Current Water Level Research Articles

Smart Irrigation System Using Soil Moisture Prediction with Deep CNN for Various Soil Types

Soil moisture sensing plays a crucial role in agriculture as it directly impacts plant growth and can significantly enhance crop productivity. With the advent of technology, agriculture applications have undergone a revolution, enabling more advanced and efficient practices. One such advancement is the use of soil moisture sensors, which provide valuable information about the current water level of the soil, including whether it is dry, wet, or excessively saturated. These sensors have become indispensable tools for farmers and growers, empowering them to make informed decisions regarding irrigation schedules, water management strategies, and overall crop health. By accurately assessing soil moisture levels, farmers can optimize water usage, prevent water stress or overwatering, and promote healthier plant development, ultimately leading to improved yields and sustainability in agriculture. The objective of the proposed study is to investigate the effective soil moisture sensors by considering three sensors and an automated system for watering the soil for agriculture. A comparative analysis is performed for different commercial off-the-shelf soil moisture sensors in cost, accuracy, durability, and corrosion resistance. Secondly, this study further gives soil moisture reading as data input to the Convolutional Neural Network (CNN) to classify whether water is required or not for the soil at a particular temperature which would help to conserve water and develop agriculture. An automated system which can help the farmer for irrigation and cultivation of the soil obtained accuracy as 95.23%.

Numerical investigation for the influence of suspended sediment on salinity distribution in the Qiantang Estuary, China

Numerous studies have demonstrated that high suspended sediment concentration (SSC) can change density distribution and affect water mixing, but few scholars have investigated this impact on numerical simulations of estuarian salinity distribution. The Qiantang Estuary is a macro-tidal estuary with high SSC, which has a more significant influence on water density than that of salinity. Therefore, this paper established a three-dimensional (3D) numerical model coupling flow, salinity and SSC based on Delft3D and first analyzes the impact of SSC on salinity distribution under different runoff and tidal conditions in the Qiantang Estuary. The results indicated that simulated salinity generally decreases when considering the impact of SSC, suggesting a weakening effect on saltwater intrusion. The distribution of salinity difference (ΔS) and SSC show a strong spatial and temporal correlation, and ΔS peak increases and shifts upstream as the tidal range increases or runoff discharge decreases. The mechanism of SSC influencing saltwater intrusion can be summarized as follows: On the one hand, SSC increases the water density, which weakens the driving force for saltwater to move upstream, causing a decrease in flood current velocity and water level, and thereby diminishing the advective transport of salinity. On the other hand, SSC enhances density stratification, which weakens vertical turbulence and reduces the dispersive transport of salinity. These combined effects reduce both the advective and diffusive salinity fluxes during the flood tide, ultimately leading to a decrease in upstream salinity. Therefore, neglecting this effect in estuaries with high SSC can cause significant deviations in salinity simulation results, especially under low-flow and high-tide conditions.

Changes in the suspended floc properties by bed erosion in a macrotidal muddy flat: Case of Asan Bay, Korea

Intertidal flats have closely connected sediment transport systems with tidal channels. The properties of suspended sediments derived by horizontal advection and local erosion were examined under various current and wave. A field campaign was conducted over two weeks (October 17–31, 2021) in the Asan intertidal flat. Suspended sediments were in the form of flocs, which are clumps of particles, with an average floc size (davg) of 70–275 μm. The maximum current velocity and water level at each tidal cycle continuously decreased from 0.19 to 0.04 m s−1 and from 5 to 2 m, respectively. In accordance with the hydrodynamic conditions, continuous decrease in davg from spring to neap tides was superimposed by flood-ebb variations in davg. Geological heterogeneity between channels and flats can be significantly influenced by tide and wind conditions. Under tide-dominant conditions, the spring tidal current was strong enough to transport macroflocs with davg of 200–500 μm into the intertidal flats. The grown macroflocs up to 1.6 times of davg at early flood tide were deposited in the flats during the slack tide and transported back to the channels by ebb tidal current. Under wind-dominant conditions, the suspended flocs originated primarily from the bed by erosion. The deposited macroflocs or microflocs were entrained into water column and transported to adjacent tidal channel as microflocs or flocculi. The structure of the advected flocs had more varied density in the range of 42–147 kg m−3, compared to the eroded flocs. Under severe erosion, the structure of suspended flocs was similar to that of advected flocs despite their smaller size. This suggests that bed erosion supplied more porous flocs into the water column than those transported by advection. Consequently, the intertidal flats are at an increased risk of erosion due to the diverse structure of flocs.

Web application of an integrated simulation for aquatic environment assessment in coastal and estuarine areas

This paper introduces the web application-type Graphical User Interface that has been developed and also presents an application example. The introduced simulator conducts hydrodynamics and ecosystems in coastal and estuarine areas. It consists of (1) a hydrodynamic model that can simulate the current velocity, water temperature, salinity, and water level; (2) an ecosystem model that can simulate dissolved oxygen, phytoplankton, zooplankton, nutrients, fish, and bivalves; and (3) a benthic ecosystem model that can simulate elution. Web GUI is the first web system of aquatic environment simulation system that can both prepare calculation conditions and visualize them. Another significant feature is that it requires no installation and can be easily used by anyone to perform calculations. Thus, the proposed system helps fill the expertise gap experienced by potential users of the model. The use of standard systems, such as those discussed in this study, will facilitate evidence-based policymaking (EBPM).

Research on the Influence Radius on the Surrounding Groundwater Level in the Beidianshengli Open-Pit Coal Mine of China

Coal mining has a certain influence on and causes disturbances in groundwater. To investigate the variation trend of groundwater around the open-pit mine in grassland area, taking Shengli No. 1 open-pit mine as an example, the impact and variation trend of groundwater level in Quaternary aquifer around the mine area was studied by using the data of hydrological monitoring wells. The results show that the water level around the mining area varies from one year to the next. Since 2008, the water level has experienced a process of reduction, stability and increase. Compared with the background water level value, the current water level of each monitoring well is lower than the background water level. The influence radius calculated by Kusakin formula ranges from 94.15 m to 906.80 m, and the aquifer is heterogeneous. On the basis of the correlations between changes in waterline in monitoring wells and the stope distance, the disturbance radius of open-pit mining on surrounding diving water in grassland area is less than 2000 m. Based on the comprehensive analysis of the alteration of diving waterline and its influencing factors, the main factors affecting the variation in the phreatic water level are atmospheric precipitation, evaporation, groundwater usage and dewatering water. All factors act on the diversification of diving water level synthetically. The internal waste dump of an open-pit mine has a positive effect on the surrounding groundwater recovery. The aim of this study is to reveal the impact of open-pit mining on surrounding groundwater and providing scientific basis for future mining in other open-pit mines.

Assessing the role of tidal cycle, waves, and wind as drivers of surf zone zooplankton on a temperate sandy beach

The surf zone is strongly affected by tides, waves, and winds. However, there are still a lack of knowledge about the response of the zooplankton community to these physical factors in the surf area, with a particular emphasis on tidal effects. The aim of this study was to conduct a preliminary assessment of two distinct tidal cycles, encompassing fluctuations in on-offshore currents, waves, and wind and their influence on the surf zooplankton community of Pehuen Co (PC) sandy beach, Argentina. The study involved field sampling at a single station in the surf zone on September 4th, 2018, and May 20th, 2019. The sampling covered four tidal phases at 3-hour intervals, when water and zooplankton samples were collected for analysis. Environmental variables, such as current velocities, water level, and wind data, among others, were also registered. The results indicated that the abundance of surf zooplankton was significantly influenced by physical forces, resulting in distinct impacts. During the Sept 2018 tidal cycle (calm conditions), an on-offshore current emerged as the primary driving force, resulting in the highest abundance of zooplankton being observed at low tide. In contrast, during the May 2019 tidal cycle (southern winds), strong winds intensified the offshore current velocities and wave height, affecting the zooplankton abundance. High velocities of on-offshore currents corresponded to lower abundance of zooplankton at low tide. This situation introduced an extra physical force -the wind- playing a significant role in restructuring the dynamic of the zooplankton community. The preliminary analysis suggests that the relationship between environmental and biological data is complex and varies depending on the physical factors involved. Notably, in rough conditions, south winds can restructure zooplankton dynamics, influenced by strong winds. This work emphasizes the importance of the surf zone waters of sandy beaches and are useful for future research or monitoring programmes of similar high-energy ecosystems.

Compound extreme inundation risk of coastal wetlands caused by climate change and anthropogenic activities in the Yellow River Delta, China

The coastal wetlands of the Yellow River Delta (YRD) in China are crucial for their valuable resources, environmental significance, and economic contributions. However, these wetlands are also vulnerable to the dual threats of climate change and human disturbances. Despite substantial attention to the historical shifts in YRD's coastal wetlands, uncertainties remain regarding their future trajectory in the face of compound risks from climate change and anthropogenic activities. Based on a range of remote sensing data sources, this study undertakes a comprehensive investigation into the evolution of YRD's coastal wetlands between 2000 and 2020. Subsequently, the potential fate of coastal wetlands is thoroughly analyzed through the Land Use/Cover Change (LUCC) simulation using System Dynamic-Future Land Use Simulation (SD-FLUS) model and the extreme water levels projection integrated future sea-level rise, storm surge, and astronomical high tide in 2030, 2050, and 2100 under scenarios of SSP1-2.6, SSP2-4.5, and SSP5-8.5. Results revealed that YRD's coastal wetlands underwent a marked reduction, shrinking by 1688.72 km2 from 2000 to 2020. This decline was mostly attributed to the substantial expansion in the areas of artificial wetlands (increasing by 823.78 km2), construction land (increasing by 767.71 km2), and shallow water (increasing by 274.58 km2). Looking ahead to 2030–2100, the fate of coastal wetlands appears to diverge based on different scenarios. Under the SSP1-2.6 scenario, the area of coastal wetland is projected to experience considerable growth. In contrast, the SSP5-8.5 scenario anticipates a notable decrease in coastal wetlands. Relative to the inundated area suffered from the current extreme water levels, the study projects a decrease of 6.8%–10.6% in submerged coastal wetlands by 2030 and 9.4%–18.2% by 2050 across all scenarios. In 2100, these percentages are projected to decrease by 0.4 % (SSP2-4.5) and 27.1% (SSP5-8.5), but increase by 35.7% (SSP1-2.6). Results suggest that coastal wetlands in the YRD will face a serious compound risk from climate change and intensified human activities in the future, with climate change being the dominant factor. More efficient and forward-looking measures must be implemented to prioritize the conservation and management of coastal wetland ecosystems to address the challenges, especially those posed by climate change.

Prediction of Streamflow in River Basin-Using ANN

In addition to the flood level predictions, our system provides valuable insights into future rainfall patterns. With the data set we have gathered, we can determine the expected amount of rainfall in the upcoming months. By combining the flood level predictions with the rainfall data, we can better understand the overall flood risk and take proactive measures to mitigate its impact. Our system equips us with the necessary information to make informed decisions and enhance flood preparedness strategies. The main difference is that we focus on predicting flood levels using a combination of current water level data and real-time weather data. This allows us to have a more accurate understanding of potential flood events. Additionally, our paper also incorporates rainfall data to assess the risk of flooding in the coming months. By considering multiple factors, we aim to provide a more holistic understanding of flood risks and enhance preparedness strategies. By combining the flood level predictions with rainfall forecasts, we can assess the flood risk in the coming months and take preventive actions, such as implementing early warning systems or strengthening infrastructure, to minimize the impact of potential flood events.

A Neural Network Model for Estimation of Maximum Next Day Energy Generation Capacity of a Hydropower Station: A Case Study from Turkey

Energy planning in a hydro power station (HPS) is essential for reservoir management, and to ensure efficient operation and financial usage. For robust energy planning, operators should estimate next day energy generation capacity correctly. This paper investigates use of a robust neural network model to estimate maximum next day energy generation capacity by using reservoir inflow rates for the previous four days, the current level of water in the reservoir, and the weather forecast for the Darıca-2 HPS in Ordu Province, Turkey. The generated energy in an HPS is directly dependent on the level of stored water in the reservoir, which depends on reservoir inflow. As the level of water in a reservoir varies during the year depending on climatic conditions, it is important to be able to estimate energy generation in an HPS to operate the HPS most effectively. This paper uses reservoir inflow data that has been collected daily during 2020 for the training phase of a neural network. The neural network is tested using a data set that has been collected daily during the first four months of 2021. Used neural network structure is called as LWNRBF (Linear Weighted Normalized Radial Basis Function) network, which is developed form of RBF network. In order to be able to be created valid model, LWNRBF network is trained with a two-pass hybrid training algorithm. After the training and testing stages, average training and testing error percentages have been obtained as 0.0012% and -0.0044% respectively.

Estimation of Equivalent Rainfall for Ungauged Reservoir Using Satellite-Based High-Resolution Terrain Data

Equivalent rainfall refers to the amount of precipitation required to reach a specific water level from the current water level in a reservoir. It serves as a flood forecasting and warning system that allows for the rapid assessment of the reservoir’s maximum water level at the moment of rainfall forecast. In reservoirs where terrain and survey data can be obtained, deriving equivalent rainfall is not difficult. However, without terrain data, satellite imagery and global topographic data are the only available options. In this study, high-resolution topographic data based on satellites were utilized to estimate the equivalent rainfall in the ungauged reservoir, Hwanggang Dam, located in the upper stream of the Imjin River in North Korea. To calculate the inflow into the reservoir, the Natural Resources Conservation Service-Curve Number method was used to determine the effective rainfall, taking into account the antecedent conditions, as the inflow into the reservoir can be changed for the same amount of rainfall depending on the soil moisture content of the watershed.

ANALISIS DAYA TAMPUNG AIR PADA SALURAN DRAINASE DI LINGKUNGAN ART CENTRE KOTA DENPASAR

Flood is a natural event that can have a negative impact, for example, causing health problems and the safety of living things. The drainage channel studied in this study is the Tukad Kelandis River which stretches from Jl. Katrangan to Jl. Nusa Indah which crosses the Denpasar City Art Center. In 2021 there was a flood at the Art Center, the impact was flooding under the Ksiranawa Building where the art exhibition was held. For this problem, it is necessary to conduct a study (research) on the profile of the flood front as a flood prevention measure. Before modeling the water level profile with HEC-RAS, when estimating the capacity of the drainage channel, a quantitative method must be calculated, namely by measuring the condition of the canal in the case study. From the results of flood simulations with return times of 2, 5, 10, 20 and 25 years. The results of the evaluation of the current channel discharge at all points of the channel experienced flooding with return periods of 2, 5, 10, 20 - 25 years because the results of the current channel discharge and water level exceeded. The profile is shown in the results at all channel points where the sum of the actual water level (E.G., level) and water level feet (W.S. level) is greater than the capacity of the water discharge in the channel. In addition, at the water level (Crit. W.S.) in the Sta. 2 is 5.05 m, which is less than (W.S. level) which is 6.69 m, so the flow is supercritical.

Field survey and analysis of water flux and salinity gradients considering the effects of sea ice coverage and rubber dam: a case study of the Liao River Estuary, China

Predicting net river fluxes is important to promote good water quality, maritime transport, and water exchange in estuaries. However, few studies have observed and evaluated net water fluxes to estuaries under complex conditions. This study used advanced survey techniques to obtain high-frequency monitoring data of cross-sectional current velocity, water level, and salinity in the Liao River Estuary (LRE) from 2017 to 2020. The net water flux into the sea was computed based on field data and the impacts of the rubber dam and sea ice cover on water flux and salinity processes were analyzed in the study region. In the Liao River Station (LRS), the fluctuations of water level and discharge were not obvious in winter due to the sea ice cover. There were significant seasonal and inter-annual changes in water fluxes due to variability in river discharge and tidal oscillations. The results also showed that the net water flux into the sea from the LRS was positive in wet season, and greater during ebb tides than flood tides. The net water fluxes in the normal and dry seasons were mostly negative due to the influence of tides, indicating that the annual runoff from the Liao River fluctuated greatly throughout the year. The water flux in the LRS was more suitable for representing water flux into the sea than the Liujianfang Hydrometric Station (LHS) in the LRE. The impacts of the rubber dam and Panshan Sluice on water fluxes to the sea were both significant. Lower salinity in the study area coincided mostly with height water fluxes to the sea and periods when the rubber dam was raised. This study results provide us new insights to measure the water flux into sea under the condition of ice cover in the tidal reach of estuary and the method can be used for water flux observation for other estuaries.

A novel assessment framework for evaluation of the current implementation level of water and wastewater management practices

Abstract A sustainable urban water cycle is critical in terms of effective water network management, efficient use of water resources, protection of the environment and human health, and reuse of treated water. The objective of this study is to develop a novel assessment framework that evaluates the data quality of components and current implementation levels of wastewater management (WWM) practices, calculates performance indicators according to the data quality of the components, and proposes the most appropriate improvement methods according to the current status of the components. This assessment framework consists of five matrices, namely the current situation analysis and management system (CSAS), data matrix (DATA), performance assessment system (PAAS), target definition system (TARGET), and method matrix (TOOL). The current situation is analyzed with a total of 231 components under 11 main headings covering WWM practices. The assessment framework was tested in pilot utilities and the results were discussed. It is observed that the scores of utility I were generally better than those of utilities II and III. The novelty of this assessment framework is to evaluate the current situation of WWM practices with a unique scoring system, to define the weaknesses and strengths in WWM, and to present a roadmap for improvement according to the current situation.

FLUCTUATIONS OF LAKE NERO DURING THE HOLOCENE<a href="#FN1"><sup>1</sup></a>

The paleohydrological condition in the Rostov depression (Yaroslavl region) has been the subject of many years of discussions. The ideas about the Holocene fluctuations of the Lake Nero level differ among researchers. We have studied the structure of bottom sediments and bottom topography in the deepest northeastern part of the lake. A bathymetric survey was carried out. Drilling with the selection of undisturbed columns, GPR profiling, radiocarbon dating and a set of lithological analyzes were performed. Stratigraphic unconformities in the structure of bottom sediments indicate a drop in the lake level during the Lateglacial and the early Holocene. The level dropped to 87 m asl, which is 7 m lower than the current water level in the lake. The size of the lake at this stage was reduced several times. From 9 to 6.5 ka BP a transgressive stage was established: the average level of the lake could have risen to 91–94 m asl, which is close to its modern level. From 6.5 to 2.4 ka BP a decrease in the level by 1–3 m below the current one is revealed, followed by a gradual increase in the level. The current level was reached 300–500 years ago. The main factor in the fluctuations in the level of Lake Nero in the Holocene is the change in the height of the runoff threshold, caused by the transformation of the Ustye, Veksa, and Kotorosl river sistems. This transformation was associated both with regional changes in fluvial activity and with the processes of self-development of river channels.

Multi-Parameter Sensor Based Automation Farming

IOT innovation is used in the development of the Smart Farming Tracking the System. An Arduino Uno, a temperature humidity sensor, soil moisture sensor, water level sensor, water pumps, and DC motors strength this system. If the smart farming tracking system turns on, the sensors find the field’s water level and the soil’s moisture level. If the irrigation water stage falls below the level defined for a specific crop grown in the growing area, the irrigation system is going to start to pump water. The IOT warns concerning current level of water, soil moisture stage, and motor beginning will be shown on the LCD panel of the section. We are able to use the pumps by hand via a webpage. The farmers are additionally getting this data via mobile phone. By hitting a system- provided link, the individual using it may firmly prevent the water’s flow within the field. While carried out, the system will assist landowners to preserve suitable soil water and moisture levels, thus boosting yields with little work. The goal of this article is to identify grow illnesses and reduce losses in money. For picture appeal, we suggested an entirely based on deep learning method. We put the three most common Neural Network Designs to the test: Faster Region-based entirely judgment (SVM)Support Vector Machine Region-based entirely (RF) Random Forest method. The method suggested in the research can correctly detect many types of disease and is capable of dealing in complicated situations. In addition, the method may be expanded to recommend fertilizer according to extent evaluation as well as measurement. artificial intelligence (AI) entirely Machine Learning Response to this the combination the issue is a supervised categorization judgment.

Understanding the Mechanism of Currents through the Malacca Strait Study Case 2020 – 2022 : Mean state, Seasonal and Monthly Variation

The Malacca Strait is the importance waters for international shipping routes and more 200 cases of ship collisions in the period 1970-2015 in this strait. That is related to some a shallow depth waters with many small islands and strong current which is making this strait have a highest risk in certain seasons. The CMEMS data used to understanding of mechanism of current, illustrate the pattern and tranport volume. The research uses descriptive and the statistical methods to understanding of mechanism and variability of current. The analysis of current patterns and water level shows that during the monsoon winds active, the current always moves to the Andaman Sea, we called the southeast current system. The Northeast (NE) and Southwest (SW) monsoon wind is strongly influence to the mechanism of formation southeast current system, which causes the varition in sea level hight in eastern and western of Malacca Strait. During the NE monsoon season, the water masses of the South China Sea are push away into the Karimata Strait, causing the sea level in the eastern part to be higher than the western part and will increase the current speed. On the other hand, during the SW monsoon season, the water masses from the Karimata Strait is pushed away from the eastern part of the Malacca Strait which causes the sea level decrease and causes the current speed to weaken. Numbers eddies phenomenon were found at the Malacca Strait each season. The anticyclonic eddies occurred almost every season centered at 3° - 5° N, 97° - 100° E. Meanwhile anticyclonic eddies appear around the northern part of Sumatra centered at 4° - 5°N, 99° - 101°E during SW Monsoon season and the eddies formation also existed during the second transition monsoon season.

Impact of hydrological processes on wetland landscapes and wintering migratory birds in a large floodplain lake (Poyang Lake, China)

AbstractHydrological processes are an important factor influencing the wetland landscapes and the quality of wintering migratory birds habitat in Poyang Lake. However, most of the research on a small spatiotemporal scale and there is a lack of studies on the impact of hydrological processes on migratory bird habitats. This study analysed the response of the Poyang Lake wetland landscape to low water levels from 1990 to 2016 and determined the relationship between hydrological processes, wetland landscape characteristics and migratory bird habitats. According to the results, the number of days during the study period when the maximum water level was higher than the current water level (MaxDay) and the average water level from the 40th to 50th day prior to the current day (D50) are two critical factors affecting the area of grassland in Poyang Lake. In particular, a D50 value of 9.5–11.0 m is important for maintaining the grassland area and growth of wetland vegetation. Besides, the water level should not exceed 11 m from mid–late October to early November and should be maintained between 7.58 and 7.97 m in mid–late December that can maximize the habitat area of migratory birds. Furthermore, this study used ecological threshold to propose the optimal inundation period of Cyperus rotundus L. community, Leersia japonica community, Polygonum criopolitanum community, Phragmites australis community, Triarrhena lutarioriparia community, Carex spp. community and Phalaris arundinacea community, which are 124–174, 31–101, 199–249, 65–147, 51–121, 110–190 and 175–253 days, respectively.

Methodology for Estimating Streamflow by Water Balance and Rating Curve Methods Based on Logistic Regression

Both water balance (WB) and rating curve (RC) are methods for estimating streamflow. The first is mostly used to estimate reservoir outflows, while the second is usually adopted in hydrometeorological network streamflow gauges. While WB uses hourly collected data, the RC estimates streamflow using current water level and extrapolation techniques. The objective of this study was to analyze variations in the reservoir’s hourly outflow at Queimado Hydroelectric Power Plant (HPP Queimado) and to propose a method to evaluate whether the estimate of the daily outflows, obtained by the WB method, is similar to the flow values obtained at a conventional station. The logistic regression (LR) model was used because it is a method that adopts binary, categorically dependent variables to identify the event of interest. The results showed that the values of streamflow, obtained from an average of two daily readings, were a good representation of the flows in the region. The LR was able to identify atypical data, especially in the rainy season. This means that data consistency analysis can be faster and safer, when adequately employed and considering the proposed conditions, contributing to both management policies and the management of water resources.

DETERMINATION OF FLOOD DISCHARGE OF MOYAN WEIR WITH HEC-RAS PROGRAM

This research was conducted to obtain the right discharge plan in the irrigation area with a study of the amount of discharge that can be used upstream of the weir so that the water supply at the intake does not lack water. The Deras II Irrigation Area covering an area of 928 hectares, has 2 weirs as a source of irrigation water, namely the Moyan weir and Aur Weir. The upstream part of the Moyan weir is a sleeping area in the form of a swamp which farmers use to become a paddy field whose source of water comes from the swift river (upstream Moyan weir). With this water uptake, the impact on the flow of water entering the Moyan intake will be reduced, so it needs to be done with the numerical method approach of the HEC-RAS program. The results of this study are graphically depicted at each review station in the channel and the existing discharge obtained from the measurement of the speed with the current meter and water level from each cross-section along the irrigation channel. The simulation results are obtained with the condition of the river crossing, which is not filled, and the discharge is 0.024 m3/sec. The water level at the downstream cross-section is filled as high as 75 cm with a flow velocity of 0.783 m/sec, and the water level downstream of the irrigation channel is as high as 40 cm.

Understanding the processes in a historically relevant thermal and mineral spring water by using mixing and inverse geochemical models.

The thermal mineral water of Peñón de los Baños spa (Mexico City) has been used for over 500years starting in pre-Hispanic times and is famous for the treatment of various pathologies. It has a temperature of 45°C, which is rich in HCO3-, and its main trace elements are B, Li and Fe, which confers healing effects. Concerns about the sustainability of this important spa have motivated this study to understand the thermal system, possible hydraulic and hydrochemical changes over time and its implications. Stable water isotope data indicate that the thermal water sources originate from local precipitation at Sierra de las Cruces with a recharge elevation of approximately 2770m above sea level. The recharged water percolates through volcanic and carbonate rock formations and ascends via fault structure conduits, where it eventually is extracted 25km downstream in Peñon de los Baños. During the gravity-driven deep circulation of up to 4.9km, the groundwater is heated up to 136-160°C. A comparison of past and current water levels and water chemical analyses indicates a water table drop and few variations in the chemical composition, confirming the presence of anthropic impact on water quality. Due to the heavy groundwater extractions in Mexico City, the spring water flow has ceased, and water must be pumped now from a 203-m deep well. In addition, the concentration of bicarbonate, sodium and chloride has been reduced by half since the onset of groundwater development. The therapeutic effects of this thermal mineral water are at risk due to the alteration of the chemical signature. However, new and different therapeutical uses may prevent a future deterioration or closure of this historically important thermal spa. It is crucial to establish a monitoring program of the thermal mineral water and reducing or minimizing nearby urban extractions which tap the regional flow component to preserve the properties of the thermal water.