2007-2016年嘉峪关市城市绿地生态评价及障碍因子分析
Ecological evaluation and obstacle factor analysis of urban green space in Jiayuguan from 2007 to 2016​
： 2019 - 09 - 23
： 2019 - 12 - 02
： 2019 - 12 - 08
31 0 0

Abstract & Keywords
Abstract: Background, aim, and scope The evaluation of urban green space can provide important support for the scientific planning and management of urban green space and realize the sustainable development of urban green space. The division of health level of green space can provide important information for the management strategy of green space, such as species selection and adjustment of vegetation structure. Etc.; The analysis of greenland vegetation ecological risk sources and the classification of risk levels can alleviate or eliminate stressors for green areas, and on the other hand, formulate corresponding countermeasures for green space health, providing important information for rational planning and management of green space in the next step. By constructing the urban green space ecological evaluation index system, the paper makes a scientific evaluation of the urban green space in Jiayuguan City, and uses certain models to identify the influencing factors affecting the ecological level of the urban green space. It is hoped that people will correctly understand and transform the urban green space construction as a follow-up city. Green space planning and management provide theoretical references. Materials and methods With the urban green space of Jiayuguan city from 2007 to 2016 as the research object, the ecological evaluation index system of urban green space is constructed from three aspects, and the obstacle degree model is adopted to identify the obstacle factors that affect the ecological level of urban green space. Results In the past 10 years, the comprehensive value of urban green space ecological level of Jiayuguan city has gradually increased, and the level has been raised from the lower level to the higher level. However, at present, the ecological level of urban green space belongs to the low level and unstable high level, and the construction pressure of urban green space is still great. From the perspective of criteria, the main threats to the ecological level of urban green space in Jiayuguan are obvious, and the quantity index and structure index are the main obstacles. From the index level, the main obstacle factors are different from year to year, and the biggest obstacle factors have evolved from per capita park green space area, tree species richness to air purification capacity. Discussion Urban green space evaluation initially focused on green space structure and ecological function, then gradually expanded to green space ecological services, ecological health level and ecological risk, and finally developed to sustainability evaluation. Urban green space more attention in the study of urban green space's ecological functions and ecosystem services, and concentrated in the eastern central region, based on "oasis" Jiayuguan city green space as the research object, from the aspects of quantity, structure, function of three comprehensive evaluation of the urban green space ecology level, using the disorder degree model to identify the obstacle factors of the development of urban green space, for the improvement of other urban ecological problems in arid areas provides a certain reference. Conclusions From 2007 to 2016, the ecological level of urban green space in Jiayuguan City gradually increased to a low-level, unstable high-level order. The barrier factors varied greatly in different years, and the biggest obstacle factor experienced the evolution from per capita park green area, tree species richness to air purification capacity. Recommendations and perspectives The urban green space evaluation initially focused on the green space structure and ecological function, and subsequently expanded to the green space's ecological service, ecological health level and ecological risk, and finally developed to sustainability evaluation. At present, the research on urban green space pays more attention to the ecological function and ecosystem service of urban green space, and concentrates on the eastern and central regions. The article takes the urban green space of Jiayuguan in the “desert oasis” as the research object, and comprehensively evaluates it from three aspects: quantity, structure and function. The ecological level of urban green space, using the obstacle model to identify the obstacle factors that restrict the development of urban green space, provides a reference for the improvement of ecological problems in other cities in the arid region.
Keywords: urban green space; green space ecology; obstacle model; Jiayuguan city

1研究区概况与数据来源
1.1研究区概况

Fig.1 Spatial distribution map of green space in study area
1.2数据来源与处理
1.2.1   数据来源

1.2.2   数据预处理

$${M}_{ij}=\frac{{Y}_{ij}-\mathrm{m}\mathrm{i}\mathrm{n}\left({Y}_{ij}\right)}{\mathrm{max}\left({Y}_{ij}\right)-\mathrm{m}\mathrm{i}\mathrm{n}\left({Y}_{ij}\right)}$$ (1)
$${M}_{ij}^{\text{'}}=\frac{\mathrm{m}\mathrm{a}\mathrm{x}\left({Y}_{ij}\right)-{Y}_{ij}}{\mathrm{max}\left({Y}_{ij}\right)-\mathrm{m}\mathrm{i}\mathrm{n}\left({Y}_{ij}\right)}$$ (2)

2研究方法
2.1   城市绿地生态评价指标体系

 目标层 Target layer 准则层 Rule layer 权重 Weight 指标层 Index layer 属性 Attribute 单位 Unit 权重1 Weight 1 权重2 Weight 2 最终权重 Final weight 城市绿地生态评价指数 Ecological evaluation index of urban green space 数量指标 Quantity index 0.319 城市绿化覆盖率 Urban greening coverage rate (C1) + % 0.069 0.072 0.070 城市绿地率 The greening rate of the city (C2) + % 0.074 0.069 0.072 人均公园绿地面积 Per capita park green area (C3) + m2/人Person 0.095 0.062 0.078 树种丰富度 Tree species richness (C4) + \ 0.087 0.110 0.099 结构指标 Structure indicators 0.350 多样性指数Diversity index (C5) + \ 0.058 0.051 0.054 蔓延度指数Spreading index (C6) + % 0.048 0.057 0.052 景观均匀度 Uniformity of landscape (C7) + \ 0.051 0.044 0.047 分形维数Fractal dimension (C8) + \ 0.052 0.043 0.048 聚集度指数Aggregation index (C9) + % 0.047 0.044 0.046 斑块密度指数Plaque density index (C10) + \ 0.051 0.062 0.057 形状指数Shape index (C11) - \ 0.046 0.046 0.046 功能指标 Function indices 0.330 吸收有毒气体能力 Ability to absorb toxic gases (C12) + t 0.066 0.076 0.071 净化空气能力 Air purification capacity (C13) + % 0.082 0.075 0.079 沙尘暴次数Dust storm frequency (C14) - 次Time 0.050 0.044 0.047 杀菌保健能力 Bactericidal and health care ability (C15) + % 0.058 0.068 0.063 滞尘量Amount of dust (C16) + t 0.066 0.075 0.071 说明：吸收有毒气体能力=单位面积绿地吸收SO2量×绿地面积；净化空气能力=城市空气质量优良天数÷当年实际监测天数×100%；杀菌保健能力=（公园绿地面积+防护绿地面积）/绿地面积；滞尘量=单位面积滞尘量×绿地面积；树种丰富度=（树种树-1）/Log2N，其中N为树种个体总数。
2.2指标权重的计算
${M}_{ij}=\frac{{Y}_{ij}-\mathrm{m}\mathrm{i}\mathrm{n}\left({Y}_{ij}\right)}{\mathrm{max}\left({Y}_{ij}\right)-\mathrm{m}\mathrm{i}\mathrm{n}\left({Y}_{ij}\right)}$
${M}_{ij}^{\text{'}}=\frac{\mathrm{m}\mathrm{a}\mathrm{x}\left({Y}_{ij}\right)-{Y}_{ij}}{\mathrm{max}\left({Y}_{ij}\right)-\mathrm{m}\mathrm{i}\mathrm{n}\left({Y}_{ij}\right)}$

$${\partial }_{j}=\frac{{D}_{j}}{\stackrel{-}{{Z}_{j}}}$$$${W}_{j}=\frac{{\partial }_{j}}{\sum _{j=1}^{n}{\partial }_{j}}$$ （3）

$${P}_{ij}={M}_{ij}/\sum _{i=1}^{n}{M}_{ij}\left(i=1,2,\dots ,n,j=1,2,\dots ,m\right)$$ (4)

$${E}_{j}=-k\sum _{i=i}^{n}{P}_{ij}\mathrm{ln}\left({P}_{ij}\right)$$ (5)

$${R}_{j}=1-{E}_{j}$$ (6)

$${W}_{j}={R}_{j}/\sum _{j=1}^{m}{R}_{j}\left(1\le \mathrm{j}\le \mathrm{m}\right)$$ (7)
2.3障碍度模型

$${O}_{ij}=\frac{\left(1-{x}_{ij}^{,}\right)×{w}_{ij}×100%}{\sum \left(1-{x}_{ij}^{,}\right)×{w}_{ij}}$$ (8)
$${O}_{i}=\sum {O}_{ij}$$ (9)

3   结果与分析
3.1嘉峪关市城市绿地生态水平分析

 评价值 Value [0,0.2] [0.2,0.4] [0.4,0.6] [0.6,0.8] [0.8,1.0] 等级 Level 低级（Ⅰ） Low-level (Ⅰ) 较低级（Ⅱ） Lower (Ⅱ) 中级（Ⅲ） Intermediate (Ⅲ) 较高级（Ⅳ） More advanced (Ⅳ) 高级（Ⅴ） Senior (Ⅴ)
3.1.1城市绿地生态水平总体评价

Fig.2 Changes in ecological level and growth rate of urban green space in Jiayuguan city (2007-2016)
3.1.2数量指标评价
2007-2016年数量指标评价分值变化最为明显，总体表现出先增长后减小再增长的走势（表3）。随着生态文明建设、绿色创新理念等的贯彻落实，嘉峪关市加速步入集约高效、绿色创新发展道路，城市绿量持续提高，数量指标值占城市绿地生态值的比重越来越大。其中：2013年伴随着城市人口的增加和建设用地的扩张，城市人均绿地拥有量相对有所减少；2015年，嘉峪关市紧跟“五位一体”总体布局和“四个全面”战略布局，以生态文明建设为统领，以环境质量改善为核心，城市生态环境取得实质性进展。期间，在城市园林绿地面积增加14490.10hm2的背景下，人均公园绿地面积以年均10.23%的速率从2007年的17.60m2/人增加到2016年的35.61m2/人，但城市绿化覆盖率仅增长4.13%，仍难以满足居民对舒适生活环境的需求。
3.1.3   结构指标评价

3.1.4   功能指标评价

 年份Year 数量指数Index number 结构指数Structure indicator 功能指数Function indices 综合评价值Comprehensive evaluation value 等级Level 2007 0.005 0.055 0.016 0.221 Ⅱ 2008 0.008 0.061 0.028 0.285 Ⅱ 2009 0.016 0.060 0.052 0.381 Ⅱ 2010 0.025 0.051 0.045 0.363 Ⅱ 2011 0.041 0.067 0.051 0.473 Ⅲ 2012 0.047 0.067 0.088 0.603 Ⅳ 2013 0.030 0.074 0.055 0.472 Ⅲ 2014 0.045 0.074 0.050 0.502 Ⅲ 2015 0.091 0.081 0.072 0.733 Ⅳ 2016 0.102 0.087 0.083 0.820 Ⅴ 标准差 Standard deviation 0.031 0.011 0.021 0.180
3.2   嘉峪关市城市绿地生态水平障碍因子分析
3.2.1准则层障碍因子

Fig.3 2007-2016 Jiayuguan urban green space ecological level subsystem barriers
3.2.2   指标层障碍因子

 障碍度（%） Barrier degree 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 平均值 Mean 标准差 Standard deviation C1 8.85 8.02 7.29 4.06 5.36 5.33 7.85 12.94 1.32 2 6.30 3.27 C2 9.58 8.4 7.93 7.66 7.18 7.57 11.39 10.83 1.04 5 7.66 2.82 C3 10.05 13.28 11.56 13.36 15.59 15.63 13.43 13.04 12.2 11.4 12.95 1.67 C4 11.26 12.19 11.7 11.95 10.31 10.82 8.13 1 6 6 8.94 3.45 C5 2.7 2.25 5.38 9.25 8.47 9.03 6.24 6.73 6.33 5 6.14 2.30 C6 2.74 3.9 2.03 0 2.91 3.78 5.68 6.13 8.44 8.88 4.45 2.68 C7 2.92 2.44 4.94 8.07 6.58 5.57 3.86 4.16 3.92 4 4.65 1.61 C8 6.73 5.79 3.02 2 3.08 4.01 6.02 6.5 11.05 10.28 5.85 2.86 C9 4.56 6.5 4.66 2.8 3.09 4.02 2.91 3.14 2.95 1 3.56 1.39 C10 6.59 4.62 4.92 5.52 3.15 4.1 1 3 6 1.1 4.00 1.83 C11 0.2 0.07 3.38 7.35 5.15 6.71 1.88 2.02 6.19 7.28 4.02 2.72 C12 8.5 8.69 8.43 7.44 6.94 6.87 4.21 2.62 1.03 0 5.47 3.09 C13 9.23 9.02 9.76 5.83 8.72 2 3.95 12.69 19.24 17.17 9.76 5.14 C14 5.12 3.46 1 1.19 4.52 4.71 8.84 2.38 7.18 8.34 4.67 2.64 C15 2.45 2.65 5.52 6.06 6 7 10.42 10.24 6.16 8.54 6.50 2.58 C16 8.53 8.72 8.48 7.46 6.95 4.84 4.19 2.59 0.95 4 5.67 2.60
4   结论与建议
（1）总体而言，2007-2016年嘉峪关市城市绿地生态水平整体呈波动上升趋势，级别由较低等级提高到高等级。但最高值0.82靠近高等级区间的下限，因此目前城市绿地生态水平仍属于低层次的高等级阶段且不稳定，城市绿地生态建设工作压力还很大。
（2）从准则层看，10年间嘉峪关市城市绿地生态水平的主要威胁变化较为明显。2007年制约性主要来自数量指标和功能指标两方面，障碍度之和为73.76%，2016年结构指标和功能指标成为主要制约因素，障碍度之和高达88.70%。从指标层看，各年份主要障碍因子不尽相同，最大障碍因子历经了从人均公园绿地面积、树种丰富度到净化空气能力的演变。。

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Ma Yaxiong

Zhang Zhibin

Da Xiaojun

Dong Jianhong

Zheng Lan

Journal of Earth Environment