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Estimating Terrestrial Water Storage (TWS) not only helps to provide a comprehensive insight into water resource variability and the hydrological cycle but also for better water resource management. In the current research, Gravity Recovery And Climate Experiment (GRACE) data are combined with the available hydrological data to reconstruct a longer record of Terrestrial Water Storage Anomalies (TWSA) prior to 2003 of the Tarim River Basin (TRB), based on a Long Short-Term Memory (LSTM) model. We found that the TWSA generated by LSTM using soil moisture, evapotranspiration, precipitation, and temperature best matches the GRACE-derived TWSA, with a high correlation coefficient (r) of 0.922 and a Normalized Root Mean Square Error (NRMSE) of 0.107 during the period 2003–2012. These results show that the LSTM model is an available and feasible method to generate TWSA. Further, the TWSA reveals a significant fluctuating downward trend (p < 0.001), with an average decline rate of 0.03 mm/month during the period 1982–2016 in the TRB. Moreover, the TWSA amount in the north of the TRB was less than that in the south of the basin. Overall, our findings unveiled that the LSTM model and GRACE data can be combined effectively to analyze the long-term TWSA in large-scale basins with limited hydrological data.
Fei Wang; Yaning Chen; Zhi Li; Gonghuan Fang; Yupeng Li; Xuanxuan Wang; Xueqi Zhang; Patient Kayumba. Developing a Long Short-Term Memory (LSTM)-Based Model for Reconstructing Terrestrial Water Storage Variations from 1982 to 2016 in the Tarim River Basin, Northwest China. Remote Sensing 2021, 13, 889 .
AMA StyleFei Wang, Yaning Chen, Zhi Li, Gonghuan Fang, Yupeng Li, Xuanxuan Wang, Xueqi Zhang, Patient Kayumba. Developing a Long Short-Term Memory (LSTM)-Based Model for Reconstructing Terrestrial Water Storage Variations from 1982 to 2016 in the Tarim River Basin, Northwest China. Remote Sensing. 2021; 13 (5):889.
Chicago/Turabian StyleFei Wang; Yaning Chen; Zhi Li; Gonghuan Fang; Yupeng Li; Xuanxuan Wang; Xueqi Zhang; Patient Kayumba. 2021. "Developing a Long Short-Term Memory (LSTM)-Based Model for Reconstructing Terrestrial Water Storage Variations from 1982 to 2016 in the Tarim River Basin, Northwest China." Remote Sensing 13, no. 5: 889.
Global warming has generally led to changes in river runoffs fed by snow and glacier meltwater in mountain ranges. The runoff of the Aksu River, which originates in the Southern Tienshan Mountains, exhibited a positive trend during 1979–2002, but this trend reversed during 2002–2015. Through a comprehensive analysis, this study aims to estimate potential reasons for changes in the runoff of its two contrasting headwaters: the Toxkan and Kumalak Rivers, based on climatic data, the altitude of the 0 °C isotherm, glacier mass balance (GMB), snow cover area (SCA), snow depth (SD) and the sensitivity model. For the Toxkan River, the decrease in spring runoff mainly resulted from reductions in precipitation, whereas the decrease in summer runoff was mainly caused by early snowmelt in spring and a much-reduced snow meltwater supply in summer. In addition, the obvious glacier area reduction in the catchment (decreased to less than 4%) also contributed to the reduced summer runoff. For the Kumalak River, a sharp decrease rate of 10.21 × 108 m3/decade in runoff was detected due to summertime cooling of both surface and upper air temperatures. Reduced summer temperatures with a positive trend in precipitation not only inhibited glacier melting but also dropped the 0 °C layer altitude, resulting in a significant increase in summertime SCA and SD, a slowing of the glacier negative mass balance, and a lowering of the snow-line altitude.
Qifei Zhang; Yaning Chen; Zhi Li; Gonghuan Fang; Yanyun Xiang; Yupeng Li; Huiping Ji. Recent Changes in Water Discharge in Snow and Glacier Melt-Dominated Rivers in the Tienshan Mountains, Central Asia. Remote Sensing 2020, 12, 2704 .
AMA StyleQifei Zhang, Yaning Chen, Zhi Li, Gonghuan Fang, Yanyun Xiang, Yupeng Li, Huiping Ji. Recent Changes in Water Discharge in Snow and Glacier Melt-Dominated Rivers in the Tienshan Mountains, Central Asia. Remote Sensing. 2020; 12 (17):2704.
Chicago/Turabian StyleQifei Zhang; Yaning Chen; Zhi Li; Gonghuan Fang; Yanyun Xiang; Yupeng Li; Huiping Ji. 2020. "Recent Changes in Water Discharge in Snow and Glacier Melt-Dominated Rivers in the Tienshan Mountains, Central Asia." Remote Sensing 12, no. 17: 2704.
A slowdown in the warming rate of the global mean surface temperature has been observed since late 1990s. However, it is still controversial whether the spatiotemporal variability of extreme temperature events will increase after global warming slowdown, and whether the regional diversity of change trends will increase. Here, we investigated the variations in extreme temperature indices over the Loess Plateau in China since 1961 and focused on the recent global warming slowdown (1998‐2018). We found that, during 1961‐2018, all the extreme temperature indices showed a significant warming trend and its intensity varied according to extreme temperature indices over different regions. A warming slowdown of annual mean temperature during 1998‐2018 was primarily due to the slight increases of annual mean maximum temperatures (TXm) while the annual mean minimum temperature (TNm) still indicated prominently warming trends. During the recent warming slowdown period, the warm indices showed continued intensification of the warming trends, while the cold indices showed a slight cooling trend. Moreover, all extreme temperature indices showed the largest warming trend in summer and a slight cooling trend in winter. Overall, the extreme temperature events have become more diverse in spatial and temporal, indicating that regional climate are more unstable than previously reported for this region. Further analyses revealed that the extreme temperature events during the recent warming slowdown were primarily the result of the natural variability of the climate system, especially the large‐scale ocean‐atmosphere interactions of the Pacific and Atlantic oceans.
Zhiyong Ding; Jia Pu; Lihong Meng; Ruijie Lu; Yuyang Wang; Yupeng Li; Yiyang Dong; Shuzhi Wang. Asymmetric trends of extreme temperature over the Loess Plateau during 1998–2018. International Journal of Climatology 2020, 41, 1 .
AMA StyleZhiyong Ding, Jia Pu, Lihong Meng, Ruijie Lu, Yuyang Wang, Yupeng Li, Yiyang Dong, Shuzhi Wang. Asymmetric trends of extreme temperature over the Loess Plateau during 1998–2018. International Journal of Climatology. 2020; 41 (S1):1.
Chicago/Turabian StyleZhiyong Ding; Jia Pu; Lihong Meng; Ruijie Lu; Yuyang Wang; Yupeng Li; Yiyang Dong; Shuzhi Wang. 2020. "Asymmetric trends of extreme temperature over the Loess Plateau during 1998–2018." International Journal of Climatology 41, no. S1: 1.
High Mountain Asia (HMA), which includes the Tibetan Plateau, Tienshan Mountains and surrounding region, has abundant snowfall and a long period of snow cover annually. The headwaters of many prominent Asian rivers depend in part on HMA meltwater. In this study, we evaluate projected changes in mean snowfall (Smean), snowfall days (Sd), and snowfall fraction (Sf) for the years 2070-2099 relative to 1976-2005, under the Representative Concentration Pathway 4.5 (RCP4.5) and 8.5 (RCP8.5) emission scenarios. An evaluation of the results shows that while NASA's NEX-GDDP (National Aeronautics and Space Administration Earth Exchange Global Daily Downscaled Projections) high-resolution daily downscaled dataset can successfully capture the distribution of mean snowfall climatology, it has a strong bias for extreme snowfall indices. In general, the projected increase of temperature under RCP4.5 and RCP8.5—especially in winter—will result in a decrease in snowfall amount (-18.9%, -32.8%), fewer snowfall days (-29.6%, -47.3%), and less precipitation falling as snow (-26.7%, -42.3%). Furthermore, under high emission scenarios, rain-dominated regions are projected to expand 53.9%, while snow-dominated areas will only account for 17.9% of the entire HMA. Spatially, snowfall shows a more robust decline in eastern HMA (e.g., East Tienshan, East Kun Lun, Qilian, South and Eastern Tibet, and Hengduan) than in western HMA (e.g., Hissar Alay, Pamir, and Karakoram). This difference can be attributed to various environmental factors, such as climatology, elevation influences, and the unique seasonal recycle between the two regions.
Yupeng Li; Yaning Chen; Fei Wang; Yaqian He; Zhi Li. Evaluation and projection of snowfall changes in High Mountain Asia based on NASA’s NEX-GDDP high-resolution daily downscaled dataset. Environmental Research Letters 2020, 15, 104040 .
AMA StyleYupeng Li, Yaning Chen, Fei Wang, Yaqian He, Zhi Li. Evaluation and projection of snowfall changes in High Mountain Asia based on NASA’s NEX-GDDP high-resolution daily downscaled dataset. Environmental Research Letters. 2020; 15 (10):104040.
Chicago/Turabian StyleYupeng Li; Yaning Chen; Fei Wang; Yaqian He; Zhi Li. 2020. "Evaluation and projection of snowfall changes in High Mountain Asia based on NASA’s NEX-GDDP high-resolution daily downscaled dataset." Environmental Research Letters 15, no. 10: 104040.
Although previous studies have characterized changes in seasonal snow cover or made predictions about snow cover in a changing climate, no comprehensive spatiotemporal analysis of snow phenology has been presented for the Tienshan Mountains, Central Asia. Relying on daily cloud-free snow cover fraction products originating from Moderate Resolution Imaging Spectroradiometer (MODIS) for 2002/03–2017/18, the snow phenology parameters (i.e., snow cover duration [SCD], snow onset date [SOD] and snow end date [SED]) are derived for each hydrological year within the study period and the characteristics analyzed for the Tienshan Mountains. The spatiotemporal changes of snow phenology have strong altitude dependence. The mean gradients of SCD, SOD, and SED with elevation are 6.0, −2.55, and 3.44 d/100 m, respectively. Because of differences in solar radiation and water vapor sources, the north-facing areas generally have a higher SCD, earlier SOD, and later SED than south-facing areas. Also, the trends of the snow phenology parameters at high and low altitudes show opposite changes. Consistent with the increase in snow cover area in recent years, SCD for the entire Tienshan region showed a clear uptick, especially in Northern Tienshan. This prolonged SCD was more related to advanced SOD than to SED, as decreased temperature and increased precipitation in autumn are conducive to snow accumulation.
Yupeng Li; Yaning Chen; Zhi Li. Climate and topographic controls on snow phenology dynamics in the Tienshan Mountains, Central Asia. Atmospheric Research 2019, 236, 104813 .
AMA StyleYupeng Li, Yaning Chen, Zhi Li. Climate and topographic controls on snow phenology dynamics in the Tienshan Mountains, Central Asia. Atmospheric Research. 2019; 236 ():104813.
Chicago/Turabian StyleYupeng Li; Yaning Chen; Zhi Li. 2019. "Climate and topographic controls on snow phenology dynamics in the Tienshan Mountains, Central Asia." Atmospheric Research 236, no. : 104813.
Using Moderate Resolution Imaging Spectroradiometer (MODIS) 500 m spatial resolution global water product data, Least Squares Method (LSM) was applied to analyze changes in the area of 14 lakes in Central Asia from 2001 to 2016. Interannual changes in lake area, along with seasonal change trends and influencing factors, were studied for the months of April, July and September. The results showed that the total lakes area differed according to interannual variations and was largest in April and smallest in September, measuring −684.9 km2/a, −870.6 km2/a and −827.5 km2/a for April, July and September, respectively. The change rates for the total area of alpine lakes during the same three months were 31.1 km2/a, 29.8 km2/a and 30.6 km2/a, respectively, while for lakes situated on plains, the change rates were −716.1 km2/a, −900.5 km2/a, and −858 km2/a, respectively. Overall, plains lakes showed a declining trend and alpine lakes showed an expanding trend, the latter likely due to the warmer and wetter climate. Furthermore, there was a high correlation (r = 0.92) between area changes rate of all alpine lakes and the lakes basin supply coefficient, although there was low correlation (r = 0.43) between area changes rate of all alpine lakes area and glacier area/lake area. This indicates that lakes recharge via precipitation may be greater than lakes recharge via glacier meltwater. The shrinking of area changes for all plains lakes in the study region was attributable to climate change and human activities.
Haijun Liu; Yaning Chen; Zhaoxia Ye; Yupeng Li; Qifei Zhang. Recent Lake Area Changes in Central Asia. Scientific Reports 2019, 9, 1 -11.
AMA StyleHaijun Liu, Yaning Chen, Zhaoxia Ye, Yupeng Li, Qifei Zhang. Recent Lake Area Changes in Central Asia. Scientific Reports. 2019; 9 (1):1-11.
Chicago/Turabian StyleHaijun Liu; Yaning Chen; Zhaoxia Ye; Yupeng Li; Qifei Zhang. 2019. "Recent Lake Area Changes in Central Asia." Scientific Reports 9, no. 1: 1-11.
Studying the relationship between agricultural irrigation water requirements (IWR) and water supply is significant for optimizing the sustainable management of water resources in Tarim River Basin (TRB). However, the related studies have not quantified the total IWR and the imbalance of irrigation water supply and requirements in the TRB. The study analyzed the spatial-temporal variations of IWR by a modified Penman–Monteith (PM) method during 1990–2015. Five major crops—rice, wheat, maize, cotton, and fruit trees—are chosen for calculating the IWR. It was found that the IWR increased significantly, from 193.14 × 108 m3 in 1990 to 471.89 × 108 m3 in 2015, for a total increase of 278.74 × 108 m3. For the first period (1990–2002), the total IWR remained stable at 200 × 108 m3 but started to increase from 2003 onwards. Significantly more irrigation water was consumed in the oasis regions of the Tienshan Mountains (southern slope) and the Yarkand River (plains). Furthermore, there was an intensified conflict between IWR and water supply in the major sub-basins. The ratios of IWR to river discharge (IWR/Q) for the Weigan-Kuqa River Basin (WKRB), Aksu River Basin (ARB), Kaxgar River Basin (KGRB), and Yarkand River Basin (YRB) were 0.93, 0.68, 1.05, and 0.79, respectively. The IWR/Q experienced serious annual imbalances, as high flows occurred in July and August, whereas critical high IWR occurred in May and June. Seasonal water shortages further aggravate the water stress in the arid region.
Fei Wang; Yaning Chen; Zhi Li; Gonghuan Fang; Yupeng Li; Zhenhua Xia. Assessment of the Irrigation Water Requirement and Water Supply Risk in the Tarim River Basin, Northwest China. Sustainability 2019, 11, 4941 .
AMA StyleFei Wang, Yaning Chen, Zhi Li, Gonghuan Fang, Yupeng Li, Zhenhua Xia. Assessment of the Irrigation Water Requirement and Water Supply Risk in the Tarim River Basin, Northwest China. Sustainability. 2019; 11 (18):4941.
Chicago/Turabian StyleFei Wang; Yaning Chen; Zhi Li; Gonghuan Fang; Yupeng Li; Zhenhua Xia. 2019. "Assessment of the Irrigation Water Requirement and Water Supply Risk in the Tarim River Basin, Northwest China." Sustainability 11, no. 18: 4941.
Soil moisture plays a critical role in land-atmosphere interactions. Quantifying the controls on soil moisture is highly valuable for effective management of water resources and climatic adaptation. In this study, we quantified the effects of precipitation, temperature, and vegetation on monthly soil moisture variability in an arid area, China. A non-linear Granger causality framework was applied to examine the causal effects based on multi-decadal reanalysis data records. Results indicate that precipitation had effects on soil moisture in about 91% of the study area and explained up to 40% of soil moisture variability during 1982–2015. Temperature and vegetation explained up to 8.2% and 3.3% of soil moisture variability, respectively. Climatic extremes were responsible for up to 10% of soil moisture variability, and the importance of climatic extremes was low compared to that of the general climate dynamics. The time-lagged analysis shows that the effects of precipitation and temperature on soil moisture were immediate and dissipated shortly. In addition, the effects of precipitation on soil moisture decreased with the increase of precipitation, soil moisture, and elevation. This study provides deep insight for uncovering the drivers of soil moisture variability in arid regions.
Yunqian Wang; Jing Yang; Yaning Chen; Gonghuan Fang; Weili Duan; Yupeng Li; Philippe De Maeyer. Quantifying the Effects of Climate and Vegetation on Soil Moisture in an Arid Area, China. Water 2019, 11, 767 .
AMA StyleYunqian Wang, Jing Yang, Yaning Chen, Gonghuan Fang, Weili Duan, Yupeng Li, Philippe De Maeyer. Quantifying the Effects of Climate and Vegetation on Soil Moisture in an Arid Area, China. Water. 2019; 11 (4):767.
Chicago/Turabian StyleYunqian Wang; Jing Yang; Yaning Chen; Gonghuan Fang; Weili Duan; Yupeng Li; Philippe De Maeyer. 2019. "Quantifying the Effects of Climate and Vegetation on Soil Moisture in an Arid Area, China." Water 11, no. 4: 767.
Daily cloud‐free snow cover products are important premise and foundation for hydrological simulation, climate system research and snow disaster monitoring in the Tienshan Mountains, Central Asia. In this study, partial clouds appearing in the Moderate Resolution Imaging Spectroradiometer (MODIS) were removed by temporal and spatial filtering, and the remaining cloud pixels were replaced by Interactive Multisensor Snow and Ice Mapping System (IMS). The results show that the retrieved annual mean snow cover obtained from the improved MODIS product data is 31.5% higher than the original MODIS product. Through validation performed via in‐situ observations, the overall accuracy, land accuracy and snow accuracy also increased to 88.2%, 91.9%, 81.9%, respectively. However, the overall accuracy shows a lower accuracy in transitional months compare to other months, which derives mainly from the difference in spatial scales between IMS and in‐situ observations.
Y. Li; Y. Chen; Z. Li. Developing Daily Cloud-Free Snow Composite Products From MODIS and IMS for the Tienshan Mountains. Earth and Space Science 2019, 6, 266 -275.
AMA StyleY. Li, Y. Chen, Z. Li. Developing Daily Cloud-Free Snow Composite Products From MODIS and IMS for the Tienshan Mountains. Earth and Space Science. 2019; 6 (2):266-275.
Chicago/Turabian StyleY. Li; Y. Chen; Z. Li. 2019. "Developing Daily Cloud-Free Snow Composite Products From MODIS and IMS for the Tienshan Mountains." Earth and Space Science 6, no. 2: 266-275.
Previous studies have reported that much of the surface wind speed (SWS) over the mid‐latitudes of the northern hemisphere has declined. However, very few studies have investigated the relatively recent phenomenon of wind recovery. Based on 68 wind data series, this paper examines changes in wind speed in northwest China between 1969 and 2015. In 1992, following a decade of sharply decreasing at a rate of 0.036 m s−1 a−1 (p < .05), the SWS began to significant increase at a rate of 0.004 m s−1 a−1. The specific reasons for this increase are as follows: (a) The decrease in SWS during the pre‐1992 slowdown period is the result of declining wind speeds in spring and summer, whereas increases in wind speed during the post‐1992 recovery period are caused by increased wind in winter. (b) The number of days featuring strongly varying wind speeds has changed. Specifically, the number of days above 2 m s−1 all show a significant decreasing trend from 1969 to 1992, whereas the number of days of 1–3 m s−1 shows a significant upward trend from 1993 to 2015. (c) Stations located between 1,000 and 1,500 m.a.s.l. (meter above sea level) are more sensitive to climate change than those at other altitudes, which shows the biggest decline (increase) trend during wind speed slowdown (recovery) period. These stations could potentially act as climatic indicators to predict future wind speed changes. SWS in northwest China have been affected by changes both in large‐scale atmospheric circulation and in regional warming. Surface pressure gradient variations between high‐ and low‐latitude regions may be important contributors to wind speed changes under asymmetric warming. However, urbanization is only moderately responsible for trend changes in SWS.
Yupeng Li; Yaning Chen; Zhi Li; Gonghuan Fang. Recent recovery of surface wind speed in northwest China. International Journal of Climatology 2018, 38, 4445 -4458.
AMA StyleYupeng Li, Yaning Chen, Zhi Li, Gonghuan Fang. Recent recovery of surface wind speed in northwest China. International Journal of Climatology. 2018; 38 (12):4445-4458.
Chicago/Turabian StyleYupeng Li; Yaning Chen; Zhi Li; Gonghuan Fang. 2018. "Recent recovery of surface wind speed in northwest China." International Journal of Climatology 38, no. 12: 4445-4458.