Water Management Plans Research Articles

Locally weighted learning based hybrid intelligence models for groundwater potential mapping and modeling: A case study at Gia Lai province, Vietnam

The groundwater potential map is an important tool for a sustainable water management and land use planning, particularly for agricultural countries like Vietnam. In this article, we proposed new machine learning ensemble techniques namely AdaBoost ensemble (ABLWL), Bagging ensemble (BLWL), Multi Boost ensemble (MBLWL), Rotation Forest ensemble (RFLWL) with Locally Weighted Learning (LWL) algorithm as a base classifier to build the groundwater potential map of Gia Lai province in Vietnam. For this study, eleven conditioning factors (aspect, altitude, curvature, slope, Stream Transport Index (STI), Topographic Wetness Index (TWI), soil, geology, river density, rainfall, land-use) and 134 wells yield data was used to create training (70%) and testing (30%) datasets for the development and validation of the models. Several statistical indices were used namely Positive Predictive Value (PPV), Negative Predictive Value (NPV), Sensitivity (SST), Specificity (SPF), Accuracy (ACC), Kappa, and Receiver Operating Characteristics (ROC) curve to validate and compare performance of models. Results show that performance of all the models is good to very good (AUC: 0.75 to 0.829) but the ABLWL model with AUC = 0.89 is the best. All the models applied in this study can support decision-makers to streamline the management of the groundwater and to develop economy not only of specific territories but also in other regions across the world with minor changes of the input parameters.

Projection of irrigation water demand based on the simulation of synthetic crop coefficients and climate change

Abstract. In the context of major changes (climate, demography, economy, etc.), the southern Mediterranean area faces serious challenges with intrinsically low, irregular, and continuously decreasing water resources. In some regions, the proper growth both in terms of cropping density and surface area of irrigated areas is so significant that it needs to be included in future scenarios. A method for estimating the future evolution of irrigation water requirements is proposed and tested in the Tensift watershed, Morocco. Monthly synthetic crop coefficients (Kc) of the different irrigated areas were obtained from a time series of remote sensing observations. An empirical model using the synthetic Kc and rainfall was developed and fitted to the actual data for each of the different irrigated areas within the study area. The model consists of a system of equations that takes into account the monthly trend of Kc, the impact of yearly rainfall, and the saturation of Kc due to the presence of tree crops. The impact of precipitation change is included in the Kc estimate and the water budget. The anthropogenic impact is included in the equations for Kc. The impact of temperature change is only included in the reference evapotranspiration, with no impact on the Kc cycle. The model appears to be reliable with an average r2 of 0.69 for the observation period (2000–2016). However, different subsampling tests of the number of calibration years showed that the performance is degraded when the size of the training dataset is reduced. When subsampling the training dataset to one-third of the 16 available years, r2 was reduced to 0.45. This score has been interpreted as the level of reliability that could be expected for two time periods after the full training years (thus near to 2050). The model has been used to reinterpret a local water management plan and to incorporate two downscaled climate change scenarios (RCP4.5 and RCP8.5). The examination of irrigation water requirements until 2050 revealed that the difference between the two climate scenarios was very small (< 2 %), while the two agricultural scenarios were strongly contrasted both spatially and in terms of their impact on water resources. The approach is generic and can be refined by incorporating irrigation efficiencies.

Virtual Water Trade as a creative water-saving technique

Understanding the idea and strategy of virtual water trade is critical for formulating informed policies to increase water usage efficiency at various levels. The implementation of the concept of virtual water as a creative water-saving technique in Egypt, however, is still in need of comprehensive testing, research, and feasibility evaluation. Egypt also requires extensive investigations, surveys, and feasibility evaluations. At present, as a percentage of water supplies, Egypt's net virtual water import has risen to 23.55 percent. The primary concern here is to apply virtual water as a strategy that meets the interests and goals set out in Egypt's National Water Management Plan. The key concern of this paper is investigating the general use of virtual water as a water-saving technique in Egypt. It outlines the water scarcity problem and its indicators, supply and demand for water resources in Egypt, and water scarcity forces in Egypt. Going to virtual water in economic ideas history, the definitions of virtual water and water footprint, then virtual water as an analytical instrument and a political strategy. Finally, water saving from virtual water trade and its advantages and disadvantages in Egypt. In order to follow the introduction of the virtual water definition in the national water management policy of Egypt, A clear vision and understanding of its advantages and disadvantages according to the conditions of Egypt is required. Further analysis and a thorough understanding of the impacts and experiences on the local social, economic, environmental, cultural, natural and political situation is needed for this new definition as a policy choice in Egypt.

HadGEM2 Küresel İklim Modeli Tahminine Dayalı Konya Kapalı Havzası İçin Olası Tarımsal Kurak Dönemleri

Drought is one of the most dangerous natural disasters that can have serious impacts on the economy and environmental systems, especially on living life. When compared with other disasters, drought has many differences with respect to structure. In particular, agricultural droughts cause great costs as well as serious consequences. According to the IPCC report of 2014, Turkey will increase in the future temperature scenarios rainfall is expected to decrease the contrast. When this situation is taken into consideration, it is estimated that the duration and severity of drought disasters likely to be experienced throughout our country will increase. The determination of agricultural droughts that are likely to occur in the future affects not only sustainable agricultural production but also all other production areas. In this study, the monthly rainfall series estimated up to 2100 under the optimistic (RCP 4.5) and pessimistic (RCP 8.5) conditions of the Representative Concentration Pathway (RCP) in the HADGEM2 global climate model for Konya Closed Basin were used. The obtained monthly rainfall series were analysis with Standardized Precipitation Index (SPI). As a result of the analysis of SPI, it was detected 4 agricultural drought periods (2043-2044, 2046-2047, 2086-2087 and 2090-2091) for RCP 4.5 scenario. According to RCP 8.5 scenario, it was detected 4 agricultural drought periods (2060- 2062, 2072-2074, 2092-2094 and 2095-2097). The severity distribution maps were prepare for the determined agricultural drought periods in the basin. It should be taken precautions in time against the water deficit that will occur in agricultural drought periods which may occur in Konya Closed Basin. In addition, losses in agricultural production should be minimized by preparing water management plans. Measures to be taken to reduce drought effects will directly contribute to the regional producer and contribute to the production and economy of the country.

Role of Integrated Approaches in Water Resources Management: Antofagasta Region, Chile

Water is essential for the survival of all living beings and plays a significant role in the growth of any country′s economy. At present, water depletion and pollution are a serious challenge due to anthropogenic, geogenic and climate change activities worldwide, including in Chile. The Antofagasta region is located in northern Chile and is the heart of its mining industry, playing a significant role in the country′s economy. The Antofagasta region′s main challenge is water shortage and contamination. Due to it, the region′s local population is facing major difficulties in obtaining the necessary water for domestic, industrial, irrigation, and other uses. Therefore, a water resources management plan is essential for the region to maintain a sustainable environment. Considering the above points, significant parameters, such as slope, aspect, elevation, hillshade, drainage, drainage density and river basin—maps of the Antofagasta region prepared using the digital elevation model (DEM) data in geographic information system (GIS) environment. Besides, a pollution risk level assessment of the study area′s cities/villages done using GIS application. The important created maps and the identification of pollution risk of cities/villages of the present study could provide significant information to policymakers and help them make a suitable water management plan for the area.

Interaction analysis of hydrochemical factors and dissolved heavy metals in the karst Caohai Wetland based on PHREEQC, cooccurrence network and redundancy analyses

In this study, to clarify the interaction between dissolved heavy metals and the coexisting chemical factors in karst wetland waters, surface water samples were collected from the Caohai Wetland during a water year, and the hydrochemistry and heavy metal pollution characteristics of the samples were analyzed. The main influencing factors of heavy metals in different water periods were identified through a cooccurrence network analysis. To further analyze the influence mechanism of these main influencing factors, the forms of heavy metals in the water were simulated with PHREEQC software, and the effects of these main influencing factors on the forms were analyzed by redundancy analysis. The results show that Ca2+ was the main cation in the wetland water, while the main anion was HCO3−. The hydrochemical facies of the Caohai Wetland in the wet and dry seasons were Ca-Mg-SO4-HCO3 and Ca-HCO3, respectively. Cd was the main pollutant in the Caohai Wetland, with Cd levels seriously exceeding the standards. The characteristics of the karst water in the Caohai Wetland are apparent. The cooccurrence network analysis shows that pH, dissolved oxygen (DO), electrical conductivity (EC), SO42− and HCO3− are the main factors regulating heavy metals. The results of morphological simulation and analysis were used to explore the mechanism of action of these factors. These data provide geochemical information useful for water quality assessment and management plans on heavy metal pollution.

Susceptibility to Gully Erosion: Applying Random Forest (RF) and Frequency Ratio (FR) Approaches to a Small Catchment in Ethiopia

Soil erosion by gullies in Ethiopia is causing environmental and socioeconomic problems. A sound soil and water management plan requires accurately predicted gully erosion hotspot areas. Hence, this study develops a gully erosion susceptibility map (GESM) using frequency ratio (FR) and random forest (RF) algorithms. A total of 56 gullies were surveyed, and their extents were derived by digitizing Google Earth imagery. Literature review and a multicollinearity test resulted in 14 environmental variables for the final analysis. Model prediction potential was evaluated using the area under the curve (AUC) method. Results showed that the best prediction accuracy using the FR and RF models was obtained by using the top four most important gully predictor factors: drainage density, elevation, land use, and groundwater table. The notion that the groundwater table is one of the most important gully predictor factors in Ethiopia is a novel and significant quantifiable finding and is critical to the design of effective watershed management plans. Results from separate variable importance analyses showed land cover for Nitisols and drainage density for Vertisols as leading factors determining gully locations. Factors such as texture, stream power index, convergence index, slope length, and plan and profile curvatures were found to have little significance for gully formation in the studied catchment.

Multi-Temporal Built-Up Grids of Brazilian Cities: How Trends and Dynamic Modelling Could Help on Resilience Challenges?

The northeastern Brazilian region has been vulnerable to hydrometeorological extremes, especially droughts, for centuries. A combination of natural climate variability (most of the area is semi-arid) and water governance problems increases extreme events’ impacts, especially in urban areas. Spatial analysis and visualisation of possible land-use change (LUC) zones and trends (urban growth vectors) can be useful for planning actions or decision-making policies for sustainable development. The Global Human Settlement Layer (GHSL) produces global spatial information, evidence-based analytics, and knowledge describing Earth’s human presence. In this work, the GHSL built-up grids for selected Brazilian cities were used to generate urban models using GIS (geographic information system) technologies and cellular automata for spatial pattern simulations of urban growth. In this work, six Brazilian cities were selected to generate urban models using GIS technologies and cellular automata for spatial pattern simulations of urban sprawl. The main goal was to provide predictive scenarios for water management (including simulations) and urban planning in a region highly susceptible to extreme hazards, such as floods and droughts. The northeastern Brazilian cities’ analysis raises more significant challenges because of the lack of land-use change field data. Findings and conclusions show the potential of dynamic modelling to predict scenarios and support water sensitive urban planning, increasing cities’ coping capacity for extreme hazards.

A Geospatial Study of Archaeological Remains at Halebidu: An Integrative Approach to Identify Unexplored Features

The site Halebidu in Karnataka, India, is famous for its ornately carved Hoysala style temples. This fortified city was the capital of Hoysala dynasty in the twelfth century AD and possessed unique and exquisite examples of temple architecture that was typical of Hoysala style, only a few of which have survived. The site of Halebidu features as one of the two sites in the "Sacred Ensembles of the Hoysala" in the tentative list of WHC (World Heritage Convention) since 2014 [ https://whc.unesco.org/en/tentativelists/5898/ (accessed on 1 January 2020).]. The other site being Belur, which was the old capital of the dynasty. The next and most important step towards attaining WH (World Heritage) status is for the State party [States Parties are countries which have adhered to the World Heritage Convention: https://whc.unesco.org/en/statesparties/ (accessed 24 Oct 2020)] to prepare a nomination file. INTACH, Bengaluru, has recently prepared the nomination dossier for the "Sacred Ensembles of the Hoysala" and has submitted to Archaeological Survey of India in Sept 2020. [ https://www.thehindu.com/news/national/karnataka/somanathapura-temple-included-for-world-heritage-site-nomination/article32709882.ece (accessed 24 Oct 2020).]. The description of the salient feature of Halebidu available on UNESCO’s WH web page lists several temples, tanks and mantap (pavilion). In addition to the ornate temples and tanks, the city was surrounded by a fort wall whose perimeter is approx. 7.3 km enclosing an area of 2.9 sq. km. surrounded by a deep and wide moat. The moat connected a series of tanks which indicates the planning of water management of the settlement. On ground, parts of the fort wall can still be seen. In accordance with the WHC criteria for geospatially identifying core and buffer zones, the property should include: (1) areas which are a direct tangible expression of the Outstanding Universal Value and (2) areas which in the light of future research possibilities offer potential to contribute to and enhance such understanding. Therefore, it is important for the nomination dossier to recognise the context of the temples in the larger landscape. Towards this agenda the present study has conducted geospatial analysis using old survey maps and remote sensing imagery and has found the extent of fort wall and demarcated several other archaeological features (unprotected and unexcavated mounds, archaeological islands in the largest tank, old settlement, and buried temples) that are worth including in the area identified for protection. The findings of this study can help the State Party in delineating the core and buffer zones in a rational and appropriate manner; hence, these have been conveyed to INTACH, Bengaluru, who prepared the nomination dossier for WH inscription.

IMPACT OF THE USE OF IRRIGATION WATER ON SOIL SALINIZATION CASE OF THE PALM GROVE OF BORDJ BEN AZOUZ BBA-BISKRA (ZIBAN OASIS, SOUTH-EASTERN ALGERIA)

This work deals with the physicochemical quality of water irrigation of agricultural land in the palm grove of Bordj ben Azouz. The aim is to evaluate their ability to irrigate palm groves and their effects on soil change under irrigation in the presence and / or absence of drainage. A hydro geochemical assessment of the groundwater, as well as drainage and. soil samples from irrigated and non-irrigated are performed. The electrical conductivity associated with the geochemical facies and SAR (Sodium adsorption Ratio) reflect a global salinity of the water irrigation, the drainage waters follow the same general trend as that the waters of the wells, the soils show a significant difference of the salinity between the irrigated / drained ones and the others not. The geochemical simulation was carried out using a thermodynamic model of the software Phreeqc Interactive 3.1.4-8929 indicates the supersaturation of the water with respect to the carbonate minerals and the under saturation for the evaporites where the gypsum is close to saturation even exceeds it so that it can precipitate itself by forming the gypso-limestone crust (Debdeb). To protect the environment from saline pollution, a sustainable water and salinity management plan must be installed as well as possible and continuous monitoring of the drainage system are required to remove salt water from irrigated soil.

Understanding the Long-Term Changes in Groundwater Level—A Tale of Highly Urbanized City

The rapid drop in the groundwater level has raised concerns in the sustainable water management plan in many cities of the world. It is important to understand the underlying factors of such depletion. To improve knowledge of the changes in groundwater, this study investigates a long-term perspective of urbanization, and evaluates the influence of several factors including land cover, water use, and abstraction. Multi-year land cover maps are used to detect urbanization and land cover types. Hotspot analysis and correlation-regression are applied to assess the relationship between changes in groundwater and the driving factors. The investigations confirm that an extensive withdrawal of groundwater due to urbanization results in a progressive drop in the water level. However, the major industrial and commercial zone shows the consistent hotspot of groundwater depletion. The results indicate that groundwater abstraction and types of water use have a high influence on the changes in urban groundwater.

Development of Soil Moisture Index for Planning Water Management in the State of Sikkim (India)

Soil moisture and soil temperature are two important parameters that have a wider implication on crop production. The drop of soil moisture and temperature has an impact involving climate, vegetation and drought. The presence of soil moisture does not ensure its availability to a crop but the force by which water is held by soil particle is important. The amount of work done to extract soil moisture is generally expressed as stress. It is necessary to understand the extent of stress for proper water resources management. The soil moisture index (SMI) is a criterion that denotes the extent of stress experienced by a crop. The temperature also has an impact on germination and production. In the present study, we developed a SMI for different locations in Sikkim. The index ranges from +5 to -5. The negative index indicates extreme stress. The study indicated during winter the index goes beyond-3. Considering wilting point stress as 500 and 700 kPa. The soil temperature was also observed to fall below 15 C. Further, it was observed that soil temperature and moisture are strongly correlated to each other. The SMI can play an important role in adopting suitable water management practices for improved crop production.

868. Investigations of Healthcare-Associated Elizabethkingia Infections – United States, 2013-2019

Background Elizabethkingia (EK) are non-motile gram-negative rods found in soil and water and are an emerging cause of healthcare-associated infections (HAIs). We describe Centers for Disease Control and Prevention (CDC) consultations for healthcare-associated EK infections and outbreaks.MethodsCDC maintains records of consultations with state or local health departments related to HAI outbreaks and infection control breaches. We reviewed consultations involving EK species as the primary pathogen of concern January 1, 2013 to December 31, 2019 and summarized data on healthcare settings, infection types, laboratory analysis, and control measures.ResultsWe identified 9 consultations among 8 states involving 73 patient infections. Long-term acute-care hospitals (LTACHs) accounted for 4 consultations and 32 (43%) infections, and skilled nursing facilities with ventilated patients (VSNFs) accounted for 2 consultations and 31 (42%) infections. Other settings included an acute care hospital, an assisted living facility, and an outpatient ear, nose, and throat clinic.Culture sites included the respiratory tract (n=7 consultations), blood (n=4), and sinus tract (n=1), and E. anophelis was the most commonly identified species. Six consultations utilized whole genome sequencing (WGS); 4 identified closely related isolates from different patients and 2 also identified closely related environmental and patient isolates.Mitigation measures included efforts to reduce EK in facility water systems, such as the development of water management plans, consulting water management specialists, flushing water outlets, and monitoring water quality, as well as efforts to minimize patient exposure such as cleaning of shower facilities and equipment, storage of respiratory therapy supplies away from water sources, and use of splash guards on sinks.ConclusionEK is an important emerging pathogen that causes HAI outbreaks, particularly among chronically ventilated patients. LTACHs and VSNFs accounted for the majority of EK consultations and patient infections. Robust water management plans and infection control practices to minimize patient exposure to contaminated water in these settings are important measures to reduce infection risk among vulnerable patients.Disclosures All Authors: No reported disclosures

Хот суурин газрын усны нөөцийн нэгдсэн менежментийн үнэлгээ: Чиг хандлага ба нөлөөллийн тогтолцоо

The large number of people living together in urban areas requires a comprehensive solutions for issues such as the reasonable allocation and adequate use of natural resources, urban planning, and efficient waste management to meet the city's needs. One of the main factors influencing the health and comfort of urban residents is the supply of clean water and sewerage systems. Therefore, in order to rationally allocate and use water resources to meet urban needs, and to create a healthy and comfortable living environment for city residents, it is necessary to develop an integrated water resources management plan at the national and basin levels, as well as an integrated water management plan and assessment for city level. In addition to assessing the current state of water management, it is important to identify factors and trends that may further strain water resources to prevent future risks. To address the pressures on water management in Ulaanbaatar and Darkhan, representing Mongolia's urban areas, the City Blueprint Approach, developed by the EU Water Innovation Partnership and the Dutch Institute of Water Cycle, was used in this study. Currently, this approach is used in about 80 cities in more than 40 countries, it is a relatively new and innovative method among Asian cities. As a result, water management in Ulaanbaatar and Darkhan is hampered by both social, economic, and environmental factors.

Characteristics of chloride loading from urban and agricultural watersheds during storm and non-storm periods

Abstract The chloride ion (Cl−) can adversely affect an aquatic ecosystem, but it is not clear how Cl− moves with runoff and how its transport processes are related to land uses and land cover. This study investigated how the loading characteristics of Cl− vary depending on storm events and land cover in a temperate region. We monitored Cl− concentrations in three study watersheds that have different compositions of urban and agricultural land uses. In addition, a Mass First Flush ratio (MFFn) was determined to quantify the effect of first flush on Cl− loading. Overall, the observed concentrations and loadings in this study were found to be less than those reported in cold northern regions. The monitoring data showed that Cl− concentrations and loads observed in an urban watershed were significantly larger than those of a rural watershed. The results suggest water management plans should focus on urbanized areas and their storm water to efficiently reduce chloride loading to downstream waterbodies. However, a further study is recommended to identify the sources and pathways of Cl− loaded to waterbodies.

Understanding Volumetric Water Storage in Monsoonal Wetlands of Northeastern Bangladesh

AbstractThe volume of water stored in seasonal wetlands is a fundamental but difficult to measure variable for developing a physical understanding of wetland behavior. For seasonal wetlands that are a major source of water for rice and fish production, this physical understanding is key to planning for water‐food security and ecosystem services. This study quantified variations in volumetric storage for the numerous seasonal wetlands of northeastern Bangladesh, locally known as “haors.” These haors receive transboundary runoff from densely vegetated and mountainous terrain in India and face persistent monsoonal cloud cover as they become full. We estimated volumetric storage for 13 haors by using extensive remote sensing data on water surface extent and elevation that was complemented with citizen‐contributed gauge data. Assuming a trapezoidal bathymetry, an area‐volume relationship was developed for selected haors. This relationship was assumed to be valid for extrapolating volumetric estimations over all the haors in the region. Results suggested that as haors get filled with the onset of monsoon rains, total estimated storage relative to the lowest observable level varied from 6.5 (±0.4) km3 in May to 30.9 (±2.0) km3 in July (peak of monsoon). Choosing a rectangular bathymetry can lead to 47% higher estimates compared to trapezoidal cross section. Estimating this intra‐annual/interannual increase in storage is important for the region to plan water management policies that balance the human and ecosystem needs. Our analytical approach has potential for application to wetlands worldwide in light of the upcoming Surface Water and Ocean Topography (SWOT) mission.

Variability and Trend Analysis of Rainfall Data of Shillong and Agartala Stations of North East India

This paper discusses the variability in rainfall and trend analysis of annual and seasonal rainfall time series of Shillong and Agartala stations located in the north-east region of India. Commonly used non-parametric statistical methods namely Mann-Kendall and Sen’s slope estimator was used to analyse the seasonal and annual rainfall time series. Statistical analysis showed less variation in annual and south-west monsoon rainfall for both Shillong and Agartala stations. In the total annual rainfall, the share of south-west (SW) monsoon, north-east (NE) monsoon, winter season and summer season rainfall was observed 64.60%, 13.22%, 1.40% and 20.80%, respectively for Shillong station of Meghalaya state. However, the contribution of SW monsoon, NE monsoon, winter season and summer season rainfall in the total annual rainfall was 59.59%, 9.55%, 1.14% and 29.72%, respectively for Agartala station of Tripura state. Non-significant increasing trends of rainfall was observed by 4.54 mm/year, 2.80 mm/year and 2.54 mm/year for annual, SW monsoon, and summer season, whereas, non-significant decreasing trends in rainfall for NE monsoon and winter season was observed with a magnitude of 1.83 mm/year and 1.63 mm/year for Shillong, Meghalaya during 1992 to 2017. Results also revealed that rainfall increased by 1.07 mm/year and 0.18 mm/year in SW monsoon and winter season whereas, rainfall decreased by 7.64 mm/year, 2.58 mm/year and 1.29 mm/year during annual, NE monsoon and summer season non-significantly during 1995 to 2019 in case of Agartala. The findings of present study will be useful for water management and crop planning in hill agriculture of Meghalaya and Tripura state of India.

Water Scarcity: Problems and Possible solutions

Iraq relies in its water resources on the Rivers Tigris and Euphrates and their tributaries. It used to be considered rich in its water resources until 1970. Then, the water quantity started to decrease due to the construction of hydrological projects within the riparian countries as well as the effect of climate change. In addition, water management planning in Iraq requires number of strategies that can help to overcome the water shortage problem. In this work, the negative problems are discussed and solutions are given to solve the water shortage problem. Keywords: Water Scarcity, Tigris, Euphrates, Climate Change, Iraq.

Natural Hydrogeochemical Background Levels in the Carste Lagoa Santa Protection Unit, Minas Gerais, Brazil

The identification of hydrogeochemical anomalies in karst water resources represents a crucial step in Brazil's water management plans. Accelerated urban and industrial development occurs in the region that includes the Carste Lagoa Santa Protection Unit, State of Minas Gerais, which may negatively impact its water quality. This paper establishes Natural Background Levels (NBL) of waters collected from deep tubular wells and springs for Si4+, Ca2+, Mg2+, Na+, K+, HCO3−, SO42, Cl− to understand sources of possible geogenic and anthropogenic anomalies. Areas with surpassed thresholds were compared with geological, hydrogeochemical, and land use data. Every parameter, except for chloride, showed elevated concentrations due to lithologic origin. The NBLs for waters of wells and springs are, respectively, 17.9 and 12.7 mg/L (silica), 97.0 and 91.5 mg/L (calcium), 4.9 and 2.9 mg/L (magnesium), 6.2 and 3.8 mg/L (sodium), 1.0 and 0.3 mg/L (potassium), 285.5 and 254.6 mg/L (bicarbonate), 9.4 and 13.6 mg/L (sulfate). Chloride, analyzed only in groundwater, presented 6.7 mg/L indicating a possible influence of upstream urban areas of Lagoa Santa and Pedro Leopoldo municipalities. Volatile and Semivolatile Organic Compounds were also analyzed, but all of them were below the detection limit. This work is important to comprehend the NBL of major elements, reveal geogenic anomalies, and distinguish carbonate aquifer units from the impure ones.

Future Changes in the Hydrologic Cycle Associated with Flood-Producing Storms in California

AbstractCalifornia receives much of its precipitation from cool-season atmospheric rivers, which contribute to water resources and flooding. In winter 2017, a large number of atmospheric rivers caused anomalous winter precipitation, near-saturated soils, and a partial melting of snowpack, which led to excessive runoff that damaged the emergency spillway of the Oroville Dam. Given the positive and negative impacts ARs have in California, it is necessary to understand how they will change in a future climate. While prior studies have examined future changes in the frequency of atmospheric rivers impacting the West Coast of the United States, these studies primarily use coarse global climate models that are unable to resolve the complex terrain of this region. Such a limitation is overcome by using a high-resolution convection-permitting regional climate model, which resolves complex topography and orographic rainfall processes that are the main drivers of heavy precipitation in landfalling atmospheric rivers. This high-resolution model is used to examine changes to precipitation and runoff in California’s cool season from 2002 to 2013, particularly in flood-producing storms associated with atmospheric rivers, in a future, warmer climate using a pseudo–global warming approach. In 45 flood-producing storms, precipitation and runoff increase by 21%–26% and 15%–34%, respectively, while SWE decreases by 32%–90%, with the greatest changes at mid-elevations. These trends are consistent with future precipitation changes during the entire cool season. Results suggest more intense floods and less snowpack available for water resources in the future, which should be carefully considered in California’s future water management plans.