Water Resources Scientists Research Articles

Impact of climate change on the distribution of the invasive water hyacinth in Ethiopia

The introduction of exotic species poses one of the greatest threats to biodiversity globally. Water hyacinth is a dangerous invasive species that has harmed Ethiopia’s wetland ecology and economy. This research aims to evaluate the current distribution of water hyacinth and the impact of environmental variables on its spread, while also mapping future habitat suitability under climate change scenarios and assessing how these changes may influence the species' potential expansion. To estimate the risks of climate change to the species, a predictive model was developed from six modeling methodologies to investigate the climatic suitability of target species for the years 2050 and 2070 under two Representative Concentration Pathway (RCP) scenarios (RCP4.5 and RCP 8.5). Under the current climatic scenario, only 69.78% (789 503.8 km2) and 16.02% (181 262.8 km2) of the country is moderately and highly suitable for species dispersion and invasion respectively. The remaining 14.2% (160 620.9 km2) is unsuitable for the distribution and invasion of the species. In 2050, under the RCP4.5 and RCP 8.5, the ‘highly suitable’ range of water hyacinth is anticipated to expand by 16.35% and 15.39%, whereas the ‘moderately suitable’ area is predicted to increase by 70.81% and 71.52%, respectively. Under the RCP8.5 scenarios, compared to the current climatic conditions, in 2070 the ‘highly suitable’ region for the species is expected to increase by 11.48%. Its continuing growth would exacerbate the issue of ecological and economic crisis, cause significant economic and environmental harm and endanger the community’s way of life. In order to avert or reduce these effects, a thorough examination of water hyacinth along the two RCPs by water resource scientists and mamangers, that takes into account how climate change is affecting water hyacinth growing locations in Ethiopia, and provides a proper solution, is mandatory.

A conceptual model for water resources circulation patterns in Andarokh-Kardeh region (NE, Iran)

Andarokh-Kardeh region is located northeast of Iran and provides notable part of potable water of Mashhad, the second most populated city of Iran with over 3 million inhabitants. Stable isotopes (18O, 2H and 13C), hydrodynamic, and hydrochemical indicators have been applied to evaluate water resources quality comprehensively and to present a hydrogeological conceptual model for the Andarokh-Kardeh region. Hydrochemical studies indicate that chemical rock weathering and ion exchange are the main factors controlling the quality of water in the region, while atmospheric (precipitation) as well as anthropogenic sources have no notable effect. Stable isotopes (18O and 2H) studies in surface and groundwater samples demonstrate enriched values in Kardeh Dam Reservoir (KDR) due to evaporation and also demonstrate that the interaction between KDR and downstream groundwater resources is negligible. The δ13C isotope and DIC and DOC concentrations indicate role of carbonate mineral dissolution from Mozdooran Formation, atmospheric and soil CO2 and also the domination of C3 vegetation coverage in the study region. The developed conceptual model for Andarokh-Kardeh demonstrates different hydrogeological conditions during wet and dry periods, and highlights the main process which affect hydrogeology of the region. Water quality studies and the developed conceptual model demonstrate the main factors controlling water quality and the main hydrogeological characteristic of Andarokh-Kardeh region which can be used by water resources scientists for the future water management programmes.

A Transdisciplinary Review of Deep Learning Research and Its Relevance for Water Resources Scientists

AbstractDeep learning (DL), a new generation of artificial neural network research, has transformed industries, daily lives, and various scientific disciplines in recent years. DL represents significant progress in the ability of neural networks to automatically engineer problem‐relevant features and capture highly complex data distributions. I argue that DL can help address several major new and old challenges facing research in water sciences such as interdisciplinarity, data discoverability, hydrologic scaling, equifinality, and needs for parameter regionalization. This review paper is intended to provide water resources scientists and hydrologists in particular with a simple technical overview, transdisciplinary progress update, and a source of inspiration about the relevance of DL to water. The review reveals that various physical and geoscientific disciplines have utilized DL to address data challenges, improve efficiency, and gain scientific insights. DL is especially suited for information extraction from image‐like data and sequential data. Techniques and experiences presented in other disciplines are of high relevance to water research. Meanwhile, less noticed is that DL may also serve as a scientific exploratory tool. A new area termed AI neuroscience, where scientists interpret the decision process of deep networks and derive insights, has been born. This budding subdiscipline has demonstrated methods including correlation‐based analysis, inversion of network‐extracted features, reduced‐order approximations by interpretable models, and attribution of network decisions to inputs. Moreover, DL can also use data to condition neurons that mimic problem‐specific fundamental organizing units, thus revealing emergent behaviors of these units. Vast opportunities exist for DL to propel advances in water sciences.

Hyphenated hydrology: Interdisciplinary evolution of water resource science

AbstractHydrology has advanced considerably as a scientific discipline since its recognized inception in the mid‐twentieth century. Modern water resource related questions have forced adaptation from exclusively physical or engineering science viewpoints toward a deliberate interdisciplinary context. Over the past few decades, many of the eventual manifestations of this evolution were foreseen by prominent expert hydrologists. However, their narrative descriptions have lacked substantial quantification. This study addressed that gap by measuring the prevalence of and analyzing the relationships between the terms most frequently used by hydrologists to define and describe their research. We analyzed 16,591 journal article titles from 1965–2015 in Water Resources Research, through which the scientific dialogue and its time‐sensitive progression emerged. Our word frequency and term cooccurrence network results revealed the dynamic timing of the lateral movement of hydrology across multiple disciplines as well as the deepening of scientific discourse with respect to traditional hydrologic questions. The conversation among water resource scientists surrounding the hydrologic subdisciplines of catchment‐hydrology, hydro‐meteorology, socio‐hydrology, hydro‐climatology, and eco‐hydrology gained statistically significant momentum in the analyzed time period, while that of hydro‐geology and contaminant‐hydrology experienced periods of increase followed by significant decline. This study concludes that formerly exotic disciplines can potentially modify hydrology, prompting new insights and inspiring unconventional perspectives on old questions that may have otherwise become obsolete.

Impact of Global Climate Change on Stream Low Flows in a Hydraulic Fracking Affected Watershed

The impact of fresh water withdrawals for hydraulic fracturing has concerned water resource scientists and communities interested in sustainable water resource management. Specifically, low flow conditions in watersheds may be further reduced due to global climate change, as it has the potential to decrease streamflow. Since an earlier study found that the current rate of fracking had some impact on water availability, this study was conducted in order to ascertain whether or not the current fracking trend will have an impact in stream low flow in the future. This study was conducted on the Muskingum watershed in Eastern Ohio, which has been subjected to the rapid expansion of hydraulic fracking. The watershed model, Soil and Water Assessment Tool (SWAT), was used for watershed simulation using the climate output of Coupled Model Intercomparison Project Phase 5 (CMIP5). Precipitation and temperatures outputs from Max Planck Institute Earth System Model (MPI-ESM) were used to evaluate the variation in streamflow during the 21 st century using three Representative Concentration Pathways (RCP) scenarios: RCP 2.6; RCP 4.5; and RCP 8.5. Three future periods, namely, 2035s (2021-2050), 2055s (2051-2070) and 2085s (2070-2099) were set against the baseline condition (1995-2009). Lowest flow was projected to increase across the watershed during 2035s period compared to the remaining 50 years period, under the highest forced climate scenario (RCP8.5). Similarly, mean flow also could be expected to decrease during 2035s in the eastern, north-western and south western portion of the watershed. Additionally, the streamflow was simulated using current fracking scenarios and 2035s climate output in order to assess the impact of water withdrawal for a continuous trend of current fracking rates. A modest effect on stream low flow was detected, when extreme scenario (RCP 8.5) was considered, especially in the headwater streams. While results indicate that 14 of 32 subbasins were affected, with maximum difference up to 55% in lowest 7 days minimum low flow (considered lowest value from each year), negligible impact was detected on mean monthly and annual streamflow. Analysis with RCP 2.6 and RCP 4.5 indicated that stream low flow would not be affected especially in higher order streams. Even though a localized effect of hydraulic fracking to reduce the environmental flow was detected; this research indicated that future climate change may not have additional adverse impacts if hydraulic fracking trends are stable.

Integral and Closed-Form Analytical Solutions to the Transport Contaminant Equation Considering 3D Advection and Dispersion

AbstractEven though numerical procedures have been tremendously enhanced over the last years, analytical closed-form solutions are of special interest to water resources scientists. In general, these solutions are used to check the consistency and validate numerical routines. Bibliographical research reveals that up-to-date analytical solutions only take into account one-dimensional (1D) advection, even when three-dimensional (3D) dispersion is considered. This assumption creates an axis dependency because the flux is assumed to be parallel to one of the three possible orthogonal directions, which does not apply to all practical situations in which diagonal advection is present. In this work an analytical solution is derived for the 3D advective-dispersive equation (ADE) by means of Fourier and Laplace integral transforms. The solution allows the contaminant plume to move angularly with respect to the coordinate axes.

Numerical simulation of water resources problems: Models, methods, and trends

Mechanistic modeling of water resources systems is a broad field with abundant challenges. We consider classes of model formulations that are considered routine, the focus of current work, and the foundation of foreseeable work over the coming decade. These model formulations are used to assess the current and evolving state of solution algorithms, discretization methods, nonlinear and linear algebraic solution methods, computational environments, and hardware trends and implications. The goal of this work is to provide guidance to enable modelers of water resources systems to make sensible choices when developing solution methods based upon the current state of knowledge and to focus future collaborative work among water resources scientists, applied mathematicians, and computational scientists on productive areas.

Meeting the Need for Water Resource Professionals: Recruiting More Women and Minorities

I decided to write this article after the sixth or seventh time a student or colleague glanced at the cover of the June 2008 issue of the Journal of Contemporary Water Research and Education (Issue 139, entitled: A Creative Critique of U.S. Water Education”) and asked me, “Why does this cover feature only elderly white men?” followed by, “aren’t there any distinguished women (or minorities) in this field?” Let me begin by saying that there is nothing wrong with honoring those whose photographs currently grace the cover of the JCWRE Issue 139. We just need another row or two to make room for engineers and scientists like Linda Abriola, Diane McKnight and Christine Shoemaker; or perhaps for Sylvia Bozeman, a professor at Spelman College and co-founder of the Enhancing Diversity in Graduate Education (EDGE) program, or S. George Philander, professor of oceanic and atmospheric sciences and one of the few AfricanAmerican members of the National Academy of Sciences (Figure 1). We have made progress in becoming a more diverse community – we should let the world know! The need to include some discussion of diversity when we are exploring ways to address the problems facing U.S. Water Resources Education was reinforced as I read through the articles in the journal issue. While documenting the increasing demand for engineers, hydrologists, and water resource professionals, and concerns over the ability of the U.S. educational system to supply those needs, the articles neglected to discuss the great potential to increase that supply through recruitment of women and minorities. For example, in an article examining the reasons why the U.S. is not producing enough engineers at all levels, Rogers (2008) fails to mention that if more women and minorities pursued bachelor’s degrees and careers in engineering and physical sciences, we could greatly increase the number of U.S. engineers and water resources scientists. In addition, none of the articles in this issue mentioned the benefits of the new perspectives, research directions, and innovative approaches that could result from the recruitment of a more diverse cohort of students, and eventually colleagues, in the water resources professions. In this article I wish to make four points:

Impacts of the 2004 tsunami on groundwater resources in Sri Lanka

The 26 December 2004 tsunami caused widespread destruction and contamination of coastal aquifers across southern Asia. Seawater filled domestic open dug wells and also entered the aquifers via direct infiltration during the first flooding waves and later as ponded seawater infiltrated through the permeable sands that are typical of coastal aquifers. In Sri Lanka alone, it is estimated that over 40,000 drinking water wells were either destroyed or contaminated. From February through September 2005, a team of United States, Sri Lankan, and Danish water resource scientists and engineers surveyed the coastal groundwater resources of Sri Lanka to develop an understanding of the impacts of the tsunami and to provide recommendations for the future of coastal water resources in south Asia. In the tsunami‐affected areas, seawater was found to have infiltrated and mixed with fresh groundwater lenses as indicated by the elevated groundwater salinity levels. Seawater infiltrated through the shallow vadose zone as well as entered aquifers directly through flooded open wells. Our preliminary transport analysis demonstrates that the intruded seawater has vertically mixed in the aquifers because of both forced and free convection. Widespread pumping of wells to remove seawater was effective in some areas, but overpumping has led to upconing of the saltwater interface and rising salinity. We estimate that groundwater recharge from several monsoon seasons will reduce salinity of many sandy Sri Lankan coastal aquifers. However, the continued sustainability of these small and fragile aquifers for potable water will be difficult because of the rapid growth of human activities that results in more intensive groundwater pumping and increased pollution. Long‐term sustainability of coastal aquifers is also impacted by the decrease in sand replenishment of the beaches due to sand mining and erosion.

DISCUSSION1

Water resource scientists, planners, and managers need to know what hydrology changes to expect due to CO{sub 2}-induced climate warming. McCabe and Ayer's study is a useful first-cut approximation of how climate change might affect seasonal soil moisture and runoff in the Delaware River basin. However, I question that the findings of this study are in agreement with those obtained in other climate-change studies. The change in runoff agree in direction, but the magnitudes differ according to region. Ayers estimated that unless precipitation increases, climate warming will cause a decrease in runoff. Will the effect of increased atmospheric CO{sub 2} on reduced transpiration rates be a major factor influencing runoff That depends on seasonal distribution of precipitation and distribution and quantity of transpiring vegetation. The effect of CO{sub 2}-induced climate warming on watershed hydrology will be complex. Runoff changes may result from several competing factors including: warmer temperatures, changes in quantity and seasonal distribution of precipitation, changes in cloudiness, windiness, and humidity, changes in soil wetness, increased length of the growing season, increased transpiration leaf area, increased leaf temperatures, species changes in vegetation communities, increased plant water used efficiency, decreased stomatal conductance and decreased stomate density due to increased CO{submore » 2}.« less

MEETING THE CHALLENGE OF POLICY‐RELEVANT SCIENCE: LESSONS FROM A WATER RESOURCE PROJECT1

ABSTRACT: Water resource scientists face complex tasks in evaluating aspects of water projects, but relatively few assessment procedures have been applied and accepted as standard applications. Decision‐makers often rely on environmental assessments to evaluate the value and operation of projects. There is often confusion about scientists' role in policy decisions. The scientist can affect policy‐making as an expert withess, an advocate or a surrogate. By understanding the policy process, scientists can make their work more “policy relevant.” Using the Terror Lake hydro project in Alaska as a guide, three lessons are discussed: (1) not all problems are able to be solved with technology; (2) policy‐relevant technology is rarely imposed on a problem; and (3) the scientist need not just react to the policy process, but can have an impact on how that process unfolds.

Groundwater Policies in the Agricultural Midwestern United States

ABSTRACT Groundwater quality in the agricultural states of Iowa, Kansas, Missouri, and Nebraska (U.S.A.) is found to vary with depth, location and ownership of well, time of sampling, and geological features. Shallow wells are much more susceptible to contamination than deep ones from surface sources. It is observed that depth and non-uniform well construction practices are two major determinants of ground-water quality. Statutes in these states recognize pesticides and herbicides as potential sources of contamination, but at this time do not specifically include any provisions to protect groundwater from contamination by other sources. This paper describes the status of groundwater quality conditions in the states of Iowa, Kansas, Missouri and Nebraska and discusses research priorities and potential policy options for the protection of groundwater in these states. These discussions would be of value to water resource scientists, planners and administrators, especially those in regions of the world where ...