Use of a Satellite-Based Aridity Index to Monitor Decreased Soil Water Content and Grass Growth in Grasslands of North-East Asia

Reiji Kimura,Masao Moriyama

doi:10.3390/rs12213556

Reiji Kimura, Masao Moriyama

Open Access

https://doi.org/10.3390/rs12213556

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Journal: Remote sensing	Publication Date: Oct 30, 2020
Citations: 6	License type: CC BY 4.0

Affiliation: Tottori University, Nagasaki University

Abstract

Numerous simulation studies of the effect of global warming on arid regions have indicated that increases in temperature and decreases in precipitation will trigger water shortages, drought, and further aridification. In north-east Asia, especially China and Mongolia, the area of degraded land has increased since 2000. Land use in arid regions is mainly natural grasslands for grazing. Growth in this land use is limited by the precipitation amount and intensity. To develop sustainable management of grasslands, it is essential to examine the relationship between water consumption and the growth patterns of the grasses. This study examined the applicability of a satellite-based aridity index (SbAI) as a way to measure the water consumption and growth of grasslands in China and Mongolia. The effective cumulative reciprocal SbAI was strongly correlated with the cumulative decreased soil water content in the root zone and changes in the normalized difference vegetation index in Shenmu, China. Application of the effective cumulative reciprocal SbAI to grasslands in Mongolia and in north-east Asia revealed a high correlation between the effective cumulative reciprocal SbAI and changes in the normalized difference vegetation index (NDVI). The effective cumulative reciprocal SbAI might be suitable for the detection of water consumption and growth in grasslands from satellite data alone.

Highlights

Drylands are highly vulnerable to climate change
Is the cumulative reciprocal of SbAI (CRSbAI) related to grass growth and represented by ∆normalized difference vegetation index (NDVI)?
The CRSbAI was significantly correlated with cumulative decreased SWC (CdSWC) in Shenmu

Summary

Introduction

Drylands are highly vulnerable to climate change. In particular, increasing global warming can increase temperatures and decrease precipitation in drylands at high latitudes [1,2,3], and their effects on ecosystems can increase [4,5]. The coverage of natural grasslands has a profound effect on the occurrence of dust outbreaks [11,12,13], which bring damage to agriculture, stock grazing, and human and animal health, locally and in neighboring regions such as Japan and Korea [14,15,16]. An early warning and monitoring system based on numerical models, remote sensing, and weather forecasts is urgently needed to guard human well-being and to control natural hazards in those regions. Such models must take into account the growth of vegetation (in this case, grasslands)

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