基于生态位模型的岷江上游典型县域乡村聚落用地适宜性评价

Land suitability evaluation using niche model for rural settlements in typical county in the upper reaches of Minjiang River

乡村聚落用地适宜性研究不仅有利于揭示人类活动与生态环境、社会经济之间的匹配程度,亦能为乡村聚落重构及国土空间优化提供科学依据。该研究基于乡村地理学、景观生态学及生态位理论方法,以岷江上游典型县域理县为研究区,采用遥感影像、社会经济统计、土地利用现状等多源数据,通过景观格局分析、数理统计分析、GIS空间分析等技术手段,首先判识了理县乡村聚落用地适宜性研究的最佳空间尺度,然后借鉴生态位适宜度测算模型,对理县乡村聚落用地适宜性进行评价。结果表明:1)根据8个乡村聚落景观指数对20种乡村聚落空间粒度的响应变化情况,综合8个景观指数的第一尺度域判识得到理县乡村聚落景观格局及适宜性研究的最佳空间尺度为60 m;2)在60 m最佳空间尺度下,利用GIS空间叠加分析得到理县乡村聚落适宜性土地面积占县域国土面积的4.58%,主要集中分布于东部、东北部乡镇及杂谷脑河下游、317国道沿线;3)理县乡村聚落低度适宜区主要位于水源保护区、生态保护区及地质灾害多发区,不适于人类长期生存发展;中度适宜区在自然资源、区位等方面具有相对优势,特色产业突出,具备现代农业发展潜力;高度适宜区在区位、经济、自然与文化资源等方面具有明显优势,乡村发展功能较齐全,应作为乡村人口和产业的主要聚集区;中、高度适宜区是理县乡村振兴战略的主要支撑空间。

Land suitability for rural settlements can greatly contribute to revealing the matching between human activities and the ecological environment,as well as social economy.Taking Li County in the uppers reaches of the Minjiang River as the study area;a systematic evaluation of land suitability was conducted using rural geography,landscape ecology,and niche model.A GIS spatial analysis was also performed on the landscape pattern using remote sensing images,socioeconomic statistics,and land use multi-source data,particularly considering the geographical scale of rural settlements and the degree of suitability between humans and natural environmental conditions.Firstly,the optimal scale was identified for land suitability of rural settlements in the study area.Secondly,the representative indicators were selected to construct an evaluation index system,according to the status quo of the region.Finally,a niche suitability model was used to evaluate the land suitability for the rural settlements.The results were as following:1)The optimal scale was supposed to be 60 m in the study area,where the suitable scale ranging from 50-60 m in the first scale domain of landscape indices.The changes of landscape indexes were also obtained in the 8 rural settlements response to 20 rural settlement scales.2)Each evaluation index was quantified to obtain the current restrictive conditions at the optimal scale of 60 m,such as forbidden construction area,water source protection area,and nature reserve.GIS spatial overlay function was also utilized to evaluate the land suitability of rural settlements.The suitable land area for rural settlement only accounted for 4.58%of the whole area.Specifically,the area of low suitable zone accounted for 0.52%,whereas,the moderate and highly suitable areas accounted for 4.06%,mainly distributing in the eastern and northeastern towns and the lower reaches of the Zagunao River Basin,along the National Highway 317.3)The low unsuitable area was 4116.03 km^(2)harsh for sustainable survival and development,mainly located in the water source and ecological protection areas prone to geological disasters.The moderately suitable areas presented outstanding characteristic industries and great potential to develop modern agriculture,in terms of natural resources and local conditions.The highly suitable areas behaved obvious advantages in terms of location,economy,natural and cultural resource conditions,indicating a relatively complete rural function and high level of economic development.It was supposed to be the main gathering area of rural population and industries.The moderate and highly suitable areas gained relatively distinct potentials for economic and social development.Therefore,the main space for rural revitalization can be concentrated on the moderate and highly suitable areas of rural settlement in the future.Additionally,it should be properly considered to explore the impact of industrial and commercial enterprises,public service facilities,and other land-use types on the land suitability of rural settlement against the requirements of rural revitalization strategy.This finding can provide a sound scientific basis to reconstruct the rural settlements for the optimization of territory space.