Assessing the large-scale plant–water relations in  the humid, subtropical Pearl River basin of China

Abstract. Vegetation interacts closely with water resources. Conventional field studies of plant–water relations are fundamental for understanding the mechanisms of how plants alter and adapt to environmental changes, while large-scale studies can be more practical for regional land use and water management towards mitigating climate change impacts. In this study, we investigated the changes in the total water storage (TWS), aridity index (AI) and vegetation greenness, productivity, and their interactions in the Pearl River basin since April 2002. Results show an overall increasing trend of vegetation greenness and productivity, especially in the middle reaches where TWS also increased. This region dominated by croplands was identified as the hot spot for changes and interactions between water and vegetation in the basin. Vegetation was more strongly affected by TWS than precipitation (P) at both the annual and monthly scales. Further examination showed that the influence of TWS on vegetation in dry years was stronger than wet years, while the impact of P was stronger in wet years than dry years; moreover, vegetation productivity responded slower but stronger to atmospheric dryness in dry years than wet years. The lag effects resulted in nonlinearity between water and vegetation dynamics. This study implies that vegetation in the basin uses rainwater prior to water storage until the soil becomes dry, and their dynamics indicate that vegetation development is subject to water availability, and that vegetation is not dominant in reducing water availability.

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Assessing the large-scale plant-water relations using remote sensing products in the humid subtropical Pearl River Basin in south China

10.5194/hess-2020-242 ◽

2020 ◽

Author(s):

Hailong Wang ◽

Kai Duan ◽

Bingjun Liu ◽

Xiaohong Chen

Keyword(s):

River Basin ◽

Water Relations ◽

Large Scale ◽

Environmental Changes ◽

Water Storage ◽

Pearl River ◽

Plant Water Relations ◽

Plant Water ◽

Pearl River Basin ◽

Vegetation Greenness

Abstract. Vegetation interact closely with water resources. Conventional studies of plant-water relations at the field scale are fundamental for understanding the mechanisms of how plants alter and adapt to environmental changes, while large-scale studies can be more practical for regional land use and water management towards mitigating climate change impacts. In this study, we investigated the changes in total water storage (TWS), aridity index (AI) and vegetation greenness, productivity and their interactions in the Pearl River Basin since 2002. Results show overall increase of TWS especially in the middle reaches where vegetation greenness and productivity also increased. This region dominated by croplands was identified as the hotspot for changes and interactions between water and vegetation in the basin. Vegetation was more strongly affected by TWS than precipitation (P) at both the annual and monthly scales. Further examination showed that the influence of P on vegetation in wet years was stronger than dry years, while the TWS impact was stronger in dry years than wet years; moreover, greenness responded faster and productivity slower to dryness changes in dry years than wet years. The lag effects resulted in nonlinearity between water and vegetation. This study implies that vegetation in the basin uses rainwater prior to water storage until it gets dry, and the degree of water restriction on vegetation was higher than that of water consumption by vegetation even in this rain-abundant region.

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Drought and flood monitoring and connection to climate variability in Pearl River Basin, Southern China using GRACE data

10.5194/egusphere-egu2020-4600 ◽

2020 ◽

Author(s):

Zhiyong Huang ◽

Jiu Jimmy Jiao ◽

Xin Luo ◽

Yun Pan

Keyword(s):

Climate Variability ◽

River Basin ◽

Water Storage ◽

Economic Losses ◽

Pearl River ◽

Climate Indices ◽

Joint Control ◽

Severe Drought ◽

Pearl River Basin ◽

Drought And Flood

<p>Drought and flood occur frequently in the Pearl River Basin (PRB), leading to severe damage and economic losses. For better basin-scale water resources management, this study investigates drought and flood&#160; and connection to climate variability in PRB using the total terrestrial water storage (TWS) data from the Gravity Recovery And Climate Experiment (GRACE) satellites. Water storage deficit (WSD) and WSD index (WSDI) are used to characterize drought in PRB. A total of nine drought events are identified during the study period 2003-2014. The period 2003-2006 experienced the most serious drought with a duration of 34 months and WSD (or total severity) of over 1200 mm. WSDI is comparable to self-calibarated Palmer Drought Severity Index (scPDSI) in timing with a correlation of 0.80. Overall, WSDI has higher magnitude than the scPDSI throughout the study period. Flood is characterized by a flood potential index (FPI) which is calculated using TWS anomaly and precipitation. The FPI peaked in June 2008 when the flood was the most serious with the largest rainfall and discharge. Strong correlation is found between FPI and rainfall/discharge in all the four seasons indicating the joint control of flood by rainfall and discharge. This study analyzes the relationship between drought, flood and four climate indices (i.e. El Ni&#241;o&#8211;Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), Indian Ocean Dipole (IOD) and North Atlantic Oscillation (NAO)). Different drought events were related to different climate indices. The severe drought during 2003-2005 was triggered by a warm PDO phase. The 2009-2010 drought was jointly influenced by the warm phase of the three indices: ENSO (i.e. El Ni&#241;o), IOD and PDO. The severe drought in 2011 was related to the cool phase of both PDO and ENSO (i.e. La Nina). The flood in 2008 was mainly induced by the cool PDO phase with the combined effect from IOD and NAO.</p>

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Influence of the root endophytePiriformospora indicaon the plant water relations, gas exchange and growth ofChenopodium quinoaat limited water availability

Journal of Agronomy and Crop Science ◽

10.1111/jac.12199 ◽

2017 ◽

Vol 203 (5) ◽

pp. 373-384 ◽

Cited By ~ 11

Author(s):

S. Hussin ◽

W. Khalifa ◽

N. Geissler ◽

H.-W. Koyro

Keyword(s):

Gas Exchange ◽

Water Relations ◽

Water Availability ◽

Plant Water Relations ◽

Plant Water

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Terrestrial water storage changes over the Pearl River Basin from GRACE and connections with Pacific climate variability

Geodesy and Geodynamics ◽

10.1016/j.geog.2016.04.008 ◽

2016 ◽

Vol 7 (3) ◽

pp. 171-179 ◽

Cited By ~ 13

Author(s):

Zhicai Luo ◽

Chaolong Yao ◽

Qiong Li ◽

Zhengkai Huang

Keyword(s):

Climate Variability ◽

River Basin ◽

Water Storage ◽

Pearl River ◽

Terrestrial Water Storage ◽

Pearl River Basin ◽

Terrestrial Water ◽

The Pearl River ◽

Pacific Climate Variability ◽

The Pearl River Basin

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Drought and flood characterization and connection to climate variability in Pearl River Basin, Southern China using long-term GRACE and reanalysis data

Journal of Climate ◽

10.1175/jcli-d-20-0332.1 ◽

2020 ◽

pp. 1-63

Author(s):

Zhiyong Huang ◽

Jiu Jimmy Jiao ◽

Xin Luo ◽

Yun Pan ◽

Taoyong Jin

Keyword(s):

River Basin ◽

Southern Oscillation ◽

Southern China ◽

Water Storage ◽

Reanalysis Data ◽

Pearl River ◽

Drought Severity ◽

Pearl River Basin ◽

Drought And Flood

Abstract:This study investigates drought and flood in the Pearl River Basin using long-term terrestrial water storage anomaly (TWSA) data from the mascon solutions based on the Gravity Recovery And Climate Experiment (GRACE) satellite measurements (2002-2019) and the reanalysis data (1980-2019). To characterize drought, water storage deficit (WSD) and WSD index are used. The GRACE mascon solutions capture two major drought periods (2003-2006, 2009-2012) with similar onsets and endings over the last two decades, but show considerable differences in quantifying total drought severity. The reanalysis data significantly overestimates drought duration and severity during 1980-2000 owing to underestimated TWSA forced by incorrect precipitation data. Flood is monitored using a flood potential index (FPI) calculated using TWSA and precipitation. The GRACE mascon solutions identify four major flood events (FPI > 0.7) in Aug. 2002, Jun. 2008, and Jul. in 2006 and 2019. The flood potential is influenced by the precipitation in both the current and antecedent months. The spatial variability of the most recent flood in 2008 is analyzed, showing a similar spatial pattern between FPI and precipitation at monthly and sub-basin scales. The precipitation/TWSA in the PRB is mainly influenced by El Niño–Southern Oscillation (ENSO). TWSA exhibits a lag of 1-3 months responding to ENSO during 1980-2019. This study emphasizes the significance of removing water storage changes in large reservoirs before long-term drought, flood characterization and teleconnection analysis. This study highlights the intensifying drought conditions in the PRB over the last four decades under the circumstances of more frequent human activities (reservoir construction and regulation) and the complex changing climate system.

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