Interpreting the seasonal and long-term trend of nitrate in both groundwater and spring water in a typical headwater wetland with well-defined groundwater flow pathways

2016 ◽  
Vol 16 (5) ◽  
pp. 1327-1338
Author(s):  
Yingjie Cao ◽  
Changyuan Tang ◽  
Zhiwei Han ◽  
Sako Yoko ◽  
Xing Li
Keyword(s):  
Groundwater Flow ◽  
Soil Water ◽  
Residence Time ◽  
Spring Water ◽  
Hydrological Process ◽  
Term Trend ◽  
Increasing Trend ◽  
Flow Pathways ◽  
Long Term Trend

Timescale problems of nitrate behavior (i.e. seasonal variation and long-term trend) in headwater are closely related to its hydrological process. In a typical agricultural headwater catchment in the Chiba prefecture, Japan, the groundwater nitrate concentration showed an increasing trend, while for spring water, a substantial decreasing trend was observed during our monitoring period. Two key issues, (1) identification of multiple flow pathways and (2) evaluation of the residence time for different pathways, were emphasized to reveal the factors controlling the different patterns of nitrate trend. Three major flow pathways including vertical soil water flow (VF), lateral groundwater flow (LG) and deep groundwater flow (DG) along the upland-slope-valley were differentiated. Different timescales of three flow pathways were identified. The residence time of VF was calculated as 9–10 years based on the soil water budget equation and the apparent age of LG was estimated as 41 years by chlorofluorocarbon (CFC) traces. The increasing trend of NO3− in groundwater agreed well with the historical nitrate loading, and the decreasing trend of NO3− in spring was mainly influenced by nitrate behavior of LF, which substantially decreased due to reduction of nitrogen fertilizer loadings since 2000.

scholarly journals Long-Term Trend Analysis of Precipitation and Extreme Events over Kosi River Basin in India

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1695
Author(s):  
Prashant K Srivastava ◽  
Rajani Kumar Pradhan ◽  
George P. Petropoulos ◽  
Varsha Pandey ◽  
Manika Gupta ◽  
...  
Keyword(s):  
River Basin ◽  
Extreme Precipitation ◽  
Trend Test ◽  
Hydrological Process ◽  
Clear Trend ◽  
Extreme Rainfall Events ◽  
Term Trend ◽  
Sen’S Slope ◽  
Long Term Trend

Analysis of spatial and temporal changes of long-term precipitation and extreme precipitation distribution at a local scale is very important for the prevention and mitigation of water-related disasters. In the present study, we have analyzed the long-term trend of 116 years (1901–2016) of precipitation and distribution of extreme precipitation index over the Kosi River Basin (KRB), which is one of the frequent flooding rivers of India, using the 0.25° × 0.25° resolution gridded precipitation datasets obtained from the Indian Meteorological Department (IMD), India. The non-parametric Mann–Kendall trend test together with Sen’s slope estimator was employed to determine the trend and the magnitude of the trend of the precipitation time series. The annual and monsoon seasons revealed decreasing trends with Sen’s slope values of −1.88 and −0.408, respectively. For the extreme indices viz. R10 and R20 days, a decreasing trend from the northeastern to the southwest part of the basin can be observed, whereas, in the case of highest one-day precipitation (RX1 day), no clear trend was found. The information provided through this study can be useful for policymakers and may play an important role in flood management, runoff, and understanding related to the hydrological process of the basin. This will contribute to a better understanding of the potential risk of changing rainfall patterns, especially the extreme rainfall events due to climatic variations.

scholarly journals Influence of the variation in inflow to East Asia on surface ozone over Japan during 1996–2005

2010 ◽  
Vol 10 (12) ◽  
pp. 30823-30856
Author(s):  
S. Chatani ◽  
K. Sudo
Keyword(s):  
East Asia ◽  
Interannual Variability ◽  
Northeast China ◽  
Surface Ozone ◽  
Transport Models ◽  
Term Trend ◽  
Chemical Transport Models ◽  
Increasing Trend ◽  
Long Term Trend

Abstract. Air quality simulation in which global and regional chemical transport models are coupled has been developed to investigate the influence of the variation in inflow to East Asia on the interannual variability and the long-term trend of surface ozone over Japan during 1996–2005. The simulation overestimates the concentration of surface ozone from summer to early winter. It is deduced that ozone formation around Northeast China is overestimated in the simulation. On the other hand, the simulation reproduces the interannual variability and the long-term trend of observed surface ozone over Japan well. Results of sensitivity experiments suggest that inflow to East Asia accounts for approximately 30% of the increasing trend of surface ozone, whereas it has much less influence on the interannual variability of observed surface ozone compared to meteorological processes within East Asia.

scholarly journals Recent changes observed in column ozone concentrations over India

MAUSAM ◽  
2021 ◽  
Vol 51 (1) ◽  
pp. 69-74
Author(s):  
S. K. PESHIN ◽  
J. N. DEWHARE ◽  
R. C. BHATIA ◽  
S. K. SRIVASTAV
Keyword(s):  
Trend Analysis ◽  
Tropospheric Ozone ◽  
Total Ozone ◽  
Term Trend ◽  
The Past ◽  
Increasing Trend ◽  
Column Ozone ◽  
Long Term Trend ◽  
Ozone Levels

Ozone observations taken during the past 23-39 years by Dobson Spectrophotometers at Delhi, Varanasi, Pune and Kodikanal have been analysed to examine its long-term trend over Indian stations. An increasing trend of this species over the years has been noticed at all the places, except at Varanasi, where a decreasing trend has been found. The cause of these trends could be attributed, partly, to the trends of ozone in the troposphere. The results also indicate that there are certain recent changes in ozone levels at the Indian stations. These changes are less apparent in long-term trend analysis of total ozone data as the increase in tropospheric ozone has a compensating effect to the decrease in ozone at stratospheric levels.

NAEP Trends: Main NAEP vs. Long-Term Trend

2010 ◽  
Author(s):  
Albert E. Beaton ◽  
James R. Chromy
Keyword(s):  
Term Trend ◽  
Long Term Trend

Analysis of the Long-Term Trend of Temperature, Precipitation, and Dominant Atmospheric Phenomena in Lake Urmia

2021 ◽  
Author(s):  
Parvin Ghafarian ◽  
Sahar Tajbakhsh ◽  
Amir H. Delju
Keyword(s):  
Lake Urmia ◽  
Term Trend ◽  
Atmospheric Phenomena ◽  
Long Term Trend

Environmental behavior and potential driving force of bisphenol A in the Elbe River: A long-term trend study

2020 ◽  
pp. 143251
Author(s):  
Zhenyu Huang ◽  
Pei Hua ◽  
Zhenyu Wang ◽  
Ruifei Li ◽  
Liang Dong ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Driving Force ◽  
Environmental Behavior ◽  
Elbe River ◽  
Trend Study ◽  
Term Trend ◽  
The Elbe River ◽  
Long Term Trend

Estimation and Long-term Trend Analysis of Surface Solar Radiation in Antarctica: A Case Study of Zhongshan Station

2021 ◽  
Author(s):  
Zhaoliang Zeng ◽  
Zemin Wang ◽  
Minghu Ding ◽  
Xiangdong Zheng ◽  
Xiaoyu Sun ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Trend Analysis ◽  
Surface Solar Radiation ◽  
Term Trend ◽  
Zhongshan Station ◽  
Long Term Trend

scholarly journals A Potential Risk Index Dataset for Landfalling Tropical Cyclones over the Chinese Mainland (PRITC dataset V1.0)

2021 ◽  
Vol 38 (10) ◽  
pp. 1791-1802
Author(s):  
Peiyan Chen ◽  
Hui Yu ◽  
Kevin K. W. Cheung ◽  
Jiajie Xin ◽  
Yi Lu
Keyword(s):  
Tropical Cyclones ◽  
Potential Risk ◽  
Risk Index ◽  
Chinese Mainland ◽  
Current Version ◽  
Term Trend ◽  
The Chinese Mainland ◽  
Landfalling Tropical Cyclones ◽  
Long Term Trend

AbstractA dataset entitled “A potential risk index dataset for landfalling tropical cyclones over the Chinese mainland” (PRITC dataset V1.0) is described in this paper, as are some basic statistical analyses. Estimating the severity of the impacts of tropical cyclones (TCs) that make landfall on the Chinese mainland based on observations from 1401 meteorological stations was proposed in a previous study, including an index combining TC-induced precipitation and wind (IPWT) and further information, such as the corresponding category level (CAT_IPWT), an index of TC-induced wind (IWT), and an index of TC-induced precipitation (IPT). The current version of the dataset includes TCs that made landfall from 1949–2018; the dataset will be extended each year. Long-term trend analyses demonstrate that the severity of the TC impacts on the Chinese mainland have increased, as embodied by the annual mean IPWT values, and increases in TCinduced precipitation are the main contributor to this increase. TC Winnie (1997) and TC Bilis (2006) were the two TCs with the highest IPWT and IPT values, respectively. The PRITC V1.0 dataset was developed based on the China Meteorological Administration’s tropical cyclone database and can serve as a bridge between TC hazards and their social and economic impacts.

Sign in / Sign up

Export Citation Format

Share Document