黄河三角洲区域海水养殖时空演变及其对滩涂湿地资源的影响

Spatio-temporal evolution of mariculture in the Yellow River Delta and its impact on tidal flat wetland resources

为揭示典型区域滩涂湿地海水养殖陆海时空演变特征及其生态影响,本研究结合遥感和海域使用确权数据,采用GIS空间分析方法,获取并分析1985—2020年间黄河三角洲区域池塘养殖、开放式养殖空间演变过程及其对滩涂湿地资源结构和景观格局的影响。结果表明,2010年之前区域陆域池塘养殖规模持续增加,面积最高达到1480.1 km^(2),形成1985—1990年和2000—2005年两个增长高峰;2010年后池塘养殖面积减少,海域开放式养殖快速发展,2019年已达到1601.8 km^(2),2007—2019年增速为84.9 km^(2)·a^(-1);空间增长格局表现为由沿海滩涂湿地不断向离岸海域纵深拓展,陆域养殖池塘质心在1990年后持续向区域西北方向迁移;海水养殖空间增长累计导致1011.7 km^(2)滩涂资源消失,使得滩涂湿地和沼泽湿地的面积比例从期初的53.5%降低为15.2%,区域湿地景观复杂性和异质性增加。研究表明,黄河三角洲区域海水养殖空间增长具有明显的时间波动性,2010年前后黄河三角洲区域海水养殖空间增长的重点从池塘养殖转向海域开放式养殖,陆域池塘养殖空间增长导致沿海滩涂资源大面积减少,促使滩涂不断向外海推进,同时加剧了自然湿地的破碎化,使得区域自然湿地和人工湿地呈现均衡化发展态势。

In this study,to understand the spatio-temporal evolution of mariculture in typical tidal flat wetlands,based on remote sensing and sea area use confirmation data obtained,using GIS spatial analysis methods,we analyzed the space evolution process of pond aquaculture and ocean aquaculture in the Yellow River Delta region from 1985 to 2020.We also investigated its impact on the wetland structure and landscape pattern of tidal flat wetland resources.The results revealed that before 2010,the scale of aquaculture in terrestrial ponds in the region increased,with the maximum area being 1480.1 km^(2);two growth peaks were observed in 1985—1990 and 2000—2005.After 2010,the area of pond aquaculture began to decrease,while open ocean aquaculture developed rapidly that the average annual growth rate was 84.9 km^(2)·a^(-1)from 2007 to 2019,and reached 1601.8 km^(2)in 2019.The spatial distribution of aquaculture showed a growth from the tidal flat wetlands toward the offshore waters in the land-ocean gradient,and the spatial centroid of aquaculture ponds continued to migrate to the northwest of the region after 1990.The cumulative increase in mariculture area led to a reduction in 1011.7 km^(2)of tidal flat resources,which resulted in a decrease in the proportion of area of tidal flat wetlands to that of marsh wetlands from 53.5%at the beginning of the period to 15.2%,and the complexity and heterogeneity of regional wetland landscapes increased.This study concluded that the spatial growth of mariculture in the Yellow River Delta region exhibited obvious temporal fluctuations.Around 2010,the focus of spatial increase shifted from pond aquaculture to open ocean aquaculture.The increase in space for aquaculture in terrestrial ponds has led to a large-scale reduction in coastal tidal flat resources and has promoted continuous outward movement from coastal tidal flats to offshore waters.In addition,it has aggravated the fragmentation of natural wetlands and led to balanced development of human-made and natural wetlands in the Yellow River Delta region.