Spatiotemporal changes of orchards in the ancient canal of the Yellow River using Landsat data

Abstract

As an important part of the Yellow River Basin, the ancient canal of the Yellow River plays a great role in promoting ecological protection and high-quality development in the Yellow River Basin. There is a need to explore the distribution of the available resources to optimally manage and utilize them more effectively. By analyzing multi-temporal characteristic of the remote sensing images, the spatial temporal distribution characteristics of orchards in the ancient canal of Yellow River were investigated. Time series of orchards were derived from the Landsat images over a nearly 30-year period at approximately 5-year intervals since 1990. And the spatial distribution characteristics were qualified basing on the spatial overlay analysis methods. The results show that from 1990 to 2020, the orchard area in the ancient canal of the Yellow River increased rapidly in the early, then slowed down after 2000; the area of orchards in 2020 was about 1268.30 km2. Dangshan County, Feng County and Xiao County were the major areas planting orchards; 86.84 % of the orchards distributed in flat terrain with an elevation of 21–60 m, 88.50 % distributing on a slope of less than 4° and 91.12 % of the orchards distributed within the distance of more than 280 km from the coastline; Moran's I index of orchard planting density was greater than 0 for all four spatial scales and was increasing when downscaling, which showed significant spatial positive correlation. These findings provide helpful information for the research in promoting ecological protection and high-quality development of the ancient canal of the Yellow River Basin.