Influence of a dual monsoon system and two sources of groundwater recharge on Kofu basin alluvial fans, Japan

2016 ◽  
Vol 48 (4) ◽  
pp. 1071-1087 ◽  
Author(s):  
Takashi Nakamura ◽  
Kei Nishida ◽  
Futaba Kazama
Keyword(s):  
Mass Balance ◽  
Groundwater Recharge ◽  
River Water ◽  
Isotopic Analysis ◽  
Alluvial Fan ◽  
Alluvial Fans ◽  
Recharge Sources ◽  
Balance Analysis ◽  
Monsoon System ◽  
Mass Balance Analysis

This study investigates the contribution ratios of different groundwater recharge sources and influence of a dual monsoon system in Kofu basin, central Japan, through the hydrogen and oxygen isotopic analysis of precipitation, river water, and groundwater. The study is focused on the area of the Kamanashigawa and Midaigawa alluvial fans, which are formed by two main rivers. Precipitation isotopic content exhibits significant seasonal variability. Also, river water presents d-excess values higher than annual precipitation at plain areas (9 and 10‰), suggesting that two different air-masses contribute to precipitation, corresponding to the monsoon and pre-monsoon periods. The results of this study allow estimation of relative contributions of different sources to groundwater and influence of a dual monsoon system. The mass-balance analysis of the δ18O to identify the groundwater source indicates the river water contributes 38–100% of the recharge, while precipitation contributes 29–62% in Kamanashigawa alluvial fan. In the case of Midaigawa alluvial fan, river water contributes 77–99% in the northern part; in the southern side, 30–93% of contribution comes from precipitation. The mass-balance analysis of the d-excess indicates pre-monsoon precipitation contributes 46–68% and 39–65% to groundwater of the Kamanashigawa and Midaigawa alluvial fans, respectively.

Multiple‐indicator study of the response of groundwater recharge sources to highly turbid river water after a landslide in the Tedori River alluvial fan, Japan

2020 ◽  
Vol 34 (16) ◽  
pp. 3539-3554
Author(s):  
Yumi Yoshioka ◽  
Kimihito Nakamura ◽  
Hiroshi Takimoto ◽  
Shinji Sakurai ◽  
Takao Nakagiri ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
River Water ◽  
Alluvial Fan ◽  
Recharge Sources ◽  
Multiple Indicator

scholarly journals Novel Lime Calcination System for CO2 Capture and Its Thermal–Mass Balance Analysis

ACS Omega ◽  
2020 ◽  
Vol 5 (42) ◽  
pp. 27413-27424
Author(s):  
Yuehan Yang ◽  
Li Wang ◽  
Dehong Xia ◽  
Zeyi Jiang ◽  
Binfan Jiang ◽  
...  
Keyword(s):  
Mass Balance ◽  
Co2 Capture ◽  
Thermal Mass ◽  
Balance Analysis ◽  
Mass Balance Analysis

scholarly journals Application of a Self-Organizing Map of Isotopic and Chemical Data for the Identification of Groundwater Recharge Sources in Nasunogahara Alluvial Fan, Japan

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 278 ◽  
Author(s):  
Takeo Tsuchihara ◽  
Katsushi Shirahata ◽  
Satoshi Ishida ◽  
Shuhei Yoshimoto
Keyword(s):  
Groundwater Recharge ◽  
Groundwater Resources ◽  
Paddy Rice ◽  
Alluvial Fan ◽  
Rice Fields ◽  
Isotopic Ratios ◽  
Self Organizing Map ◽  
Recharge Sources ◽  
Different Origins ◽  
Self Organizing

Paddy rice fields on an alluvial fan not only use groundwater for irrigation but also play an important role as groundwater recharge sources. In this study, we investigated the spatial distribution of isotopic and hydrochemical compositions of groundwater in the Nasunogahara alluvial fan in Japan and applied a self-organizing map (SOM) to characterize the groundwater. The SOM assisted with the hydrochemical and isotopic interpretation of the groundwater in the fan, and clearly classified the groundwater into four groups reflecting the different origins. Two groundwater groups with lower isotopic ratios of water than the mean precipitation values in the fan were influenced by the infiltration of river water flowing from higher areas in the catchments and were differentiated from each other by their Na+ and Cl− concentrations. A groundwater group with higher isotopic ratios was influenced by the infiltration of paddy irrigation water that had experienced evaporative isotopic enrichment. Groundwater in the fourth group, which was distributed in the upstream area of the fan where dairy farms dominated, showed little influence of recharge waters from paddy rice fields. The findings of this study will contribute to proper management of the groundwater resources in the fan.

Leaf-litter accretion and decomposition in interior and coastal old-growth redwood stands

1993 ◽  
Vol 23 (3) ◽  
pp. 552-557 ◽  
Author(s):  
Michael D. Pillers ◽  
John D. Stuart
Keyword(s):  
Mass Balance ◽  
Litter Decomposition ◽  
Balance Method ◽  
Litter Fall ◽  
Old Growth ◽  
Litter Bag ◽  
Mass Balance Method ◽  
Balance Analysis ◽  
Average Relative Humidity ◽  
Mass Balance Analysis

Litter fall and litter decomposition were measured in old-growth coastal redwood (Sequoiasempervirens (D. Don) Endl.) forests. Hillside and bottomland areas at inland and coastal locations were selected as representative sites. Both litter-bag and insitu mass-balance analyses were used to determine decomposition rates. Average annual litter fall at the four sites ranged from 3120 to 4690 kg•ha−1•year−1. Decomposition rate constants (k) calculated from the mass-balance analysis ranged from 0.117 to 0.238 year−1. Values of k estimated from the litter-bag analysis ranged from 0.273 to 0.405 year−1. Equilibrium litter loads from mass-balance analysis ranged from 15 700 to 30 000 kg•ha−1. Equilibrium litter loads estimated from litter-bag analysis ranged from 7760 to 14 500 kg•ha−1. Litter-layer equilibrium was between 12 and 26 years using the mass-balance analysis and between 7 and 11 years with the litter-bag study. The mass-balance method for calculating decomposition constants showed that litter at coastal sites decomposed faster than at inland sites. There were no differences between upland and bottomland sites. The litter-bag method, in contrast, indicated that litter at inland sites decomposed faster than at coastal sites. Significant regressions of litter decomposition constants as functions of summer average relative humidity, temperature, vapor-pressure deficit, and litter moisture were found with the mass-balance method. There were no significant regressions of temperature and moisture variables with litter decomposition constants calculated with the litter-bag analysis.

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