巢湖流域土地景观格局变化及生态风险驱动力研究

健康的流域生态系统是区域经济社会可持续发展的重要基础。探讨流域土地景观格局变化及生态风险驱动机制有助于生态系统状况诊断与风险来源认识,为有效制定生态风险管控措施提供决策依据。应用空间信息技术平台及计量分析方法,探讨了基于县域行政单元的快速城市化阶段巢湖流域土地景观格局变化及生态风险驱动力。研究表明:(1)2000~2013年,巢湖流域土地景观类型变化表现出农地、林地、水体景观面积下降,建设用地景观面积显著增加的趋势;流域景观水平上多样性和均匀度呈下降、优势度呈上升趋势,景观空间异质性下降;(2)近15 a来,巢湖流域9个行政单元内生态风险均呈上升趋势,生态风险整体恶化,需加强对流域生态风险上升的管控;(3)生态风险驱动力分析表明,快速城市化阶段巢湖流域生态风险的主要驱动因子为第二产业值、城市化率、人口密度和固定资产投资,而人均GDP的增加在一定程度上会降低生态风险水平。     

Halogenated organic contaminants (HOCs) in sediment from a highly eutrophicated lake, China: Occurrence, distribution and mass inventories

Halogenated organic contaminants (HOCs) including 16 polybrominated diphenyl ethers (PBDEs) and 37 polychlorinated biphenyls (PCBs) were determined in 49 surfacial sediments from Chaohu Lake, a highly eutrophicated lake, China. PBDEs were detected in almost samples with the range of the total concentration (defined as Σ₁₆PBDEs) from 0.84 to 86.6 ng g⁻¹. Compared with the occurrence of PBDEs in Pearl River Delta and Yangtze River Delta in China, lower percentage of BDE-209 over the concentration of Σ₁₆PBDEs was inferred by the high-volume application of penta-BDE mixture product for local domestic furniture purpose. The total concentration of 37 PCBs (Σ₃₇PCBs) ranged from 0.05 to 3.36 ng g⁻¹ with the most detection of PCB-1, -4, -52 and -71. Both the concentrations of Σ₁₆PBDE and Σ₃₇PCB poorly correlated with total organic carbon (TOC), suggesting the significant contribution of phytoplankton organic carbons to sediment TOC. The contamination by PBDEs and PCBs in western region of the lake was significantly more serious than in eastern lake. Our findings about the higher residues of PBDEs and PCBs in sediments at the estuary of Nanfei River compared to the other estuaries also supported the conclusion that urban area (Hefei city) was the main source of PBDEs and PCBs. The comparison with the concentration of HOC in the present study with those in other lacustrine sediments around the world suggested the contamination by PBDEs in Chaohu Lake is at middle of the global concentration range, whereas PCBs is at low end of the global range which could be elucidated by local economic development and historical usage of PBDEs and PCBs. The mass inventories of HOCs in the lake were estimated at 561 and 38 kg, which corresponds to only 0.000006% and 0.0001% of these global historical produce volumes, respectively.     

区域生态环境的未确知测度评价模型及应用

基于生态环境的信息不确定性特点,建立了区域生态环境评价的未确知测度模型。根据未确知测度的大小,确定样本所属的质量级别及样本间的优劣排序。以巢湖流域为例,运用所建模型对其生态环境质量状况进行了评价。研究表明,未确知测度模型对于多指标的区域生态环境质量评价,理论上是可行的,结果是可信的。      

长江中下游湖泊沉积速率的测定及环境意义——以洪湖、巢湖、太湖为例

对长江中下游洪湖、巢湖和太湖沉积物采用210Pb和137Cs相结合的方法测定沉积速率。洪湖钻孔中210Pbex随深度的增加没有呈现指数衰减分布,因此获得的平均沉积速率并不可靠;而根据137Cs蓄积峰计算得出洪湖钻孔在1963~1986年沉积速率最大,这可能是因为当时大规模开垦导致湖区周围水土流失,大量的侵蚀物质被带入湖中,从而导致沉积速率上升。对巢湖钻孔用210Pb法和137Cs得到的沉积速率具有可比性,研究发现20世纪70年代以来随着深度的减少,巢湖钻孔中沉积通量在增加,说明巢湖流域内水土流失逐步加重,可能与土地开发、植被破坏等人为活动有关。对太湖钻孔利用137Cs 1963年对应的蓄积峰进行校正,采用210Pb计年的CRS模式获得不同时段的沉积速率发现在80年代末尾沉积物堆积通量最高,达到0.6 g·cm-2·a-1。两种计年方法的结合有助于认识沉积速率的变化情况。     

环巢湖地区旅游资源可持续发展研究

根据环巢湖地区旅游资源的特点,分析了旅游资源开发中存在的问题,主要集中在水环境、特色旅游项目、景区环境、经营管理等方面,从宏观调控、法规法律、资源调查和保护、地区联动和环境教育等角度,提出了环巢湖地区旅游业可持续发展的主要对策。     

巢湖流域灾害链成因机制与减灾对策

在对巢湖流域灾害进行深入研究的基础上,提出以"流域"为边界条件,自然和人文因素叠加下的灾害链作用机制和成因机理,着重从人-地关系地域系统的调控上来制定区域减灾对策,为流域可持续发展提供科学的理论依据与实践指导。从流域内灾害产生的地质—地貌、气象—水文、过渡区环境以及灾害产生的文化与经济四方面原因,分析灾害链产生的三条途径。针对性地提出了该流域减灾防灾必须以关键点为中心,采取生物措施与工程措施相结合、上下协同控制的六条减灾对策措施。     

基于熵权的巢湖水生态健康模糊综合评价

在对巢湖水生态状况深入调查研究的基础上,确立了湖泊生态系统健康评价指标体系,确定了各指标健康等级的阙值范围,建立了基于熵权的湖库水生态健康模糊综合评价模型。并选取1980年巢湖的水质和水生态数据作为本底值。运用熵权法对2000～2005年整个湖泊生态系统的健康状况进行了客观评价,结果表明2004—2005年巢湖水生态系统均处于较差健康状态。本方法的计算结果表明采用熵权综合健康指数法对其进行生态系统健康评价具有很好的可靠性和实用性。最后根据实际提出了湖库水生态安全综合管理对策。     

内河岸线资源评价与开发研究——以安徽巢湖市域长江岸线为例

内河岸线资源是国家重要的国土资源和特殊的土地资源。随着“T”战略的实施、沿江开发的逐步深入,岸线资源在沿江区域经济发展中的地位越来越重要。如何客观、科学地评价岸线资源,合理利用并发挥其最大的资源效益具有重要意义。经过甄别,遴选了岸前水深、岸线稳定性、岸前航道水域宽度和后方陆域场地条件4项指标作为评价指标,并运用GIS手段进行了实际评价,经过综合评价得出安徽巢湖段岸线资源的基本情况是Ⅰ、Ⅱ级优良岸线比例高,适合建港和发展工业、仓储的岸线资源量大,并根据评价结果分段提出了开发方向和建议。     

Understanding the anthropogenic phosphorus pathway with substance flow analysis at the city level

Excessive input of phosphorus into natural water bodies as a result of anthropogenic processes is an escalating factor that leads to eutrophication. Hence, quantifying the pathway of phosphorus throughout the socioeconomic system is essential for the selection of appropriate measures to mitigate phosphorus discharge. The study develops an analytical model of anthropogenic phosphorus flows within a socioeconomic system based on substance flow analysis. The model consists of five major subsystems: the phosphorous chemical industry, agriculture, animal feeding, human consumption, and waste management. The results show that the total input and output of phosphorus in Chaohu City over 2008 are 8517.70 ton (t) and 4682.76 t, respectively. The estimation of phosphorus discharged into local surface water is 544.22 t, which primarily comes from agriculture (391.99 t, 72.03%), followed by large-scale farming (55.70 t, 10.23%), rural consumption (56.81 t, 10.44%), urban consumption (30.42 t, 5.59%), and waste management (9.30 t, 1.71%). Intensive input of fertilizers in agricultural practices was identified as the most important source of phosphorus load on local surface water. Hence, we propose that the eutrophication of local water bodies could be addressed by optimizing local industrial structure, developing ecological and organic-based agriculture, and improving waste collection and disposal practices.     

Anthropogenic phosphorus flow analysis of Lujiang County, Anhui Province, Central China

Anthropogenic phosphorus load in the aquatic environment of Lujiang County, central China, may be a serious problem, greatly contributing to surface water eutrophication. Using substance flow analysis, this study develops a phosphorus-flow analytical model to trace the pathways of this limiting nutrient throughout Lujiang's socioeconomic system. The model includes six major subsystems: extraction, phosphorous chemical industry, agriculture, animal husbandry, human consumption, and phosphorous waste management. We conducted qualitative and quantitative analyses of the primary phosphorous flows and stocks within these subsystems in Lujiang County over 2008. Approaches to data include statistical reports and literature reviews, face-to-face interviews and questionnaire-based surveys. The results show the total phosphorus input and output were 8311.5 tons and 5664.6 tons, respectively, in Lujiang in 2008, resulting in a phosphorus surplus of 2646.9 tons in the socioeconomic system. The phosphorus load in the recipient waters, as part of the total phosphorus output, was estimated to be 1666.7 tons. Large-scale livestock operations contributed the most phosphorus to local surface waters, accounting for 55.8% and followed by human consumption (23.0%) and agriculture (21.2%). Consequently, it should be of central concern for policy makers to improve phosphorous reuse efficiency in order to reduce phosphorus release into the aquatic environment. Limitations of the methodology and data are also discussed.