干热河谷区生态系统服务价值时空变化分析—以凉山州宁南县为例

Spatial-temporal Variation Analysis of Ecosystem Service Value in Dry-hot Valley: A Case Study in Ningnan County, Liangshan Prefecture*

关键词:  土地利用  生态系统服务价值  时空变化  空间自相关  热点分析

Key words:  land use  ecosystem services value  spatial and temporal changes  spatial autocorrelation  hotspot analysis

摘要:

【目的】探明生态系统服务价值的时空变化规律，有利于土地规划和资源管理等决策的制定。【方法】文章基于宁南县2000—2020年5期土地利用数据，以0.5 km×0.5 km的格网为评价单元，采用ArcGIS 10.8软件和当量因子法，结合空间统计分析方法，探究其生态系统服务价值（Ecosystem Service Value，ESV）的时空变化特征。【结果】（1）宁南县土地利用类型以林地为主，占总面积的60%以上；其次为耕地，占比约为30%；草地和建设用地的面积有着较快的年际变化，水域和未利用地则基本保持稳定。（2）ESV总价值量除在2010—2015年有略微回升，其他阶段均下降，其中草地转化造成的损失高达98.66%，是生态系统服务总价值减少的根本原因；水资源供给功能的ESV为负值且持续减少，水域面积狭小、季节性缺水严重，这是限制宁南县区域发展的根本原因。（3）研究区ESV总体水平较高。在空间分布上，ESV存在东翼高于西翼的分异特征，且ESV高值区主要呈条带状（沿西北—东南走向）横跨整个县域；在时间序列上，高值区逐渐萎缩、低值区逐渐扩展。（4）宁南县ESV增值热点和损失冷点分布较为分散。从研究期整体来看，ESV增值热点主要分布在低海拔的乡镇交界处和主要农产区的局部区域；而损失冷点主要分布在松新镇、幸福镇、俱乐镇、石梨镇和西瑶镇等乡镇。【结论】应着重加强生态保护重点领域的监管，进行有效治理消除极端冷点，保障国土空间的生态安全。

Abstract:

[Purpose] Exploring the spatiotemporal variation of ecosystem service value is conducive to the decision-making of land planning and resource management. [Method] Based on the 5-period land use data of Ningnan County from 2000 to 2020, with a 0.5 km×0.5 km grid as the evaluation unit, this paper used ArcGIS 10.8 software and equivalent factor method, combined with spatial statistical analysis method, to explore the temporal and spatial change characteristics of the ecosystem service value. [Result] (1) The land use types in Ningnan County are predominantly forest land, accounting for over 60% of the total area; followed by arable land, which takes up about 30%; the areas of grassland and construction land undergo rapid interannual changes, while the areas of water bodies and unused land remain relatively stable. (2) The total value of ESV showed a slight rebound between 2010 and 2015, but declined in all other periods. Among them, the loss caused by the conversion of grasslands to other land uses was as high as 98.66%, which is the fundamental reason for the reduction in the total value of ecosystem services. The ESV for water supply function is negative and continues to decrease. The limited water area and severe seasonal water scarcity are the fundamental reasons restricting the development of Ningnan County. (3) The overall level of ESV in the study area is relatively high. In terms of spatial distribution, ESV has differentiation characteristics that the east wing is higher than the west wing, and the ESV high-value areas are mainly in strips (along the northwest-southeast direction) across the entire county; in the time series, the high-value area gradually shrinks, and the low-value area gradually expands. (4) The distribution of ESV hot spots and cold spots in Ningnan County is scattered. From the overall perspective of the study period, ESV hotspots are mainly distributed in low-altitude township junctions and local areas of major agricultural production areas; the cold spots are mainly distributed in towns such as Songxin Town, Xingfu Town, Jule Town, Shili Town, and Xiyao Town. [Conclusion] Emphasis should be placed on strengthening the supervision of key areas in ecological protection, effectively managing to eliminate extreme cold spots and ensuring the ecological security of the national territory's spatial domain.