三江平原典型区水田时空变化及驱动因素分析

Spatial-temporal variations and driving factor analysis of paddy fields in typical regions of Sanjiang Plain

为阐明区域水田时空变化特征及其驱动因素,该文以三江平原典型地区富锦市为例,运用网格单元法和地理探测器模型分析不同时段(1989—2002年、2002—2015年)水田时空变化特征及驱动因素,探讨各驱动因子在水田时空变化中的作用及其相互关系。结果表明:1)1989—2015年富锦市水田扩张明显,新增水田34.99万hm^2,垦区水田化进程早于农区。1989—2002年,东部垦区水田扩张度较高,南部次之;2002—2015年,水田扩张度较高的地区主要分布在西南部农区与北部垦区。2)1989—2002年,水田扩张的主要驱动因素为政策因素和土壤类型,各因子间的交互作用大部分是双因子增强;2002—2015年,自然因素对水田变化影响减弱,水田扩张的主要驱动因素是到河流距离和到铁路距离,各因子间的交互作用大部分是非线性增强,水田化发展到成熟阶段。富锦市水田时空变化差异是由多种驱动因子共同作用的结果,研究结果可为三江平原耕地资源合理利用及水田规模科学管控提供借鉴和参考。

Over the last three decades,paddy fields on the Sanjiang Plain have experienced rapid expansion.It has an important impact on regional food security,ecological environment and socio-economic development.Fujin is a typical area of Sanjiang Plain,with both common agricultural area and reclamation area,and the land use pattern is the epitome of Sanjiang Plain.In our study,used 1 000 m×1 000 m grid cell to scientifically analyze the spatial-temporal variation and driving factors of paddy fields,in Fujin from 1989 to 2002 and from^2002 to 2015.And elevation,slope,soil type,distance to railway,distance to river,distance to town and policy factors were selected as driving factors in this paper.With the help of GeoDetector,we analyzed the role of these seven factors in paddy field change and their relationship.The results indicated that such paddy fields have increased by approximately 349 900 hm^2 from 1989 to 2015,and the paddy field process of reclamation area was earlier than that of common agricultural area.In the early 1990s,in order to adjust the agricultural planting structure,the local government began to encourage farmers to plant paddy rice in large areas.During this period,paddy rice planting area increased rapidly.From 1989 to 2002,the areas with the high proportion of paddy field expansion were mainly located in the reclamation areas in the northeast and southeast of Fujin County,and some other agricultural areas.From^2002 to 2015,the project of cultivated land development and improvement was implemented,and the cultivated land in Fujin reached a high level of agricultural development,and all the conditional areas were basically converted to paddy fields.The areas with higher proportion of paddy field expansion were mainly located in the southwestern common agricultural area and the northern reclamation area of Fujin City.In addition,the main driving factors of paddy field expansion in 1989-2002 were policy factors and soil types.The interaction between these factors was mostly enhanced by two factors.It showed that in the 1990s,under the guidance of the policy of agricultural structure adjustment,Fujin took the lead in reforming the soil types suitable for paddy fields and the land with superior location conditions.As a result,a large number of cultivated land resources with superior development conditions in the eastern reclamation area of Fujin were reclaimed into paddy fields.From^2002 to 2015,the influence of natural factors on paddy field change becomes weaker.The main driving factors of paddy field expansion are the distance from rivers to railways,and the interaction among these factors is mostly non-linear.Natural factors are no longer the key to restrict the development of paddy fields.Driven by market interests,dryland that meets the conditions of paddy field transformation is converted to paddy fields.The spatial difference of paddy field change in Sanjiang Plain is the result of the interaction of various driving factors.The driving factors and their relationships are different in different periods.Geographic detectors can make a more comprehensive analysis of various influencing factors.The results can provide theoretical basis for the protection of cultivated land and the rational utilization of cultivated land resources in Sanjiang Plain.