韧性视角下的天津市土地生态安全评价

Evaluation of the land eco-environmental security in Tianjin from the perspective of the exploitation resilience

基于韧性视角,以30 m×30 m栅格为评价单元,借助GIS空间分析功能,运用层次模糊物元模型,从多功能性、适宜性、冗余度、稳定性4个维度构建评价指标体系,评价了天津市土地生态安全等级及空间分布状况。结果表明：1）天津市综合土地生态安全属较安全等级,主要制约因子为水源影响度、地下水开采程度、分维指数及生态用地聚集程度; 2）天津市土地生态安全可划分为高度安全、较安全、临界安全和不安全4级,各级面积占比分别为16. 81%、33. 62%、27. 05%和22. 52%; 3）天津市综合土地生态安全空间差异明显,呈现北高南低、中心低四周高的空间分布。高度安全区主要分布在蓟州区北部和宝坻区;较安全区分布广泛,主要用地类型为耕地及水域湿地;临界安全区主要分布在武清区南部及静海区;不安全区主要分布在“环城四区”及滨海新区。

The purpose of this paper is to present a scientific evaluation of the ecological security level and the spatial distribution features of the municipality from the perspective of the exploitation resilience. To achieve the said purpose, we have taken 30m x 30m grid as the evaluation unit and adopted the analytic hierarchy process （AHP） and fuzzy matter element analysis method as the aid of the GIS＇s spatial analysis function. At the same time, we have chosen 11 indexes from the 4 aspects, that is, the versatility, the suitability, the redundancy and the stability to build up an evaluation index system and its urban-feature do- main plus the classical domain for the evolutional goal. The resuits of our evaluation can be shown in the following ways： （ 1 ） The comprehensive land ecological security in Tianjin has been found belonging to relatively security level. In view of the single indicators, the main restrictive factors of the land ecological security in the municipality are dominated by the water resource influential degree, the groundwater resource exploitation degree, the grain production yield promising degree, the fractal dimension and the aggregation degree of the ecological usability; （2） The ecological security of land in the municipality can be divided into 4 grades： highly secure, relatively secure, critically secure and insecure. The respective areas of each grade can be illustrated as follows： 1 972.56 km2, 3 944.34 km2, 3 174.22 km2, 2 642. 20 km2. Thus, 50. 43% of the land areas in Tianjin can be taken as being in a secure state; （3） The spatially different features of the comprehensive security areas can be said mainly spread in the northern parts of the city districts, like those of Jizhou and Baodi, whereas the relatively security areas can be said broadly scattering in a mixed way with the farmlands and water-coveting or green-rice fields as the main land use type. Among them, the critical security areas are mainly spreading in the south of Wuqing District and Jinghai District. But, in contrast, the insecure areas are mainly covering Ring 4 of the urban areas （ such as Dongli District, Xiqing District, Jinnan District and Beichen District） as well as the Binhai New District.