Air Photo Interpretation for Spatial Analysis of Heritage Agrarian Structures in Mediterranean Settings as Sea-Breezes Proxy-Data. Application to the Island of Mallorca

Historical aerial photographs are valuable sources of climate information. In the present article, a reconstruction of the sea-breezes in Mallorca is described, based on wind-direction interpretation of threshing floors captured by the aerial photographs in 1956–1957 by the United States Army Map Service. These pre-industrial agricultural structures constitute a novel ethnographic proxy of cartographic wind direction at each site. The overall analysis of these directions has made it possible to recreate and model the spatial arrangement of the breezes in Mallorca, and to compare this recreation with that of the existing theoretical-experimental breeze models. The result is a relatively good fit between both recreations, which demonstrates the accuracy of the proposed method. This can be extrapolated to many other aerial-photographed Mediterranean regions prior to full mechanisation of the field.

Historical air photo missions in the Maritimes during the early 1920s: coverage, thematic scope, and utility 100 years later

The historical and technological developments of powered flight and aerial photography have early connections in the Maritimes. Following the Great War (1914-18), a series of pioneering survey missions were initiated by the Canada Air Board in the civilian domain. From a science perspective, the air photos offer a unique opportunity for the detection of environmental change at an unusual centennial time scale. The missions of the early 1920s initially relied on military surplus seaplanes and innovative camera equipment that yielded several thousand high-resolution vertical air photos. This paper is focussed on the scope and outcome of the first experiments carried out over Nova Scotia and New Brunswick between 1921 and 1925, prior to more systematic use for topographic mapping during the remainder of that decade. The research is based on archival records and partial reconstruction of the digitized air photos into image mosaics. Photo interpretation and comparison with recent high-resolution satellite imagery offer insights concerning land use and land cover changes, coastal dynamics, and transformation of urban, rural and industrial landscapes. Experience todate with these early air photos and mosaics of the Maritimes holds promise for examining similar aerial survey missions in other parts of Canada.

Steep Creek Risk Assessment for Pipeline Design : A Case Study From British Columbia, Canada

ABSTRACT Pipelines in mountainous terrain often cross alluvial fans formed by steep creek processes of debris flows and debris floods and are thus exposed to their associated hazards. The design of new pipeline infrastructure and maintenance of existing pipelines necessitates steep creek risk assessments and appropriate mitigation design. We present methodology for assessing steep creek risk along pipeline routes that evaluates the probability of such processes causing a pipeline loss of containment or disruption in service. The methodology consists of estimating event frequency, scour potential, and the vulnerability of the pipeline to break if impacted by boulders. The approach can be adapted to other landslide geohazards so that different geohazard locations can be evaluated with a common metric. Steep creek process frequency is estimated based on field observations and review of documented events, historical air photo records, and terrain mapping based on LiDAR-generated topography. Scour potential is estimated based on channel morphology, presence of bedrock, and grain size distribution of channel bed material. Vulnerability is estimated based on flow width and velocity and can be modified for different pipe diameters and wall thicknesses. Mitigation options for buried pipelines include those intended to decrease the likelihood of the pipeline being exposed and to increase the resiliency of the pipeline to boulder or organic debris impacts, if exposed. The methodology presented is embedded in risk-informed decision making where pipeline owners and regulators can define probability thresholds to pipeline exposure or rupture, and pipeline designers can demonstrate that proposed mitigation measures achieve these threshold criteria.

A Pilot Study on Remote Sensing and Citizen Science for Archaeological Prospection

Cost-effective techniques for systematic archaeological prospection are essential to improve the efficiency of preventive archaeology and the preservation of cultural heritage. Web Mapping Services, such as Microsoft Bing Maps, provide imagery covering extensive areas at high resolution. These can, in some cases, reveal cropmarks of buried historical structures. Given that archaeological prospection is not generally the priority of most common Web Mapping Services, the conditions under which images are acquired are not always suitable for the appearance of cropmarks. Therefore, their detection is typically serendipitous. This pilot project attempts to assess the potential to use the Microsoft Bing Maps Bird’s Eye service within a crowdsourcing platform to systematically search for archaeological cropmarks in the surroundings of the city of Rome in Italy. On this platform, which is hosted by the company Scifabric (Southampton, UK) and based on PyBossa, an Open Source framework for crowdsourcing, members of the public are invited to interpret oblique air photo tiles of Bing Maps Bird’s Eye. While the project is still on-going, at least one seamless coverage of tiles in the area of interest has been interpreted. For each tile, the Bing Maps Bird’s Eye service provides oblique air photo coverage in up to four possible orientations. As of 5 July 2020, 18,765 of the total 67,014 tasks have been completed. Amongst these completed tasks, positive detections of cropmarks were recorded once for 1447 tasks, twice for 57 tasks, and three or more times for 10 tasks. While many of these detections may be erroneous, some correspond with archaeological cropmarks of buried remains of buildings, roads, aqueducts, and urban areas from the Roman period, as verified by comparison with archaeological survey data. This leads to the conclusion that the Bing Maps Bird’s Eye service contains a wealth of information useful for archaeological prospection, and that to a certain extent citizen researchers could help to mine this information. However, a more thorough analysis would need to be carried out on possible false negatives and biases related to the varying ease of interpretation of residues of different archaeological structures from multiple historical periods. This activity forms the first part of a research project on the systematic prospection of archaeological cropmarks. The ultimate aim is to reach a critical mass of training data through crowdsourcing which can be augmented and used as input to train a machine learning algorithm for automatic detection on a larger scale.

Channel narrowing by inset floodplain formation of the lower Green River in the Canyonlands region, Utah

The lower Green River episodically narrowed between the mid-1930s and present day through deposition of new floodplains within a wider channel that had been established and/or maintained during the early twentieth century pluvial period. Comparison of air photos spanning a 74-yr period (1940–2014) and covering a 61 km study area shows that the channel narrowed by 12% from 138 ± 3.4 m to 122 ± 2.1 m. Stratigraphic and sedimentologic analysis and tree ring dating of a floodplain trench corroborates the air photo analysis and suggests that the initial phase of floodplain formation began by the mid-1930s, approximately the same time that the flow regime decreased in total annual and peak annual flow. Tamarisk, a nonnative shrub, began to establish in the 1930s as well. Narrowing from the 1940s to the mid-1980s was insignificant, because floodplain formation was approximately matched by bank erosion. Air photo analysis demonstrates that the most significant episode of narrowing was underway by the late 1980s, and analysis of the trench shows that floodplain formation had begun in the mid-1980s during a multi-year period of low peak annual flow. Air photo analysis shows that mean channel width decreased by ∼7% between 1993 and 2009. A new phase of narrowing may have begun in 2003, based on evidence in the trench. Comparison of field surveys made in 1998 and 2015 in an 8.5 km reach near Fort Bottom suggests that narrowing continues and demonstrates that new floodplain formation has been a very small proportion of the total annual fine sediment flux of the Green River. Vertical accretion of new floodplains near Fort Bottom averaged 2.4 m between 1998 and 2015 but only accounted for ∼1.5% of the estimated fine sediment flux during that period. Flood control by Flaming Gorge Dam after 1962 significantly influenced flow regime, reducing the magnitude of the annual snowmelt flood and increasing the magnitude of base flows. Though narrowing was initiated by changes in flow regime, native and nonnative riparian vegetation promoted floodplain formation and channel narrowing especially through establishment on channel bars and incipient floodplains during years of small annual floods.

Orthomosaics of Historical Aerial Photographs and Horizontal Accuracy Analysis

<p>Orthomosaics from aerial photographs play a pivotal role in understanding land-use/land cover in broad area and the advent of image processing technology allows us to produce orthoimagery. However, recent advanced technologies are seldom applied to produce historical orthophotos from early or mid 20C old aerial photos in broad extent since they have limited information (e.g. camera position, flying altitude, and yaw) which is critical information for orthomosaics. In this context, this study aims to orthomosaic and georectify historical aerial photographs and validate the horizontal accuracy of orthomosacicked outputs. In order to achieve this, firstly, we collected 117 aerial photographs of 1934 (scale 1:12,000) and 68 of 1951 (scale 1:20,000) from UConn air photo achieve focused on Woodstock town in Connecticut, USA. Secondly, we created GCPs (Ground Control Points) as referenced points where they have not changed over time by overlaying multiple datasets such as LiDAR DEM, hillshade map, recent orthoimagery. Thirdly, we align photos with Control Points (CPs), build a mesh, and build orthomosaics of 1934 and 1951, respectively, using Agisoft Photoscan 1.5. Lastly, calculating RMSE (Root Mean Square Error) and offsets comparing between set of GCPs and CPs from Lidar DEM and set of them digitized from orthomosaics. As a result, RMSE values of GCPs and CPs between 1934 and 1951 mostly show that output of this work is acceptable to use for standard mapping and GIS work or visualization based on ASPRS 1990 horizonal accuracy standard. In addition, we found several factors affect horizontal accuracy of orthomosaics; resolution of aerial photos, spatial distribution of GCPs and CPs, the number of CPs and GCPs, the percentage of lateral overlapping area along flight strips, and margin area. Overall, applying automated orthomosaicking image processing to historical aerial photographs has the potential to represent historical landscape and even detect its change in broad extent.</p>

ANALYSIS AND EVALUATION OF EFFECTIVENESS OF THE USE OF UNMANNED AIRCRAFTS FOR ENVIRONMENT MONITORING

The present article reviews the problems of economic effectiveness of air photography by unmanned aircrafts equipped with photographic systems of low class. The structure and effectiveness of work is shown. Keywords: unmanned aircrafts, economic effectiveness, monitoring, air-photo images.

Pembuatan Peta Foto Udara Kelurahan Wates

ABSTRAK Kelurahan Wates merupakan sebuah kelurahan yang berada di Kecamatan Wates, Kabupaten Kulon Progo. Pada awal bedirinya Kelurahan Wates ini berbentuk desa, dimana seluruh asset menjadi milik desa dan digunakan seluasnya untuk kemakmuran dan kesejahteraan warga Desa Wates. Pada tanggal 1 Desember 2010 status Desa Wates berubah menjadi Kelurahan Wates. Kelurahan Wates merupakan pusat pemerintahan Kabupaten Kulon Progo, sehingga secara tidak langsung aktivitas kelurahan berpengaruh terhadap kelangsungan Pemerintahan Kabupaten Kulon Progo karena terbatasnya anggaran, beberapa aspek dasar dalam hal data geospasial juga tidak muncul di dalam Renja 2017. Sebagai contoh belum adanya rencana kegiatan dalam hal pemetaan desa/kelurahan. Sehingga hal ini bisa menjadi peluang bagi perguruan tinggi untuk melaksanakan kegiatan penelitian dan pengabdian kepada masyarakat, khususnya dalam penyediaan data geospasial. Dari pemaparan permasalahan di atas, dimana yang menjadi pokok permasalahan adalah ketiadaan data geospasial, maka dapat diberikan solusi dengan pengadaan salah satu bentuk data geospasial, yaitu Peta Foto Udara Kelurahan Wates skala besar, yaitu antara 1:1000 – 1:5000. luaran dari pengabdian ini, yaitu berupa Peta Foto Udara Kelurahan Wates skala besar. Dari peta foto yang akan dihasilkan ini, nantinya dapat dikembangkan untuk membuat peta-peta turunan lainnya, seperti peta sarana-prasarana, peta jaringan jalan, dan sistem informasi desa yang direncanakan akan dibuat dalam pengabdian masyarakat pada tahun-tahun berikutnya. Kata Kunci: peta foto, foto udara, Wates, geospasial ABSTRACT Kelurahan Wates located in Wates District, Kulon Progo Regency. In the beginning, the Kelurahan Wates Wates was in the form of a village, where all assets belonged to the village and the company to the Wates community and village. On December 1st, 2010, the status of Wates Village changed to Kelurahan Wates. Wates Subdistrict is the center of Kulon Progo Regency government, indirectly for the kelurahan that is related to Kulon Progo Regency Government due to limited budgets, some things in the geospatial data will not appear in Renja 2017. For example, there are no planned activities regarding village / kelurahan mapping. Thus, this can be an opportunity for universities to carry out research and community service activities, especially in the availability of geospatial data. From the presentation of the problem, the main thing is the absence of geospatial data, and it can be provided with one form of geospatial data, namely the large-scale Wates Urban Air Photo Map, which is between 1: 1000-1: 5000. The output from this service, in the form of Large-scale Wates Urban Air Photo Map. From the maps that will be produced, it can be developed to make other derivative maps, such as facilities and infrastructure maps, road network maps, and village information systems that will be created in community service in the following years.. Keywords: aerial map, aerial photograph, Wates, Geospatial