This article presents results from an unmanned aircraft system (UAS) aerial remote sensing study to improve understanding of Pueblo agricultural features in the Northern Rio Grande area of New Mexico that were in use by the 13th century ad. It builds on previous archaeological research that has focused on recording precontact and historic Pueblo agricultural practices, pollen analyses and paleoclimatic reconstruction. Evidence suggests that Pueblo people were successfully growing crops including maize, cotton and wheat, in areas where, based on environmental conditions, they could not necessarily grow. This study seeks to better understand the environmental modifications employed by Pueblo peoples to enable growth of these crops. Cobble-bordered gravel mulch field systems, thought to retain heat and moisture, are located throughout the study area. This article discusses the utility of airborne photogrammetry to locate and map gravel mulch fields on the landscape. Geographic information system (GIS) analysis of the UAS-derived digital surface model includes slope, aspect and water flow direction and sink to shed light on gravel mulch field function. The article also discusses the potential of handheld and airborne infrared imaging for assessing the thermoregulation of these fields. Final consideration of how the survey results align with the priorities of the Tewa people for future arid-land farming demonstrates additional utility of the approach.

Understanding the interactions among agricultural processes, soil, and plants is necessary for optimizing crop yield and productivity. This study focuses on developing effective monitoring and analysis methodologies that estimate key soil and plant properties. These methodologies include data acquisition and processing approaches that use unmanned aerial vehicles (UAVs) and surface geophysical techniques. In particular, we applied these approaches to a soybean farm in Arkansas to characterize the soil–plant coupled spatial and temporal heterogeneity, as well as to identify key environmental factors that influence plant growth and yield. UAV-based multitemporal acquisition of high-resolution RGB (red–green–blue) imagery and direct measurements were used to monitor plant height and photosynthetic activity. We present an algorithm that efficiently exploits the high-resolution UAV images to estimate plant spatial abundance and plant vigor throughout the growing season. Such plant characterization is extremely important for the identification of anomalous areas, providing easily interpretable information that can be used to guide near-real-time farming decisions. Additionally, high-resolution multitemporal surface geophysical measurements of apparent soil electrical conductivity were used to estimate the spatial heterogeneity of soil texture. By integrating the multiscale multitype soil and plant datasets, we identified the spatiotemporal co-variance between soil properties and plant development and yield. Our novel approach for early season monitoring of plant spatial abundance identified areas of low productivity controlled by soil clay content, while temporal analysis of geophysical data showed the impact of soil moisture and irrigation practice (controlled by topography) on plant dynamics. Our study demonstrates the effective coupling of UAV data products with geophysical data to extract critical information for farm management.

We are developing a fixed-frame system employing a small Unmanned Aerial System (sUAS) for performing low elevation, fast and affordable aeromagnetic surveys over geothermal or volcanic areas. We tested two different magnetometer systems (scalar and vector) that are both designed for sUAS surveys. The sensor systems are each fixed on a frame at a distance of 0.5 m below the sUAS. Magnetic signals originating from the sUAS that interfere with the intended measurements of geologic features must be removed from the recordings, a process typically referred to as magnetic compensation. This correction requires performing specific maneuvers in a magnetically low gradient area at the beginning of each survey. We employed different compensation methods for the two systems which we applied to data collected during field experiments where we flew a grid pattern over a ~5000m area. We compare the different magnetometer systems and their compensation methods. Both sensors yield relatively small differences in their flightline-tieline crossings, and results that are in close agreement with each other and with a ground-based survey. The sUAS performed very stable flights with our system, and yielded results from the scalar magnetometer, that were of comparable precision to a setup using 2.8 m tethers – a configuration suggested by the manufacturer. The configuration we developed, employing a fixed frame combined with the use of compensation algorithms, allows for a small system that is easy to fly in a wide range of conditions (terrain, vegetation, low-altitude, wind), that provides advantages over previous applications using tethers, while yielding similar accuracy.

Archaeologists have long recognized that precise three-dimensional coordinates are critical for recording objects and features across sites and landscapes. Traditionally, for relatively small areas, an optical transit or, more recently, an electronic distance measurement device (EDM) has been used to acquire these three-dimensional points. While effective, such systems have significant limitations in that they require a clear line of site. Real-time kinematic (RTK) GPS/GNSS systems (Global Positioning System/Global Navigation Satellite Systems) have been available for well over a decade, and can provide quick and accurate point measurements over a wide area without many of the limitation of older technologies. The cost of such systems, however, has generally been prohibitive for archaeologists, and so their use has been rare. Recently, a new generation of low-cost systems has become available, making this technology more accessible to a wider user base. This article describes the use, accuracy, and limitations of one such low-cost system, the Emlid Reach RS, to show why this is an important tool for archaeological fieldwork.

LIDAR-based analyses of the first theropod dinosaur trackways known from the state of Arkansas, USA are reported. The trackways were found on a limestone bedding plane in the Albian De Queen Formation in an active gypsum quarry. Because limited access precluded thorough field study, fieldwork focused on preserving the entire site digitally with ground-based LIDAR, and detailed measurements were later taken digitally from point cloud data. The site contains eight tridactyl trackways associated with sauropod trackways and numerous isolated tracks. Although there appear to be two different tridactyl morphotypes, we show that the tracks are all likely from a single species of trackmaker. We apply a simple method of estimating substrate consistency by comparing the differences between true track dimensions and apparent track dimensions. The tridactyl tracks at the southern end of the site are preserved with significantly greater differences in true vs. apparent dimensions and are shallower than the rest of the tridactyl tracks at the site, which we interpret as the result of outward expansion of the soft tissues of the foot upon contact with a firm substrate. We interpret the firm substrate as having high bulk density and high shear strength, which also explain associated manus-only sauropod tracks. We show that the tridactyl tracks are likely from theropod trackmakers and that footprint lengths, trackway paces, stride lengths, and pace angulations of the De Queen trackways are statistically indistinguishable from equivalent measurements of theropod trackways in the Glen Rose Formation. The Glen Rose tracks are attributed to the large-bodied theropod, Acrocanthosaurus and we likewise attribute the De Queen tracks to Acrocanthosaurus, which is known from skeletal remains in temporally equivalent units and from the mine itself.

This study presents preliminary observations of the first year of a crop monitoring experiment occurred in two soybean agriculture fields in the Arkansas delta. The project focuses on developing image processing and data integration techniques for UAV-based images to optimize advanced farm management such as soil microbial amendments. In particular, we present an effective algorithm that can use high-resolution UAV images efficiently to estimate sprout density and plant vigor/health throughout the growing season. Such plant characterization is extremely important for the identification of anomalous areas and provide easily interpretable information for a better decision making. We also present an integrative analysis of UAV-data with geophysical data and harvesting data, which shows high correlation between persistent spatial pattern of soil, plant phenology/growth, and crop yield.

: Over the past three decades, extensive field studies of wetland plant communities have been conducted in the Mississippi Alluvial Valley. These field studies have been carried out for various purposes under the auspices of federal and state research programs or in conjunction with Corps of Engineers project planning efforts. In the process, a wetland site classification approach has evolved based on hydrology, soils, and geomorphic setting. The research data and classification system have been recently used for a new purpose: to create a set of Potential Natural Vegetation (PNV) maps covering more than 26,000 square miles within the region. The purpose of PNV maps is to serve as blueprints for restoration planning and prioritization. Due to the fact that the hydrology of the landscape has been permanently changed by major flood control projects, the PNV maps do not represent the distribution of the original, pre-settlement vegetation. Rather, they identify the natural communities that are appropriate to the modern altered site conditions. By using these maps, persons interested in restoring particular tracts of land can identify the plant communities appropriate to the conditions present. Conversely, individuals interested in restoring particular plant communities can identify parts of the landscape that can support each respective type. The PNV maps are available for use in a Geographic Information System, where a range of complex restoration scenarios (such as the development of wildlife travel corridors or refuge areas) can be explored efficiently, and alternative approaches can be compared to one another in terms of costs and ecological effectiveness. This report is one of six Field Atlases that present the same data in a downloadable, printable format at a scale of 1 in. = 1 mile.

The potential visual impact of offshore wind facilities on coastal lands has emerged as a major concern for the siting and future development of these facilities in Europe and the United States. The visibility and visual contrast of offshore wind facilities depend on complex interactions among facility size, turbine size and color, distance from shore, lighting, and weather and atmospheric conditions, as well as other factors that affect overall visibility. However, little systemic study of visibility and visual contrast of offshore wind facilities in real seascape settings has been conducted. As a result, there is uncertainty about the potential effects of offshore wind facilities on sensitive visual resource areas in coastal regions, such as national seashores, historic sites, and trail corridors. As part of a research study sponsored by the U. S. Department of the Interior's Bureau of Ocean Energy Management, an assessment of the visibility and visual contrast of 11 utility-scale offshore wind facilities was conducted in the United Kingdom in August and September of 2011. The observed facilities ranged from 25 to 140 turbines and were located within 5.5-52.0 km (3.4-32.3 mi) of 29 coastal viewpoints. Turbine power output ranged from 2.0 to 5.0 MW, with blade tip heights ranging from 113.5 to 153 m (372 to 502 ft). Study objectives included identifying the maximum distances at which the facilities could be seen from the coastal viewpoints in both daytime and night-time views and assessing the effect of distance on the degree of visual contrast associated with the facilities. Observers included a landscape architect, a geospatial visualization developer, and an archaeologist. For each facility, the observers recorded data about weather and lighting conditions, photographed the facilities at different focal lengths, and used a numeric scale to assess the facilities' degree of visibility. A total of 48 daytime observations of 11 offshore wind facilities were made, and an additional 6 observations were made at night. Weather and visibility conditions varied widely during the 10-day field study. In the course of this study, under favorable but not exceptional viewing conditions, moderate-sized offshore wind facilities were frequently found to be visible at distances exceeding 21 mi (34 km); they were visible at a maximum distance of 43 km (27 mi), as seen from an elevated viewpoint. With few exceptions, regardless of facility size or lighting conditions, on days with good visibility, offshore wind facilities were judged to be major foci of visual attention at distances of 16 km (10 mi) or less, suggesting potentially high levels of visual impact for sensitive viewers. Smaller wind facilities (25-48 turbines) were generally judged to be easily visible at distances of 23-24 km (14-15 mi). Larger offshore wind facilities (100 or more turbines) were judged likely to be seen easily by casual observers as far away as 29 km (18 mi), and were visible with extended or concentrated viewing at distances greater than 40 km (25 mi). That these distances are greater than those reported in previous studies is likely a function of the long-term trend toward larger offshore wind facilities with more and larger turbines than those assessed in previous studies. Turbine blade movement was visible in 42 of the 49 daytime observations, at distances as great as 42 km (26 mi) as seen from an elevated viewpoint, and was observed routinely at distances of 34 km (21 mi) or less.At night, aerial hazard navigation lighting was visible at distances greater than 39 km (24 mi). The study suggests that as countries begin siting offshore wind facilities with hundreds or even thousands of large wind turbines, there is potential for impacts on sensitive visual resources in coastal areas at greater distances than past studies have indicated.

BACKGROUND: The Mississippi Alluvial Valley (MAV) once contained the most extensive and diverse lowland forest in North America. The complexity and productivity of the ecosystem were the result of the influx of massive amounts of outwash from episodes of continental glaciation that occurred north of the region, as well as the dynamic behavior of the large rivers that have repeatedly migrated across the landscape, eroding and depositing sediments and regularly flooding millions of acres. Beginning with the arrival of the first European settlers, the rivers have been stabilized and prevented from inundating most of the former floodplain, and agriculture has largely replaced the native vegetation. The deforestation of the MAV has contributed to a variety of problems such as the extinction of wildlife species and pollution of receiving waters, including the Gulf of Mexico. Various government policies and private initiatives have been implemented to reverse this damage through restoration of native plant communities, particularly wetlands. Much of this work has been conducted through the Wetland Reserve Program, administered by the Natural Resources Conservation Service, and by the U.S Fish and Wildlife Service (FWS) Wildlife Refuge System. In addition, Corps of Engineers Planning and Regulatory responsibilities often include the development or evaluation of ecosystem restoration plans or compensatory mitigation proposals that involve wetland restoration, and large reforestation projects have been carried out in the region as a result.

Natural gas production in the Fayetteville shale area (Arkansas, USA) might create critical levels of water discharge due to diversion of surface water used for horizontal hydraulic fracturing. In fact, each well requires between 12000 m3 and 26500 m3 of water for hydraulic fracturing and the number of wells is expected to grow in the future. This usage, combined with drinking and farming needs, could pose water resource management concerns.

Alternating braided and meandering stream flow regimes throughout the Quaternary Period have left a subtly complex landscape of depositional features within the Mississippi Alluvial Valley (MAV). Prior to European settlement, those variations produced tremendous spatial complexity and diversity within vast forested wetlands and extensive fire-maintained prairies and savannas, with the distribution of specific plant communities largely reflecting abiotic site characteristics such as geomorphology, soils, and hydrology. Agricultural development, river engineering, flood protection, and drainage projects over the past century have destroyed most of the natural vegetation and obscured the patterns of plant community distribution. Recent studies have established hydrogeomorphic criteria for wetland classification over a large part of the MAV. Detailed, spatially explicit geomorphology and soils data are available for the entire MAV, and hydrologic mapping has been completed in many areas. Thus, even in areas that are currently in agriculture, the tools exist to adapt the hydrogeomorphic classification and to develop maps of potential plant community distribution based on abiotic characteristics of sites. These Potential Natural Vegetation maps provide an indication of the multi-scale complexity that once characterized the MAV, and serve as planning tools for ecosystem restoration.