洞庭湖区生态承载力响应的时空分异

Spatial-temporal differentiation ecological carrying capacity response in Dongting lake region

不同时空尺度下,自然条件变化和人类社会经济活动引起了生态承载力响应的时空分异。运用生态承载力响应模型,采用标准差、变异系数、相对发展率、离差、比率等统计分析方法对洞庭湖区生态承载力响应的时空分异特征及演化机理进行分析。研究结果表明:(1)整体上来看,近15 a来洞庭湖区生态承载力响应值呈现波折式下降趋势,县域生态承载力响应强度的绝对差异和相对差异呈现"扩大—缩小—扩大"变化趋势。(2)2001—2015年县域生态承载力响应状态分为强超载、超载、弱低载和低载4类,县域差异明显;空间格局上,洞庭湖中部地区的响应状态优于周围地区,从西南向东北呈现"M"型格局。(3)2001年—2015年洞庭湖区17个县域生态承载力响应值的变化幅度和相对发展率差异明显,沅江市和南县2个县域与整个湖区生态承载力响应强度的差距最大;空间格局上,洞庭湖中部地区高于周围县域,西南地区高于东北地区,低载地区高于超载地区。(4)2001—2015年洞庭湖区17个县域生态承载力响应值的离差和比率的时空差异性明显,岳阳市区、常德市区、益阳市区、湘阴县、沅江市、南县和桃江县7个县域相对整个湖区平均水平的差距最大,响应强度高于其它10个县域;地域分布上集中在洞庭湖中部地区和经济社会发展水平较高的地区。(5)产业结构特征及变化、经济社会高速发展、城镇化快速推进、资源开发和基础设施建设是主导洞庭湖区生态承载力时空分异特征的演化机理。

The ecological carrying capacity responsivity presented spatial-temporal differentiation with the change of natural condition and human socioeconomic activities at different spatial-temporal scales.Using ecological carrying capacity response mode and statistical analysis method such as standard deviation,variance coefficient,relative developmental rate,deviation and coeffficient ratio,ecological carrying capacity response in Dongting lake area from2001to2015were analyzed.The results indicate that:(1)Ecological carrying capacity responsivity in Dongting lake area appeared wavelike decreasing trend in the recent15years,the absolute difference and relative difference of ecological carrying capacity response intensity in17countries presented a overall trend of enlarging-shrinkingenlarging.(2)Ecological carrying capacity response was divided into four categories:severely overload,overload,slightly under-load and under-load.the middle countries of Dongting lake area had better ecological carrying capacity responsivity than the surrounding region,presenting M-shaped spatial pattern from southwest to northeast.(3)The rangeability and relative development rate of17counties in Dongting lake area were of great different from2001to2005,Yuanjiang and Nanxian were the most different counties compared to others.Seen from spatial pattern,the middle counties of Dongting lake area had higher ecological carrying capacity responsivity than the surrounding area,southwest higher than northeast,under-load area higher than overload area.(4)The deviation and coeffficient ratio of ecological carrying capacity responsivity of17counties Dongting lake area were apparently different from2001to2015,the ecological carrying capacity responsivity of these7counties including Yueyang,Changde,Yiyang,Xiangyin,Yuanjiang,Nanxian and Taojiang were higher than the average value of Dongting lake area and the strength of response were stronger than the other10counties too.These counties were located at the middle of Dongting lake area and where the socio-economic development had higher levels from geographical distribution.(5)Industrial structure characteristics and change,rapid socioeconomic development,promotion of urbanization,resource development and infrastructure construction and so forth,were the evolutionary mechanism which affected spatial-temporal differentiation of ecological carrying capacity.