Spatiotemporal Evolution of Landscape Ecological Risk Based on Geomorphological Regionalization during 1980–2017: A Case Study of Shaanxi Province, China

Di Liu,Qinqin Shi,Hang Zhang,Tianwei Geng,Hai Chen

doi:10.3390/su12030941

Abstract

Land surface elements, such as land use, are in constant change and dynamically balanced, driving changes in global ecological processes and forming the regional differentiation of surface landscapes, which causes many ecological risks under multiple sources of stress. The landscape pattern index can quickly identify the disturbance caused by the vulnerability of the ecosystem itself, thus providing an effective method to support the spatial heterogeneity of landscape ecological risk. A landscape ecological risk model based on the degree of interference and fragility was constructed and spatiotemporal differentiation of risk between 1980 and 2017 in Shaanxi Province was analyzed. The spatiotemporal migration of risk was demonstrated from the perspective of geomorphological regionalization and risk gravity. Several conclusions were drawn: The risk of Shaanxi Province first increased and then decreased, at the same time, the spatial differentiation of landscape ecological risk was very significant. The ecological risk presented a significant positive correlation but the degree of autocorrelation decreased. The risk of the Qinba Mountains was low and the risk of the Guanzhong Plain and Han River basin was high. The risk of Loess Plateau and sandstorm transition zone decreased greatly and their risk gravities shifted to the southwest. The gravity of the Guanzhong Plain and Qinling Mountains had a northward trend, while the gravity of the Han River basin and Daba Mountains shifted to the southeast. In the analysis of typical regions, there were different relationships between morphological indicators and risk indexes under different geomorphological features. The appropriate engineering measures and landscape management for different geomorphological regionalization were suggested for effective reduction of ecological risks.

Highlights

Land use is a comprehensive reflection of human economic and social activities acting on terrestrial surface resources and the natural environment
In the absence of ecological monitoring data, the landscape pattern characteristics reflected by land use can clarify the impact of quantitative change and spatial allocation of land use on the ecosystems and processes to reflect the spatial differentiation of the ecological environment [26,27,28]
The ecological risk value was classified using the ArcGIS10.2 natural breakpoint method [44]: grade I (ERI < 0.1190), grade II (0.1190 ≤ ERI < 0.1271), grade III (0.1271 ≤ ERI < 0.1353), grade IV (0.1353 ≤ ERI < 0.1445), and grade V (ERI > 0.1445); this method enabled us to generate the spatial distribution of ecological risk in Shaanxi Province from 1980 to 2017 (Figure 2)

Summary

Introduction

Land use is a comprehensive reflection of human economic and social activities acting on terrestrial surface resources and the natural environment. Using the landscape of heterogeneous land units composed of different types of ecosystems as the perspective of evaluation, this paper explores the impact of human activities on land use based on the landscape pattern, providing the best generalized approach for further clarifying the evolutionary mechanism of ecological risks [5]. This method has been applied in many areas, such as watersheds [7,29], coastal zones [30] and administrative regions [25]

Objectives

Methods

Results

Conclusion