Distribution Of Drainage Networks Research Articles

Miocene basement exhumation in the Central Alps recorded by detrital garnet geochemistry in foreland basin deposits

Abstract. The Neogene evolution of the European Alps was characterized by the exhumation of crystalline basement, the so-called external crystalline massifs. Their exhumation presumably controlled the evolution of relief, distribution of drainage networks, and generation of sediment in the Central Alps. However, due to the absence of suitable proxies, the timing of their surficial exposure and thus the initiation of sediment supply from these areas are poorly constrained. The northern Alpine foreland basin preserves the Oligocene to Miocene sedimentary record of tectonic and climatic adjustments in the hinterland. This contribution analyses the provenance of 25 to 14 Myr old alluvial fan deposits by means of detrital garnet chemistry. Unusually grossular- and spessartine-rich garnet is found (1) to be a unique proxy for identifying detritus from the external crystalline massifs and (2) to occur abundantly in ca. 14 Myr old deposits of the foreland basin. In contrast to previous assumptions, we therefore propose that the external massifs were already exposed to the surface ca. 14 Myr ago.

شبکة الصرف الصحى في مدينة أجا محافظة الدقهلية دراسة جغرافية بإستخدام نظم المعلومات الجغرافية

هذا البحث يهدف الى دراسة شبکة الصرف الصحى بمدينة أجا منذ إنشاؤها إلى الأن وسوف يتم دراسة شبکة الصرف الصحى القائمة بمنطقة الدراسة من حيث نظام الصرف الصحى المتبع وتاريخ تشغيلها وتطورها ودراسة توزيع شبکة الإنحدار من حيث الأقطار والأطوال والأنماط وکثافتها ومحطات الرفع والمعالجة وتطورها ودراسة طاقتها التصميمية والفعلية لها ومراحل معالجة مياه الصرف الصحى وخطوط الطرد وکفاءتها ومتوسط التصرفات الواردة من مدينة أجا ومتوسط کميات مياه الرشح التي يمکن أن تتسرب لخطوط الصرف الصحى والعوامل المؤثرة في توزيع شبکات الصرف الصحى بمنطقة الدراسة إلى جانب دراسة توزيع الأسر والمبانى على حسب الإتصال بشبکة الصرف الصحى لمعرفة عدد الأسر والمبانى المستفيدة من هذه الخدمة وعدد الأسر والمبانى المحرومة منها . Abstract: . This research aims at studying the drainage network in the city of Aga since it was established up till now and will be a study of the drainage network where the sewage system followed the history and evolution of operating and the study which is the distribution of gradient from the diametres, lengths, patterns and intensity. And The lift stations , treatment stations , evolution and the study of its design and actual capacity ,The phases of the wastewater treatment and the lines of expulsion and its efficiency.The average behavior of the city of Aga and average quantities of leaching water that could be leaked through lines. The effective factors in the distribution of drainage networks in the area of the study, besides the study of the distribution of families and buildings related to the sewage network to know the number of families and buildings benefiting from this service and the number of families and buildings that are deprived from it.

Spatial point pattern analysis of piping erosion in loess-derived soils in Golestan Province, Iran

Point pattern analysis of collapsed pipes as a subsurface erosion in natural and manmade conditions plays an important role to understand their landforms/features, predisposing factors, and for prevention and forecasting purposes. Thus, the present study aimed to evaluate the spatial pattern and the associated land factors of piping erosion in loess-derived soils in a semiarid climate in Golestan Province, Iran by applying numerical summary statistics. To this end, a 105 ha area with homogeneous environmental conditions (gentle slope and loess-derived soil) was selected and the maps related to 101 collapsed pipes and their features were obtained by the aerial photos provided by an unmanned aerial vehicle (UAV) with a 50 cm resolution and field survey. The mean of spatial distances between pipe locations was 309 m, and the frequency of pipes per hectare was 0.97. Moreover, soil samples of the pipe locations were collected and physical-chemical soil properties were measured in laboratory. Approximately 95% simulation envelopes were selected using the 5th-lowest and 5th-highest values of 199 Monte Carlo simulations of the null model of homogeneous complete spatial randomness. Based on the results of univariate pair correlation function, the significant aggregation of 101 collapsed pipes was observed at a scale of 0–50 m in both rangeland and agricultural land use types. The bivariate pair correlation function, which is considered to be the most informative second-order summary characteristic, was used for analyzing the statistical correlations between collapsed pipes and linear phenomena including distance from drainage networks, ridges, and roads. Based on bivariate summary statistics, collapsed pipes had positively been affected by both the distribution of drainage networks and ridges. However, the negative statistical correlations occurred between pipes and roads at the scales of 1–50 m. Also, the correlations of soil characteristics (silt content, exchangeable sodium percentage (ESP), the weight of soil in a given volume (bulk density), soil electrical conductivity (EC), and organic matter (O.M.)) of neighboring collapsed pipes were evaluated by mark correlation function. Based on mark correlation function kmm(r), a significantly positive correlation was found between the pipes density and silt content, ESP, and bulk density, when they are more than overall average. In addition, less values of EC and O.M. were positively related to the aggregation of collapsed pipes. Similar to the results of summary statistics, the maps confirmed all statistical correlations. Consequently, the outcome of this study highlights the spatial pattern of collapsed pipes and their associations in the study area.

Sensing the Hydrogeomorphology and Palaeohydrologic Features of Mars Planet with Inference from the Egyptian Desert: An Insight from Satellite Images

The water access in any planet of the universe can be considered a crucial evidence for life existence. The study of Mars has special importance where it has a complex preserved geological record of a time period longer than on Earth. Many regions of Mars planet are subjected to observations through the obtained satellite images in comparison to similar areas from the Earth (Egyptian deserts). The present study presents observations from the High Resolution Imaging Science Experiment (HiRISE) and Mars Orbiter Laser Altimeter (MOLA) colorized digital terrain model (DTM), indicate that many existed landforms could reveal the palaeohydrology of Mars. The regional structural lineaments (joints and/or faults) are extracted and mapped where the main trend is NE-SW. These lineaments are thought to be responsible with erosion processes about the origination of the drainage network of Mars. The hydrogeomorphology of Mars planet suggests past wetter conditions where the transition from wet to dry surface conditions is evidenced through a variations in the spatial distribution of drainage networks. It can be thought that the selected landforms in this study (drainages, deltas, gorges, paleo-lakes, paleo-channel), are revealing an ancient wet climates where precipitation was leading to surface runoff with main role of the tectonic influences existed on structural lineaments and rifts. The current study suggests two landing sites (Jazero delta and Eberswalde Delta) for the next Mars 2020 mission taking in consideration that these sites had potential of water resources that may be provide chances for past life existence until the microbial level.

Extraction of drainage networks from large terrain datasets using high throughput computing

Advanced digital photogrammetry and remote sensing technology produces large terrain datasets (LTD). How to process and use these LTD has become a big challenge for GIS users. Extracting drainage networks, which are basic for hydrological applications, from LTD is one of the typical applications of digital terrain analysis (DTA) in geographical information applications. Existing serial drainage algorithms cannot deal with large data volumes in a timely fashion, and few GIS platforms can process LTD beyond the GB size. High throughput computing (HTC), a distributed parallel computing mode, is proposed to improve the efficiency of drainage networks extraction from LTD. Drainage network extraction using HTC involves two key issues: (1) how to decompose the large DEM datasets into independent computing units and (2) how to merge the separate outputs into a final result. A new decomposition method is presented in which the large datasets are partitioned into independent computing units using natural watershed boundaries instead of using regular 1-dimensional (strip-wise) and 2-dimensional (block-wise) decomposition. Because the distribution of drainage networks is strongly related to watershed boundaries, the new decomposition method is more effective and natural. The method to extract natural watershed boundaries was improved by using multi-scale DEMs instead of single-scale DEMs. A HTC environment is employed to test the proposed methods with real datasets.