基于压力-状态-响应模型的黑河中游张掖市生态安全评价

Ecological security evaluation of Zhangye City in the middle reaches of the Heihe River based on Pressure-State-Response model

生态系统服务的状态与生态是否安全密切相关,生态系统服务的正常发挥是实现生态安全的前提。近年来,中国西北荒漠-绿洲扩张速度加快,改变了生态系统服务的供给与传输,进而影响了区域生态安全。以典型荒漠-绿洲区域黑河中游的张掖市为例,基于压力-状态-响应模型,耦合生态系统服务理论,构建了黑河中游生态安全评价指标体系,评估了2001-2015年黑河中游生态安全演变趋势。研究结果表明黑河中游生态系统面临的资源消耗和环境污染压力越来越大,压力指数有所降低;部分地区出现植被退化、破碎化增加等现象,状态指数略有降低;在实施节水灌溉、产业转移、湿地保护等举措后,响应指数显著增加。总体来看,2001-2015年黑河中游生态安全水平呈现波动增长趋势,生态安全综合指数由0.3748增至0.5888,生态安全等级由"较不安全"达到"临界安全"状态,其中高效节水灌溉面积、生态用水量、地下水开采率等水资源相关要素是影响绿洲生态安全水平的主要因子。基于以上研究,提出了坚持生态保护优先、调整种植和产业结构、发展高效节水灌溉技术、提高公众生态保护意识等提高生态安全水平的相关对策与建议,以期为促进区域生态经济可持续发展提供支撑。

The state of ecosystem services is closely related to whether the ecosystem is safe or not.The normal play of ecosystem services is the premise of realizing ecological security.Recently,the expansion speed of desert oasis in Northwest China has accelerated which has changed the supply and transmission of ecosystem services,and further affected the regional ecological security.Taking the middle reaches of the Heihe River in typical desert oasis region as an example,based on Pressure-State-Response model,coupled with the ecosystem service theory,the ecological security evaluation index system of the middle reaches of the Heihe River was constructed,and the evolution trend of ecological security in the middle reaches of the Heihe River from 2001 to 2015 was evaluated.The results showed that the ecosystem in the middle reaches of the Heihe River was facing increasing pressure of resource consumption and environmental pollution,and the pressure index decreased accordingly.As vegetation degradation and fragmentation increased in some areas,the state index decreased slightly.After the implementation of water-saving irrigation,industrial transfer,wetland protection and other positive measures,the response index increased significantly.Overall,from 2001 to 2015,the ecological security level in the middle reaches of the Heihe River showed a fluctuating growth trend,the ecological security index increased from 0.3748 to 0.5888,and the ecological security level reached the state of"critical safe"from"less safe".Among them,water resources related factors such as area of efficient water-saving irrigation,ecological water consumption and groundwater development rate were the main factors affecting the ecological security level of oasis.Based on the above research,this paper puts forward relevant countermeasures and suggestions to improve the ecological security level,such as adhering to the priority of ecological protection,adjusting planting and industrial structure,developing efficient water-saving irrigation technology and improving public awareness of ecological protection,in order to provide support for promoting the sustainable development of regional ecological economy.