Effect of Climate Variability on Green and Blue Water Resources in a Temperate Monsoon Watershed, Northeastern China

Junchao Jiang,Yuechi Han,Leting Lyu,Caizhi Sun

doi:10.3390/su13042193

Abstract

Over 80% of global grain production relies on green water, water from precipitation that is stored in unsaturated soil and supports plant growth. Blue water, precipitation that turns into surface water and groundwater, is also a vital surface water resource, and it can be directly utilized. The Tanghe River Basin is a typical temperate continental monsoon watershed in Northern China where residents and crops rely on blue and green water resources. In this study, the spatiotemporal distributions of water resources in the Tanghe River Basin were simulated using the soil and water assessment tool (SWAT) model for the period between 1970 and 2015. The results demonstrate that the Nash–Sutcliffe efficiency and coefficient of determination were both higher than 0.64 during the calibration and validation periods at all hydrological stations, indicating high simulation accuracy. The average annual water resources of the Tanghe River Basin are 759.37 mm. Green and blue water account for 68% and 32% of the total water resources, respectively. The study period was divided into the reference period (1970–1976) and the variation period (1977–2015), to explore the impact of climate change on the green and blue water resources of the Tanghe River Basin water resources. Compared with the reference period, the average green and blue water resources in the variation period decreased by 78.48 and 35.94 mm/year, and their rate changes were −13.45% and −13.17%, respectively. The water resource relative change rates were high in the south and low in the north, and they were predominantly affected by precipitation. This study improves our understanding of the hydrological processes as well as the availability of blue and green water in the study region, and can prove beneficial in promoting the sustainable development of small basins and the integrated watershed management in areas with similar climatic conditions.

Highlights

Introduction iationsWater is vital to people and ecosystems
Considerable attention has been paid to blue water resources, which are generated by surface and underground runoff
Green water resources refer to the water from precipitation that is stored in unsaturated soil and supports plant growth

Summary

Introduction

As the global economy and population have grown, human demand for water resources has increased, affecting the health of the global ecosystem [1,2,3,4]. Due to this ongoing competition between humans and the environment for water resources, the availability of water resources must be comprehensively assessed to deepen our understanding of renewable water sources and realize sustainable, effective, and fair water resource management [5,6]. Green water resources have been gaining attention in recent years.

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Methods

Results

Discussion

Conclusion