Khanka Research Articles

COMPOSITION, MICROSTRUCTURE AND PROPERTIES OF QUATERNARY CLAYS OF THE PRIKHANKAYSKAYA DEPRESSION (PRIMORYE)

The article considers the study results of composition, microstructure and physical-chemical properties of the quaternary clays of the Prikhankayskaya depression in district of the lake Khanka (Primorye) on the example of air-dry samples of geological borehole 45-b in the range of 18–62 m. The objective of research was to obtain new information about the properties of widespread clay sediments in this area using geologic-lithological materials and laboratory data. The schematic geologic-lithological column was composed with the selection of various zones in the quaternary clay sediments section and the border with sediments of the Neogene System. The methodological scheme of laboratory studies of clays was proposed. This scheme includes the determination of chemical and microelement composition, clay minerals, contents of carbonates, water-soluble salts, mobile forms of aluminum oxide, humus, as well as microstructural parameters (method «Microstructure») and some physical-chemical properties. Geochemical coefficients (Kz, CIA, CIW, ICV) determined the degree of chemical maturity of clays and confirmed the results of palynological studies reflecting the fluctuations of the climatic conditions of their formation. For the group of toxic microelements for the first time the special indicator (Zc) was calculated. Which was the criterion for a degree of pollution of the clay sediments section. Clay minerals of the quaternary clays are represented by smectite and hydromica. The clear change in the mineral association was found when passing to the Neogene sediments (kaolinite prevails). The method «Microstructure» revealed the aggregated type of clays microstructure, the domination of the particles of coarse dust fraction among the primary (free) particles and the almost complete absence of the particles of fine-grained sand fraction, the participation of various fractions in the composition of aggregates. The variants of the formation of certain types of aggregates (on sizes) in the fluviolacustrine «khankayskiy» clays are presented. Solid part density, water resistance (soaking time), sedimentation volume, plasticity, relative swelling (samples-pastes) were determined using standard methods for clays. By special methods, the cation exchange capacity was measured and the calculated values of the plasticity index were obtained from forecasting formulas using the yield limit. The proposed methodological scheme of complex laboratory studies of clay sediments can be recommended for problematic geologic-lithological and engineering-geological sections.

The First Attempt at Studying the Species Diversity of Fish in Lake Khanka Using DNA Barcoding Techniques

Lake Khanka is the largest lake in the northeastern part of Asia, being a valuable part of the resources of freshwater fisheries. Lake Khanka has a low value of endemism owing to the recent origin and connection to large river systems of the Amur and Ussuri. The list of fish species present in the lake has been constantly updated owing to invasions that occur both unintentionally and because of the introduction of hydrobionts to maximize the potential of natural productivity. In this regard, the Lake Khanka is a suitable testing ground for the development and implementation of complex methods for monitoring species diversity. The cases of invasion have become more frequent in the lake recently. Moreover, the introduction of some fish species for stabilization of relationships among communities and exhaustive utilization of the natural productivity is now being carried out, which makes challenging the development and implementation of powerful techniques for monitoring of the local fauna species diversity. For the first time, we present a complex approach to the solution of that problem. We collected 64 fish specimens from 16 species representing four families of ray-finned fishes and analyzed their taxonomy and species diversity using both classic methods and DNA barcoding techniques. Specimens have been genotyped based on the mitochondrial Co-1 gene marker. The mean values of K2P-corrected intraspecific genetic distances were 0.15 ± 0.01%; the distances between different species within the same genera were 4.08 ± 0.01%. Phylogenetic analysis revealed monophyletic origin of all species clusters with high support (98–100% of bootstrap values). Thus, reciprocal complement of morphological and genetic techniques for the purpose of species delimitation and high effectiveness of DNA barcoding in application for documentation of species diversity in Lake Khanka has been demonstrated. New molecular genetic data generally are in agreement with taxonomic relationships previously shown for these fish taxa, but an additional investigation is required to verify the composition of genus Acheilognathus in Lake Khanka.

Использование водных ресурсов в бассейне озера Ханка

The article deals with investigation of the Lake Khanka water resources’ use. We have stated that the predominant development of agriculture determines the water resources use on both the Russian part and the Chinese part of the basin. We have assessed the irrigated land areas and water volumes used for this end, as well as economic activities’ impact of the lake water level. On the basis of statistical data, satellite images and published scientific articles we have assessed for the first time the irrigated lands’ dynamics in the Lake Khanka basin over the 1960–2015 period. Analysis of the official information and the expert-restored data on water withdrawal made it possible firstly to estimate the dynamics of water use for irrigation and establish the values of water consumption (irrevocable water losses) during irrigation in the Russian part of the lake basin for the same period. We have established that the source for irrigating rice crops in Russia is the lake itself. The use of Lake Khanka’s waters in China is possible only in low water years. The influence of water use on irrigation in the Russian part of the basin at the lake level for the entire period of rice cultivation was manifested only in its reduction, and to a very small extent. In high water years, the Lake Malaya Khanka acts as a reservoir for the flood waters of the Mulinghe River, which, if discharged into the Lake Khanka, can have an impact on the growth of the Lake Khanka level.

Migratory flyways in Far-East Asia and spatial-temporal relationship to HPAI H5N6 outbreaks in South Korea

Event Abstract Back to Event Migratory flyways in Far-East Asia and spatial-temporal relationship to HPAI H5N6 outbreaks in South Korea Seong-Keun Hong1*, Kwang-Nyeong Lee1, Hachung Yoon1, Dae-Sung Yoo1, Ilseob Lee1 and Han-Mo Son1 1 Animal and Plant Quarantine Agency (South Korea), Republic of Korea Since 2016, 365 cases of highly pathogenic avian influenza virus (HPAIv) outbreaks by the Asian-origin H5N6 lineage of HPAIv have reported in South Korea and resulted in serious socio-economical losses. In this study, we demonstrated that the risk of HPAIv H5N6 in domestic poultry is related to wild birds. We expanded previous geospatial risk analysis method to East Asia including South Korea and integrated the analysis method with migration data of satellite-tracked wild birds along the far-east Asian flyway. We caught wild migratory birds around Lake Khanka (southeast area) collaborate with Russian researchers and attached a location tracker. From April to November 2018, we studied movement of 21 wild birds which carrying location tracker: 4 mallards, 2 spot-billed ducks, and 15 great egrets. The great egrets showed highest tracking success rate. During the migration, they stopped at several stopover sites (Russia to Japan; 1 mallard, 1 spot-billed duck, 1 great egret), and stayed for several weeks at those sites. We also demonstrated that migratory pathway of wild birds is correlated with HPAI H5N6 outbreaks, poultry density and latitude in East Asian Flyways. Spatial and statistical analysis was performed in ArcGIS 10.4.1(ESRI) and R 3.5.3. In addition, satellite-based movement patterns of wild birds showed that wild birds followed the East Asian flyway along the coast to breeding areas in eastern Russia. Taken together, our results suggest that it is important to analyze the tracking records of the movement of wild birds in various ways for making inference on the relationship between the migration of wild birds and outbreaks of HPAIv. Acknowledgements For field assistance with wild bird studies, we acknowledge the corperation of dedicated staff at Russian institutions, including Igor Katin and Ivan Tinuov(NSCMB FEB RAS). Additional support for tracking system was also provided by Korea Ecology Environment Research Institute, South Korea, including Han-Soo Lee. Any use of product or firm names is for descriptive purposes and does not imply endorsement by the South Korea Government.

Tracking and analysis of the movements of the migratory birds susceptible to highly pathogenic avian influenza located in Khanka Lake in Primorsky krai, Far East Russia

Tracking and analysis of the movements of the migratory birds susceptible to highly pathogenic avian influenza located in Khanka Lake in Primorsky krai, Far East Russia

Current geo-ecological problems within the Lake Khanka drainage basin.

Current geo-ecological problems within the Lake Khanka drainage basin.

The Results of Introduction of the Pike-Perch, Sander lucioperca, into Lake Khanka

As reported in the 1930s, the level of the forage base in Lake Khanka could provide from 2600 to 17 000 t of fish. The low fish capacity of the lake was explained mainly by a high abundance of small non-commercial species. For the purpose of increasing the fish capacity, a proposal was made in 1961 to introduce the Pike-Perch into Lake Khanka. This fish was expected to provide 200–300 tons extra fish product a year and also increase the proportion of valuable fish species in the lake by “destroying harmful rough fish” within 10–12 years. The introduction of pike-perch into Lake Khanka was carried out in 1970–1978. An analysis of data on the current status of the pike-perch population in the lake shows that this species has formed a stable self-reproducing population, whose biomass is now comparable to the level of the native common predatory fishes (80–100 t). In preying mainly on the sharpbelly (genus Hemiculter) and other abundant rough fish, it does not compete with other predators. Nevertheless, the pike-perch provides 20 t of marketable product a year, being rated as the second or third most commercially valuable fish species in catches from the lake.

Holocene overbank deposition in the drainage basin of Lake Khanka

Overbank deposits in the Komissarovka River valley consist of alternating silt, clay silt, sand, and soils produced by lacustrine, alluvial, and aeolian deposition and by soil formation. Silt and sand layers in the lower part of the section correlate with the events of Early Holocene transgression and Middle Holocene regression of Lake Khanka. Deposition in the lowermost reaches of the Komissarovka River provides a faithful record of local Holocene landscapes controlled by level changes in Lake Khanka.

Long-term Changes in the Main Components of Lake Khanka Water Regime

Changes in annual total precipitation and annual pan evaporation for the Lake Khanka water area during the period of 1949–2015 are analyzed based on observational data of weather stations within the lake basin. The reliability of the calculated values of characteristics affecting evaporation changes was confirmed by their comparison with observations at the 20-m2 evaporation pan installed at Astrakhanka lake station. It is shown that against a background of significant interannual fluctuations of annual precipitation during the whole period under study, its trends are almost absent. However, a rather stable increase in annual precipitation value caused by the summer precipitation rise has been noted since the early 2000s. The value of annual pan evaporation decreased from 1949 to 2015, and the rate of its decrease till 1980 was higher than in the next period. Moreover, some evaporation increase has been observed in the recent decade. The main contribution to the evaporation change is made by wind speed changes which cause about 50% of evaporation variance. Air humidity deficit is the second affecting factor that determines a little over 20% of annual evaporation variance. It is demonstrated that the increase in annual precipitation is possible by the middle of the 21st century, while the change in annual evaporation from the Lake Khanka water area would be minimal. Under such changes in the main components of the lake water regime, no reduction of its level due to natural climate processes should be expected.

Three new species of the fairy shrimp Eubranchipus Verill, 1870 (Branchiopoda: Anostraca) from northern Japan and far Eastern Russia

BackgroundSmall crustaceans in the order Anostraca that lack a carapace are commonly referred to as fairy shrimps. Eubranchipus is an Anostracan genus distributed across the Holarctic region. E. uchidai has been recorded only in Japan and has been considered the only species of Eubranchipus in the region.ResultsWe obtained fairy shrimps from three previously unsampled locations (Shiretoko and Chokai in Japan, and Khanka in Russia). Each specimen shares morphological similarities with E. uchidai, but can be discriminated by the second antenna of males and the genital morphology of females. Based on these specimens, we describe three new species of fairy shrimp: Eubranchipus asanumai n. sp. from the banks of the Shiretoko Five Lakes (Japan: Hokkaido), Eubranchipus hatanakai n. sp. from the base of Mt. Chokai (Japan: Yamagata) and Eubranchipus khankanus n. sp. from the banks of Lake Khanka (Russia: Primorsky). Phylogenetic analysis of mitochondrial DNA reveals significant differences from other known Eubranchipus species, including E. uchidai.ConclusionBoth morphological and molecular analyses show that the three new species are similar to E. uchidai but constitute distinct species. Pronounced differences in female morphological features correspond to variability of the amplexus structure previously reported in the genus.

Linkage between Lake Xingkai sediment geochemistry and Asian summer monsoon since the last interglacial period

In this study, we present the element geochemical data of Core XK08-A2 drilled from Lake Xingkai (Khanka), northeast China. The study aims to examine the changes of sediment provenance and geochemical composition in response to Asian summer monsoon variability since the last interglacial period. Major elemental analyses on lacustrine samples and sand samples from Lake Xingkai and the surrounding sandy ridges in northeast China indicate that their abundance varied in relatively narrow ranges. The samples had only undergone the primary stage of chemical weathering. Similar Ti/Al and K/Al ratios between the lacustrine samples from Lake Xingkai and the loess-paleosol samples in north China were observed, which suggests that they come from broadly similar desert sources. Due to the significant dependence on grain-size and influence of sediments recycling, Chemical Index of Alteration of the lacustrine sediments could not be regarded as sensitive indicators of source regions' weathering on the glacial-interglacial timescale. Alternatively, the geochemical proxies of the lacustrine sediments could be linked to the Asian summer monsoon through the development of runoff and physical erosion in the catchment. Weakened Asian summer monsoon caused more fine particles transported to the lake basin by reduced runoff in the last glacial period. In contrast, coarser and less-weathered detritus are transported into the lake accompanying strengthened Asian summer monsoon during the warm periods.

Herbicide accumulations in the Xingkai lake area and the use of restored wetland for agricultural drainage treatment

The plains surrounding the northern part of the Xingkai Lake (XL) straddling the border between China and Russia, is a major agricultural production area in Northeastern China. The accumulations from herbicides applied in the farmlands are an important factor affecting the local wetland environment. In this paper, top soil and surface water samples collected from different land use types were analysed. The sediments of a restored wetland receiving agricultural drainage (RW) were tested for two representative herbicides (butachlor and acetochlor). The removal of the two herbicides were calculated based on the herbicide differences between the sediments of RWO and RWI. Results showed that herbicides were widespread in XL area. The highest acetochlor concentration was detected in soybean dry land soil (117.1 ng g−1) and RWI water (402.2 ng L−1) compared with the average concentration of 121.63 ng g−1 in the riparian soils of the Sanjiang Plain, and the highest butachlor concentration was in the paddy field soil (140.55 ng g−1), which mainly originated from human activities related to agricultural production. Due to the selective removal of RW and the differences in the characteristics of the herbicides, removal by RW was higher for butachlor than acetochlor, with removal efficiencies of 29.9% and 0.5%, respectively, indicating that butachlor was more degradable in wetlands. We conclude that herbicide accumulations do exist in the Lake Xingkai area, while RW used for agricultural drainage treatment can remove limited parts of herbicides. More rigid pesticide controls are recommended for the protection and management of the wetland environment in XL area.

Distribution characteristics of iron, carbon, nitrogen and phosphorus in the surface soils of different land use types near Xingkai Lake

The purpose of this study was to research the differences in iron, phosphorus, nitrogen and organic matter contents at two soil depths in areas with different land use types in the Xingkai Lake National Nature Reserve and to determine the causes of those differences. Additionally, this study sought to analyse the correlations between the contents of different nutrients and to determine the reasons for those correlations. Five typical land use types, namely, lakeshore sandy land, grassland, forestland, dryland and wetland, were selected in the Xingkai Lake National Nature Reserve. The contents of amorphous iron (Feo), complexed iron (Fep), dithionite-extractable iron (Fed), total iron (TFe), total phosphorus (TP), total nitrogen (TN) and organic matter (OM) were measured in these soils at two depths: 0–5 cm (soil depth 1) and 5–10 cm (soil depth 2). For soil depth 1 and soil depth 2, the land use type had no significant effect on the element contents. For the entire soil depth range (0–10 cm), the land use type had the most significant impact on the TP content (p < 0.01). Furthermore, soil depth had a significant effect on the contents of Feo (p < 0.01), TP (p < 0.01) and OM (p < 0.05). Overall, the element content at soil depth 2 was higher than that at soil depth 1. The interaction between land use type and soil depth significantly influenced the contents of TN and OM (p < 0.05). The contents of TN and OM in the lakeshore sandy land and dryland were high, and the contents of TN and OM were highly positively correlated (r = 0.90652, p < 0.01). Different land use types caused different degrees of disturbance in the soil, resulting in differences in the element contents in the soils. The differences in the distribution of soil element contents in the topsoil were the result of important natural and human factors.

Environmental variables influencing phytoplankton communities in hydrologically connected aquatic habitats in the Lake Xingkai basin

Hydrological connectivity can strongly influence phytoplankton communities and ecological status through the interchange of nutrients and organisms in interconnected aquatic habitats. However, there is little consensus regarding the distinction of environmental variables influencing phytoplankton communities related to hydrological connectivity in different aquatic habitats. In this two-year (2013–2014) study, we investigated phytoplankton communities and their relationships with environmental variables in four hydrologically connected aquatic habitats (from upstream to downstream: the Nur Dongbei wetland, Lake Xiaoxingkai, Lake Xingkai, and the Song′acha River) in the Lake Xingkai basin in northeast China. Our aim was to study the effects of hydrological connectivity on phytoplankton communities, and to identify potential indicators of water quality for the basin. We observed that environmental variables and phytoplankton communities showed spatial and temporal heterogeneity in the four habitats, with higher phytoplankton metrics in Lake Xiaoxingkai and lower phytoplankton metrics in the Song′acha River, including species richness, abundance, biomass, and diversity. Increased nutrient concentrations occurred in those habitats connected to the eutrophic Lake Xiaoxingkai during the hydrologically connected period. Lake Xiaoxingkai, Lake Xingkai, and the Song′acha River were dominated by Chlorophyta, whereas Bacillariophyta was the major component of phytoplankton composition in the Nur Dongbei wetland. Environmental variables influencing phytoplankton communities differed during connected and disconnected periods across the four habitats. Results of Pearson correlation analysis and canonical correspondence analysis (CCA) showed that phytoplankton community was mainly affected by concentrations of iron (Fe2+), total nitrogen (TN), and total phosphorus (TP) in the lakes; by water depth and transparency in the river; and by pH and silicate concentrations in the wetland. Based on the results of non-metric multidimensional scaling (NMDS) analysis, hydrological connectivity increased phytoplankton community similarity among different habitats during the connected period. Cyclotella meneghiniana and Anabaena azotica could be used as useful indicators to determine water quality conditions due to their strong sensitivity to nutrient concentrations in freshwater bodies. Our findings provide a scientific basis for water quality protection and management at the basin scale.

RESULTS OF PIKE PERCH SANDER LUCIOPERCA INTRODUCTION IN LAKE KHANKA

Pike perch was introduced into Lake Khanka in 1970–1978. The introduction was founded on concept of low commercial productivity of the lake prevailed in those times. For the past 50 years, the species acclimatized successfully in the lake. However, the process of its naturalization was not easy, with periodic disappearance from the catches succeeded by blooms. In recent years, the species became one of the most important objects of commercial fishery. Studies of its ecology show that Lake Khanka environments are rather good for pike perch breeding, in particular the food supply for all stages of its larvae and juveniles. As the result, pike perch in Lake Khanka is distinguished by earlier puberty in comparison with the same species in the Amur River and the Curonian Lagoon. Its adults consume low-valued fish and shrimps abundant in the lake. After successful acclimatization in Lake Khanka, pike perch penetrated through the Sungacha to the Ussuri River by 1985, and further to the Amur where in decade it extended upstream to the Bira tributary and downstream to Yelabuga village. Currently, pike perch is a common species in catches on the middle and low Amur from Blagoveshchensk to Mago, i.e. > 1 500 km from Lake Khanka.

Effects of floodgates operation on nitrogen transformation in a lake based on structural equation modeling analysis

Floodgates operation is one of the primary means of flood control in lake development. However, knowledge on the linkages between floodgates operation and nitrogen transformation during the flood season is limited. In this study, water samples from six sampling sites along Lake Xingkai watershed were collected before and after floodgates operation. The causal relationships between environmental factors, bacterioplankton community composition and nitrogen fractions were determined during flood season. We found that concentrations of nitrogen fractions decreased significantly when the floodgates were opened, while the concentrations of total nitrogen (TN) and NO3− increased when the floodgates had been shut for a period. Further, we proposed a possible mechanism that the influence of floodgates operation on nitrogen transformation was largely mediated through changes in dissolved organic matter, dissolved oxygen and bacterioplankton community composition as revealed by structural equation modeling (SEM). We conclude that floodgates operation has a high risk for future eutrophication of downstream watershed, although it can reduce nitrogen content temporarily. Therefore, the environmental impacts of floodgates operation should be carefully evaluated before the floodwaters were discharged into downstream watershed.

Effect of Wetland Reclamation on Soil Organic Carbon Stability in Peat Mire Soil Around Xingkai Lake in Northeast China

Content and density of soil organic carbon (SOC) and labile and stable SOC fractions in peat mire soil in wetland, soybean field and rice paddy field reclaimed from the wetland around Xingkai Lake in Northeast China were studied. Studies were designed to investigate the impact of reclamation of wetland for soybean and rice farming on stability of SOC. After reclamation, SOC content and density in the top 0–30 cm soil layer decreased, and SOC content and density in soybean field were higher than that in paddy field. Content and density of labile SOC fractions also decreased, and density of labile SOC fractions and their ratios with SOC in soybean field were lower than that observed in paddy field. In the 0–30 cm soil layer, densities of labile SOC fractions, namely, dissolved organic carbon (DOC), microbial biomass carbon (MBC), readily oxidized carbon (ROC) and readily mineralized carbon (RMC), in both soybean field and paddy field were all found to be lower than those in wetland by 34.00% and 13.83%, 51.74% and 35.13%, 62.24% and 59.00%, and 64.24% and 17.86%, respectively. After reclamation, SOC density of micro-aggregates (< 0.25 mm) as a stable SOC fraction and its ratio with SOC in 0–5, 5–10, 10–20 and 20–30 cm soil layers increased. SOC density of micro-aggregates in the 0–30 cm soil layer in soybean field was 50.83% higher than that in paddy field. Due to reclamation, SOC density and labile SOC fraction density decreased, but after reclamation, most SOC was stored in a more complex and stable form. Soybean farming is more friendly for sustainable SOC residence in the soils than rice farming.

Glacial-interglacial vegetation changes in northeast China inferred from isotopic composition of pyrogenic carbon from Lake Xingkai sediments

Understanding the changes in monsoon intensity and ecosystem response at different timescales is crucial for the well-being of humans, yet the paleoclimatic interpretation of stable carbon isotope (δ13C) values from northeast China records is debatable. In this study, reported δ13C data from 76 surface soils in northeast China are compiled, and a δ13C record of pyrogenic carbon (δ13CPyC) from Lake Xingkai in northeast China since the last interglacial period is presented. The aim was to investigate the orbital timescale environmental implication of geological δ13CPyC data for northeast China. The results showed a distinct increase in δ13C values of surface soils, which correlated with increasing temperature of the warmest month. Higher temperature favored the expansion of C4 plants, while precipitation had only a weak correlation with δ13C values of surface soils in the region. On an orbital timescale, the δ13CPyC record from Lake Xingkai generally reflected paleovegetation change, suggesting that the abundance of C4 plants was relatively high during the warm periods, changing to almost purely C3 plants during the cold periods. Both modern and geological analysis suggest that the climatic factor determining the δ13C in northeast China was temperature of the warmest month. This is similar to the situation for mid-latitudes such as the Chinese Loess Plateau, in contrast to low latitudes such as southern China.

Traces of Genetic Subdivision in the Current Single Population of Epischura chankensis Rylov, 1928 (Copepoda, Calanoida) in Lake Khanka

The analysis of genetic polymorphism of Epischura chankensis from Lake Khanka, one of the key species of zooplankton, identified traces of geographical subdivision in the past in the current single population, probably owing to the formation of isolated reservoirs in the lake valley during its regression.

Dynamics of habitat suitability for waterfowls from 1990 to 2015 in the ecological function zone of Sanjiang Plain, Northeast China

As a wetland of international importance, the ecological function zone of the Sanjiang Plain (EFZSP) plays an important role in maintaining waterfowl habitat. With the increasing disturbance of human beings, land use and climate changes, habitat suitability for waterfowls (HSW) has drawn greater attention of ecologists. In this study, Landsat TM/ETM+/OLI and HJ-1B images in 1990, 2000, 2010 and 2015 were used to obtain land cover classification by object-based image analysis, and the entropy and analytic hierarchy process methods were adopted to determine the factors and their weights, the factors selected in this study included water condition (lake and river density), disturbance factor (residence and road density), shelter condition (land cover type and slope), and food abundance (NDVI). Finally, the evaluation results of habitat suitability of year 1990, 2000, 2010, and 2015 were achieved based on the habitat suitability index (HSI) system, and the spatio-temporal dynamics and driving forces causing the changes were analyzed. The results showed that the excellent level of HSW mainly distributed in abundant water areas, especially along the riparian zone of the Heilongjiang River, Naoli River, Ussuri River, Muling River and Xingkai Lake. Its area decreased by 3.2% from 1990 to 2015 because of wetland reclamation. The good level of HSW concentrated in Raohe County over the past 25 years, the condition of Hulin County and Fuyuan County were improved to a good level from 2010 to 2015 due to the substantial increase of paddy field areas. The fair level of HSW distributed dispersedly, and the areas first increased from 1990 to 2000 and then decreased during 2000-2010 and 2010-2015 periods. The areas of poor le-vel increased by 6.7% from 1990 to 2000 and decreased by 3.1% from 2000 to 2015. The change of HSW level in this study area was dominated by land cover change, and both of the increasing population and economy and the drying and worming climate resulted in the decline of the HSW level, whereas the establishment of nature reserves is crucial to protect habitat for waterfowls.