Management of sustainable ecological water levels of endorheic salt lakes in the Inner Mongolian Plateau of China based on <scp>eco‐hydrological</scp> processes

Zhang

et al. 2022

IJERPH

Hydrological processes play a key role in ecosystem stability in arid regions. The operation of water conservancy projects leads to changes in the natural hydrological processes, thereby damaging the ecosystem balance. Ecological regulation is an effective non-engineering measure to relieve the influence of water conservancy projects on ecosystems. However, there are still some problems, such as an insufficient understanding of hydraulic processes and difficulty evaluating the application effects. In this study, the theory of ecological reservoir regulation coupled with hydrological and ecological processes was examined and ecological protection and remediation were investigated using the valley forests and grasslands in the Irtysh River Basin as a case study. The results demonstrated that (1) to meet the demand of the hydrological processes in the valley forests and grasslands, in terms of ecological regulation, the peak flow and flood peak duration of the reservoir, named 635, in the Irtysh River Basin should be 1000 m3 s−1 and 168 h, respectively, and the total water volume of ecological regulation should be 605 million m³. Ecological regulation can guarantee that the floodplain range reaches 64.3% of the core area of ecological regulation and the inundation duration in most areas is between 4–8 d; (2) an insufficient ecological water supply would seriously affect the inundation effects. The inundation areas were reduced by 2.8, 5.1, 10.3, and 19.3%, respectively, under the four insufficient ecological water supply conditions (528, 482, 398, and 301 million m3), and the inundation duration showed a general decreasing trend; (3) the construction of ecological sluices and the optimization of the reservoir regulation rules could effectively relieve the influences of an insufficient ecological water supply. At water supply volumes of 528 and 482 million m3, the regulation rules should assign priority to the flood peak flow; at water supply volumes of 398 and 301 million m3, the regulation rules should assign priority to the flood peak duration. Consequently, this study provides a reference for ecological protection in arid regions and the optimization of ecological regulation theories.

Section: Discussionmentioning

confidence: 99%

Reservoir Regulation for Ecological Protection and Remediation: A Case Study of the Irtysh River Basin, China

Zhang

et al. 2022

IJERPH

“…The annual surface inflow of the Dalinor Lake watershed was 40 million m 3 in the past decade. Groundwater and spring recharge the lake from the south, with a relatively large flow of approximately 115 million m 3 annually (Zhen et al, 2014) [25].…”

Section: Study Areamentioning

confidence: 99%

“…The Dalinor Lake watershed has the characteristics of a special physical geographic environment, a complex geological structure, and a fragile ecosystem, and is closely related to groundwater (GW) [24]. The surface area of Dalinor Lake has shown a shrinking trend given the lack of a significant decrease in PRE in recent years, which has attracted widespread attention [25,26]. The lake surface area changes are mainly caused by the water budget status at the watershed scale in the changing environment.…”

Section: Introductionmentioning

confidence: 99%

Water Deficit Caused by Land Use Changes and Its Implications on the Ecological Protection of the Endorheic Dalinor Lake Watershed in Inner Mongolia, China

Zheng

et al. 2023

Water

Dalinor Lake, the second-largest endorheic salt lake in Inner Mongolia, has shown a shrinking trend given the lack of a significant decrease in precipitation (PRE). Based on high-spatial-resolution datasets, we employed a linear regression model, Theil–Sen median trend analysis, the Mann–Kendall test, and a land use transfer matrix to identify the spatio-temporal distribution and trends of PRE and actual evapotranspiration (AET) at the watershed scale during 2001–2019; then, the water deficit (WD) caused by land use changes in different surface lithology zones was analyzed. The results showed that the annual PRE and WD of the Dalinor Lake watershed showed insignificant upward trends, while the annual AET showed a significant upward trend. Spatially, about 89% of the watershed showed a significant upward trend for AET, while 12% showed a weak significant upward trend for PRE. The WDs of the aeolian sand zone and the sand, gravel, and silt accumulation zone were most heavily affected by the new increased land use from 2001 to 2019, accounting for 43.14% and 25.56% of the total WD of the watershed, respectively. Specifically, the WD of the aeolian sand zone caused by the new increased grassland and farmland in 2019 accounted for 41.92% and 18.52% of the total WD of the zone, respectively. The WD of the sand, gravel, and silt accumulation zone caused by the new increased grassland and farmland in 2019 accounted for 37.07% and 35.59% of the total WD of the zone, respectively. The WD caused by the new increased land use was increased by 7.78 million m3 in 2019 compared with the corresponding land use type in 2001, which would decrease the water yield. It is necessary to strengthen the protection of regional forest ecosystems in the granite and terrigenous clastic rock zone; standardize pasture management and reduce farmland reclamation in the sand, gravel, and silt accumulation zone, the aeolian sand zone, and the basalt platform zone; and reduce unnecessary impervious land construction in the aeolian sand zone.

“…The balance between human and ecosystem needs is an important task for e‐flow management. Xing et al (2021) pointed out that previous e‐flow studies mainly focused on determining e‐flow requirements, while much less attention was paid to a more important problem—how such e‐flows could be reached under changed watershed hydrological processes. They further proposed to conduct a basin water balance analysis based on a hydrological process analysis of the watershed.…”

Section: Environmental Flow Managementmentioning

confidence: 99%

Environmental flow mechanism and management for river–lake‐marsh systems

Yin

Peng

Zhou

2022

Hydrological Processes

Sustaining environmental flows (e‐flows) is a basic requirement for river, lake and marsh management. Rivers, lakes and marshes have close hydrological and ecological connections in a river basin, and form river–lake‐marsh systems. Any measure that is designed to address problems related to only one of these water bodies in isolation of the others may lead to unexpected, undesired and sub‐optimal consequences for one or all of the water bodies. Papers were selected for this special issue ‘Environmental Flow Mechanism and Management for River‐Lake‐Marsh Systems’ to illustrate recent advances in revealing new mechanisms connecting hydrological and environmental/ecological processes, developing new methods for e‐flow calculation, and establishing new measures for e‐flow management.