Subterranean Channels Research Articles

Deep learning-based detection of qanat underground water distribution systems using HEXAGON spy satellite imagery

Qanats are a remarkable type of ancient hydraulic structure for sustainable water distribution in arid environments that use subterranean channels to transport water from highland or mountainous areas. The presence of the qanat system is marked by a line of regularly spaced shafts visible from the surface, which can be used to detect qanats using satellite imagery. Typically, qanats have been documented by field mapping or manual digitisation within a Geographic Information System (GIS) environment. This process is time-consuming due to the numerous shafts within each qanat line. However, several automated methods for detecting qanat structures have been explored, using techniques such as morphological filters, custom convolutional neural networks (CNN) and, more recently, YOLOv5 and Mask R-CNN. These approaches used high-resolution RGB images and CORONA images. However, the use of black and white CORONA in CNNs has been limited in its applicability due to a high rate of false positives.This paper explores the potential of YOLOv9 in processing the black and white HEXAGON (KH-9) high-resolution spy satellite system launched in 1971. Two areas in Afghanistan (Maiwand) and Iran (Gorgan Plain) were selected to train the system images extracted from HEXAGON imagery and artificial synthetic data. The training dataset was augmented using the Albumentation library, which increased the number of tiles used. The model was tested using two types of HEXAGON imagery for selected areas in Afghanistan (Maiwand), Iran (Gorgan Plain) and Morocco (Rissani), and CORONA imagery in Iran (Gorgan Plain).Our study provided a model capable of predicting the location of qanat shafts with a precision of over 0.881 and a recall of 0.627 for most of the case studies tested. This is the first case study aimed at detecting qanats in different landscapes using different types of satellite imagery. Using real, augmented, and artificial data allowed us to generalise the representation of qanats into lineal groups of circular features. Thanks to applying labelling for individual qanats and their pairs as separate classes, our approach eliminated most of the isolated and clustered false positives.

Water Engineering at Precolumbian AD 600–1100 Tiwanaku’s Urban Center (Bolivia)

The pre-Columbian World Heritage site of Tiwanaku (AD 600–1100) located in highland altiplano Bolivia is shown to have a unique urban water supply system with many advanced hydraulic and hydrological features. By use of Computational Fluid Dynamics (CFD) modeling of the city water system, new revelations as to the complexity of the water system are brought forward. The water system consists of a perimeter drainage channel surrounding the ceremonial center of the city. A network of surface canals and subterranean channels connected to the perimeter drainage channel are supplied by multiple canals from a rainfall collection reservoir. The perimeter drainage channel provides rapid draining of rainy season rainfall runoff together with aquifer drainage of intercepted rainfall; water collected in the perimeter drainage channel is then directed to the Tiwanaku River then on to Lake Titicaca. During the dry season aquifer drainage continues into the perimeter drainage channel; additional water is directed into the drainage channel from a recently discovered, reservoir connected M channel. Two subterranean channels beneath the ceremonial center were supplied by M channel water delivered into the perimeter drainage channel that served to remove waste from the ceremonial center structures conveyed to the nearby Tiwanaku River. From control of the water supply to/from the perimeter drainage channel during wet and dry seasonal changes, stabilization of the deep groundwater level was achieved—this resulted in the stabilization of monumental ceremonial structure’s foundations, a continuous water supply to inner city agricultural zones, water pools for urban use and health benefits for the city population through moisture level reduction in city ceremonial and secular urban housing structures.

Tipon: Insight into Inka Hydraulic Engineering Practice

The site of Tipon, Peru, located about 30 km east of Cuzco, provides an example of Inka knowledge of hydraulic engineering and the civil engineering practices used in the design and operation of the complex water system. The inhabitants of Tipon used river- and spring-sourced surface and subterranean channels to convey, distribute, and drain water to and from multiple agricultural platforms, reservoirs, and urban ceremonial centers. Intricate intersecting surface and subterranean channel systems that combined and regulated water flows from different sources controlled the water to and drainage from 13 terraced agricultural platforms. This design served to maintain different ground moisture levels to sustain specialty crops. Within the site are fountains and multiple water display features requiring sophisticated hydraulic engineering necessary for aesthetic displays. To understand the technology used by the Inka to design the water systems at Tipon, I used computational fluid dynamics methodology and modern hydraulic engineering theory. I made computer models of key elements of the Principal Fountain and the Main Aqueduct to reproduce water flow patterns in these features as intended by Inka engineers’ designs and calculations. The Inka hydraulic technology used complex engineering principles similar to those in modern civil engineering practice centuries ahead of their formal discovery in Western hydraulic science.

Headward growth and branching in subterranean channels.

We investigate the erosive growth of channels in a thin subsurface sedimentary layer driven by hydrodynamic drag toward understanding subterranean networks and their relation to river networks charged by ground water. Building on a model based on experimental observations of fluid-driven evolution of bed porosity, we focus on the characteristics of the channel growth and their bifurcations in a horizontal rectangular domain subject to various fluid source and sink distributions. We find that the erosion front between low- and high-porosity regions becomes unstable, giving rise to branched channel networks, depending on the spatial fluctuations of the fluid flow near the front and the degree to which the flow is above the erodibility threshold of the medium. Focusing on the growth of a network starting from a single channel, and by identifying the channel heads and their branch points, we find that the number of branches increases sublinearly and is affected by the source distribution. The mean angles between branches are found to be systematically lower than river networks in humid climates and depend on the domain geometry.

Large-Scale Experimental and Numerical Study of Blast Acceleration Created by Close-In Buried Explosion on Underground Tunnel Lining

Despite growing demands for structures in water transportation tunnels, underground installations, subsurface dams, and subterranean channels, there is limited field knowledge about the dynamic behavior of these structures in the face of near-fault earthquakes or impulse excitations. This study conducted a large-scale test on underground tunnel excited by two close-in subsurface explosions. The horizontal and vertical acceleration were recorded on the vertical wall of the tunnel and the free field data including the acceleration on the ground surface at 11-meter distance from the tunnel. The frequency domain analysis of recorded results determined the frequency 961 Hz and 968 Hz for 1.69 kg and 2.76 kg equivalent T.N.T., respectively. Then, finite element analysis results were compared with the test data. The comparisons demonstrated a good correlation and satisfied the field data. Finally, based on numerical modeling, a parametric study was applied to determine the effects of shear wave velocity distance of the crater with respect to the tunnel on impulse response of the tunnel.

Geochemical Modeling of Reaction Paths and Geochemical Reaction Networks

From the discussions in previous chapters, we can see that in order to understand the kinetics of dissolution and precipitation reactions, we really need to understand geochemical reaction networks. The previous chapters have depicted a complex picture of the details of chemical reactions and kinetics. The complexity comes from the nature of chemical kinetics. Unlike thermodynamics, which describes one state versus another, independent of the reaction paths, the kinetics of chemical reactions is path dependent. Lasaga (1998) cited Benson (1960) who described the time- and path-dependent nature of reaction kinetics “ a body of water on top of a hill may be described thermodynamically in terms of its composition, pressure, and temperature. At a later time, this same body of water may find its way to a lake below. The thermodynamic description of the body of water in the lake is again well defined. However, if we try to describe the transition—the water in process of flowing from the hilltop—we see that it may depend on almost innumerable factors: on the outlets, on the contour of the hillside, on the structural stability of the contour, and on the numerous subterranean channels through the hillside that may exist and permit seepage. ” What this familiar quote highlights is the path dependent nature of chemical kinetics, which helps to weave together a bewildering variety of geochemical reaction networks in many geologic systems. How can we handle this complexity and apply chemical kinetics to the geological systems? It is certainly impossible to conduct laboratory experiments to determine every reaction path and explore every type of geochemical reaction network. It appears that geochemical modeling, if standing on solid building blocks of theory and experimental data, can play a critical role in exploring the ranges of behaviors of geochemical reaction networks and extrapolate laboratory experimental …

Indoor radon levels and their dynamics in relation with the geological characteristics of La Garrotxa, Spain

Indoor radon concentration has been measured in workplaces and dwellings of the volcanic region of La Garrotxa and in the vicinity of the recently active Amer fault, in northeastern Spain. The radon levels obtained do not constitute a relevant risk for workers. Higher indoor radon levels have been found on volcanic materials (mean 133 Bq m −3, range 15–1464 Bq m −3) than on non-volcanic materials (mean 67 Bq m −3, range 16–327 Bq m −3). A summertime elevation of radon levels that does not happen in buildings placed on non-volcanic materials has been observed as consequence of convective airflow from the soil to indoor environments through a network of subterranean channels present in volcanic materials. This effect is very important if the subterranean channel reaches the indoor environment through natural holes called blowholes. A possible influence of the Amer fault has been seen in La Vall d'en Bas, one of the five villages studied, which has a more homogeneous underlying geology.

Ecology of benthic diatoms from Lake Macro Prespa (Macedonia)

Lake Prespa belongs to the group of ancient lakes. By subterranean channels it is connected with Lake Ohrid. In the past two decades, Lake Prespa has been characterized by a decrease of its water level and an increased cultural and natural eutrophication. In this period, very few ecological studies were performed, based mainly on composition and biomass of the phytoplankton community. From June 2002 to May 2003 analyses of 18 physical and chemical parameters and composition of benthic diatoms were performed on 12 sampling sites of Lake Macro Prespa. About 300 diatom taxa were identified in the lake. Relative abundances were calculated by counting 200 diatom valves, and 143 diatom taxa had abundances of more than 1 % in at least one sampling site. Deep benthic communities were dominated by Cyclotella ocellata and Diploneis mauleri, while in the littoral region these communities were dominated by small Navicula sensu lato species. For statistical analyses, the 17 most abundant diatom taxa (> 1 % in total abundance) were used. Contrarily to the expectations, TP had a negligible influence on diatom community structure. The main environmental factors controlling species distribution and abundances were ammonium and metallic cations (Cu, Mn, K) and, secondarily, dissolved oxygen and Secchi depth, as inferred from both correlation and multivariate (CCA) analysis.

Assessment of the Contributions of Traditional Qanats in Sustainable Water Resources Management

Qanats (Kanats) have been an ancient, sustainable system facilitating the harvesting of water for centuries in Iran, and more than 34 additional countries of the world. These subterranean channels have been used for the transference of snowmelt water from the mountainous terrain for thousands of years. Agricultural, industrial and urban demands for fresh water have brought about increasing demands for water, the elixir of life. In response, the harvesting of water via deep groundwater wells throughout arid zones has disturbed the aquifers, and resulted in the abandonment of some qanats. Qanats in the province of Yazd City are witnessing this depletion. This paper introduces qanats, objectives causing their creation, construction materials, locations and their importance in different times, as well as their present role in Iran. Further, current qualitative and quantitative analyses of the qanats in Tehran are identified.

New excavations at the Barbar Temple, Bahrain

In 2004 excavations at the Barbar Temple dating to c. 2000 BC established that the function of the southeastern subterranean channel connected to the temple pool was to supply the pool with water and not to divert water away from the pool. North and west of the temple the oval terrace wall of its third phase was located. In the centre of the Northeast Temple the remains of a shaft‐stairway leading down to a well‐chamber was uncovered and shown to be furnished with two subterranean channels leading water into the chamber. South of the Northeast Temple a house with late pottery was excavated. Two stamp seals and two seal‐impressed tokens were found.

Early concepts and charts of ocean circulation

Early concepts and charts of ocean circulation

Observations on the Ecology of Caves

1. The principal energy sources of cave ecosystems are (a) organic matter swept underground by sinking streams, and (b) the feces, eggs, and dead bodies of animals which remain in the cave for shelter but feed outside (trogloxenes). In temperate zone caves flooding and the entrance of cold air during winter and early spring disturb the relatively constant physical conditions of the cave environment. 2. Species density, dispersal potential, and other aspects of the ecology of troglobites (obligate cavernicoles) are profoundly influenced by continuity of limestone outcrops in which the caves are developed. In the Appalachian valley, where limestone is exposed in many narrow, anticlinal strike belts, species density per unit area is high, and dispersal of troglobites through subterranean channels is severely restricted by geologic structure. In the Mississippian plateaus, where thick, caverniferous limestone is widely and continuously exposed, there are fewer species per unit area; and subterranean dispersal...

Water Pollution and Agriculture

For the purposes of this paper, I would like to define (1) natural runoff pollution as pollution resulting from all silts and organic materials carried by watercourses not originating from municipal, industrial, or agricultural operations; (2) agricultural pollution as pollution resulting from surface runoff, seepage, percolation, and return flow from cultivated land used for producing food and feed crops; and (3) animal-feedlot pollution as pollutants originating from animal-feeding operations in restricted areas where the feed supply is nutritionally balanced for maximum animal-weight gain. Pollution has existed for a long time: only recently have we become conscious of it. We generally think of pollution as originating from some industrial plant with black clouds of smoke pouring from its stack and equally black liquids pouring from subterranean channels. Secondly, we recognize the wastes from municipalities, although perhaps reluctantly, because this includes ourselves as contributors. Perhaps only a fisherman who has practiced his art in a highly intensified farming-livestock area is well-acquainted with the subject of this paper.

Karst-tunnel

Parts of karst subterranean rivers sometimes survive as tunnels, when the former subterranean channels are destructed at two places making surface streams above and below. Such karst-tunnels in Taishakukyo, Hiroshima Pref. and in Kienshui, Yunnan, arc described.

Sur les phosphorites du Bas-Languedoc

Abstract The phosphate deposits of Bas-Languedoc, France, are karst deposits which were formed in subterranean solution cavities and stream channels, from the Ludian to the Stampian (Tertiary).

Analysis of snow‐cover and runoff in Upper Snake, Upper Yellowstone, and swift current watersheds

In the use of snow‐survey data, particularly water‐content measurements, as a basis for estimating or predicting the runoff from a given watershed, it has long been recognized that other factors enter in which disturb the relationship that appears to exist between the amount of water stored in the snow‐blanket at the end of winter and the amount of runoff which occurs during the spring and summer months or runoff‐season.Among the factors which affect the correlation between water‐content and runoff, the following are considered important: (1) precipitation on the watershed during the runoff‐period; (2) evaporation and transpiration‐losses from the watershed, including evaporation or sublimation from the snow‐cover itself; (3) ground‐storage, as reflected by the fluctuations in water‐table caused by draining and recharging of the ground‐water reservoir; and (4) deep percolation‐losses that is, drainage through deep subterranean channels which does not appear again as springs tributary to the stream in question.

Geophysical interpretation of ground‐water levels

The theory of rock‐pressure as a cause of artesian‐head dates back at least to early Grecian times. Thus the philosopher Thales, about 600 B.C., taught that the springs derive their water from the ocean through subterranean channels and that the water is lifted to the springs by rook‐pressure. The theory of rock‐pressure has had a number of recent advocates, chief among whom was the British geologist, J. W. Gregory, but apparently no effective attempt was made by any of them to apply critical data to the problem. In general, geologists and hydrologists have rejected rock‐pressure as a vague heresy and have assumed that the artesian formations function as perfectly rigid and inert containers, not recognizing the fact that the data in regard to the performance of wells appear to conflict with such an interpretation.

Irrigation Systems of Persia

IN this tract of country there is no water appearing on the surface, though there are many subterranean channels which have well-shafts sunk to them, at spots in the desert unknown to persons unacquainted with the district. A true account of these channels has been preserved among the natives to the effect that, during the Persian ascendency, they granted the enjoyment of the profits of the land to the inhabitants of some of the waterless districts for five generations, on condition of their bringing fresh water in; and that, there being many large streams flowing down Mount Taurus, these people at infinite toil and expense constructed these underground channels.

Notes on Lateritization in Sierra Leone

Summary1. Lateritization has been found to affect a variety of rocks in Sierra Leone, including norite, granitic rocks, and detrital deposits.2. The norite of Sierra Leone is not deeply lateritized except in highly jointed areas or in certain bands readily susceptible to the alteration. It yields a gibbsitic laterite. A core of unaltered norite is enclosed in a light-coloured halo (“zone of leaching” of Professor Lacroix), which passes gradually into a red-brown laterite (“zone of concretion”). The transition from core to laterite is a rapid one. The minerals of the norite are attacked in the following order: felspar, diallage, hypersthene, magnetite (titanomagnetite).3. Norite containing only a small quantity of disseminated magnetite is less readily lateritized than norite containing a moderate amount. Where, however, the norite includes an unusually high proportion, as in the streaks of magnetite, lateritization proceeds very slowly.4. The granitic rocks of the Protectorate are frequently lateritized to a depth of 15 feet, and sometimes even to 30 feet. Nevertheless laterite is only slightly developed in the inselberg mountain districts of the northern part of the country. Lateritization of granitic rocks proceeds as follows: the rocks decompose into a white kaolinitic product, which passes into.brown lateritic clay (“zone of leaching”); this lateritic clay then develops into laterite (“zone of concretion”). There is a progressive change from the unaltered rock to the laterite crust, the granitic rocks in this respect presenting a marked contrast to the basic rocks.5. Lateritization affects detrital deposits also, particularly the Pleistocene sands and clays of the coastal plain. The phenomenon is most pronounced in the felspathic sands and diminishes in the more argillaceous beds until it is practically non-existent in pure clay. The typical lateritite is a red-brown scoriaceous rock, moderately hard, and in the hand specimen coarsely porous. It forms a crust about 10 feet thick at the top of the Pleistocene beds. This lateritite is indistinguishable from the laterite derived from other rocks.6. The scoriaceous laterite (lateritite) was produced by the growth and ultimate coalescence of numerous small ferruginous concretions, followed by the removal of the soft material between the concretions.7. The laterite formed from detrital deposits passes locally into lateritic iron-ore by increase in the percentage of iron oxide. Such iron-ores are well developed along the inner margin of the coastal plain encircling the colony, and occur principally in the neighbourhood of Devil Hole, near Waterloo. They were derived originally from the titanomagnetite which enters largely into the composition of the norite, and they are consequently very rich in titanium.8. Lateritization is frequently an important factor in the production of caves and subterranean channels, owing to the ease with which the unconsolidated material is removed from beneath the thick hard crust of laterite.

XIX.—The Bone-Cave in the Valley of Allt nan Uamh (Burn of the Caves), near Inchnadamff, Assynt, Sutherlandshire

A characteristic feature of the plateau of Cambrian Limestone in the neighbourhood of Inchnadamff is the occurrence in it of swallow-holes, caves, and subterranean channels which are intimately associated with the geological history of the region. The valley of Allt nan Uamh (Burn of the Caves), locally known as the Coldstream Burn, furnishes striking examples of these phenomena. One of the caves in this valley yielded an interesting succession of deposits, from which were collected abundant remains of mammals and birds. The discovery of bones of the Northern Lynx, the Arctic Lemming, and the Northern Vole among these relics, and the collateral evidence of the materials forming some of these layers, seem to link the early history of this bone-cave with late glacial time, or at least with a period before the final disappearance of local glaciers in that region.