GIS Analysis of Changes in Ecological Vulnerability Using a SPCA Model in the Loess Plateau of Northern Shaanxi, China

Abstract

Changes in ecological vulnerability were analyzed for Northern Shaanxi, China using a geographic information system (GIS). An evaluation model was developed using a spatial principal component analysis (SPCA) model containing land use, soil erosion, topography, climate, vegetation and social economy variables. Using this model, an ecological vulnerability index was computed for the research region. Using natural breaks classification (NBC), the evaluation results were divided into five types: potential, slight, light, medium and heavy. The results indicate that there is greater than average optimism about the conditions of the study region, and the ecological vulnerability index (EVI) of the southern eight counties is lower than that of the northern twelve counties. From 1997 to 2011, the ecological vulnerability index gradually decreased, which means that environmental security was gradually enhanced, although there are still some places that have gradually deteriorated over the past 15 years. In the study area, government and economic factors and precipitation are the main reasons for the changes in ecological vulnerability.

Quantitative assessment model of ecological vulnerability of the Silk Road Economic Belt, China, utilizing remote sensing based on the partition–integration concept

“…and North China Plain. The dominant ecological problems in this region constitute drought, catastrophic floods, rainstorms, sandstorms, and soil water erosion (Hou et al 2015). Owing to the increase in population, the scope and intensity of reclaimed land have been continuously spread, and the vegetation has been seriously damaged (Fan et al 2015).…”

“…The Loess Plateau is the oldest known area of loess accumulation in the world. However, the development of loess accumulation indicates a general trend toward a dry climate in northern China (Hou et al 2015). Thus, drought is also one of its major ecological problems.…”

“…During recent decades, various ecological vulnerability assessment frameworks have been proposed, such as the vulnerability scoping diagram assessment framework (Polsky et al 2007), the environmental sensitivity index (Amiri et al 2014;Kang et al 2018), and the pressure-stateresponse assessment framework (Zhang et al 2017). In addition, specific vulnerability assessment methods have often been utilized as follows: the principal component analysis method , the analytic hierarchy process (AHP) method (Guo et al 2016;Shen et al 2016;Topuz and van Gestel 2016), the fuzzy comprehensive evaluation method (Enea and Salemi 2001;Adriaenssens et al 2004;) and the entropy method (Amiri et al 2014;Hou et al 2015). With its development, aeronautical remote sensing has become one of the most important technologies available for collecting biological parameters (Liu et al 2006;Rogers and Xue 2015).…”

“…Over recent decades, various investigations have been conducted to qualitatively or quantitatively evaluate ecological vulnerability, on varying scales, of the Silk Road Economic Belt of China (Liu et al 2006;Hou et al 2015;Jin and Wang 2016). However, spatial heterogeneity patterns of the eco-environment have not been considered in previous research.…”

Crops' sensitivity and adaptive capacity to drought occurrence

“…Some of the variables used to compute the different indicators of the Exposure, Sensitivity and Adaptive Capacity components (Table 1) might correlate as they have a certain amount of overlap (Anselin and Getis, 1993;Kang et al, 2015). For this reason, a principal components analysis was performed, since it converts potentially correlated variables into uncorrelated variables that capture the variability in the underlying data (Abson et al, 2012).…”