Richard Barnes

• Computational Science
• Researcher at University of California, Berkeley

Ice-free land comprises 26 % of the Earth's surface and holds liquid water that delineates ecosystems, affects global geochemical cycling, and modulates sea levels. However, we currently lack the capacity to simulate and predict these terrestrial water changes across the full range of relevant spatial (watershed to global) and temporal (monthly to...

Ice-free land comprises 26 % of Earth’s surface and holds liquid waters that delineate ecosystems, affect global geochemical cycling, and modulate sea level. However, we currently lack capacity to simulate and predict these terrestrial water changes over the full range of relevant spatial (watershed to global) and temporal (monthly to millennial) s...

Language models demonstrate both quantitative improvement and new qualitative capabilities with increasing scale. Despite their potentially transformative impact, these new capabilities are as yet poorly characterized. In order to inform future research, prepare for disruptive new model capabilities, and ameliorate socially harmful effects, it is v...

Watershed delineation and flow direction representation are the foundations of streamflow routing in spatially distributed hydrologic modeling. A recent study showed that hexagon-based watershed discretization has several advantages compared to the traditional Cartesian (latitude-longitude) discretization, such as uniform connectivity and compatibi...

Functional, usable, and maintainable open-source software is increasingly essential to scientific research, but there is a large variation in formal training for software development and maintainability. Here, we propose 10 “rules” centered on 2 best practice components: clean code and testing. These 2 areas are relatively straightforward and provi...

Depressions – inwardly draining regions – are common to many landscapes. When there is sufficient moisture, depressions take the form of lakes and wetlands; otherwise, they may be dry. Hydrological flow models used in geomorphology, hydrology, planetary science, soil and water conservation, and other fields often eliminate depressions through filli...

Antarctica’s Pole of Inaccessibility (Southern Pole of Inaccessibility (SPI)) is the point on the Antarctic continent farthest from its edge. Existing literature exhibits disagreement over its location. Using two revisions of the Scientific Committee on Antarctic Research’s Antarctic Digital Database, we calculate modern-day positions for the SPI a...

We present BusTr, a machine-learned model for translating road traffic forecasts into predictions of bus delays, used by Google Maps to serve the majority of the world’s public transit systems where no official real-time bus tracking is provided. We demonstrate that our neural sequence model improves over DeepTTE, the state-of-the-art baseline, bot...

We present BusTr, a machine-learned model for translating road traffic forecasts into predictions of bus delays, used by Google Maps to serve the majority of the world's public transit systems where no official real-time bus tracking is provided. We demonstrate that our neural sequence model improves over DeepTTE, the state-of-the-art baseline, bot...

Depressions – inwardly draining regions of digital elevation models – present difficulties for terrain analysis and hydrological modeling. Analogous “depressions” also arise in image processing and morphological segmentation, where they may represent noise, features of interest, or both. Here we provide a new data structure – the depression hierarc...

Abstract. Depressions – inwardly-draining regions – are common to many landscapes. When there is sufficient moisture, depressions take the form of lakes and wetlands; otherwise, they may be dry. Hydrological flow models used in geomorphology, hydrology, planetary science, soil and water conservation, and other fields often eliminate depressions thr...

Depressions – inwardly-draining regions of digital elevation models – present difficulties for terrain analysis and hydrological modeling. Analogous depressions also arise in image processing and morphological segmentation where they may represent noise, features of interest, or both. Here we provide a new data structure – the depression hierarchy...

Spatial analyses involving binning often require that every bin have the same area, but this is impossible using a rectangular grid laid over the Earth or over any projection of the Earth. Discrete global grids use hexagons, triangles, and diamonds to overcome this issue, overlaying the Earth with equally-sized bins. Such discrete global grids are...

What actions can we take to foster diverse and inclusive workplaces in the broad fields around data science? This paper reports from a discussion in which researchers from many different disciplines and departments raised questions and shared their experiences with various aspects around diversity, inclusion, and equity. The issues we discuss inclu...

To answer geomorphological questions at unprecedented spatial and temporal scales, we need to (a) parse terabyte-scale datasets (DEMs), (b) perform millions of model realizations to pinpoint the parameters which govern landscape evolution, and (c) do so with statistical rigor, which may require thousands of additional realizations. A core set of op...

To answer geomorphological questions at unprecedented spatial and temporal scales, we need to (a) parse terabyte-scale datasets (DEMs), (b) perform millions of model realizations to pinpoint the parameters which govern landscape evolution, and (c) do so with statistical rigor, which may require thousands of additional realizations. A core set of op...

Solving inverse problems and achieving statistical rigour in landscape evolution models requires running many model realizations. Parallel computation is necessary to achieve this in a reasonable time. However, no previous algorithm is well-suited to leveraging modern parallelism. Here, I describe an algorithm that can utilize the parallel potentia...

The shape of an electoral district may suggest whether it was drawn with political motivations, or gerrymandered. For this reason, quantifying the shape of districts, in particular their compactness, is a key task in politics and civil rights. A growing body of literature suggests and analyzes compactness measures mathematically, but little conside...

Continent-scale datasets challenge hydrological algorithms for processing digital elevation models. Flow accumulation is an important input for many such algorithms; here, I parallelize its calculation. The new algorithm works on one or many cores, or multiple machines, and can take advantage of large memories or cope with small ones. Unlike previo...

For many taxa and systems, species richness peaks at midelevations. One potential explanation for this pattern is that large-scale changes in climate and geography have, over evolutionary time, selected for traits that are favored under conditions found in contemporary midelevation regions. To test this hypothesis, we use records of historical temp...

Algorithms for extracting hydrologic features and properties from digital elevation models (DEMs) are challenged by large datasets, which often cannot fit within a computer's RAM. Depression filling is an important preconditioning step to many of these algorithms. Here, I present a new, linearly-scaling algorithm which parallelizes the Priority-Flo...

This paper presents a parallel algorithm for calculating the eight-directional (D8) up-slope contributing area in digital elevation models (DEMs). In contrast with previous algorithms, which have potentially unbounded inter-node communications, the algorithm presented here realizes strict bounds on the number of inter-node communications. Those bou...

In the interest of diversifying the global food system, improving human nutrition, and making agriculture more sustainable, there have been many proposals to domesticate wild plants or complete the domestication of semi-domesticated “orphan” crops. However, very few new crops have recently been fully domesticated. Many wild plants have traits limit...

Agriculture is now called to achieve sustainable intensi-fication by producing more food, feed, bioproducts, and bioenergy, while also improving conservation of soil, water, and biodiversity (Garnett et al., 2013; Heaton et al., 2013). One strat-egy for such intensification is cultivation of winter-annual and perennial crops at spatiotemporal locat...

In processing raster digital elevation models (DEMs) it is often necessary to assign drainage directions over flats—that is, over regions with no local elevation gradient. This paper presents an approach to drainage direction assignment which is not restricted by a flat's shape, number of outlets, or surrounding topography. Flow is modeled by super...

Depressions (or pits) are low areas within a digital elevation model that are surrounded by higher terrain, with no outlet to lower areas. Filling them so they are level, as fluid would fill them if the terrain were impermeable, is often necessary in preprocessing DEMs. The depression-filling algorithm presented here—called Priority-Flood—unifies a...

Over the last half century, ‘Green Revolution’ technologies have dramatically enhanced crop yields, but because of the emphasis on annual row cropping systems these increases have often come at the expense of food security and sustainability. Globally, many fear that agriculture 229 is nearing a tipping point, with concerns that population pressure...

Background/Question/Methods Agricultural production has increased greatly over the past century, but gains have often come at the cost of long-term sustainability. Crop systems often require fossil fuel-based fertilizers, strain sources of fresh water, contribute to soil loss, and may ultimately reduce arable land. Addressing these shortfalls is e...

Bovine spongiform encephalopathy, otherwise known as mad cow disease, can spread when an individual cow consumes feed containing the infected tissues of another individual, forming a one-species feedback loop. Such feedback is the primary means of transmission for BSE during epidemic conditions. Following outbreaks in the European Union and elsewhe...

Numerous studies have shown electromyographic signals (EMGs) as useful for controlling prostheses and ortheses. Their great potential stems from the degree of voluntary control we wield over these signals, even if limbs are missing, especially in the EMGs of skeletal muscles. However, despite several decades of exploration, the potential of electri...

Agricultural regions of the world have vast natural watersheds of lakes, ponds, rivers, and streams. Interwoven are large artificial watersheds of drain tiles and ditches. Just as household plants benefit from drains in their pots, so agricultural crops benefit from drain tiles in their fields. In today's world the drain tiles carry not only water...

This briefing describes the first deployment of a new electronic tracer (E-tracer) for obtaining along-flowpath measurements in subsurface hydrological systems. These low-cost, wireless sensor platforms were deployed into moulins on the Greenland Ice Sheet. After descending into the moulin, the tracers travelled through the subglacial drainage syst...

Intractable problems in modeling ecosystems and their services can often be solved through the application of appropriate algorithms: reconceptualization of a problem may reduce computation times from days to minutes. Despite this, many popular analysis packages—and many modelers—use inefficient algorithms. For example, statewide DEMs have reached...

Interwoven with the natural watersheds of the United States—made up of lakes, ponds, and rivers—are large artificial watersheds of drain tiles and ditches which prevent fields from becoming too damp by draining them of excess water. The drained water carries fertilizers, antibiotics, pesticides, hormones, and other chemicals into natural watersheds...

Given vast increases in computing capacity, applications in science and engineering that were formerly interpreted with ordinary or partial differential equations, or by integro-partial differential equations, can now be understood through microscale modeling. Interactions among individual particles—be they molecules, viruses, or individual humans—...

This paper presents a parallel algorithm for calculating the eight-directional (D8) up-slope contributing area in digital elevation models (DEMs). In contrast with previous algorithms, which have potentially unbounded inter-node communications, the algorithm presented here realizes strict bounds on the number of inter-node communications. Those bou...

A significant hurdle to the understanding of ice sheet basal hydrology and its coupling with ice motion is the difficulty in making in-situ measurements along a flow path. While dye tracing techniques may be used in small glaciers to determine transit times of surface melt water through the sub-glacial system, they provide no information on in situ...

We present the outline of a class project in which entry-level students in our CS1 course spent a full day developing a text-based massively multi-player online role-playing game (MMORPG) using Scheme. We describe briefly our CS1 course, the specifics of the game we asked students to im- plement, and the project organization. Comments from the stud...