from 1977 to 2021
Biqing Tian1 Gao Peng12 Mu
Xingmin12 Zhao Guangju12
1 Institute of Soil and Water Conservation, Northwest
A&F University, Yangling 712100, Shaanxi, China
2 Institute of Soil and Water Conservation, Chinese
Academy of Science and Ministry of Water Resources, Yangling 712100,
Shaanxi, China
Corresponding Author : Institute of Soil and Water Conservation,
Northwest A&F University, Yangling 712100, Shaanxi, China
E-mail address:gaopeng@ms.iswc.ac.cn(Gao
Peng)
Abstract:
Lake has an essential role in
Earth’s hydrologic cycle. The changing of lake water areas shows the
ecological health of lakes by instant feedback. Remote sensing
monitoring reflects the changes in lake water intuitively. This study,
based on remote sensing, combined with the hydrological data,
meteorological data, and land use survey, investigated the Poyang lake
water area changes from 1977 to 2021. Examined the relationship between
the lake water area and the impact factor and analyzed the influence of
river lake interaction on the lake water area. The results showed that:
(1) From 1977 to 2017, the water area of Poyang Lake in flood season
(June to September) and dry season (November to Next February) showed a
significant downward trend by years. (2) In flood season, runoff,
sediment, and precipitation significantly correlate with a water area.
In the dry season, sediment significantly correlated with a water area.
(3) The Three Gorges Dam water impoundment at the upper reaches of the
Yangtze River weakened and eliminated the block and reverse flow of the
Yangtze River on Poyang lake, causing the water area to decrease in
advance at the end of the flood season after 2005, and decrease rapidly
in the dry season after 2003. (4)
The change in lakebed elevation
caused by sedimentation and human activities also accelerated the
shrinkage of the water area. Results demonstrated that the variation of
river lake interaction is the primary cause of the Poyang Lake water
area’s dramatic change.
Keywords: Poyang Lake remote sensing image, climate change,
human influence,
river
lake interaction
1.
INTRODUCTION
Lake
is the natural reservoir of water formed by stagnant water in the
depressions of the Earth and has a broad expanse of water and slow
current, which is an essential role in Earth’s hydrologic cycle (Qi et
al. 2020). Lake provides water to the surrounding area and influences
river flow regulation and groundwater levels. The ecosystem formed by
the lake also provides an essential living habitat for the creature. The
stable state of the lake is essential for the overall ecological
balance.(Vaheddoost and Aksoy 2018; Rosenberry et al. 2015; Y. Li et al.
2017). In recent years, the average global temperature has climbed
sharply, accompanied by the influence of human activities, which has
changed the major lakes in the world to different degrees. The Changes
in the lake have led to cascading changes in the surrounding
environment. Some scholars use big data to analyze the characteristics
of global lake changes and confirm that the changes in lake area affect
the overlying atmosphere and lake-air interactions, thus causing the
changes in lake temperatures(Huang et al. 2022). In ecologically
sensitive areas, these cascading changes are more prominent. Lakes on
the Qinghai-Tibet Plateau (QTP) have notably expanded over the past 20
years, which degrades the permafrost occurring beneath the bottom and
surrounding the lake. That leads to the release of organic carbon into
lakes, affecting the water environment, and further discharged into the
atmosphere affecting regional climate changes(G. Zhang et al. 2020; Y.
Zhang et al. 2022). Hence, Mastering Lake Changes is significant for
controlling the regional ecological balance.
Lake
water areas will visually show the changes in the lake morphology.
Variations of lake morphology are affected by many factors, such as the
runoff exchange, climate, or topography of the lake basin. Keeping a
grip on changes in the lake morphology will help us better understand
the actual state of the lake. In particular, the large lakes are more
complex and variable. Therefore, comprehensive, actual, and detailed
research will master the hydrological processes of large lakes. Remote
sensing obtains lake water areas easily, quickly, and dynamically
monitors the changes in the lake water areas, which is an excellent way
to master the actual change characteristics of the lake.
Some scholars combining multiple
remote sensing data retrieve Lake Chad, Africa’s second-largest Shallow
endorheic Lake, available surface water area series. They showed that
from the 1960s to 2020, Lake Chad experienced a change from shrinking to
gradually expanding. It truthfully reflects the response process of the
lake to climate and anthropogenic events in the basin. (Mahmood and Jia
2019; H. Li et al. 2021).
Lake
Poyang, the largest freshwater fluvial lake in China, is located in
China’s most important economic development region-The Middle-lower
Yangtze Plain. (Fig.1) As the largest lake connected to the Yangtze
River, Poyang Lake is an alternately inflow-outflow lake with complex
hydrological relationships and unique rhythmic changes. Poyang Lake
appears as a lake landscape in flood season and a river landscape in the
dry season. These unique lake water area changes in the Poyang Lake were
jointly affected by the Poyang basin and Yangtze River runoff, which has
important implications. (F. Li et al. 2014). After the 21st century,
Hydrological monitoring finds the interval between the flood and dry
season is getting shorter; seasonal drought events aggravate; meanwhile,
floods often occur during the flood season (Wu and Zhan 2020; Z. Zhang
et al. 2015). Some scholars suggest that building a dam at the estuary
of Poyang Lake and artificially regulating the interaction between the
Yangtze River and Poyang Lake will effectively avoid disaster events.
Therefore, having a comprehensive grasp of the hydrologic process of
Poyang Lake is necessary.
This
study uses 40 years of Poyang lake historical images to extract the lake
water area data of flood and dry seasons and combine it with the basin
hydrology, meteorology, and land use data. Use statistical methods to
analyze the influence process of climate change and human activities on
the
hydrological
relationship of Poyang Lake. Moreover, providing the theoretical basis
for Poyang Lake water resources regulation.