Dynamics of Land Use and Land Cover Changes in An Arid Piedmont Plain in the Middle Reaches of the Kaxgar River Basin, Xinjiang, China

Tianfeng Wei,Yongjian Ding,Shuhua Yi,Xia Shen,Donghui Shangguan

doi:10.3390/ijgi9020087

Abstract

The Kaxgar River Basin, a key section of the Tarim River Basin, is a typical ecologically fragile region that has undergone rapid changes to its spatial patterns over the preceding few decades. In particular, the expansion of salinized land has posed a severe threat to ecological restoration and economic development. This study monitored the rates and patterns of land use and land cover (LULC) changes in the plain area of Aketao County in the middle reaches of the Kaxgar River Basin. Five Landsat images (captured in 1990, 1998, 2002, 2013, and 2018) were divided into seven LULC types: built-up land, cultivated land, woodland and grassland, light-moderate salinized land, heavy salinized land, water areas, and bare land. Subsequently, their dynamic processes were analyzed. The results revealed that in 1990, the dominant LULCs were cultivated land, woodland and grassland, and bare land. Throughout the study period (from 1990 to 2018), the coverage of built-up land, cultivated land, bare land, water areas, and light-moderate salinized land increased; by contrast, that of the other LULC types decreased. The most marked LULC changes were the expansion of light-moderate salinized land (by 6.2% of the study area) and the shrinkage of woodland and grassland (by 9.4% of the study area). Almost all the analyzed LULC types underwent conversion to other types; such conversion occurred most frequently between 1998 and 2018. The conversions of woodland and grassland into cultivated land and light-moderate salinized land were the most notable phenomena. Another highly evident change was the conversion of heavy salinized land into bare land. These results revealed that the expansion of salinized land and the shrinkage of woodland and grassland in the study area were the most severe environmental changes. Therefore, ecological protection and salinization control are urgently required to enable local economic development while not exceeding the environmental carrying capacity and ensuring the safety of the “green corridor” in the lower reaches of the Kaxgar River Basin.

Highlights

The term land use and land cover (LULC) refers to an interface between natural systems and human systems; the dynamics of this interface are the primary factor influencing environmental change both globally and locally [1–3]
The study area accounts for only a small part of Aketao County, industrial production and oasis agriculture in the county are primarily concentrated in this area
Atn−i where Atn is the area of a specific LULC class at time tn, Atn−i is the area of the same class at time tn − i, and net change in area (NC) is the percentage change in the area of a specific class between times tn and tn − i

Summary

Introduction

The term land use and land cover (LULC) refers to an interface between natural systems and human systems; the dynamics of this interface are the primary factor influencing environmental change both globally and locally [1–3]. The land surface has undergone complex and profound changes because of human activity and climate change [4]. The extent and pace of land surface alterations due to human activity have increased rapidly over the preceding three centuries, in the most recent 30 years [8–10]. Over the preceding few decades, the Tarim River Basin have undergone considerable change in terms of LULC. The trends and processes of LULC changes are fairly consistent in various parts of the Tarim River Basin, the extent and pace of such changes are inconsistent [22,24,25]. Research on LULC on a small spatial scale is crucial for the development of reasonable strategies for environmental protection and the utilization of regional land resources

Methods

Discussion

Conclusion