Coupled processes of groundwater dynamics and land subsidence in the context of active human intervention, a case in Tianjin, China.

To address the crisis of water shortage in the North China Plain, the Chinese government implemented the South-to-North Water Transfer Project (SNWTP). In this context, Tianjin, one of the main beneficiaries of this project, has been relieved from water shortages and begun to implement Groundwater Management Plans (GMP) since 2018, which undoubtedly have a significant effect on the groundwater recovery. Meanwhile, this provides a good case for studying the coupled process of ground settlement and groundwater dynamics, especially the soil deformation pattern driven by groundwater level (GWL) rebound. To analyze these issues in detail, field well data was collected to depict groundwater flow field. Moreover, geodetic data was also collated, including leveling, GPS, and InSAR, so that a vertical deformation field with high spatiotemporal resolution could be generated. The results reveal that the GWL of the third confined aquifer which is the main exploitation layer in Tianjin recovered significantly since 2018 with a rate of 2.1 m/yr. The dynamic deformation patterns indicate that the area of land subsidence cones in Tianjin has reduced significantly, accompanied by a sharply declining subsidence rate (decreased from -32.2 mm/yr to -4.5 mm/yr.). Particularly, a significant poroelastic rebound has occurred in the Wuqing and Beichen districts since 2020. Furthermore, due to the delayed pore pressure dissipation in the aquitard, we find a time delay of 0.3-5.5 years between land subsidence and GWL time series, which is far less than that estimated by hydrogeological parameters, as the latter ignored the recharge and recovery capacity of the aquifer system. Finally, an evolution models in Tianjin was presented to illustrate interactive process among the deformation, pore pressure, and hydraulic head. In general, the SNWDP and the GMP has restored the pore pressure of aquifer, reduced the land subsidence, and alleviated the groundwater storage depletion of Tianjin.

[Change of drinking water quality in Shijiazhuang South-to-North Water Diversion area from 2014 to 2021].

OBJECTIVE: To analyze the change of drinking water quality in the receiving area of Shijiazhuang South-to-North Water Transfer Project. METHODS: 2029 monitoring data of drinking water in the receiving areas of the South-to-North Water Transfer Project in Shijiazhuang from 2014 to 2021 were collected and collated according to the Sanitary Standard for Drinking Water(GB 5749-2006). Off-work water and pipe water before and after the total coliform group of South-to-North Water Transfer Project, heat-resistant coliform bacteria, escherichia coli, the total number of colonies, arsenic, cadmium, chromium, lead, mercury, nitrate, fluoride, selenium, cyanide, chloroform, carbon tetrachloride, chromaticity and turbidity, odor and taste, visible to the naked eye, pH, aluminum, iron, manganese, copper, zinc, chloride, sulfate, total soluble solids, total hardness, oxygen consumption, volatile phenols, anionic synthetic detergent, ammonia nitrogen, residual chlorine and chlorine dioxide were evaluated and compared. χ~2 test was used to compare the qualified rate, Mann-Whitney rank sum test was used to compare the test values of each index, and simple superposition comprehensive water environmental quality index method was used to evaluate the water quality comprehensively. RESULTS: Before the South-to-North Water Transfer Project, the total qualified rate of drinking water was 84.21%, that of factory water was 81.29%, and that of end water was 85.97%. The total qualified rate of drinking water after the South-to-North Water Transfer Project was 98.72%, that of factory water was 98.89%, and that of end water was 98.66%. The total qualified rate of water quality, the qualified rate of factory water and the qualified rate of end water after the South-to-North water transfer were higher than those before the transfer(P<0.05). The qualified rates of microbial indexes and total hardness of ex-factory water before the South-to-North Water Transfer Project were 94.37% and 89.94%, and those of microbial indexes and total hardness of end water were 94.32% and 93.35%, respectively. After the South-to-North Water Transfer, the qualified rates of microbial indexes and total hardness of the ex-factory water were 100.00% and 98.90%, and the qualified rates of microbial indexes and total hardness of the end water were 100.00% and 99.24%, respectively. After the South-to-North water transfer, the qualified rate of microbial indexes and total hardness of factory water and peripheral water were higher than those before the transfer(P<0.05). After the South-to-North Water Transfer, the M of total coliform group, total colony number, total hardness, fluoride, nitrate nitrogen, chloride, sulfate and dissolved total solids were lower than those before water transfer(For example, the median number of colonies and total hardness of factory water before the South-to-North Water Transfer were 20.00 CFU/100 mL and 248.00 mg/L, respectively. After the South-to-North Water Transfer, the median number of colonies and total hardness were 1.00 CFU/100 mL and 129.00 mg/L, respectively), while the M of trichloromethane, aluminum, pH and oxygen consumption were higher than those before water transfer(For example, the median of trichloromethane and aluminum before the South-to-North Water Transfer is 0.04×10~(-2) and 0.04×10~(-1) mg/L, respectively. After the South-to-North Water Transfer, the median of chloroform and aluminum were 0.06×10~(-2) and 0.25×10~(-1) mg/L, respectively)(P<0.05). The median WQI of comprehensive water environmental quality index before and after the South-to-North Water Transfer was 4.58 and 2.37(P<0.05), respectively. CONCLUSION: The introduction of the South-to-North Water Transfer has significantly improved the quality of drinking water in Shijiazhuang city. Microbial contamination and total hardness exceedance have been greatly improved.

Rapid prediction of pollutants behaviours under complicated gate control for the middle route of South-to-North water transfer project.

Many crossing hydraulic structures have been constructed in the Middle Route of the South-to-North Water Transfer Project (MR-SNWTP), which increases the likelihood of sudden water pollution accidents. After an accident, managers need to assess the extent of pollution under conditions of gate control, and it's necessary to make suitable emergency control decision under this assessment. Therefore, we researched the rapid prediction of pollutants behaviours under conditions of complicated gate control in this paper, by presenting three characteristic parameters of pollutant migration and diffusion. According to the simulation results, the influencing reasons and rapid prediction formulas for the characteristic parameters (peak transport distance, pollutant longitudinal length and peak concentration) after a sudden water-soluble pollution accident are proposed. Also, the approval results show that the formulas can accurately predict the location and range of the pollutant after the emergency accident. Finally, the rapid prediction formulas for the characteristic parameters played a fundamental role in the decisions involved in the Emergency Environmental Decision Support System is proved by two application examples.

Changes in nutrient transport from the Yangtze River to the East China Sea linked to the Three-Gorges Dam and water transfer project.

River-sea transition plays a key role in global geochemical cycles. The Yangtze River Estuary of China was selected as the research area, and the Section-Segmented Method was applied to determine the nutrient discharge from the Yangtze River to the East China Sea. A 3-D numerical model for the estuary was established and validated against the field investigated data. By numerical experiments the dynamics of hydrology and nutrient from 1950 to 2016 were simulated under four varied schemes. The individual and combined impacts on the nutrient flux induced by the Three-Gorges Dam (TGD) and the South-to-North Water Transfer Project (SNWTP) were explored. The following results were observed: (1) During the Pre-TGD period, the Yangtze River delivered the loads of 1.32 Tg/yr and 0.08 Tg/yr for TN and TP, respectively. July and Feb. were characterized by the highest and lowest monthly flux, respectively. (2) TGD played a significant role in regulating the temporal nutrient deliveries. After the closing of TGD, the discharges of TN and TP in the dry season respectively went up to 0.55 Tg and 0.032 Tg, with a mean increase of 28.3%. (3) SNWTP reduced the nutrient transport at a relatively stable level, and the total loads of 40.66 Gg and 2.4 Gg were reduced per year for TN and TP, respectively. (4) The combined impacts of TGD and SNWTP varied with seasons. October was characterized by the greatest cumulative effects. In dry seasons, the reduction caused by SNWTP was leveled by TGD-induced increase, limiting the flux variation linked to project operations.

An evolutionary game analysis of governments' decision-making behaviors and factors influencing watershed ecological compensation in China.

As a way to coordinate the interests of multi-government and solve the problem of transboundary water pollution, watershed ecological compensation system has been promoted in China. It is necessary to understand the influencing factors of watershed ecological compensation from the perspective of how interactions occur between different governments. This paper analyses the interaction among upstream governments, downstream governments and the central government in the Eastern Route of South-to-North Water Transfer Project, using evolutionary game theory. In particular, how ecological benefits are distributed between upstream and downstream governments is analyzed. Simultaneously, numerical simulation is used to analyze the effects of influencing factors on governments' behaviors. The results show that: (1) the initial willingness of governments to corporate affect their final behaviors; (2) upstream and downstream governments cannot spontaneously cooperate to implement watershed ecological compensation system without supervision of the central government; (3) opportunity costs only have a significant impact on upstream governments; (4) punishment on downstream governments can effectively influence the behaviors of governments at all levels; (5) high ecological compensation fee improve downstream governments' willness not to pay; (6) upstream governments get about 78% of ecological benefits due to the implementation of watershed ecological compensation system.

Changes in Ecosystem Services Value and Establishment of Watershed Ecological Compensation Standards.

Ecological compensation standards and the allocation of compensation funds have always been the core issues of watershed ecological compensation. Due to the construction of the Eastern Route of the South-to-North Water Transfer Project (SNWTP), Jiangsu Province has paid a huge cost for the protection of water resources, and local economic development has been greatly affected. Therefore, this paper takes Jiangsu Province, the water source area of the Eastern Route of the SNWTP as an example, and combines a geographic information system (GIS) and remote sensing technology, using the ecosystem services value method to calculate the ecosystem services value of Jiangsu Province from 2005 to 2018. Then the change of this ecosystem services value in Jiangsu Province from 2015 to 2018 is taken as the basis for watershed ecological compensation standards of the Eastern Route. Through a compensation fund allocation model, watershed ecological compensation funds are allocated to four cities, Yangzhou, Huai'an, Suqian and Xuzhou, which are located along the Eastern Route of this SNWTP in Jiangsu Province. The results show that: (1) The ecosystem services value of Jiangsu Province has changed greatly. Urbanization and market environment of grain crops are the main reasons for this change; (2) the relationship between ecosystem services in Jiangsu Province is mainly synergistic; (3) Suqian receives US$24.73 million; Huai'an receives US$16.49 million; Yangzhou receives US$54.88 million and Xuzhou receives US$0.95 million in watershed ecological compensation, respectively. Watershed ecological compensation standards based upon the value of ecosystem services, and the allocation of compensation funds at the municipal level, are conducive to the improvement in efficiency of watershed ecological compensation in mainland China.

The spectrum of chronic diseases and influential factors of immigrants moving water source area of South-to-North Water Diversion Project / 中华疾病控制杂志

Objective To understand the prevalence and disease distribution of migrants within the water source area of the Middle Route Project of South-to-North Water Diversion Project and analyze the influencing factors. Methods By multi-stage stratified cluster sampling method, 307 immigrants and 676 immigrants were selected from Danjiangkou reservoir area, Shiyan city, Hubei Province. Results The prevalence of chronic diseases among in-migration was 51.8%. The prevalence rates of the top five chronic diseases were waist and leg pain, hypertension, gastritis, heart disease and diabetes. The prevalence of chronic diseases among out-migration was 65.1%. The prevalence rates of the top five chronic diseases were waist and leg pain, hypertension, gastritis, heart disease and bronchitis. The rate of chronic disease, the rate of two weeks and the rate of two weeks' visit were higher than that of emigration(all P<0.05). The results of multivariate analysis showed that the factors influencing the chronic diseases of immigrants were 60 years old (OR=59.928，P<0.001), unsatisfied family income (OR=0.377, P=0.002) and poor economic status (OR=0.517, P=0.028). The factors influencing the chronic diseases of immigrants were 60 years old (OR=26.190, P<0.001), smoking (OR=1.856,P=0.004), unsatisfactory family income (OR=0.598,P=0.029) and poor economic status (OR=0.460,P<0.001). Conclusions The prevalence of migrants within a high level is at a high level. Actually raising the income of immigrants is conducive to improving the health condition of immigrants.

Emergency control system based on the analytical hierarchy process and coordinated development degree model for sudden water pollution accidents in the Middle Route of the South-to-North Water Transfer Project in China.

Water transfer projects are important for realizing reasonable allocation of water resources, but once a water pollution accident occurs during such a project, the water environment is exposed to enormous risks. Therefore, it is critical to determine an appropriate emergency control system (ECS) for sudden water pollution accidents that occur in water transfer projects. In this study, the analytical hierarchy process (AHP) integrated with the coordinated development degree model (CDDM) was used to develop the ECS. This ECS was developed into two parts, including the emergency risk assessment and the emergency control. Feasible emergency control targets and control technology were also proposed for different sudden water pollution accidents. A demonstrative project was conducted in the Fangshui to Puyang channel, which is part of the Beijing-Shijiazhuang Emergency Water Supply Project (BSP) in the Middle Route of the South-to-North Water Transfer Project (MR-SNWTP) in China. However, we could not use an actual toxic soluble pollutant to validate our ECS, so we performed the experiment with sucrose to test the ECS based on its concentration variation. The relative error of peak sucrose concentration was less than 20 %.

Study on shell shape changes of filial generation Oncomelania hupensis snails in Weishan Lake region,Shandong Province / 中国血吸虫病防治杂志

Objective To explore the shape change characteristics of Oncomelania hupensis snail shell after the snails being passively migrated into Shandong intake area of the South-to-North Water Diversion Project. Methods The snails raised on the Dushan island in Weishan Lake region were captured,and 115 the first filial generation snails and 107 the second filial generation ones were selected. The length and width of shells and apertures,and the labial ridge thickness of those snails were measured,the longitudinal rib number of snail spiral was counted,and 107 parental snails were chosen as controls. Results The labial ridge thickness of the filial generation snail was significantly reduced with the increase of algebras,and the labial ridge thickness among the 3 generations had a significant difference(P<0.01). Both the length of snail shell and the width of snail apertures were de-creased,while the width of snail shell,the length of snail apertures,the multiplication product of snail aperture’s length and width and the longitudinal rib number of snail spiral were all increased. Conclusion The body size of Oncomelania snails in Weishan Lake region becomes smaller,and their shells become thinner,which indicates that the environment of the lake region is not suitable for snail breeding,and the snails have natural decay tendency with the extension of time.