| Citation: |
Lu-chen Wang, Kun Yu, Liang Chang, Jun Zhang, Tao Tang, Li-he Yin, Xiao-fan Gu, Jia-qiu Dong, Ying Li, Jun Jiang, Bing-chao Yang, Qian Wang, 2021. Response of glacier area variation to climate change in the Kaidu-Kongque river basin, Southern Tianshan Mountains during the last 20 years, China Geology, 4, 389-401. doi: 10.31035/cg2021055
|
Response of glacier area variation to climate change in the Kaidu-Kongque river basin, Southern Tianshan Mountains during the last 20 years
-
Abstract
Glaciers are crucial water resources for arid inland rivers in Northwest China. In recent decades, glaciers are largely experiencing shrinkage under the climate-warming scenario, thereby exerting tremendous influences on regional water resources. The primary role of understudying watershed scale glacier changes under changing climatic conditions is to ensure sustainable utilization of regional water resources, to prevent and mitigate glacier-related disasters. This study maps the current (2020) distribution of glacier boundaries across the Kaidu-Kongque river basin, south slope of Tianshan Mountains, and monitors the spatial evolution of glaciers over five time periods from 2000–2020 through thresholded band ratios approach, using 25 Landsat images at 30 m resolution. In addition, this study attempts to understand the role of climate characteristics for variable response of glacier area. The results show that the total area of glaciers was 398.21 km2 in 2020. The glaciers retreated by about 1.17 km2/a (0.26%/a) from 2000 to 2020.The glaciers were reducing at a significantly rapid rate between 2000 and 2005, a slow rate from 2005 to 2015, and an accelerated rate during 2015–2020. The meteorological data shows slight increasing trends of mean annual temperature (0.02°C/a) and annual precipitation (2.07 mm/a). The correlation analysis demonstrates that the role of temperature presents more significant correlation with glacier recession than precipitation. There is a temporal hysteresis in the response of glacier change to climate change. Increasing trend of temperature in summer proves to be the driving force behind the Kaidu-Kongque basin glacier recession during the recent 20 years.
-
-
References
Adina R, Williams MW. 2012. Decision tree and texture analysis for mapping debris-covered glaciers in the Kangchenjunga area, Eastern Himalaya. Remote Sensing, 4(10), 3078–3109. doi: 10.3390/rs4103078. Andreassen LM, Paul F, Kääb A, Haussberg JE. 2008. Landsat-derived glacier inventory for Jotunheimen, Norway, and deduced glacier changes since the 1930s. The Cryosphere, 2(3), 131–145. doi: 10.5194/tcd-2-299-2008. Bolch T, Kamp U. 2006. Glacier mapping in high mountains using DEMs, Landsat and ASTER data. Proceedings 8th International Symposium on High Mountain Remote Sensing Cartography, 41, 37–48. doi: http://web.unbc.ca/~bolch/publications/BolcKamp06_GeoRaum Bolch T, Menounos B, Wheate R. 2010. Landsat-based inventory of glaciers in western Canada, 1985–2005. Remote Sensing of Environment, 114(1), 127–137. doi: 10.1016/j.rse.2009.08.015. Braithwaite RJ, Zhang Y. 2000. Sensitivity of mass balance of five Swiss glaciers to temperature changes assessed by tuning a degree-day model. Journal of Glaciology, 46(152), 7–14. doi: 10.3189/172756500781833511. Brun F, Berthier E, Wagnon P, Kääb A, Treichler D. 2017. A spatially resolved estimate of High Mountain Asia glacier mass balances from 2000 to 2016. Nature Geoscience, 10, 668–673. doi: 10.1038/ngeo2999. Burns P, Nolin A. 2014. Using atmospherically-corrected Landsat imagery to measure glacier area change in the Cordillera Blanca, Peru from 1987 to 2010. Remote Sensing of Environment, 140(1), 165–178. doi: 10.1016/j.rse.2013.08.026. Che YJ, Zhang MJ, Li ZQ, Wang SJ, Du MX, Wang PY, Wang J, Zhou PP. 2018. Quantitative evaluation of glacier change and its response to climate change in the Chinese Tien Shan. Cold Regions Science and Technology, 153(9), 144–155. doi: 10.1016/j.coldregions.2018.05.010. Chen WH. 2016. Research of Glacier Change based on RS and GIS in the Tomur Region, Tianshan Mountains. Xi’an, Northwest Normal University, M.D. thesis, 1–38 (in Chinese with English abstract). Di BG. 2019. Glacier Change in the Nianqing Tanggula Mountains in 36 Years and Its Response to Climate Change. Beijing, China University of Geosciences, M.D. thesis, 1–64 (in Chinese with English abstract). Ding YJ. 1995. Response of global glacier variation to climate change in recent 40 years. Science in China (Series B), 25(10), 1093–1098. doi: 10.1360/zb1995-25-10-1093. Dong P, Cheng W, Ding J. 2013. Estimating glacier volume loss using remotely sensed images, digital elevation data, and GIS modelling. International Journal for Remote Sensing, 34(23–24), 8881–8892. doi: 10.1080/01431161.2013.853893. Du WB. 2014. Research on glacier extraction based on multisource RS imagery and changes monitoring of Eastern Tienshan Mountains. Luoyang, Henan Polytechnic University, Ph.D thesis, 1–118 (in Chinese with English abstract). Du WB, Ji WQ, Xu LJ, Wang ST. 2020. Deformation time series and driving-force analysis of glaciers in the Eastern Tienshan Mountains using the SBAS InSAR method. International Journal of Environmental Research and Public Health, 17(8), 2836. doi: 10.3390/ijerph17082836. Dyurgerov MB, Meier MF. 2000. Twentieth century climate change: Evidence from small glaciers. Proceeding of the National Academy of Science, the United States of America, 97(4), 1406–1411. doi: 10.1073/pnas.97.4.1406. Farinotti D, Longuevergne L, Moholdt G, Duethmann D, Mölg T, Bolch T, Vorogushyn S, Güntner A. 2015. Substantial glacier mass loss in the Tien Shan over the past 50 years. Nature Geoscience, 8, 716–722. doi: 10.1038/ngeo2513. Gao XQ, Tang MC, Feng S. 2000. Discussion on the relationship between glacial fluctuation and climate change. Plateau Meteorology, 19(1), 9–16 (in Chinese with English abstract). Goldstein RM, Engelhardt H, Kamb B, Frolich RM. 1993. Satellite Radar Interferometry for Monitoring Ice Sheet Motion: Application to an Antarctic Ice Stream. Science, 262(5139), 1525–1530. doi: 10.2307/2882472. Granshaw FD, Fountain AG. 2006. Glacier change (1958–1998) in the North Cascades National Park Complex, Washington, the United States of America. Journal of Glaciology, 52(177), 251–256. doi: 10.3189/172756506781828782. Guan JW. 2020. Modern glacier changes in the main peak area of West Kunlun Mountains. Lanzhou, Lanzhou University, M.D. thesis, 1–95 (in Chinese with English abstract). Hall DK, Ormsby JP, Bindschadler RA, Siddalingaiah H. 1987. Characterization of snow and ice reflectance zones on glaciers using Landsat thematic mapper data. Annals of Glaciology, 9, 104–108. doi: 10.1017/s0260305500000471. Han N. 2019. Research of glacier variations and its impact on runoff in Sugan Lake basin, Northwest China. Beijing, China Institute of Water Resources and Hydropower Research, M.D. thesis, 1–70 (in Chinese with English abstract). He Y, Yang TB, Ji Q, Li J. 2014. Comparative analysis of glacier changes between eastern and western part of Northern Tianshan. Journal of Arid Land Resources and Environment, 6, 108–113 (in Chinese with English abstract). doi: 10.13448/j.cnki.jalre.2014.06.009. He ZG. 2019. Analysis on ecological water transportation and restoration countermeasures in the lower reaches of the Kongque river. Shaanxi Water Resources, 9(9), 39–40. doi: 10.16747/j.cnki.cn61-1109/tv.2019.09.013. IPCC. 2014. Climate change 2014: Impacts, adaptation, and vulnerability. Part A: Global and sectoral aspects. Contribution of Working Group Ⅱ to the fifth assessment report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom and New York, the United States of America, Cambridge University Press, 1132. Ji Q, Yang TB, Dong J, He Y. 2018. Glacier variations in response to climate change in the eastern Nyainqêntanglha Range, Tibetan Plateau from 1999 to 2015. Arctic Antarctic and Alpine Research, 50(1), 1435844. doi: 10.1080/15230430.2018.1435844. Ji Q, Dong J, Liu R, Xiao ZL, Yang TB. 2020. Glacier changes in response to climate change in the Himalayas in 1990–2015. Sientia Geographica Sinica, 40(3), 486–496 (in Chinese with English abstract). doi: 10.13249/j.cnki.sgs.2020.03.017. Kaushik S, Dharpure JK, Joshi PK, Ramanathan AL, Singh T. 2020. Climate change drives glacier retreat in Bhaga basin located in Himachal Pradesh, India. Geocarto International, 35(11), 1179–1198. doi: 10.1080/10106049.2018.1557260. Ke LH, Ding XL, Li WK, Qiu B. 2017. Remote sensing of glacier change in the central Qinghai-Tibet Plateau and the relationship with changing climate. Remote Sensing, 9(2), 114. doi: 10.3390/rs9020114. Kumar V, Shukla T, Mehta M, Dobhal DP, Bish MPS, Nautiyal S. 2021. Glacier changes and associated climate drivers for the last three decades, Nanda Devi region, Central Himalaya, India. Quaternary International, 575, 213–226. doi: 10.1016/j.quaint.2020.06.017. Li BL, Zhang YC, Zhou CH. 2004. Remote sensing detection of glacier changes in Tianshan Mountains for the past 40 years. Journal of Geographical Sciences, 14(3), 296–302. doi: 10.1007/bf02837410. Li SS. 2013. Characteristics and spatial differences of terminus for representative glacier in different areas of the Tianshan Mountains, China. Xi’an, Northwest Normal University, M.D. thesis, 1–50 (in Chinese with English abstract). Li SS, Zhang MJ, Li ZQ, Li HL, Luo SF. 2013. Variation of glacier terminuses in the Tianshan Mountains, China, during the period of 1960–2009. Arid Zone Research, 30(2), 378–384 (in Chinese with English abstract). doi: 10.13866/j.azr.2013.02.028. Li ZQ, Wang FT, Li HL. 2018. Science and long-term monitoring of continental-type glaciers in arid region in China. Bulletin of Chinese Academy of Sciences, 33(12), 1381–1390 (in Chinese with English abstract). doi: 10.16418/j.issn.1000-3045.2018.12.012. Lin CQ, Yi YJ, Liu T. 2020. Water system connectivity evaluation and optimization control in Bosten lake basin. Environmental Engineering, 38(10), 24–28 (in Chinese with English abstract). doi: 10.13205/j.hjgc.202010004. Liu CH, Shi YF, Wang ZT, Xie ZC. 2000. Glacier resources and their distributive characteristics in China: A review on Chinese Glacier Inventory. Journal of Glaciology and Geocryology, 22(2), 106–112 (in Chinese with English abstract). doi: 10.3969/j.issn.1000-0240.2000.02.002. Liu JZ, Li WH, Chen YJ, Jing SH, Ma RZ. 2018. Analysis on desertification of degraded riparian forest in the lower reaches of Peacock river. Journal of Liaocheng University (Natural Science), 31(1), 65–71 (in Chinese with English abstract). doi: 10.19728/j.issn1672-6634.2018.01.010. Liu SY, Ding YJ, Zhang Y, Shangguan DH, Li J, Han HD, Wang J, Xie WC. 2006. Impact of the glacial change on water resources in the Tarim River Basin. Acta Geographica Sinica, 61(5), 482–490 (in Chinese with English abstract). doi: 10.11821/xb200605004. Liu SY, Yao XJ, Guo WQ, Xu JL, Shangguan DH, Wei JF, Bao WJ, Wu LZ. 2015. The contemporary glaciers in China based on the Second Chinese Glacier Inventory. Acta Geographica Sinica, 70(1), 3–16 (in Chinese with English abstract). doi: 10.11821/dlxb201501001. Liu YQ, Liu JZ, Chen YJ, Jing SH, Feng RA. 2017. Environmental characteristics and interspecific associations in the lower reaches of the Kongque river. Acta Encologica Sinica, 37(8), 2706–1728 (in Chinese with English abstract). doi: 10.5846/stxb201511302400. Mamt A, Halik Ü, Keram A, Song ZL. 2017. Remote sensing monitoring of Bosten lake water resources and its driving factor analysis. Xinjiang Agricultural Sciences, 54(4), 184–192 (in Chinese with English abstract). doi: 10.6048/j.issn.1001-4330.2017.04.023. Mohammdy M, Moradi HR, Zeinivand H, Temme AJAM, Pourghasemi HR, Alizadeh H. 2014. Validating gap-filling of Landsat ETM+ satellite images in the Golestan Province, Iran. Arabian Journal of Geosciences, 7(9), 3633–3638. doi: 10.1007/s12517-013-0967-5. Naito N. 2011. Encyclopedia of Snow, Ice and Glaciers: Summer Accumulation Type Glaciers. Encyclopedia of Earth Sciences Series, Springer, Dordrecht, Netherlands, 1107–1108. doi: 10.1007/978-90-481-2642-2_552. Narama C, Kaeaeb A, Duishonakunov M, Abdrakhmatov K. 2010. Spatial variability of recent glacier area changes in the Tien Shan Mountains, Central Asia, using Corona (~1970), Landsat (~2000), and ALOS (~2007) satellite data. Global and Planetary Change, 71(1-2), 42–54. doi: 10.1016/j.gloplacha.2009.08.002. Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences. 2018. Tianshan Glaciological Station, Chinese Academy of Sciences. Bulletin of Chinese Academy of Sciences, 33(12), 50–58. Oerlemans J. 2001. Glaciers and climate change. Netherlands, A.A. Balkema Publishers, Dordrecht, 148. Oerlemans J. 2005. Extracting a climate signal from 169 glacier records. Science, 308(5722), 675–677. doi: 10.1126/science.1107046. Oerlemans J, Giesen RH, Van de Broeke MR. 2009. Retreating alpine glaciers increased melt rates due to accumulation of dust (Vadret da Morteratsch, Switzerland). Journal of Glaciology, 55(192), 729–736. doi: 10.3189/002214309789470969. Ou JB, Xu LB, Pu T. 2020. Dynamic monitoring of glacier change and their response to climate change in the Que’er Mountins. Journal of Glaciology and Geocryology, 42(2), 36–48 (in Chinese with English abstract). doi: 10.7522/j.issn.1000-0240.2019.1099. Pan XZ. 2016. Analysis of salinization causes of phreatic water in upper and middle Peacock river basin, Xinjiang. Xinjiang Nonferrous Mental, 39(2), 51–54. doi: 10.16206/j.cnki.65-1136/tg.2016.02.019. Paul F. 2000. Evaluation of different methods for glacier mapping using Landsat TM. Proceedings of 20th EARSeL symposium land ice and snow. Dresden, European Association of Remote-Sensing Laboratories, 239–245. Paul F, Kääb A. 2005. Perspectives on the production of a glacier inventory from multispectral satellite data in Arctic Canada: Cumberland Peninsula, Baffin Island. Annals of Glaciology, 42(1), 59–66. doi: 10.3189/172756405781813087. Qian LX, Li SF, Cui HS, Zhang YL. 2012. Image quality evaluation of Landsat 7 ETM SLC-OFF based on a single image local regression model retrieved. Geography and Geo-Information Science, 28(5), 21–24 (in Chinese with English abstract). Schmidt S, Nüsser M. 2017. Changes of high altitude glaciers in the Trans-Himalaya of Ladakh over the past five decades (1969–2016). Geosciences, 7(2), 27. doi: 10.3390/geosciences7020027. Su R. 2019. Study on forecast method for annual runoff in the source area of Kaidu river. Shaanxi Water Resources, 227(12), 54–55. doi: 10.16747/j.cnki.cn61-1109/tv.2019.12.016. USGS, NASA, Landsat 7 Science Team. 2003. Preliminary assessment of the value of Landsat 7 ETM+ data following Scan Line Corrector malfunction. Available online at: http://Landsat.usgs.gov/data_products/slc_off_data_products/documents/SLC_off_Scientific_Usability.pdf. USGS EDC and NASA GSFC. 2004. SLC-off gap-filled products gap-fill algorithm methodology. Available online at: https://prd-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/atoms/files/L7SLCGapFilledMethod.pdf Wang GF, Zhang TB, Zhang JP, Wu H, Yang QL, Ge XY. 2010. Comparative study of glaciers information extraction method based on remote sensing image. Geospatial information, 8(3), 43–49 (in Chinese with English abstract). doi: 10.3969/j.issn.1672-4623.2010.03.015. Wang NL, Zhang XS. 1992. Mountain glacier fluctuations and climatic change during the last 100 years. Journal of Glaciology and Geocryology, 14(3), 242–250 (in Chinese with English abstract). Wang PY, Li ZQ, Li HL, Li KM, Xu CH. 2017. Analysis of the relation between glacier volume change and area change in the Tianshan Mountains. Journal of Glaciology and Geocryology, 39(1), 9–15 (in Chinese with English abstract). doi: 10.7522/j.issn.1000-0240.2017.0002. Wang R, Giese E, Gao QZ. 2003. The recent change of water level in the Bosten lake and nalysis of its causes. Journal of Glaciology and Geocryology, 25(1), 60–64 (in Chinese with English abstract). doi: 10.3969/j.issn.1000-0240.2003.01.009. Wang SJ, Zhang MJ, Li ZQ, Wang FT, Li HL, Li YJ, Huang XY. 2011. Response of glacier area variation to climate change in Chinese Tianshan Mountains in the past 50 years. Acta Geographica Sinica, 66(1), 38–46 (in Chinese with English abstract). doi: 10.11821/xb201101004. Wang X, Xie ZC, Li QY, Wang SH, Cheng L. 2008. Sensitivity analysis of glacier systems to climate warming in China. Journal of Geographical Sciences, 18, 190–200. doi: 10.1007/s11442-008-0190-6. Wang XY, Zhu LF, Dong JQ, Zhang J, Yin LH. 2019. Influence of underlying surface change on hydrogeological conditions in arid and semi-arid regions. Northwestern Geology, 52(2), 227–235 (in Chinese with English abstract). doi: 10.19751/j.cnki.61-1149/p.2019.02.024. Wang YY, Yao JM, Han HD, Liu SY. 2014. Analysis of the microclimatic characteristics in the debris-covered area of the Koxkar Glacier on the southern slope of the Tianshan Mountains. Journal of Glaciology and Geocryology, 36(3), 546–554 (in Chinese with English abstract). doi: 10.7522/j.issn.1000-0240.2014.0065. Worni R, Huggel C, Stoffel M. 2013. Glacial lakes in the Indian Himalayas—From an area-wide glacial lake inventory to on-site and modeling based risk assessment of critical glacial lakes. Science of the Total Environment, 468(Supplement), S71–S84. doi: 10.1016/j.scitotenv.2012.11.043. Wubuli WJ, Li WH, Zhu CG, Chen HY, Chen YN. 2017. Research on Ecological degradation, protection and restoration of Peacock river basin, Xinjiang. Environmental Protection of Xinjiang, 39(1), 8–12 (in Chinese with English abstract). doi: 10.3969/j.issn.1008-2301.2017.01.002. Xu CH, Wang FT, Li ZQ, Wang L, Wang PY. 2016. Glacier variation in the Manas river basin during the period from 1972 to 2013. Arid Zone Research, 33(3), 546–554 (in Chinese with English abstract). doi: 10.13866/j.azr.2016.03.24. Yan LL, Wang J. 2013. Study of extracting glacier information from remote sensing. Journal of Glaciology and Geocryology, 35(1), 110–118 (in Chinese with English abstract). doi: 10.7522/j.issn.1000-0240.2013.0013. Yang BY, Zhang LX, Gao Y, Xiang X, Mou NX, Sonam DB. 2016. An integrated method of glacier length extraction based on Gaofen satellite data. Journal of Glaciology and Geocryology, 38(6), 1615–1623 (in Chinese with English abstract). doi: 10.7522/j.issn.1000-0240.2016.0189. Zhang J, Yin LH, Gu XF, Li Y, Yang BC, Jiang J, Jia WH, Xie WB, Wang T, Tang XP, Dong JQ, Wang Q, Chang L. 2021. Study on the relationship between groundwater and surface water in Xinjiang Kongque river basin using isotopes and hydrochemistry method. Northwestern Geology, 54(1), 185–195 (in Chinese with English abstract). doi: 10.19751/j.cnki.61-1149/p.2021.01.06. Zhang JF, Meng FH, Bao AM, Li CC, Qi XD, Liu T, Zhang PF. 2018. LUCC analysis of the upstream of the Kongque river, Xinjiang, China. Journal of Desert Research, 38(3), 223–231 (in Chinese with English abstract). doi: 10.7522/j.issn.1000-694X.2016.00185. Zhang QF, Chen YN, Li Z, Li YP, Xiang YY, Bian W. 2019. Glacier changes from 1975 to 2016 in the Aksu river basin, Central Tianshan Mountains. Journal of Geographical Sciences, 29(6), 984–1000. doi: 10.1007/s11442-019-1640-z. Zhang T, Wu JF, Lin J, Wu M, Zhang HJ. 2015. Analysis of water level change of Bosten Lake based on water balance. Journal of China Hydrology, 35(3), 78–83 (in Chinese with English abstract). doi: 10.3969/j.issn.1000-0852.2015.03.015. Zhang W. 2016. Research on glacier extraction methods based on multi-source remote sensing data. Lanzhou, Lanzhou Jiaotong University, M.D. thesis, 1–55 (in Chinese with English abstract). Zhao GN. 2020. Change of glacier mass balance based on multi-source remote sensing data in Tianshan Mountains, China. Shihezi, Shihezi University, M.D. thesis, 1–54 (in Chinese with English abstract). Zhou JM, Li Z, Li XW. 2009. A comparative study of coherence patterns of C-band and L-band interferometric SAR in western glacier areas. Remote Sensing for Land and Resources, 2, 9–13, 18 (in Chinese with English abstract). doi: 10.6046/gtzyyg.2009.02.02. Zhou YS, Wang YJ, Zhou WM. 2012. Monitoring the change of Tianshan glacier area based on the remote sensing image. Mine Surveying, 6(3), 21–25 (in Chinese with English abstract). doi: 10.3969/j.issn.1001-358X.2012.03.006. Zhou ZH, Han N, Cai JY, Liu JJ. 2017. Variation characteristics of glacier and their response to climate change in the Qilian Mountains: Take the Suganhu basin as an example. Journal of Glaciology and Geocryology, 39(6), 1172–1179 (in Chinese with English abstract). doi: 10.7522/j.issn.1000-240.2017.0130. -
Access History
Figures(11)
Tables(3)
Export File
Citation
Lu-chen Wang, Kun Yu, Liang Chang, Jun Zhang, Tao Tang, Li-he Yin, Xiao-fan Gu, Jia-qiu Dong, Ying Li, Jun Jiang, Bing-chao Yang, Qian Wang, 2021. Response of glacier area variation to climate change in the Kaidu-Kongque river basin, Southern Tianshan Mountains during the last 20 years, China Geology, 4, 389-401. doi: 10.31035/cg2021055
Format
Content
DownLoad:
-
Figure 1.
Location map of Kaidu-Kongque river basin.
-
Figure 2.
Location map of meteorological station and grided data in Kaidu-Kongque river basin.
-
Figure 3.
Variation of mean annual temperature (T) and 5-year moving average temperature (5-MAT) between 1990 and 2020.
-
Figure 4.
Variation of mean annual precipitation (P) and 5-year moving average precipitation (5-MAP) between 1990 and 2020.
-
Figure 5.
Variation of mean annual temperature (T) and 5-year moving average temperature (5-MAT) in relation to glacier area changes (1995–2020).
-
Figure 6.
Variation of mean annual precipitation (P) and 5-year moving average precipitation (5-MAP) in relation to glacier area changes (1995–2020).
-
Figure 7.
Variation of mean temperature (T) and 5-year moving average temperature (5-MAT) in relation to glacier area changes in summer (1995–2020).
-
Figure 8.
Variation of mean precipitation (P) and 5-years moving average precipitation (5-MAP) in relation to glacier area changes in summer (1995–2020).
-
Figure 9.
Variation of mean temperature (T) and 5-year moving average temperature (5-MAT) in relation to glacier area changes in winter (1995–2020).
-
Figure 10.
Variation of mean precipitation (P) and 5-year moving average precipitation (5-MAP) in relation to glacier area changes in winter (1995–2020).
-
Figure 11.
Positive correlations are displayed in blue and negative correlations in red color. Color intensity and the size of the circle are proportional to the correlation coefficients. In the right side of the correlogram, the legend color shows the correlation coefficients and the corresponding colors.