| 摘要: |
| 基于1995、2005、2013年3期Landsat TM/ETM+遥感影像及DEM,应用GIS方法开展巢湖流域景观格局特征分析及生态风险网格化定量评估. 研究表明:(1)近20年来,巢湖流域景观格局特征变化明显,表现为建设用地景观破碎度、分离度均呈先下降后上升趋势;农地、林地与水体景观破碎度、分离度均呈上升趋势. (2)生态风险时序分析表明,19952013年,巢湖流域低、较低和中等级生态风险区域面积在逐渐缩小,而较高和高等级生态风险区域范围在不断蔓延. 近20年来,巢湖流域生态风险主要由低级向高级转化,面积达6025 km2,是由高级向低级转化面积的2.30倍. (3)生态风险时空演化机制分析表明,巢湖流域生态风险变化区域主要集中在北、西南和东南部,具有明显的阶段性和区域性. 近20年来,巢湖流域经历了快速的城市化、工业化以及受到行政区划调整的政策影响,高强度土地利用模式及县域经济活力的释放叠加于本身脆弱的流域生态条件,对景观生态系统造成的强烈干扰促进流域生态风险整体有恶化趋势,需重点加强中级以上生态风险区域的生态保护与建设工作. 因此,生态风险演化趋势体现了该流域自然特点和区域社会经济发展对景观生态系统干扰的压力响应. |
| 关键词: 景观格局 生态风险 网格化采样 城市化 巢湖流域 |
| DOI：10.18307/2016.0411 |
| 分类号: |
| 基金项目:国家自然科学基金项目(41471422)、安徽省高校省级优秀青年人才基金重点项目(2013SQRL047ZD)和安徽省财政、住建厅徽派建筑保护省级专项(HPZX2013-01)联合资助. |
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| Landscape ecological risk assessment and its mechanism in Chaohu Basin during the past almost 20 years |
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HUANG Muyi, HE Xiang
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School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei 230601, P.R.China
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| Abstract: |
| Based on landscape classification maps that are conducted from 1995, 2005 and 2013 by Landsat TM/ETM+ remote sensing images interpretation and scope of study area extracted from DEM and cell sampling by GIS platform, the landscape pattern characteristics and changes of ecological risk in Chaohu Basin during the past 20 years (1995-2013) are analyzed quantitatively. Meanwhile, the spatial-temporal change of ecological risk has been explained in the paper. The results show: (1) in recent 20 years, the landscape structure and the landscape pattern characteristics have changed greatly in Chaohu Lake Basin. Rapid urbanization has impact on catchment landscape pattern significantly, whose fragmentation and isolation index of construction land show a trend of decrease first and then increase, but that of woodland, farmland, and water landscape have increasing trends. (2) ecological risk index in Chaohu Basin shows that, during the past almost 20 years, the area of ecological risk at low, lower and medium level decreases gradually, along with significant increase in area with high and higher level of ecological risk. In 1995, the Chaohu Basin is dominated by medium and low ecological risk, which accounts for nearly 70% of the total area. In 2005, the scope at medium and high ecological risk is in the majority, accounting for nearly 71% of the total area. Ecological risk level transfer matrix analysis shows that in recent 20 years, there are 17 types of ecological risk level transformation change, in which 8 types convert from superior to inferior with transformation area of 2618 km2, and other 9 types convert from junior to senior with transformation area of 6025 km2, which is 2.30 times of area that converted from superior to inferior. (3) Analysis of spatial difference characteristic about ecological risk shows that the spatial distribution of ecological risk grade change obviously, the main change occurred in the north, southwest and southeast of Chaohu Basin. The evolution of the ecological risk in Chaohu Basin has obvious periodicity and regional characteristics, which reflects not only the natural characteristics of the Chaohu Basin, but the response of pressure that regional social and economic development has a huge impact on the land ecosystem. The study shows that the ecological status of the Chaohu Basin has deteriorated with the development of urbanization and industrialization in the last 20 years. The scope of ecological risk at medium or higher level must to give more attention. |
| Key words: Landscape pattern ecological risk cell sampling urbanization Chaohu Basin |
