多尺度生态分析与嵌套在乡村景观规划前期的应用——以长株潭绿心跳马片区为例

Application of Multi-Scale Ecological Analysis and Nesting in the Early Stage of Rural Landscape Planning:A Case Study of Tiaoma Area of Green Heart of Changsha-Zhuzhou-Xiangtan

在反对乡村“大拆大建”的背景和国土空间规划中“三生空间”融合发展的语境下,乡村生态环境、人居环境优化与协调发展已经成为新时代主要探索的课题,其中如何构建多尺度的乡村生态网络从而解决乡村生态规划设计不同层面的问题亟待解决。本文以长株潭绿心跳马片区为例,首先基于遥感数据对乡村空间进行识别;其次依托MSPA、InVEST及Linkage Mapper等模型和工具识取绿心和跳马片区尺度下的生态源地、廊道及生态节点;对于更小尺度的典型片区,进行无人机测绘与现场调研,明确场地水系、植被、生境现状概况;最后叠合三尺度下的生态网络格局,并综合生态嵌套特征对典型片区提出相应的景观优化方向及需求。研究结果表明:研究区内4个共有源地、6条共有廊道、2处重合夹点及6处重合障碍点的保护与修复对于跨尺度生态连通具有重要意义;应积极疏通小尺度上识别存在但大尺度上没有的和潜在的廊道,这有利于源地扩张;对于源地间较长的廊道,应结合更小尺度的生态要素识别,提出低层级尺度的廊道以及生态踏脚石的优化方向。研究不仅可为长株潭绿心的乡村景观规划提供方向,所归纳基于多尺度分析与嵌套的景观规划路径还可为乡村景观在地发展提供参考。

At present,there are frequent exchanges between urban and rural areas,and villages and towns bear the overflow needs of many urban function construction,which leads to more acute contradictions in the function,resources and environment of rural space.Demolition and reconstruction was the mainstream of rural construction in the past few years.However,it has been opposed.In the background of the context of integrated development of“three-life space”in territorial spatial planning,the optimization and coordinated development of rural ecological environment and living environment have become the main issues to be explored in the new era.Building a multi-scale ecological network is the first step to solve the above problems.Based on the three scales of“region-village-district”and the source-corridor method,the ecological elements and networks at each scale are nested,the nesting characteristics are clearly defined,the direction of rural landscape ecological planning is proposed,and an effective multi-scale collaborative optimization path is concluded.As for the scale of green heart of Changsha-Zhuzhou-Xiangtan urban and Tiaoma,the paper identifies the spatial distribution of site three species based on ArcGIS platform,screens important ecological source areas in combination with MSPA and InVEST models,then extracts ecological corridors and ecological nodes based on circuit theory,and conducts nested analysis of ecological structures under the scale of“green heart-Tiaoma”.It was determined that there were four common sources of the two scales,with a total overlapping area of 26.48 km2,accounting for 33.26%of the source area of the green heart and 74.36%of the source area of the Tiaoma area.There are six overlapping corridors between the two scales,with a combined length of 8.67 km,accounting for 19.3%of the corridor length in green heart area and 22.6%of the corridor in Tiaoma area.And the common ecological sources basically overlaps with the ecological sources of Tiaoma area,and the total corridor accounts for 46.84%of the total corridor length of the Tiaoma area within the green heart scale.Common corridors and ecological sources are the focus to realize the connection of different scales.A high proportion of common corridors indicates a high degree of connection between the two scales,which can effectively promote the flow of ecosystems and promote the stability of ecological networks.There are 14 unrecognized corridors in the Tiaoma area under the green heart scale.They and the potential corridors within the green heart scale are areas with great development potential,and their sorting and connection play an important role in the expansion of ecological sources.There were two overlapping pinch points under the two scales,accounting for 11.76%and 10.53%of the pinch points in the green heart and Tiaoma areas respectively.There were six overlapping obstacle points,accounting for 26.09%and 31.58%of the total obstacle points in green heart and Tiaoma area.The overlap degree of ecological nodes across scales is not high,indicating that in future ecological optimization,attention should be paid to the transfer of ecological processes across scales to promote the flow of matter and energy.Moreover,the protection of ecological pinch points and the restoration of obstacle points play an important role in the construction of the whole ecological network on the green heart and even on a larger scale.For the protection and restoration of these two types of key nodes,the focus of ecological construction is clearly defined to achieve the goal of efficient and sustainable ecological services.For smaller typical areas,UAV mapping and field investigation methods commonly used in planning and design were used to obtain the details of habitat type and distribution,vegetation type and structure,and water resources distribution,etc.In combination with large-scale ecological structure,smallscale three-dimension data,and vegetation status of field investigation,four feasible points of ecological stepping stones were preset,and corridors were identified again.The result shows that seven corridors have been added.It shows that small-scale ecological stepping stones can effectively increase the number of ecological corridors and ecological pinch points,and promote the stable development of ecological network.This study proposes the following ecological planning paths for rural landscapes:firstly,macro ecological network as a base to guarantee the stability of ecological structure;secondly,ecological network nestingas a basis toprotect overlapping or optimise missing areas;thirdly,micro-scale upward thrusting counterfactuals to improve regional ecological network;fourthly,multi-scalar ecological analysis linkage to stabilise the structure of rural landscapes.This study not only provides a direction for rural landscape planning in the green heart of Changsha-Zhuzhou-Xiangtan urban but also summarises a landscape planning approach based on multi-scale analysis and nesting can provide references for the development of rural landscape.