京张区域生态系统健康评价与应对策略

利用遥感和GIS空间分析方法,以66个小流域为评价单元,对京张区域生态系统状况进行了分析,提出了相应对策。研究表明:(1)京张区域生态系统健康水平整体较差,近6成面积区域生态不健康或较不健康;(2)京张两市交界处存在一个健康指数高的生态绿带,由此向东南、西北两侧健康指数逐渐降低,北京生态健康指数整体高于张家口;(3)京张区域生态健康状况在县域尺度上出现了两级分化的情况,健康等级面积占比高于80%的县区和低于30%的县区占大多数;(4)平均斑块面积指数低是制约京张全域生态健康的全局性因素;初级生产力低、人类干扰程度高、河网密度低等是生态不健康区域的主要影响因素。对策:(1)保护好京张交界处的生态绿带,重点加强37号小流域生态建设;(2)加强京张区域东南、西北两翼边缘地区生态建设,坝上边缘加大退耕还林草,北京东南缘的66号和39号小流域要重点控制城市面积扩展,提高自然植被斑块面积;(3)加强对一般健康流域的监管,促使小的镶嵌斑块发展为连片面状健康区域;优先治理张家口连片生态较不健康区域;(4)生态建设重点是提高植被斑块面积和植被覆盖度,降低大规模的耕种和城市化建设,修复河网;(5)在张家口建立生态特区。

Assessment and Countermeasures of Ecosystem Health in the Beijing-Zhangjiakou Area

In this paper,the status of ecosystem in the Beijing-Zhangjiakou region was analyzed,the strategy was put forward using the RS means and GIS spatial analysis,and 66 drainage basins were taken as the evaluation units.The results showed that the ecological health level in the Beijing-Zhangjiakou region was low,and the ecology in nearly 60%area was unhealthy or relatively unhealthy.At the junction of Beijing and Zhangjiakou cities,there was an ecological green belt with high health index.From this junction to the southeast and northwest,the index of ecological health was in a decrease trend.The ecological health index in Beijing was higher than that in Zhangjiakou.A polarization of regional ecological health status at county scale occurred in the Beijing-Zhangjiakou region,and the counties and districts where the proportion of areas with healthy ecology was higher than 80%and lower than 30%were in the majority.The low average patch area index was the overall factor restricting the ecosystem health in the Beijing-Zhangjiakou region.The low primary productivity,high level of human disturbance and low drainage density are the main factors affecting the unhealthy ecosystem.Some countermeasures were put forward:(1)The ecological green belt at the junction of Beijing and Zhangjiakou should be protected well,and the ecological construction in the small watershed No.37 should be emphasized;(2)It was suggested to promote the ecological construction in the southeast and northwest marginal zones of the Beijing-Zhangjiakou region,enhance the implementation of the Grain for Green Project in the Bashang Plateau,and control the expansion of the urban area and enlarge the area of the natural vegetation patches in the small catchments No.66 and No.39;(3)It was suggested to focus on the supervision of the drainage basins with general ecological health and promote the connection of small mosaic patches with healthy ecosystem;(4)The focuses of ecological construction are to enlarge the vegetation patch area and increase the vegetation coverage,reduce the large-scale construction of farming and urbanization,and improve the restoration of drainage basins.(5)It was also suggested to establish a special ecological zones in Zhangjiakou.