EFFECT OF EXTREME PRECIPITATION ON STABLE ISOTOPE COMPOSITIONS OF DRIP WATER AND SEDIMENT DURING AUTUMN AND WINTER IN LIANGFENG CAVE AT GUILIN, SOUTHWEST CHINA

2018 ◽  
Author(s):  
Wu Xia ◽  
◽  
Jianhua Cao
Keyword(s):  
Stable Isotope ◽  
Extreme Precipitation ◽  
Southwest China ◽  
Drip Water ◽  
Water And Sediment ◽  
Autumn And Winter ◽  
Liangfeng Cave

scholarly journals Hydrogeochemical Responses of Cave Drip Water to the Local Climate in Liangfeng Cave, Southwest China

2021 ◽  
Author(s):  
Xia Wu ◽  
Moucheng Pan ◽  
Meiliang Zhang ◽  
Jianhua Cao
Keyword(s):  
Southwest China ◽  
Regional Climate ◽  
Climate Data ◽  
Environmental Index ◽  
Local Climate ◽  
Drip Water ◽  
Cave Drip Water ◽  
The Difference ◽  
High Precipitation ◽  
Liangfeng Cave

Abstract The hydrogeochemistry of cave drip water is an important environmental index in cave systems, and drip water monitoring may be an essential solution for paleoclimate reconstructions. We measured the hydrogeochemical properties of the seasonal and perennial drip water and CO2 concentrations from 2015 to 2019 in Liangfeng Cave, Guilin, Southwest China. This study identified the difference in the regional environmental records in perennial and seasonal drip water. By comparing the regional climate data recorded by the drip water, the results showed the perennial drip water recorded regional climate information throughout the year, while the seasonal drip water only recorded the high precipitation periods. The precipitation during the 2015 dry season was abnormally high, which not sure what index is higher than the values in other rainy seasons. This indicates that hydrogeochemistry only represents changes in precipitation and not the alternation of dry and rainy seasons during this period.

Comparative Analysis or Precipitation Variation Characteristics between Subtropical Monsoon Climate and Temperate Monsoon Climate-Take Changsha and Chengde for Example

2021 ◽  
Vol 7 (5) ◽  
pp. 1113-1122
Author(s):  
Bo Chen ◽  
Shi-jun Xu ◽  
Xin-ping Zhang ◽  
Yi Xie
Keyword(s):  
Climate Change ◽  
Extreme Precipitation ◽  
Precipitation Intensity ◽  
Annual Precipitation ◽  
Wet Season ◽  
Precipitation Frequency ◽  
Extreme Precipitation Events ◽  
Average Precipitation ◽  
Autumn And Winter ◽  
Average Annual Precipitation

Using the methods of literature review, regression analysis and moving average, this paper selects the daily precipitation of Changsha and Chengde from 1951 to 1986 as samples, and analyzes the average precipitation, precipitation frequency, precipitation intensity, extreme precipitation time and other indicators of Changsha and Chengde from the perspective of interannual and seasonal changes Trends. The researches show that: the average precipitation of Changsha in the 36 years is 1151.2mm, spring is the wet season, autumn and winter are the dry seasons, and the maximum average precipitation is in spring; the average annual precipitation, precipitation frequency in spring, summer and winter, annual precipitation frequency, annual precipitation intensity and extreme precipitation events show a decreasing trend. The average annual precipitation of Chengde city is 454.1 mm, wet season in summer and dry season in spring, autumn and winter; the average annual precipitation, precipitation in four seasons, annual precipitation frequency, precipitation frequency in spring, autumn and winter, annual precipitation intensity and extreme precipitation events show a decreasing trend, while the precipitation frequency in summer shows an increasing trend. The study of regional climate change based on the time series data of this stage is of great significance to comprehensively understand the law of regional climate change and predict the future trend of climate change.

Impact of intensive mining on the distribution of heavy metals in water and sediment of Anning River, southwest China

2018 ◽  
Vol 19 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Zeming Shi ◽  
Xinyu Wang ◽  
Yue Shi ◽  
Shijun Ni ◽  
Yunzhen Li ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Southwest China ◽  
Water And Sediment

Evaluation of High-Resolution Precipitation Products over Southwest China

2020 ◽  
Vol 21 (11) ◽  
pp. 2691-2712
Author(s):  
Yanbo Nie ◽  
Jianqi Sun
Keyword(s):  
High Resolution ◽  
Root Mean Square ◽  
Extreme Precipitation ◽  
Southwest China ◽  
Daily Precipitation ◽  
The Other ◽  
Future Research ◽  
Monthly Precipitation ◽  
Mean Square ◽  
Mean Square Errors

AbstractThe evaluation of gridded high-resolution precipitation products (HRPPs) is important in areas with complex topography, because rain gauges that are unevenly and sparsely distributed over an area cannot effectively reflect the spatial variabilities of the precipitation and related extremes in detail. In this study, the applicability of six satellite-based precipitation products (TMPA 3B42V7, IMERG, GSMaP-Gauge, CMORPH-CRT, PERSIANN-CDR, and GPCP) and five gauge-based precipitation products (APHRODITE, CN05.1, GPCC-D, GPCC-M, and CRU) over southwest China from 1998 to 2016 is evaluated by performing a comparison with meteorological station observations. The results show that GPCC-M exhibits the best performances for annual, seasonal, and monthly precipitation, which is supported by the lowest root-mean-square errors (RMSEs) for annual and seasonal precipitation and the lowest normalized root-mean-square error (NRMSE) for monthly precipitation. According to the NRMSE and critical success index (CSI), CN05.1 outperforms the other HRPPs at detecting daily precipitation; however, CN05.1 tends to overestimate the frequencies of light precipitation and underestimate the frequencies of heavy precipitation, which is reflected by the probability density function (PDF) for daily precipitation. The bias ratio (BIAS) and extreme precipitation indices show that IMERG shows numerous advantages over the other HRPPs in detecting extreme precipitation and estimating the precipitation intensity. Such results are helpful for future research on precipitation/extremes and related hydrometeorological disasters that occur throughout southwest China.

scholarly journals Trends in Arctic seasonal and extreme precipitation in recent decades

2021 ◽  
Author(s):  
Lejiang Yu ◽  
Shiyuan Zhong
Keyword(s):  
Extreme Precipitation ◽  
The Arctic ◽  
Positive Trend ◽  
Weather Forecasts ◽  
Ice Melt ◽  
Circulation Patterns ◽  
Water Vapor Feedback ◽  
Daily Precipitation Data ◽  
Autumn And Winter ◽  
Thermodynamic Processes

Abstract Daily precipitation data from the European Centre for Medium-Range Weather Forecasts (ERA-Interim) from 1979 to 2016 are analyzed to determine the trends in seasonal and extreme precipitation across the pan-Arctic and estimate the contributions to the trends from the dynamic (e.g. changes in circulation patterns) and thermodynamic processes (e.g., sea ice melt – water vapor feedback) and their interactions. The trends in the seasonal total precipitation are generally consistent with the trends in the occurrence of seasonal extreme precipitation. Although the trends vary considerably in direction and magnitude across the pan-Arctic and the seasons, more regions experience a statistically significant positive trend than negative trend, particularly in autumn and winter seasons and over areas of the Arctic Ocean and the northern North Atlantic. Statistically significant negative trends are mostly found in areas of northern Eurasian and North America. The thermodynamic processes account for more than 85% of the total trends, with the rest of the trends explained by the dynamic processes (e.g., changes in circulation patterns) and the interaction between dynamic and thermodynamic processes.

scholarly journals Effects of Farming Activities on the Temporal and Spatial Changes of Hydrogen and Oxygen Isotopes Present in Groundwater in the Hani Rice Terraces, Southwest China

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 265
Author(s):  
Chengjing Liu ◽  
Yuanmei Jiao ◽  
Dongmei Zhao ◽  
Yinping Ding ◽  
Zhilin Liu ◽  
...  
Keyword(s):  
Stable Isotope ◽  
High Intensity ◽  
Southwest China ◽  
Isotope Composition ◽  
Agricultural Watershed ◽  
Spatial Effects ◽  
Elevation Gradients ◽  
Groundwater Circulation ◽  
Spatial Changes ◽  
Temporal And Spatial

Landform changes caused by human activities can directly affect the recharge of groundwater, and are reflected in the temporal and spatial changes in groundwater stable isotope composition. These changes are particularly evident in high-intensity farming areas. In this study, we tested and analyzed groundwater stable isotope samples at different elevations of rice terraces in a typical agricultural watershed of the Hani Terraces, a World Heritage Cultural Landscape in southwest China. Thus, we determined the characteristic variations and factors that influence the temporal and spatial effects on groundwater stable isotopes in the Hani Terraces, which are under the influence of high-intensity farming activities. The elevation gradients of δ18O and δ2H in groundwater are significantly increased due to farming activities. The values were 0.88‰ (100 m)−1 and −4.5‰ (100 m)−1, respectively, and they changed with time. The groundwater circulation cycle is approximately three months. We also used the special temporal and spatial variation characteristics of the groundwater isotopes as a way to evaluate the source and periodic changes of groundwater recharge. In addition, high-intensity rice farming activities, such as ploughing every year from October to January can increase the supply of terraced water to groundwater, thus ensuring the sustainability of rice cultivation in the terraces during the dry season. This demonstrates the role of human wisdom in the sustainable and benign transformation of surface cover and the regulation of groundwater circulation.

Monitoring activities in several caves along a transect stretching from the Adriatic Sea to the Aggtelek Karst (NE-Hungary): trace element and stable isotopic compositions of drip waters and cave carbonates

2020 ◽  
Author(s):  
György Czuppon ◽  
Attila Demény ◽  
Neven Bocic ◽  
Nenad Buzjak ◽  
Krisztina Kármán ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Trace Element ◽  
Adriatic Sea ◽  
Isotope Composition ◽  
Winter Precipitation ◽  
Trace Element Composition ◽  
Drip Water ◽  
Cave System ◽  
The Mediterranean ◽  
Monitoring Activities

<p>Several caves have been monitored along a transect stretching from the Adriatic Sea to the Aggtelek Karst (NE-Hungary) including two caves in Croatia and three caves in Hungary:  1) Cerovacke cave (~25 km far from the sea, Velebit Mt.), 2) Baraceve cave (~70 km far from the sea), 3) Csodabogyós Cave (~320 km far from the sea, Keszthely Mt.), 4) Béke and Baradla Caves (~700 km far from the sea, Aggtelek Karst). The monitoring activities in each caves included microclimate measurements, analyses of the elemental and stable isotope compositions of drip water and precipitation, as well as stable isotope measurements of modern calcite precipitates formed on light bulbs or glass plates.</p><p>The stable isotope compositions of the drip waters in all cases (except one) show systematically lower values than those found in amount-weighted annual precipitation suggesting that the source of the infiltrating water dominantly derives from winter precipitation. Moreover, the relative contribution of winter precipitation can vary even within same cave system reflecting also the local morphology of the karst above the cave. The d-excess values of the drip waters show an increasing trend from the Aggtelek Karst towards to Adriatic Sea, showing higher values than 10‰ (Béke-C.: 10.3‰; Csodabogyós-C.: 11‰, Baraceve-C.: 12‰, Cerovacke: 15‰). These observations indicate significant contribution from moisture originated from the Mediterranean Basin to the infiltrating water. The monitoring of the precipitation support these findings as among the marine moisture source the Mediterranean is the most dominant even relative far from the sea.</p><p>The trace element systematics in drip waters indicate that PCP likely took place during relatively dry periods. In some caves the change of the hydrological condition affected both the trace element composition of the drip water and the stable isotope composition of the modern calcite precipitates. Although the calcite-water isotope fractionations show significant scatter even within individual caves, the majority of the data fall close to the Coplen (2007) and the Tremaine et al. (2011) fractionation values in both Croatian and Hungarian caves.</p><p>The research was supported by the Ministry for Innovation and Technology, the National Research, Development and Innovation Office (project No. PD 121387).</p>

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