Water level changes of Hulun Lake in Inner Mongolia derived from Jason satellite data

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Abstract

Water levels in lakes can reflect changes in such bodies. Therefore, there is value in identifying the variations in water levels using observations from altimetry satellites and analyzing the possible causes. In this work, the water-level changes of Hulun Lake in Inner Mongolia during the period from 2002 to 2015 are monitored by the use of Jason satellite data, the results of which are compared with historical data. Landsat TM/ETM/OLI_TRIS remote sensing images are analyzed, and the surface area of the lake extracted from them and converted to the corresponding water level to verify the values obtained from the Jason observations. The results show a downward trend after 2000 (−0.98 mm/year) and a sharp increase after 2012 (3.07 mm/year). The root mean square error (RMSE) between the two methods was 0.2369 m, and the correlation coefficient was 0.986. By analyzing the various influencing factors, we draw the conclusion that the water level of Hulun Lake is affected by both natural factors (e.g., rainfall, runoff, evapotranspiration etc.) and anthropogenic influences (e.g., water consumption in coal mining, overgrazing, etc.). These are the main causes of the decrease in the area of Hulun Lake and other lakes in the Inner Mongolia Autonomous Region. By comparing the lake storage anomalies of Hulun Lake with the terrestrial Total Water Storage anomalies (TWSA) inverted from GRACE satellite data and the Surface Water Storage anomalies (SWSA) from WaterGAP Global Hydrology Model (WGHM) within the Hulun Basin, we find that not only do Hulun Lake and basin interact with each other, but also that Hulun Lake has an important function with regards to the changes within the basin as a whole. This work therefore provides a method for monitoring the dynamic changes of lake water levels, while analyzing the influencing factors based on multi-scale data. Such a method shows potential for being applied to efforts to ensure environmental protection.

Introduction

Satellite altimetry is a high-tech measurement technology developed in the 1970s. By using satellites as the carrier of measuring instruments, the spaceborne radar or laser altimeter measures the height of the satellite to the sea, the effective wave height, the backscattering coefficient of the electromagnetic wave, and the sea surface in real time [1], [2], [3]. Since satellite altimetry provides a large amount of high-precision data, it has made a great contribution to research on the marine geoid, gravity anomalies, tides, polar ice cover, and geophysical and oceanographic parameters. Hydrologic stations and continuous observations are generally used to obtain inland water level information but this requires a certain amount of manpower, materials, and financial resources. In reality, many inland water areas are in remote locations and it is difficult to set up ground observation sites nearby. In this situation, satellite radar altimetry has been applied and has ranged from the initial observations of global sea-level change to the monitoring of the changes in polar ice cover thickness and inland water levels, particularly in some inland water areas lacking ground hydrographic observations such as rivers, lakes, and wetlands [4], [5], [6], [7].

Recently, Tao et al. [8] monitored all lakes larger than one km2 in areas in the Mongolia Plateau and determined that the number of lakes decreased from 785 prior to 1987 (427 in the Inner Mongolia Autonomous Region and 358 in Mongolia) to 577 in 2010 (decreased by 145 in the Inner Mongolia Autonomous Region, accounting for 34.0% of the total number of lakes in the autonomous region and decreased by 63 in Mongolia, accounting for 17.6% of the total number of lakes in Mongolia). In addition, accompanied by a decrease in the number of lakes, the lake area also decreased significantly, especially in the Inner Mongolia Autonomous Region, where the total area of the lakes decreased from 4160 km2 in 1987 to 2901 km2 in 2010, representing a decrease of 30.3%.

Hulun Lake is the largest lake in the Inner Mongolia Autonomous Region. Therefore, it is important from a research perspective to obtain the variation in the water level in the recent decade and to analyze its causes using satellite altimetry. The successful application of the Jason satellite altimetry data for monitoring the water level of Hulun Lake does not only compensate for the lack of data for Hulun Lake but also provides basic data that can be applied to the ecological protection of the basin and the rational allocation of water resources [9], [10], [11]. The current on-orbit altimetry satellites include Jason-3, Jason-2, CryoSat-2, HY-2, and SARAL, among others. In recent years and in future decades, various countries around the world will continuously launch satellite platforms with radar altimeters, as shown in Table 1.

At present, satellite altimetry technology and performance have matured. The height measurement accuracy has reached the centimeter level, representing an increase in three orders of magnitude since 2001 and the data resolution is 10 km. Since the late 1980s, scholars have applied radar altimetry to the monitoring of the variation in the water level of inland lakes and rivers, which was further extended to wetland monitoring. Satellite altimetry has good application prospects for monitoring water level changes in inland waters, especially in large inland lakes. Birkett [4], Ponchaut and Cazenave [12], Medina et al. [6], Seyler and Frederique used Topex/Poseidon (T/P), ENVISAT-1, and Jason-2 data to study the relationship between the variations in the water levels of inland waters and the climate environment in North America, South America, Central America, and East Africa. Recently, Masters et al. [13] used T/P, Jason-1, and Jason-2 data to study time series data of the global sea level [14]. Li et al. [5], Chu et al. [15], and Jiang et al. [16] also used satellite altimetry data such as Jason-1, T/P, and ENVISAT-1 to monitor water levels and study the relationship between variations in the water level and climate in Hulun Lake, Qinghai Lake, and four lakes in the middle and lower reaches of the Changjiang River.

Moreover, Zhang et al. [17] used T/P data to study the application of satellite altimetry data for river flow measurements, which provided a new approach for estimating river flow by remote sensing. Recently, some domestic and foreign scholars, such as Jiang et al. [18], combined the gravity altimetry data of the Jason satellite with the GRACE satellite gravity data to study global sea level change. Li et al. [19] studied the water level of Lake Baikal by waveform reconstruction using Jason-2 satellite data and achieved favorable results. Chen et al. [20] examined recent Caspian Sea level change by using both satellite radar altimetry and satellite gravity data from 2002 to 2015. The authors corrected for spatial leakage in the GRACE spherical harmonic (SH) estimates by constrained forward modeling. Ni et al. [21] investigated the possibility of using GRACE data for quantitative long-term monitoring; the results showed that the GRACE-derived Lake Volta water storage changes agreed remarkably well with independent estimates from satellite altimetry at interannual and longer timescales. This demonstrated the value of GRACE estimates to monitor and quantify water storage changes in lakes, especially in relatively small regions with complicated topography. Other researchers have also used remote sensing data to monitor changes in the water level and volume successfully [22], [23], [24], [25], [26], [27], [28], [29], [30].

However, due to the small area of inland lakes, the tracks of altimetry satellites seldom cover inland lakes. Hulun Lake is the largest lake in North China, has a large water area, and a portion of the satellite tracks cover Hulun Lake. Therefore, it is suitable for an in-depth study of the variations in the water level using the Jason satellite with a revisit period of 10 days. For example, Chu et al. [15] used Jason-1 data to monitor the water level of Hulun Lake. The monitoring period was from 2002 to 2004 and the authors concluded that the water level of Hulun Lake decreased each year due to the amount of precipitation. On this basis, this research extends the time series to 2015. The Jason satellite data were used to monitor the water level changes and verified by Landsat data. The lake water storage was the calculated from the water level and compared with the TWSA and SWSA determined for Hulun Basin to analyze the relationship between the lake and the whole basin. Moreover, the fluctuations of the water level and its underlying causes are comprehensively analyzed in combination with precipitation data.

Section snippets

Study area

Hulun Lake, also known as Hulun Pond or Dalai Lake, is the fourth largest lake in China and the largest lake in Inner Mongolia. It is located in the west of the Hulun Buir Grassland (116°58′–117°47′E and 116°58′–117°47′N) between New Barag Left Banner, New Barag Right Banner, and Manzhouli City, as shown in Fig. 1. The Hulun Lake has an irregular rectanglar shape with its long axis running from southwest to northeast. The lake is 93 km long, the largest width is 41 km, the average width is

Water level calculations

The water levels calculated by the BRAT software are based on the geoid height. A total of 322 data records from February 15th, 2002 to October 30th, 2008 and 336 data records from May 6th, 2009 to November 1st, 2015 are obtained, resulting in 658 data records. Jason-1 lacks the data for January–April and December and Jason-2 lacks the data for January–April, November, and December. The water levels at the anomaly points are in the range of 580–590 m. The maximum water level values for Jason-1

Conclusion

In this study, we monitored the water level changes of the Hulun Lake in Inner Mongolia from 2002 to 2015 using Jason satellite data and compared the results with historical data and Landsat images. We took into account the rainfall data of the region and analyzed the factors affecting the water level changes of Hulun Lake. By combining the TWSA from GRACE satellite data and SWSA from WGHM, the relationships between the Hulun Lake and the Hulun Basin were studied. The following are the main

Acknowledgements

This research was financially supported by National Natural Science Foundation of China (No. 41490634) and the Ministry of Science and Technology of the People’s Republic of China (No. 2015FY210500).

Conflicts of interest

Authors have no competing interests to declare.

References (35)

  • G.Q. Han et al.

    Sea level and geostrophic current features from tandem TOPEX/Poseidon: Jason data in the Newfoundland offshore

    Int. J. Remote Sens.

    (2008)
  • J.G. Li et al.

    Application of Jason-2 Altimetry data in monitoring of continental water level fluctuations: a case study in South Dongting Lake, China

    J. Natur. Resour.

    (2010)
  • Y.C. Cheng et al.

    Sea-level trend in the South China Sea observed from 20 years of along-track satellite altimetric data

    Int. J. Remote Sens.

    (2014)
  • C.M. Birkett

    The contribution of TOPEX/POSEIDON to the global monitoring of climatically sensitive lakes

    J. Geophys. Res.

    (1995)
  • Y. Troitskaya et al.

    Adaptive retracking of jason-1 altimetry data for inland waters: the example of the Gorky Reservoir”

    Int. J. Remote Sens.

    (2012)
  • S. Tao et al.

    Rapid loss of lakes on the Mongolian Plateau

    Proc. Natl. Acad. Sci. USA

    (2015)
  • C. Hwang et al.

    Lake level variations in China from TOPEX/Poseidon altimetry: data quality assessment and links to precipitation and ENSO

    Geophys. J. Int.

    (2005)
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