Charles F Harvey

Charles F Harvey
Massachusetts Institute of Technology | MIT · Department of Civil and Environmental Engineering

PhD Stanford University

About

191
Publications
41,928
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
9,573
Citations
Citations since 2017
48 Research Items
3883 Citations
20172018201920202021202220230200400600
20172018201920202021202220230200400600
20172018201920202021202220230200400600
20172018201920202021202220230200400600

Publications

Publications (191)
Article
Full-text available
Groundwater supports agriculture and provides domestic water for over 250 million people in the Bengal Basin. Here we investigate the source of groundwater recharge using over 2500 stable water isotope measurements from the region. We employ a Monte Carlo statistical analysis to find distributions of possible components of recharge by accounting fo...
Article
Full-text available
Tropical peatlands are estimated to hold carbon stocks of 70 Pg C or more as partly decomposed organic matter, or peat. Peat may accumulate over thousands of years into gently mounded deposits called peat domes with a relief of several meters over distances of kilometers. The mounded shapes of tropical peat domes account for much of the carbon stor...
Article
Full-text available
Peatlands account for 15 to 30% of the world's soil carbon (C) stock and are important controls over global nitrogen (N) cycles. However, C and N concentrations are known to vary among peatlands contributing to the uncertainty of global C inventories, but there are few global studies that relate peatland classification to peat chemistry. We analyze...
Article
Full-text available
When organic peat soils are sufficiently dry, they become flammable. In Southeast Asian peatlands, widespread deforestation and associated drainage create dry conditions that, when coupled with El Niño-driven drought, result in catastrophic fire events that release large amounts of carbon and deadly smoke to the atmosphere. While the effects of ant...
Article
Unless a toxicant builds up in a deep compartment, intake by the human body must on average balance the amount that is lost. We apply this idea to assess arsenic (As) exposure misclassification in three previously studied populations in rural Bangladesh (n=11,224), Navajo Nation in the Southwestern United States (n=619), and northern Chile (n=630),...
Preprint
Full-text available
*Note well: This is a preprint that has not yet been peer-reviewed.* We used neural networks (trained on data from the NASA SMAP satellite) to model soil moisture in peatlands of Sumatra, Borneo and Peninsular Malaysia as a function of climate, degradation, and location. The neural networks were forced with regional climate model projections for 19...
Article
Full-text available
Background Water arsenic (As) sources beyond a rural household’s primary well may be a significant source for certain individuals, including schoolchildren and men working elsewhere. Objective To improve exposure assessment by estimating the fraction of drinking water that comes from wells other than the household’s primary well in a densely popul...
Article
Full-text available
Peatlands contain a significant fraction of global soil carbon, but how these reservoirs will respond to the changing climate is still relatively unknown. A global picture of the variations in peat organic matter chemistry will aid our ability to gauge peatland soil response to climate. The goal of this research is to test the hypotheses that 1) pe...
Poster
Full-text available
We evaluate retrieval of ground elevations and canopy metrics derived from GEDI waveform data, as well as single-photon data from the Advanced Topographic Laser Altimeter System (ATLAS) instrument on the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory, with reference to an airborne laser scanning dataset covering an area of over 10...
Article
Full-text available
Well‐switching programs in Bangladesh have successfully lowered arsenic exposure. In these programs, households switch from wells that are labeled “unsafe” to nearby wells labeled “safe,” but these designations are usually based on inherently inaccurate field kit measurements. Here, we (a) compare the efficacy of field‐kit measurements to accurate...
Preprint
Full-text available
Field kits for testing the level of a toxicant in the environment are inherently less accurate than a laboratory instrument. Using a specific example, we argue here that kit measurements still have a key role to play when the spatial distribution of a toxicant is very heterogeneous. The context is provided by the groundwater arsenic problem in Bang...
Preprint
Full-text available
Groundwater supports agriculture and provides domestic water for over 250 million people in the Bengal Basin. Our analysis of stable water isotope ratios in rain, surface, and groundwater shows that the proportion of groundwater recharge originating from stagnant surface water bodies has increased by about 50% over the last seventy years while the...
Article
Full-text available
Drainage canals associated with logging and agriculture dry out organic soils in tropical peatlands, thereby threatening the viability of long‐term carbon stores due to increased emissions from decomposition, fire, and fluvial transport. In Southeast Asian peatlands, which have experienced decades of land use change, the exact extent and spatial di...
Article
Full-text available
Peatlands represent large terrestrial carbon banks. Given that most peat accumulates in boreal regions, where low temperatures and water saturation preserve organic matter, the existence of peat in (sub)tropical regions remains enigmatic. Here we examined peat and plant chemistry across a latitudinal transect from the Arctic to the tropics. Near-su...
Preprint
Millions of people in Bangladesh drink well water contaminated with arsenic. Despite the severity of this heath crisis, little is known about the extent to which groundwater arsenic concentrations change over time: Are concentrations generally rising, or is arsenic being flushed out of aquifers? Are spatially patterns of high and low concentrations...
Article
Rice is the primary crop in Bangladesh and rice yield is diminished due to the buildup of arsenic (As) in soil from irrigation with high-As groundwater. Soil testing with an inexpensive kit could help farmers target high-As soil for mitigation or decide to switch to a different crop that is less sensitive to As in soil. A total of 3240 field kit me...
Article
Full-text available
Tropical peatlands store over 75 gigatons of carbon as organic matter that is protected from decomposition and fire by waterlogging if left undrained. Over millennia, this organic matter builds up between channels or rivers into gently mounded shapes called peat domes. Measurements of peat accumulation and water flow suggest that tropical peat dome...
Article
Iron oxides control the mobility of a host of contaminants in aquifer systems, and the microbial reduction of iron oxides in the subsurface is linked to high levels of arsenic in groundwater that affects greater than 150 million people globally. Paired observations of groundwater and solid-phase aquifer composition are critical to understand spatia...
Article
The role of man-made ponds on arsenic mobilization was examined in Bangladesh. Here, we describe a field experiment that shows how recharge from a newly constructed pond creates a reactive front that moves downward into the underlying aquifer, but only advances slowly, less than 8 cm/year. We found that pond recharge introduces organic carbon that...
Article
Full-text available
Over the last three decades, most of the 25 million hectares of tropical peatlands in Southeast Asia have been deforested and drained. As a consequence, declining water tables are exposing peat to oxidation, converting plant material accumulated over millennia to carbon dioxide, and causing land subsidence. Here, we quantify the widespread peat car...
Article
Full-text available
Worldwide, peatlands are important sources of dissolved organic matter (DOM) and trace metals (TMs) to surface waters, and these fluxes may increase with peatland degradation. In Southeast Asia, tropical peatlands are being rapidly deforested and drained. The blackwater rivers draining these peatland areas have high concentrations of DOM and the po...
Article
Full-text available
Elevated arsenic in Bengal Basin aquifers threatens human health. Most deep (>150 m) groundwater in Pleistocene aquifers is low in arsenic; however higher concentrations have been reported in the southwest border region. Here, we establish that this extensive arsenic contamination at depth is not associated with well failure. A combination of geoch...
Article
Full-text available
Peatlands cover many low-lying areas in the tropics. Tropical peatlands are intriguing systems because of their tight coupling between hydrology and carbon storage: they accumulate carbon over thousands of years because of waterlogging, and they remain waterlogged after growing into domed shapes because peat restricts drainage. This feedback betwee...
Article
Full-text available
Fires that emit massive amounts of CO2 and particulate matter now burn with regularity in Southeast Asian tropical peatlands. Natural peatlands in Southeast Asia are waterlogged for most of the year and experience little or no fire, but networks of canals constructed for agriculture have drained vast areas of these peatlands, making the soil vulner...
Article
Full-text available
Worldwide, peatlands are important sources of dissolved organic matter (DOM) and trace metals (TM) to surface waters and these fluxes may increase with peatland degradation. In Southeast Asia, tropical peatlands are being rapidly deforested and drained. The black rivers draining these peatland areas have high concentrations of DOM, and the potentia...
Article
Full-text available
Widespread contamination of groundwater with geogenic arsenic is attributed to microbial dissolution of arsenic‐bearing iron (oxyhydr)oxides minerals coupled to the oxidation of organic carbon. The recharge sources to an aquifer can influence groundwater arsenic concentrations by transport of dissolved arsenic or reactive constituents that affect a...
Poster
Full-text available
Anaerobic oxidation of methane (AOM) is a significant but poorly constrained biological sink in the global carbon cycle. While several studies estimate AOM is responsible for consuming ~80-90% produced in marine sediments, its role in curbing the CH4 atmospheric flux in terrestrial freshwater systems, particularly the deep continental biosphere, is...
Article
Full-text available
Emission of CO2 from tropical peatlands is an important component of the global carbon budget. Over days to months, these fluxes are largely controlled by water table depth. However, the diurnal cycle is less well understood, in part, because most measurements have been collected daily at midday. We used an automated chamber system to make hourly m...
Article
Rice is the primary crop in Bangladesh, and rice yield is diminished due to the buildup of arsenic (As) in soil from irrigation with high-As groundwater. Implementing a soil inversion, where deeper low-As soil is exchanged with the surface high-As soil in contact with rice roots, may mitigate the negative impacts of As on yield. We compared soil As...
Article
Background: Concentrations of arsenic (As) are elevated in a large proportion of wells in Bangladesh but are spatially variable even within a village. This heterogeneity can enable exposed households to switch to a nearby well lower in As in response to blanket (area-wide) well As testing. Objectives: We document the evolution of As exposure in Ara...
Article
Full-text available
Significance We report radiocarbon ( ¹⁴ C) measurements of carbonaceous aerosol originating from fires on the islands of Sumatra and Borneo. These data provide information about what types of ecosystems burned and are critical for linking the human health effects of fires to the anthropogenic build-up of atmospheric CO 2 . Our measurements confirm...
Article
Full-text available
Peatlands represent large terrestrial carbon banks. Given that most peat accumulates in boreal regions, where low temperatures and water saturation preserve organic matter, the existence of peat in (sub)tropical regions remains enigmatic. Here we examined peat and plant chemistry across a latitudinal transect from the Arctic to the tropics. Near-su...
Article
Full-text available
Rice was traditionally grown only during the summer (aman) monsoon in Bangladesh but more than half is now grown during the dry winter (boro) season and requires irrigation. A previous field study conducted in a small area irrigated by a single high-arsenic well has shown that the accumulation of arsenic (As) in soil from irrigating with high-As gr...
Conference Paper
Radium isotopes are used as tracers in multitude of hydrogeological applications1. However, a complex mileu of geochemical and physical processes occurring in subsurface environment result in spatial and temporal variability in radium isotopic activities, including alpha-recoil, a primary mechanism of mobilization for multiple isotopes 3. Numerous...
Article
Full-text available
Significance A dataset from one of the last protected tropical peat swamps in Southeast Asia reveals how fluctuations in rainfall on yearly and shorter timescales affect the growth and subsidence of tropical peatlands over thousands of years. The pattern of rainfall and the permeability of the peat together determine a particular curvature of the p...
Article
Full-text available
The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world (“International Peat Congress with over 1000 participants!,” 2016). The congress covered all aspects of peatland ecosystems and their management, with a...
Poster
Groundwater Radon (Rn222) activity is primarily controlled by alpha recoil process (radioactive decay), however, evaluating the rate and extent of this process, and its impact on porewater radioactivity, remains uncertain. Numerous factors contribute to this uncertainty, including the spatial distribution of parent radionuclides (e.g. U238, Th232 ,...
Article
Groundwater contamination by arsenic (As) is a serious public health concern in many different areas worldwide, particularly in the Bengal region. Mobilization and fate of As in natural waters is controlled by a variety of factors including the presence of natural organic matter (NOM). This study experimentally determined conditional distribution c...
Article
Full-text available
Many of the world's megacities depend on groundwater from geologically complex aquifers that are over-exploited and threatened by contamination. Here, using the example of Dhaka, Bangladesh, we illustrate how interactions between aquifer heterogeneity and groundwater exploitation jeopardize groundwater resources regionally. Groundwater pumping in D...
Data
Supplementary Figures 1-17, Supplementary Tables 1-2
Conference Paper
Hydraulic fracturing alters the pore size distribution and increases the effective surface area of gas-bearing earth materials, which may enhance transfer of short-lived radionuclides into porewater-wastewater through alpha recoil (radionuclide decay). However, evaluating the rate and extent of this process, and its impact on porewater radioactivit...
Article
Full-text available
The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world ("International Peat Congress with over 1000 participants!," 2016). The congress covered all aspects of peatland ecosystems and their management, with a...
Article
Full-text available
Many aquifers that are highly contaminated by arsenic in South and Southeast Asia are in the floodplains of large river networks. Under natural conditions, these aquifers would discharge into nearby rivers; however, large-scale groundwater pumping has reversed the flow in some areas so that rivers now recharge aquifers. At a field site near Hanoi V...
Conference Paper
Full-text available
Flowback and produced water (referred to as flowback water) resulting from hydraulic fracturing contains a complex milieu of anthropogenic and natural chemical constituents including naturally occurring toxic inorganic elements such as strontium, barium and naturally occurring radioactive materials such as 226radium. The chemical profile of flowbac...
Article
Tropical peatland burning in Asia has been intensifying over the last decades, emitting huge amounts of gas species and aerosol particles. Both laboratory and field studies have been conducted to investigate emission from peat burning, yet a significant variability in data still exists. We conducted a series of experiments to characterize the gas a...
Conference Paper
Groundwater extracted from deeper than 150 m often provides a safe alternative to shallow groundwater that is highly contaminated by arsenic in the Bengal Basin. Generally, deep groundwater is tens of thousands of years old and As-safe. However, based on field kit testing we found high As (>100 ppb) in 14 deep (150 - 240 m) groundwater samples coll...
Conference Paper
Full-text available
Community wells tapping deep (>150 m) aquifers have become the mainstay of efforts to reduce exposure to As of millions of villagers throughout the Bengal basin. A number of surveys have indicated that one sizeable area where these aquifers do not appear to be consistently low in As straddles the border of India and Bangladesh between 23.1-23.3o N...
Article
Peatlands of Southeast Asia store large pools of carbon but the mechanisms of peat accumulation in tropical forests remain to be resolved. Patch dynamics and forest disturbance have seldom been considered as drivers that can amplify and dampen rates of peat accumulation. Here we used a modified piston corer, non-invasive geophysical measurements, a...
Article
Full-text available
Groundwater recharge affects water budgets and groundwater quality on the deltas and floodplains of South and Southeast Asia. Rain and flooding rivers recharge groundwater during the monsoon; irrigated rice fields and surface-water bodies recharge aquifers during the dry season. Groundwater throughout the region is severely contaminated by arsenic...
Conference Paper
Groundwater pumping beneath Dhaka, a mega-city in Bangladesh, has created an extensive drawdown cone. Outside the city, shallow groundwater is often contaminated with dangerous concentrations of arsenic (As) and deep groundwater is considered a reliable source of As-safe drinking water. Unfortunately, vertical head gradients induced by Dhaka pumpin...
Patent
Full-text available
The systems and methods described herein related to measuring hydraulic parameters across a surface water-aquifer interface. In particular, the systems include a pressure differential sensor within a watertight housing. The pressure differential sensor has two inlets, one of which is connected to a piezometer located in an aquifer, and the other of...
Chapter
Terrascope is a learning community for freshmen (first-year students) at the Massachusetts Institute of Technology (MIT) that incorporates Earth system and environmental education into a problem-based, student-centered, team-oriented series of classes. In the fall semester, in the program’s core class, students are given a complex, “unsolvable” pro...
Article
Turfgrass covers a large fraction of the urbanized landscape, but the carbon exchange of urban lawns is poorly understood. We used eddy covariance and flux chambers in a grassland field manipulative experiment to quantify the carbon mass balance in a Singapore tropical turfgrass. We also assessed how management and variations in environmental facto...