基于系统仿真模拟的三峡库区生态承载力分区动态评价

Dynamic Zoned Assessment of Ecological Carrying Capacity of Three Gorges Reservoir Area Based on System Simulation

针对现有生态承载力评价研究中时间动态性、空间差异性考虑不足等问题,引入系统动力学（SD）模型,围绕生态承载力关键指标实施三峡库区分单元的系统仿真模拟和预测,整合生态承载力综合评价方法,对不同控制单元承载力状况进行动态评价.结果表明：12010年三峡库区生态承载力指数为0.55,为弱可承载状态.生态承载力限制因素分析显示,长江嘉陵江重庆市辖区控制单元、长江涪陵区万州区控制单元主要受制于资源、环境要素,其他3个控制单元（澎溪河开县控制单元、长江云阳县巫山县控制单元、长江恩施州宜昌市控制单元）主要受制于社会、经济要素.2现有发展趋势下,2010—2025年三峡库区生态承载力指数为0.48-0.57,呈先增后减的趋势,拐点出现在2015年附近,整体亦处于弱可承载状态.2015年后,以资源、环境为主要限制因素的2个控制单元生态承载力指数开始逐年下降;以社会、经济为主要限制因素的其他3个控制单元生态承载力指数则呈延续上升态势.3综合调控方案下,三峡库区生态承载力指数在2015年达到0.60,由弱可承载提升为基本可承载;至2018年,所有控制单元均达到基本可承载,生态承载力指数为0.60-0.76.可见,综合调控方案对各控制单元人口、经济、环境、资源因素的调控行之有效.

In view of the inadequate consideration of temporal and spatial heterogeneity in current Ecological Carrying Capacity （ECC） assessments, a system dynamic （SD） model was introduced in the present study. Focusing on the key indicators of ECC, simulation and prediction for each control unit in Three Gorges Reservoir （TGR） Area was completed. Using comprehensive evaluation method of ECC, dynamic evaluation for different control units was realized. The results showed that： 1 ） The TGR ECC index was 0.55 in 2010, showing a weak bearing state. According to the analysis of constraint factors, the ECCs of two control units, namely Chongqing City of YangtzeJialing River control unit and Fuling-Wanzhou district of Yangtze River control unit, were mainly limited by resource and environment elements. However, those of the other three control units, namely Kaixian County of Pengxi River control unit, Yunyang-Wushan county of Yangtze River control unit and Enshi-Yichang City of Yangtze River control unit, were more subject to social and economic elements. 2） Under the scenario of maintaining existing development trends, the TGR ECC index was within 0. 48-0.57 from 2010-2025. It was on the whole still in the weak bearing state, but the index would first increase and then decrease, with a break point in 2015. In particular, the ECCs of the two control units limited by resource and environment elements would decrease after 2015. The ECCs of the other three control units limited by social and economic elements would continue to increase after 2015. 3） Under the scenario of implementing an integrated control program, the TGR ECC index would reach 0.60 in 2015, showing an improvement from weak bearing state to basic bearing state. In 2018, all control units would be in the basic bearing state, with the index varying from 0. 60 to 0. 76. This proves the effectiveness of the control program for each control unit in population, economy, environment and resources factors.