Study on Ecological Water Table in a Reclaimed Water Irrigation Area in the North China Plain

2012 ◽  
Vol 518-523 ◽  
pp. 4088-4092
Author(s):  
Chang Shui Yu ◽  
Ji Lai Liu ◽  
Yu Long Liu ◽  
Su Fen Wang
Keyword(s):  
Water Quality ◽  
Water Table ◽  
Unsaturated Zone ◽  
Time Lag ◽  
Water Quality Management ◽  
Reclaimed Water ◽  
Groundwater Depth ◽  
Irrigation Area ◽  
Groundwater Environment ◽  
Reclaimed Water Irrigation

The paper sets the definition of ecological water table in reclaimed water irrigation area, on which reclaimed water would not make the pollutants infiltrate into groundwater and not deteriorate groundwater environment. Case study from a soil profile in Daxing, Beijing shows that the ecological water table is changing due to the pollutants down movement in the unsaturated zone. Results show that the critical ecological groundwater depth is about 19.45 m in 2050 while the current is 8.25 m. The current water table depth of 18 m is within the ecological groundwater depth. The time lag between the human activities and water quality due to the relatively thick unsaturated zone should be paid attention to for sustainable water quality management.

scholarly journals Understanding nitrogen transport in the unsaturated zone with fluctuations in groundwater depth

2021 ◽  
Author(s):  
Jianmin Bian ◽  
Qian Wang ◽  
Siyu Nie ◽  
Hanli Wan ◽  
Juanjuan Wu
Keyword(s):  
Support Vector Machine ◽  
Unsaturated Zone ◽  
Prediction Models ◽  
Groundwater Depth ◽  
Support Vector ◽  
Nitrogen Transport ◽  
Irrigation Area ◽  
Leaching Loss ◽  
The Relationship ◽  
Hydrus 1D

Abstract Fluctuations in groundwater depth play an important role and are often overlooked when considering the transport of nitrogen in the unsaturated zone. To evaluate directly the variation of nitrogen transport due to fluctuations in groundwater depth, the prediction model of groundwater depth and nitrogen transport were combined and applied by least squares support vector machine and Hydrus-1D in the western irrigation area of Jilin in China. The calibration and testing results showed the prediction models were reliable. Considering different groundwater depth, the concentration of nitrogen was affected significantly with a groundwater depth of 3.42–1.71 m, while it was not affected with groundwater depth of 5.48–6.47 m. The total leaching loss of nitrogen gradually increased with the continuous decrease of groundwater depth. Furthermore, the limited groundwater depth of 1.7 m was found to reduce the risk of nitrogen pollution. This paper systematically analyzes the relationship between groundwater depth and nitrogen transport to form appropriate agriculture strategies.

scholarly journals A Simple Method to Map Groundwater Depth and Water Quality for Leogane, Haiti and Elsewhere

2021 ◽  
Vol 16 (1) ◽  
pp. 1-19
Author(s):  
Michael Edward Kalinski ◽  
Nicholas Duda ◽  
Herby Lissade ◽  
Harry Donaghy
Keyword(s):  
Water Quality ◽  
Water Table ◽  
Cost Effective ◽  
Groundwater Depth ◽  
Simple Method ◽  
Deep Aquifers ◽  
Water Wells ◽  
Effective Manner ◽  
System 2 ◽  
The Impact

In the aftermath of the January 2010 Haiti Earthquake, the streets of downtown Leogane were paved to mitigate waterborne disease using humanitarian relief funds. After paving, many of the shallow water wells in Leogane dried up. It was believed that the new pavement disrupted groundwater recharge and negatively impacted the wells. Therefore, a project was performed to assess groundwater conditions in a cost-effective manner using a rapid, inexpensive, non-intrusive geophysical approach. The scope of the project included 1) surveying the new pavement system, 2) surveying water wells in Leogane, 3) testing the well water for coliforms, 4) performing geophysical DC resistivity testing to map groundwater depth and 5) developing a groundwater map to assess the impact of the pavement on the water table. As a result of this project, it could not be concluded that the new pavement was a factor in the groundwater fluctuations observed in the water wells in Leogane. It is more likely that some of the drop in the water table was due to the earthquake itself and some of it was caused by seasonal fluctuations in the water table. It was also observed that all the water wells that extract water from shallow (less than 6 m deep) aquifers in Leogane contain coliforms due to their proximity to household latrines, although a second deeper aquifer was identified and found to be coliform-free. With respect to broader impact, this methodology represents a relatively simple approach to mapping groundwater and assessing water quality that can be easily applied to other communities in the developing world to guide their efforts to develop and manage groundwater.

Factors Controlling the Distribution and Fate of Nitrate in the Unsaturated Zone and Groundwater in a Semiarid Agriculture Area

2012 ◽  
Vol 518-523 ◽  
pp. 4892-4895
Author(s):  
Su Fen Wang ◽  
Tian Ming Huang ◽  
Ji Lai Liu ◽  
Yu Long Liu
Keyword(s):  
Soil Moisture ◽  
Water Table ◽  
Unsaturated Zone ◽  
Water Quality Management ◽  
Nitrate Pollution ◽  
Movement Direction ◽  
Nitrate Content ◽  
Movement Velocity ◽  
Moisture Movement ◽  
Pollute Groundwater

Overuse of fertilizers in agriculture could cause groundwater nitrate pollution. However, this is related to nitrate input, soil moisture movement (direction and rate), and depth of water table in (semi)arid areas, where nitrate can be preserved and nitrate loss by denitrification can be limited. A 18-m soil profile to water table in Daxing, Beijing shows that the nitrate is accumulated in the upper unsaturated zone and has not reached water table; and then groundwater nitrate remains at baseline level (5.6 mg/L). The soil moisture movement velocity is 0.28 m/yr based on nitrate use history. It takes another ~35 years for the moisture with high nitrate content to reach water table and pollute groundwater, to which attention should be paid in water quality management.

Surface water quality management using an integrated discharge permit and the reclaimed water market

2014 ◽  
Vol 70 (5) ◽  
pp. 917-924 ◽  
Author(s):  
Shervin Jamshidi ◽  
Mohammad Hossein Niksokhan ◽  
Mojtaba Ardestani
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Quality Management ◽  
Water Quality Management ◽  
Reclaimed Water ◽  
Surface Water Quality ◽  
Treatment Costs ◽  
Point Sources ◽  
Penalty Cost ◽  
Total Treatment

Water quality trading is a sustainable framework for surface water quality management. It uses discharge permits to reduce the total treatment costs. For example, the case of Gharesoo River in Iran shows that the nitrogen permit market between point and non-point sources is 37% more economical than the command and control framework. Nevertheless, the cost saving may be reduced to 6% by the end of the study period (2050). This depression may be due to the limited technical support for wastewater treatment plants. Therefore, an integrated market is recommended in which the discharge permits and the reclaimed water are traded simultaneously. In this framework, the allocation of secondary treated domestic wastewater for irrigation can provide capacity for other pollutants to discharge into the surface water. This innovative approach may decrease the total treatment costs by 63% at present, while 65%, may be achieved by the end of the study period. Furthermore, this market is able to determine the environmental penalty, trading permits, and reuse prices. For example, the maximum ratio of the average reuse price to the penalty cost is determined as 1 to 10. It is introduced as an incentive indicator for stakeholders to consider the integrated market. Consequently, the applicability and the efficiency of using this approach are verified long term.

scholarly journals Hydrogeochemical Characterization and Quality Assessment of Groundwater in a Long-Term Reclaimed Water Irrigation Area, North China Plain

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1209 ◽  
Author(s):  
Xiaomin Gu ◽  
Yong Xiao ◽  
Shiyang Yin ◽  
Qichen Hao ◽  
Honglu Liu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Groundwater Quality ◽  
Reclaimed Water ◽  
Shallow Groundwater ◽  
Deep Groundwater ◽  
Irrigation Area ◽  
Deep Aquifers ◽  
Drinking And Irrigation ◽  
Reclaimed Water Irrigation

Water scarcity has led to wide use of reclaimed water for irrigation worldwide, which may threaten groundwater quality. To understand the status of groundwater in the reclaimed water irrigation area in Beijing, 87 samples from both shallow and deep aquifers were collected to determine the factors affecting groundwater chemistry and to assess groundwater quality for drinking and irrigation purposes. The results show that groundwater in both shallow and deep aquifers in the study area is weakly alkaline freshwater with hydrogeochemical faces dominated by HCO3-Na·Mg·Ca, HCO3-Mg·Ca·Na, HCO3-Ca·Na, and HCO3-Na. The chemical composition of groundwater in both shallow and deep aquifers is dominantly controlled by the dissolution of halite, gypsum, anhydrite, and silicates weathering, as well as ion exchange. Geogenic processes (rock weathering and ion exchange) are the only mechanisms controlling groundwater chemistry in deep aquifers. Besides geogenic processes, evaporation and anthropogenic activities also affect the chemistry of shallow groundwater. Quality assessment reveals that both shallow and deep groundwater are generally suitable for drinking and irrigation purposes. The quality of deep groundwater is more excellent for drinking than shallow groundwater. However, long-term use of deep groundwater for irrigation exhibits higher potential risks to deteriorate soil property due to the relative higher permeability indexes (PI). Therefore, it is recommended that deep groundwater is preferentially used for drinking and domestic purpose, and shallow groundwater for agricultural irrigation.

scholarly journals Time lags of nitrate, chloride, and tritium in streams assessed by dynamic groundwater flow tracking in a lowland landscape

2021 ◽  
Vol 25 (6) ◽  
pp. 3691-3711
Author(s):  
Vince P. Kaandorp ◽  
Hans Peter Broers ◽  
Ype van der Velde ◽  
Joachim Rozemeijer ◽  
Perry G. B. de Louw
Keyword(s):  
Water Quality ◽  
The Netherlands ◽  
Groundwater Flow ◽  
Travel Time ◽  
Unsaturated Zone ◽  
Time Lag ◽  
Agricultural Fields ◽  
Drainage Network ◽  
Trend Reversal

Abstract. Surface waters are under pressure from diffuse pollution from agricultural activities, and groundwater is known to be a connection between the agricultural fields and streams. This paper is one of the first to calculate long-term in-stream concentrations of tritium, chloride, and nitrate using dynamic groundwater travel time distributions (TTDs) derived from a distributed, transient, 3D groundwater flow model using forward particle tracking. We tested our approach in the Springendalse Beek catchment, a lowland stream in the east of the Netherlands, for which we collected a long time series of chloride and nitrate concentrations (1969–2018). The Netherlands experienced a sharp decrease in concentrations of solutes leaching to groundwater in the 1980s due to legislations on the application of nitrogen to agricultural fields. Stream measurements of chloride and nitrate showed that the corresponding trend reversal in the groundwater-fed stream occurred after a time lag of 5–10 years. By combining calculated TTDs with the known history of nitrogen and chloride inputs, we found that the variable contribution of different groundwater flow paths to stream water quality reasonably explained the majority of long-term and seasonal variation in the measured stream nitrate concentrations. However, combining only TTDs and inputs underestimated the time lag between the peak in nitrogen input and the following trend reversal of nitrate in the stream. This feature was further investigated through an exploration of the model behaviour under different scenarios. A time lag of several years, and up to decades, can occur due to (1) a thick unsaturated zone adding a certain travel time, (2) persistent organic matter with a slow release of N in the unsaturated zone, (3) a long mean travel time (MTT) compared to the rate of the reduction in nitrogen application, (4) areas with a high application of nitrogen (agricultural fields) being located further away from the stream or drainage network, or (5) a higher presence of nitrate attenuating processes close to the stream or drainage network compared to the rest of the catchment. By making the connection between dynamic groundwater travel time distributions and in-stream concentration measurements, we provide a method for validating the travel time approach and make the step towards application in water quality modelling and management.

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