearly reflected the spatial distribution characteristics of the fragile degree of ecological security in Altay region, and indicated the fragile and strong regions of ecological security. The evaluation results were further analyzed, the reasons for the fragility of ecological security were discussed in detail, and several reasonable protection and restoration countermeasures and suggestions were put forward. This analysis can provide a decision basis and support for solving the contradictions between man and land in the Altay area, for accelerating the pace of sustainable development of the regional economy and for better realizing the harmonious coexistence and coordinated development of man and nature. At the same time, the research results of this article are compared with those of previous studies (Ye et al., 2019; Yang et al., 2020; Li et al., 2021), and each has its own advantages and disadvantages in the evaluation methods. The previous studies mostly used remote sensing ecological indexes to construct an evaluation index system for the ecological safety evaluation research. However, the constructed evaluation index system better reflects the relationship between the environment, economy, society and human engineering activities; so, the research results have a higher consistency with other scholars’ research, but the presentation and analysis of the results in this article are still incomplete. There is a certain amount of room for expansion to facilitate more in-depth research in the future.

(1) The overall ecological security status in Altay region was safe, while the partial ecological security status was relatively fragile. Among them, the areas with safe and safer ecological environment accounted for 38.72%, while the areas with critically safe status accounted for 30.83%, and the areas with a less safe and unsafe environment accounted for 30.45%. In terms of spatial characteristics, the areas with unsafe ecological environment were mainly distributed in the west and east of the study area, while the areas with good ecological environment were distributed in the north of the study area.

(2) According to the evaluation results of land ecological security in Altay region, the main factors affecting the ecological environment security included large-scale mining activities, frequent geological disasters, large-scale reclamation and long-term cultivation of cultivated land, long-term and large-scale grazing activities resulting in the destruction of grassland and vegetation, and others. Therefore, in the process of the continuous development of the urban economy, we should pay attention to the harmony between man and nature, actively and effectively advocate and implement appropriate policies and measures such as returning farmland to forest, returning grazing land to grassland and integrating the mining of mineral resources. For areas with frequent geological disasters, prevention should be given top priority, treatment should be supplemented, and prevention and control should be combined. These efforts will reduce the damage from geological disasters to human life, property safety and the ecological environment.