Economics of Flood Protection in India

The peculiar rainfall pattern in Indiarenders the country highly vulnerable to floods. Forty million hectares of land, roughlyone-eighth of the country's geographical area, is prone to floods. Each year, floods cause extensive damage to life and property, losses being exacerbated by rapid population growth, unplanned development and unchecked environmental degradation. The country has been tackling the problem through structural and non-structural measures. While non-structural measures like flood forecasting aim at improving the preparedness to floods by seeking to keep people away from floodwaters, structural measures involve the construction of physical structures like embankments, dams, drainage channels, and reservoirs that prevent floodwaters from reaching potential damage centres. Almost 48% of the vulnerable area has been provided with reasonable protection, though floods continue to cause widespread losses year after year. This paper examines the incidence of floods and the trends in consequent losses in the eastern region of the country – one of the most vulnerable – with the objective of studying the efficacy of flood protection measures in the region. Based on a simple regression exercise for three highly vulnerable states in the region, the paper argues that flood protection measures have been inadequate in controlling losses and reducing vulnerability. Regressions for the three states over the period 1971 to 1996 indicate that the level of protection is an insignificant explanatory variable in explaining the number of people (adjusted for increases in density) affected by floods; while area affected, as an indicator of the intensity of floods remains the main loss-determining factor.     

Geospatial modelling for sub-watershed prioritization in Western Himalayan Basin using morphometric parameters

Natural Hazards - Geographical information system and remote sensing are proven to be an efficient tool for locating water harvesting and recharge structures, groundwater potential, runoff,...     

A comprehensive study on the surface chemistry of particulate matter collected from Jeddah,Saudi Arabia

In this work, the X-ray Photoelectron Spectroscopy (XPS) technique is utilized to analyze the surface chemical composition of particulate matter (PM) which was collected from various locations at Jeddah, Saudi Arabia. The main elements found on the surface of PM are carbon (C), oxygen (O) and silicon (Si) with combined percentage of 89.4–94.9 while traces of nitrogen (N), calcium (Ca), aluminum (Al), sodium (Na), chlorine (Cl), manganese (Mg), and sulfur (S) were also present. The analyzed XPS chemical state of C, O and Si was further used to determine their bonding with other elements occurring over the surface of PM. Carbon was found in the form of carbides (18.86%), fluorides (2.39%) and carbonates (78.75%); oxygen was observed as oxides (21.05%) and hydroxides (73.42%) of other metals; and silicon was detected as silicones (12.16%), nitrides (82.53%) and silicates (5.25%). The particle size of a PM is also of great concern for health issues, and thus has been investigated by the Field Emission Scanning Electron Microscope (FESEM). The Energy Dispersive X-ray Spectroscopy (EDS) was employed for cross verification of detected elements by XPS.     

Recognition of the time and level of emplacement of the Sillai Patti carbonatite complex,Malakand Division,Northwest Pakistan: Constraints from fission-track dating

The Sillai Patti carbonatite complex represents the second largest carbonatite body of the Peshawar Plain Alkaline Igneous Province of northern Pakistan. It is situated about 20 km west of Malakand, near Sillai Patti village. Here, the carbonatite occurs along a fault in the form of a sheet striking in the NNE–SSW direction and dipping towards south. The carbonatite body is about 12 km long and 2–20 m thick, predominantly intruded along the faulted contact of metasediments and granite gneiss but locally, within the metasediments.A fission-track age of 29.40 ± 1.47 Ma was obtained for the Sillai Patti carbonatite complex. Close resemblance of fission-track apatite age of this study with the fission-track as well as other high temperature radiometric ages from the same and the neighboring carbonatite complexes of the alkaline belt of northern Pakistan suggests emplacement of the Sillai Patti carbonatite complex at higher crustal level and subsequent extremely fast cooling to near ambient temperatures (<60 °C) required for the complete retention of fission tracks in apatite. The age data also point out that the fission-track age of 29.40 ± 1.47 Ma of this study is the age of intrusion of the carbonatitic magma of Sillai Patti carbonatite complex to shallow, near-surface level.Comparison of the uplift induced denudation rates of the region with the world data clearly reflects the presence of a post collisonal extensional environment in the region south of Main Mantle Thrust during Oligocene time. This strongly negates the idea of the earlier workers of emplacement of the carbonatite complexes of the Loe-Shilman and Sillai Patti areas along thrust faults during Oligocene.     

Characteristics of mountain glacier surge hazard: learning from a surge event in NE Pamir,China

Abnormal glacier movement is likely to result in canyon-type hazards chain, such as the barrier lake of Yarlung Zangbo Grand Canyon formed by glacier debris flow in October 2018 in China.Glacier hazard usually evolves from the glacier surge and may occur in a regular cycle. Understanding the characteristics and process of glacier surge is important for early hazard recognition and hazard assessment. Based on field investigations, remote sensing interpretations and SAR offset-tracking surveys, this study confirms a typical glacier surge in the northeast Pamir, and presents its characteristics and processes. "Black ice" mixed moraines choking uplift and overflowing lateral marine are the most important scenic characteristics, which were formed under the conditions of stagnant glacier downstream and abundant super-glacial moraine. Glacier movement event can be divided into a five-period cycle including quiescent, inoculation, initiation,fracture and decline. This surge event lasted for about 300 days, initiated in February 2015 developed extensive fracturing zone in spring and early summer at maximum velocity of 10±0.95 m/day, declined after August 2015 and recovered to quiescent status in October 2015 for the next inoculation. The average height of glacier "receiving" area increased by 20-40 m with 2.7-3.6×10~8 m~3 ice transferred from glacier "reservoir", and this volume accumulation again require 50-100 years for glacier mass balance which gives approximately 100 years frequency of the glacier surge. Nevertheless, long-period increase of precipitation and temperature were favorable for the occurrence, hydrological instability is the direct triggering mechanism, and while the Glacier Lake Outburst Flood(GLOF) hazards are unlikely to occur with this surge.     

Long-term activity of earthquake-induced landslides: A case study from Qionghai Lake Basin,Southwest of China

Earthquake-triggered landslides are a major geological hazard in the eastern Tibetan Plateau, and have prolonged impact on earth surface processes and fluvial system. To determine how long co-seismic landslides affect basins, a massive number of landslides existing in Qionghai Lake Basin were investigated for landslide distribution characteristics and geomorphological evidences, with further comparison and analysis using historic seismic analog method. The landslides found in Qionghai Lake Basin showed clear features of seismic triggering with strongly controlled by Zemuhe fault. These landslides are still active at present. Some new slides generally occur in ancient slope failure zones causing serious secondary hazards in recent years. In this study we strengthen the idea that the landslides triggered by the 185o Xichang earthquake （Ms7.5） have long term activity and prolonged impact on the mountain disasters with a period of more than 16o years. Our results support growing evidence that coseismic landslides have a prolonged effect on secondary disasters in a basin, and invite more careful consideration of the relationship between current basin condition and landslide history for a longer period.     

Outlining a stepwise,multi-parameter debris flow monitoring and warning system: an example of application in Aizi Valley,China

In recent years, the increasing frequency of debris flow demands enhanced effectiveness and efficiency of warning systems. Effective warning systems are essential not only from an economic point of view but are also considered as a frontline approach to alleviate hazards. Currently, the key issues are the imbalance between the limited lifespan of equipment, the relatively long period between the recurrences of such hazards, and the wide range of critical rainfall that trigger these disasters. This paper attempts to provide a stepwise multi-parameter debris flow warning system after taking into account the shortcomings observed in other warning systems. The whole system is divided into five stages. Different warning levels can be issued based on the critical rainfall thresholds. Monitoring starts when early warning is issued and it continues with debris flow near warning, triggering warning, movement warning and hazard warning stages. For early warning, historical archives of earthquake and drought are used to choose a debris flow-susceptible site for further monitoring. Secondly, weather forecasts provide an alert of possible near warning. Hazardous precipitation, model calculation and debris flow initiation tests, pore pressure sensors and water content sensors are combined to check the critical rainfall and to publically announce a triggering warning. In the final two stages, equipment such as rainfall gauges, flow stage sensors, vibration sensors, low sound sensors and infrasound meters are used to assess movement processes and issue hazard warnings. In addition to these warnings, community-based knowledge and information is also obtained and discussed in detail. The proposed stepwise, multi-parameter debris flow monitoring and warning system has been applied in Aizi valley China which continuously monitors the debris flow activities.     

Nickel sulphide fire assay for the collection of the platinum group elements and gold from chromitites using reduced bead size

Summary Fire assay is a classical method for the separation of the platinum group elements and gold (PGE + Au). In nickel sulphide fire assay nickel and sulphur are used for the preconcentration of PGE + Au. In the past the authors have successfully reduced the weight of the collectors used without affecting the recovery of the elements from silicate material and eliminated the reagent blank problem. In this work the authors have applied the small bead size to chromitites. Chromitites can be difficult to fuse, and the authors have applied their modified technique to improve the dissolution of chromitites. This paper describes the application of the reduced bead size to the preconcentration of the PGE + Au from chromitites, by using only 0.5 g of nickel compared to the 10 g used by other fire assay workers.

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Nickelsulfid Fire assay zur Anreicherung von Platingruppenelementen und Gold aus Chromititen

Zusammenfassung Fire assay ist die klassische Methode um Platingruppenelemente und Gold (PGE + Au) vor der Analyse anzureichern und von der Matrix abzutrennen. Zum Sammeln der PGE und Au wird Nickelsulfid verwendet. Durch Verwendung möglichst kleiner Mengen konnte das Problem eventueller Verunreinigung der verwendeten Reagenzien ausgeschaltet werden. In der vorliegenden Arbeit wird diese Methode bei Chromititen angewendet, wobei hier ein modifiziertes Verfahren zum Lösen dieser Gesteine verwen det wird. Es werden 0.5 g Nickel zum Abtrennen der PGE und Au von Chromititen verwendet, was einer 20-fachen Mengenreduktion des Kollektormaterials gegenüber herkömmlichen Methoden entspricht.

     

GCP collection for corona satellite photographs: Issues and methodology

Use of high-resolution and historic CORONA satellite photographs for mapping and other purposes requires Ground Control Points (GCPs), as ephemeris data and image parameters are not available. However, the alterations in landscape in last 34 years (i.e., since the acquisition of these photographs) prevent identification and collection of large number of GCPs in the field. This paper presents a methodology for collection of GCPs for CORONA photographs. The advantages and limitations of the methodology are discussed. For a study site, situated in Siwaliks and Lower Himalayas, the GCPs were identified in CORONA photographs and their WGS84 coordinates were estimated through a process of datum transformation and georeferencing. Estimated GCP coordinates from the topo sheets and 2D and 3D views of photographs, helped in identifying the GCP locations in field, which were observed using DGPS. Investigations were carried out to relate Differential Global Positioning System (DGPS) accuracy with base line length and time of observation. Abase line of 350 km and half an hour observation were found appropriate to yield accuracy in GCP collection by DGPS method, which conforms to CORONA resolution of 3 m.