基于DPSIR模型的崩岗侵蚀风险评价及时空特征

    Risk assessment and spatial-temporal characteristics of Benggang erosion based on DPSIR model

    • 摘要: 崩岗是中国南方红壤区最为严重的土壤侵蚀形式之一,不仅具有突发性且危害巨大,对其进行全方面的风险评价有利于崩岗综合整治。该研究引入驱动力-压力-状态-影响-响应模型(driving force-pressure-state-impact-response,DPSIR),并结合自然灾害风险理论,根据崩岗侵蚀过程从易发性、脆弱性、暴露性和防灾减灾能力等方面构建了较为综合的崩岗侵蚀风险评价体系,然后对安溪县官桥镇2010、2015和2020年的崩岗侵蚀风险进行了评价。结果表明:1)基于DPSIR的崩岗侵蚀风险评价模型精度结果良好,ROC曲线下方的面积AUC(area under curve,AUC)均大于0.59;其中沟壑密度、土壤侵蚀强度和人口密度指标权重较大,分别为0.217、0.182 和 0.174。2)3个年份的官桥镇崩岗侵蚀风险主要为低风险等级(占总面积57.49%~62.90%),在空间上呈中部高、四周低的分布特征;风险变化主要分布在中西部和东部地区,且中风险、高风险和极高风险主要向低一级的风险等级转变,但在2015—2020年该区域的空间变化速度放缓。3)与崩岗侵蚀易发性风险评价结果相比,二者的空间分布趋势大致相似,但综合性风险评价结果的空间变异性更大,即综合性崩岗侵蚀风险的描述更为全面,更能体现崩岗侵蚀风险体系中不同指标产生的影响。研究结果不仅提供了一种综合的崩岗侵蚀风险评价思路和方法,并且可以为崩岗预警、防治与管理工作提供更为全面的参考。

       

      Abstract: Benggang (collapsing hill) is one of the most severe forms of soil erosion in the red soil region of southern China. This typical erosion is also characterized by sudden damage. Therefore, it is extremely necessary to assess the risk of Benggang erosion for subsequent comprehensive rectification. In this study, the Driving Force-Pressure-State-Impact-Response (DPSIR) model was applied to assess the risk of Benggang erosion, together with the natural disaster risk theory. A comprehensive system of risk assessment was constructed from the perspectives of susceptibility, vulnerability, exposure, disaster prevention, and mitigation capabilities. The case area selected was Guanqiao Town located in the southeast part of Anxi Country, Quanzhou City in Fujian Province, China. First, the spatial distribution of Benggang erosion risk was obtained using the ArcGIS spatial analysis for the years 2010, 2015, and 2020. The transition probability matrix of Benggang erosion risk class in the two periods of 2010-2015 and 2015-2020 was then calculated to characterize the temporal and spatial evolution of risk changes. Last, the relationship between the comprehensive evaluation and simple susceptibility was further analyzed to compare the spatial distribution. The results indicated that: 1) The DPSIR model was suitable for the comprehensive risk assessment of Benggang erosion in the study area, indicating high accuracy (the AUC of the three years were all greater than 0.59). Among them, gully density performed the most on the Benggang erosion risk (weight of 0.217), followed by soil erosion intensity and population density (weights of 0.182 and 0.174 respectively). 2) The risk of Benggang erosion was mainly low-risk grade areas ( accounting for 57.49%-62.90% of the total area ), with the distribution pattern of high-risk areas in the central and low-risk areas in the surrounding areas. The changes in the risk grades were distributed mainly in the central-western and eastern regions. The medium-, high-, and extremely high-risk grades were transitioned to lower-risk grades. However, the spatial change rate slowed down from 2015 to 2020. 3) Comparative analysis showed that there were broadly consistent trends of spatial distribution between the evaluation and simple susceptibility. Nevertheless, larger spatial variability was found in the comprehensive risk assessment. Therefore, the comprehensive Benggang erosion risk can significantly contribute to a better understanding of the influence of different indicators in the erosion risk system. The findings also provide an overall strategy and technique guideline to prevent, control, and manage erosion risk in Benggang regions.

       

    /

    返回文章
    返回