Drivers of Long-Term Land-Use Pressure in the Merguellil Wadi, Tunisia, Using DPSIR Approach and Remote Sensing

Applying the projection pursuit and DPSIR model for evaluation of ecological carrying capacity in Inner Mongolia Autonomous Region, China

The ecological carrying capacity (ECC) of Inner Mongolia is the foundation of its sustainable development. As a result, a comprehensive investigation of Inner Mongolia's ECC and its influencing factors is critical for promoting regional sustainable development. However, an ECC evaluation index system for the ecological environment and economic development features of Inner Mongolia has not yet been developed. In addition, as ECC attributes rise, traditional methods become ineffective at extracting the structural characteristics of high-dimensional data, leading to an incomplete evaluation. In view of this, based on the driver-pressure-state-impact-response (DPSIR) framework, we developed an ECC evaluation index system that takes into account the ecological environment and economic development features of Inner Mongolia. The projection pursuit model based on real coded accelerating genetic algorithm (RAGA-PP), which can analyze high-dimensional data, was applied to achieve ECC comprehensive assessment in Inner Mongolia. Finally, the analysis of the ECC obstacle factors in the study area was conducted. The findings reveal that (1) from 2000 to 2020, there was an average increase of 28.4% in the ECC for all of Inner Mongolia cities. The spatial divergence feature is obvious, and the northeastern cities' ECC is higher than the southwestern. (2) From 2000 to 2020, the value of the drive, pressure, and state subsystems primarily shows fluctuation. The impact and response subsystems both exhibit an increase, while the response subsystem's characteristic values are lower. (3) The obstacle degree of driving force subsystem is significant and ranges from 17.6 to 33.9% between 2000 and 2020. Main obstacles to ECC are the average annual temperature, the disposable income of farmers and herdsmen, the urban registered unemployment rate, and the seeded area per capita. The findings of the research can provide useful guidance to developing efficient policies that take into account the various ECC in different cities in order to improve ECC performance throughout Inner Mongolia.

Driving Force Analysis of Natural Wetland in Northeast Plain Based on SSA-XGBoost Model

Globally, natural wetlands have suffered severe ecological degradation (vegetation, soil, and biotic community) due to multiple factors. Understanding the spatiotemporal dynamics and driving forces of natural wetlands is the key to natural wetlands' protection and regional restoration. In this study, we first investigated the spatiotemporal evolutionary trends and shifting characteristics of natural wetlands in the Northeast Plain of China from 1990 to 2020. A dataset of driving-force evaluation indicators was constructed with nine indirect (elevation, temperature, road network, etc.) and four direct influencing factors (dryland, paddy field, woodland, grassland). Finally, we built the driving force analysis model of natural wetlands changes to quantitatively refine the contribution of different driving factors for natural wetlands' dynamic change by introducing the sparrow search algorithm (SSA) and extreme gradient boosting algorithm (XGBoost). The results showed that the total area of natural wetlands in the Northeast Plain of China increased by 32% from 1990 to 2020, mainly showing a first decline and then an increasing trend. Combined with the results of transfer intensity, we found that the substantial turn-out phenomenon of natural wetlands occurred in 2000-2005 and was mainly concentrated in the central and eastern parts of the Northeast Plain, while the substantial turn-in phenomenon of 2005-2010 was mainly located in the northeast of the study area. Compared with a traditional regression model, the SSA-XGBoost model not only weakened the multicollinearity of each driver but also significantly improved the generalization ability and interpretability of the model. The coefficient of determination (R2) of the SSA-XGBoost model exceeded 0.6 in both the natural wetland decline and rise cycles, which could effectively quantify the contribution of each driving factor. From the results of the model calculations, agricultural activities consisting of dryland and paddy fields during the entire cycle of natural wetland change were the main driving factors, with relative contributions of 18.59% and 15.40%, respectively. Both meteorological (temperature, precipitation) and topographic factors (elevation, slope) had a driving role in the spatiotemporal variation of natural wetlands. The gross domestic product (GDP) had the lowest contribution to natural wetlands' variation. This study provides a new method of quantitative analysis based on machine learning theory for determining the causes of natural wetland changes; it can be applied to large spatial scale areas, which is essential for a rapid monitoring of natural wetlands' resources and an accurate decision-making on the ecological environment's security.