Steven M. Gorelick

Stanford University | SU · Earth System Science

In countries where severe drought is an anticipated effect of climate change and in those that heavily depend on upstream nations for fresh water, the effect of drier conditions and consequent changes in the transboundary streamflow regime induced by anthropogenic interventions and disasters leads to uncertainty in regional water security. As a cas...

Significance The notion that sudden impacts on shared international waters can be detected and quantified, even in a war zone, is important to scientists and policy makers, who have been stifled in the past by inaccessibility to such regions and the consequent inability to collect relevant data. Our study uses satellite imagery of war-torn Syria, s...

Transboundary aquifers are ubiquitous and strategically important to global food and water security. Yet these shared resources are being depleted at an alarming rate. Focusing on the Disi aquifer, a key nonrenewable source of groundwater shared by Jordan and Saudi Arabia, this study develops a two-stage game that evaluates optimal transboundary st...

Intertidal marshes develop between uplands and mudflats, and develop vegetation zonation, via biogeomorphic feedbacks. Is the spatial configuration of vegetation and channels also biogeomorphically organized at the intermediate, marsh-scale? We used high-resolution aerial photographs and a decision-tree procedure to categorize marsh vegetation patt...

Groundwater exploitation is a major cause of land subsidence, which in coastal areas poses a flood inundation hazard that is compounded by the threat of sea-level rise (SLR). In the lower Mekong Delta, most of which lies <2 m above sea level, over-exploitation is inducing widespread hydraulic head (i.e., groundwater level) declines. The average rat...

Driven by the need for integrated management of groundwater (GW) and surface water (SW), quantification of GW–SW interactions and associated contaminant transport has become increasingly important. This is due to their substantial impact on water quantity and quality. In this review, we provide an overview of the methods developed over the past sev...

Scarce and unreliable urban water supply in many countries has caused municipal users to rely on transfers from rural wells via unregulated markets. Assessments of this pervasive water re-allocation institution and its impacts on aquifers, consumer equity and affordability are lacking. We present a rigorous coupled human–natural system analysis of...

Over the past several decades, China has rapidly depleted groundwater storage, and has lagged in managing and protecting this resource. As a result, dried up rivers, land subsidence, saltwater intrusion, and wetland losses are extensive. To assist with managing this vital groundwater resource, we constructed the first national-scale numerical groun...

Large cities worldwide are increasingly suffering from a nexus of food, water, and energy supply challenges. This complex nexus can be analyzed with modern physico-economic system models. Only when practical knowledge from those affected, experts, and decision makers is incorporated alongside various other data sources, however, are the analyses su...

Systems models of the Food–Water–Energy (FWE) nexus face a conceptual difficulty: the systematic integration of local stakeholder perspectives into a coherent framework for analysis. We present a novel procedure to co-produce and systematize the real-life complexity of stakeholder knowledge and forge it into a clear-cut set of challenges. These are...

In India, the second-largest sugarcane producing country in the world, accurate mapping of sugarcane land is a key to designing targeted agricultural policies. Such a map is not available, however, as it is challenging to reliably identify sugarcane areas using remote sensing due to sugarcane’s phenological characteristics, coupled with a range of...

Wetlands worldwide are under threat from anthropogenic impacts. In large protected North American areas such as Yellowstone and Wood Buffalo National Parks, aquatic habitats are disappearing and wetland-dependent fauna are in decline1–3. Here we investigate population dynamics of an indicator species in Canada’s Peace-Athabasca Delta (“the delta”),...

We document a substantial increase in global N2O emissions from mangroves. Based on our analysis of two decades of mangrove N2O emission studies, we estimate N2O emission of 0.023 Tg N year−1 from global mangrove ecosystems. N2O fluxes from mangrove ecosystems are strongly increased by sediment dissolved inorganic nitrogen (DIN) concentration trans...

Significance Jordan is facing an unfolding water crisis, exacerbated by climate change and conflict-induced refugee influxes. We present a freshwater security analysis for the country, enabled by an integrated systems model that combines simulation of Jordan’s natural and built water environment with thousands of representative human agents determi...

Using CWatM to model water resources on the Bhima basin in India. This basin is highly anthropized and with a moonson climate, a big challenge for hydrological models. We developped the coupling between CWatM and a groundwater flow model. We included important human impacts on water resources (water demand fed by either reservoirs management throug...

Sugar is the second largest agro-based industry in India and has a major influence on the country's water, food, and energy security. In this paper, we use a nexus approach to assess India's interconnected water-food-energy challenges, with a specific focus on the political economy of the sugar industry in Maharashtra, one of the country's largest...

Managed aquifer recharge (MAR) enhances freshwater security and augments local groundwater supplies. However, geochemical and hydrological shifts during MAR can release toxic, geogenic contaminants from sediments to groundwater, threatening the viability of MAR as a water management strategy. Using reactive transport modeling coupled with aquifer a...

To support the increasing demand of a growing population for freshwater, small-sized (<0.1 km ² ) water reservoirs are necessary in areas with limited infrastructure, especially in water-stressed regions having seasonal and variable precipitation. Seasonal storage in small reservoirs is often overlooked in present inventories. Accordingly, we asses...

Ecosystem service approaches to watershed management have grown quickly, increasing the importance of understanding the streamflow response to realistic land-cover change. Previous work has investigated the relationship between watershed characteristics and streamflow in catchments around the world, but little has focused on systematic relationship...

The quantification of impervious surface through remote sensing provides critical information for urban planning and environmental management. The acquisition of quality reference data and the selection of effective predictor variables are two factors that contribute to the low accuracies of impervious surface in urban remote sensing. A hybrid meth...

Semiaquatic muskrat (Ondatra zibethicus) are in decline throughout their native range. We report on the environmental and behavioural mechanisms responsible for a half‐century of muskrat decline in a model system floodplain region of the Peace–Athabasca Delta (“Delta”). Using the Landsat satellite record, trapping and population survey records, and...

Increased water yield and baseflow and decreased peak flow are common goals of watershed service programs. However, is the forest management often used in such programs likely to provide these beneficial watershed services? Many watershed service investments such as water funds typically change less than 10% of watershed land cover. We simulate the...

Cholera has been eliminated as a public health problem in high-income countries that have implemented sanitation system separating the community's fecal waste from their drinking water and food supply. These expensive, highly-engineered systems, first developed in London over 150 years ago, have not reached low-income high-risk communities across A...

Empirical and anecdotal reports suggest that muskrat are in decline across North America, including in the Peace-Athabasca Delta ('Delta'), Canada, one of the largest inland deltas in the world and part of a World Heritage Site with 'in Danger' status pending. Muskrat are a key ecological indicator in the Delta. We investigate whether the large-sca...

A U.S. court decision unlocks vast potential to improve sustainable freshwater management

Evaporation from the water surface of a reservoir can significantly affect its function of ensuring the availability and temporal stability of water supply. Current estimations of reservoir evaporative loss are dependent on water area derived from a reservoir storage-area curve. Such curves are unavailable if the reservoir is located in a data-spar...

The estimation of spatially-variable actual evapotranspiration (AET) is a critical challenge to regional water resources management. We propose a new remote sensing method, the Triangle Algorithm with Variable Edges (TAVE), to generate daily AET estimates based on satellite-derived land surface temperature and the vegetation index NDVI. The TAVE ca...

Rice production in Cambodia, essential to food security and exports, is largely limited to the wet season. The vast majority (96%) of land planted with rice during the wet season remains fallow during the dry season. This is in large part due to lack of irrigation capacity, increases in which would entail significant consequences for Cambodia and V...

Physical, chemical, and biological factors influence vegetation zonation in salt marshes and other wetlands, but connections among these factors could be better understood. If salt marsh vegetation and marsh pore water geochemistry co-organize, e.g., via continuous plant water uptake and persistently unsaturated sediments controlling vegetation zon...

1) To develop a hydroeconomic model that combines spatially explicit simulation of hydrologic systems with hierarchical, multi-agent representation of human decision-making that is designed for comprehensive scenario and intervention analysis. 2) To learn about freshwater provision in an arid region where there is a poor understanding of the combin...

Global freshwater vulnerability is a product of environmental and human dimensions, however, it is rarely assessed as such. Our approach identifies freshwater vulnerability using four broad categories: endowment, demand, infrastructure, and institutions, to capture impacts on natural and managed water systems within the coupled human–hydrologic env...

Vilarrasa and Carrera (1) dissent from our view (2) that pore pressure increases resulting from large-scale CO2 injection could potentially trigger earthquakes that would threaten long-term CO2 storage. Since our article appeared, the National Academy of Sciences (3) has expressed an even greater concern about large-scale carbon capture and storage...

Jordan, with limited rainfall, has per capita water availability of 135 m3/yr making it one of the water-poorest countries in the world. We analyzed the most comprehensive modern rainfall data set to date, consisting of 44 years of daily measurements from 58 stations primarily in the western, populated and agricultural portion of Jordan over the pe...

With rivers in critical regions already exploited to capacity throughout the world and groundwater overdraft as well as large-scale contamination occurring in many areas, we have entered an era in which multiple simultaneous stresses will drive water management. Increasingly, groundwater resources are taking a more prominent role in providing fresh...

Salem, Oregon was inadvertently included in the analysis, but it does not meet the study threshold population of 750 000 people. This reduces the number of cities in this study from 71 to 70. Changes to figure 1, and tables 1, 2 and 3 as well as the text are shown below. The changes do not affect the overall results or conclusions.

This study presents a global analysis of urban water supply vulnerability in 71 surface-water supplied cities, with populations exceeding 750 000 and lacking source water diversity. Vulnerability represents the failure of an urban supply-basin to simultaneously meet demands from human, environmental and agricultural users. We assess a baseline (201...

Understanding the characteristics of high-quality avian habitat is critical for guiding salt marsh management and restoration. Existing insights into salt marsh avian habitat are often based on the composition of marsh vegetation, e.g., individual plant species cover. This study investigated whether the spatial configuration of marsh surface cover...

Groundwater exploitation is rising in the Mekong Delta, Vietnam, potentially exacerbating arsenic contamination from natural sources. We investigate trends and controls on contamination patterns throughout the Delta's multi-aquifer system as observed in a spatially exhaustive data set of arsenic measured in >40,000 wells, 10.5% of which exceed the...

The San Francisco Estuary, California, contains mercury (Hg) contamination originating from historical regional gold and Hg mining operations. We measured hydrological and geochemical variables in a tidal marsh of the Palo Alto Baylands Nature Preserve to determine the sources, location, and magnitude of hydrological fluxes of methylmercury (MeHg),...