Variability of Sand Spits at the Mouth of Estuaries: A Disastrous Impact Study of Phanase , Tambaldeg and Tondavali of Sindhudurg Coasts

Mane M.M., Sapkale J.B. and Susware N.K.

Page No. 1-5

Numerous coastal landforms have been found in the parts of west coast of Maharashtra. The depositional coastal land forms like sand bars, sand dune and sand spits are continuously varying coastal landforms in the region. These coastal landforms are changing their characteristics seasonally due to the coastal and fluvial processes and also changes due to the human intervention. An attempt has been made to assess the size and shapes of sandspits of Phanase, Tambaldeg, and Tondavali for the year 2003 ,2011 and 2019.

The variations in the spits have also been evaluated periodically for the considered years. Every year the dimension of the sand spits has changed at these sites. The data variation in the shape, size and aerial extent of the sand spit has been procured from the Remote Sensing Technique and Google Earth Satellite Images. Besides this, a field survey with the in situ observation of sand spits at primary stage was also conducted at the coastal area of Phanase, Tambaldeg and Tondavali.

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Using Facebook for Relief Operations during Earthquakes: Experiences of Netizen-Solicitors in Southern Philippines

Tudy Randy A.

Page No. 6-8

Earthquakes are unpredictable and can cause enormous damages to people and properties. Communication plays a crucial role for both victims and responders, especially in relief operations. In the advent of the internet, Facebook and other social media platforms emerged as a more convenient and effective means of disaster communication. The main purpose of this study is to explore the use of Facebook in relief operations during the four major earthquakes in Southern Philippines. Employing a phenomenological research design, nine netizen-solicitors who were involved in relief operations using their Facebook accounts willingly participated in the key informant interview (KII).

The results of the study revealed three emerging themes as to the use of Facebook in the relief operations. These were (1) providing credible information about the situation, (2) inspiring people to donate and (3) building trust from donors. Hence, individuals or organizations can maximize the use of Facebook as an effective medium in helping the victims of disasters.

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Community Perceptions on Climate Change and Natural Resources Degradation in a Tribal Context: An Empirical Study in Koraput, Odisha

Rath Jyoti Prakash, Jena Damodar and Dibiat Nibal

Page No. 9-13

Tribal communities which are considered to be deprived section of population in Odisha especially in its non-coastal parts, mainly practise farming and Non-Timber Forest Products (NTFPs) gathering from the surrounding natural resources as livelihood options. They have an inalienable relationship with their surrounding natural resources. They perceive climate change and natural resource degradation as one of the major reasons for their state of vulnerability. In this context, the present study attempts to analyse with empirical support the following questions: 1. How do these groups perceive the climate change and natural resources degradation and 2. How do they qualify their perceptions on climate change and natural resources degradation?

Interestingly it was found that the tribal communities primarily dependent on biodiversity-based livelihoods are more vulnerable to climate change. Declined rainfall, rainy days and increased temperature during agriculture period, increased rainfall during harvest, loss of top soil, declined stream flow and surface flow were some of the important areas on climate change and natural resource degradation as perceived and qualified by the tribal communities.

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Prediction of landslide hazard potential Tapanuli Utara district

Kiki Riris Nababan and Mangapul P. Tambunan

Page No. 14-20

Landslides are natural disasters that often occur in Indonesia which are caused by various factors. North Tapanuli Regency is an area with undulating characteristics, steep altitude, an area with a type of clay and high rainfall throughout the year. Facts show that in North Tapanuli Regency, natural disasters in the last ten years have been dominated by landslides. Look at the losses that have occurred based on the history of landslides in the Tapanuli Utara Regency. There is need for mapping potential landslides as a mitigation effort to minimize losses landslide effect and an attempt to make good regional spatial plans. The efforts to produce maps landslide potential hazards are presented by direct field observations, interpretations of images and presentation of fact data through authorized institutions and will be processed using the SMORPH (Slope Morphology) method. Data processing in SMORPH will consider slope factors with a combination of topographic and soil types analyzed through DEM (Digital height model) data.

This study uses spatial modeling, the use of geographic information systems as tools and media in conducting classification in predicting potential landslides. DEM data processing in the SMORPH method will be validated through land use analysis with image interpretation, rainfall data analysis and geological conditions in the study area. This research will explain the influence of topographic conditions with regional planning patterns as a form of mitigation for welfare and regional development. In addition, the results also will provide a potential landslide hazard model in North Tapanuli District to make a sustainable spatial plan that mitigates the natural disasters.

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Climate Risk to Resilience-Analyzing short duration extreme rainfall for water planning in the megacity of Delhi

Chaudhuri Ranjana Ray and Sharma Prateek

Page No. 21-30

Rising summer daytime temperatures, rising short duration high intensity rainfalls and absence of long duration rainfall are not so rare events in urban areas of semi-arid and arid regions in the last decade. With rising population and increasing water demand, the megacity of Delhi needs to address extreme events in its planning. The trend analysis for duration of one hour(1h), three hours (3h), six hours (6h), twelve hour(12h) and twenty-four hour(24h) was carried out using Mann Kendall test and the magnitude of the trend was estimated using Sen’s slope. Except for the 1h duration rainfall, the 3h, 6h, 12h rainfall durations show a falling trend in rainfall intensity.

In order to determine the magnitude of rainfall intensity for return periods (10 years, 25 years,50 years and 100 years), probability models GEV and log normal are used. The choice of selection of the probability model is determined using the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). These are information theory-based criteria and use the log of maximum likelihood estimation and penalize the models against the parameters. The BIC emerges as a better tool for model selection for the durations chosen. It is seen from these models that extreme value intensity of 100mm/h may have a return period of less than 100 years. The blue green city is the best option to prepare the city against such climate disasters in an otherwise semi-arid region of erratic rainfall.

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A Study on Landslide Hazards through Microzonation Approach - A case of Gangtok, Sikkim

Kalita Kamaleswar and Gogoi Mouchumi

Page No. 31-36

Microzonation approach or hazard mapping is one of the modern options towards the management and mitigation of landslide hazards of a region. Landslides, mass movements and slope instability are common and serious geoenvironmental hazards in the Himalayas. Gangtok, the capital of Sikkim State has been struck by different types of landslides in recent years. Study shows that the developmental activities in and around Gangtok particularly in the past three decades have aggravated the landslide incidences to a great extent. However, the landslide hazard studies on Gangtok have been carried out by using data for various geoenvironmental parameters viz. lithology, geology, slope, soil, drainage, rainfall and forests.

A numerical weightage called Landslide Susceptibility Index (LSI) has also been assigned for this purpose. Based on the data and their relationship, a microzonation map has been prepared to show the different categories of landslide hazards of the region.

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Influence of deficit and surplus of precipitation on the forest fire risk in area of Timočka Krajina

Živanović Stanimir

Page No. 37-41

This study focuses on impact of deficits and excess rainfall on the distribution of forest fires in area of Timočka Krajina. We investigated the variability of the dynamics of the occurrence of forest fires depending on the deficit and the surplus in the expected rainfall. Analyzing the data for the period 20092018, we can see pronounced oscillations in the dynamics of the occurrence of forest fires which change in accordance with the lack of atmospheric precipitation in that period.

It was very warm and dry in 2012, while 2014 was one of the rainiest years in Serbia. The highest incidence of forest fires was in 2012 (69) which correlated with the lack of precipitation. The lowest incidence of forest fires (1) was in 2014, which correlated with the rainfall surplus. The aridity index was low during 2011, 2012 and 2017, correlating with a large number of forest fires.

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Exogeneity of Flood Hazardousness and Cereal Crops Production in Indian States

Hussain Md Aktar and Guha Pradyut

Page No. 42-50

Using data collected from various published sources, present study made an attempt to evaluate the hazardousness of flood on principal cereal crops output across fourteen Indian states covering the period 1990-2016. Seemingly unrelated regression (SUR) estimation technique was applied for jointly determining the exogeneity of flood hazardousness on principal cereal crops output together with impact of rainfall and irrigation infrastructure on the spread of flood. Though acreage expansion helped in realization of higher output level, yet area affected by flood observed to be inversely associated with output of each cereal crop across the selected states.

The excessive rainfall as anticipated and surprisingly irrigation infrastructure is noticed to be contributory towards occurrence of flood in the study area. Across the study area relatively poor irrigation infrastructure is noticed where flood has been a regular phenomena while the frequency of flood is recorded to be minimal in states having sufficient irrigation infrastructure. Initiative towards improving base and spread of irrigation infrastructure especially in flood plain agriculture may be instrumental towards minimising the threat of flood in agriculture thereby enhancing the cereal crop output.

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Drought Assessment of Eastern Satara District of Maharashtra using Standardized Precipitation Index

Waghmare Prakash T., Panhalkar Sachin S., Patil Abhijit S. and Pawar Somanath D.

Page No. 51-56

Drought is one of the natural disasters which adversely affects living things. The proper management of drought is an essential need to reduce the intensity of drought. The present study assesses the spatial distribution of meteorological drought observed over the last 35 years for the eastern Satara district of Maharashtra. Standardized Precipitation Index (SPI) is used to study the meteorological drought of the study area. SPI was computed for medium (6 months) time scale with 35 years of rainfall data.

In the distribution of rainfall, high and irregular variability is depicted with wet and dry periods over the study area. The SPI reveals near-normal drought for 313 months (74%) and moderately dry condition ranging from -1.49 to -1.0 SPI index value for 93 months (22%) of 35 years of rainfall. The present investigation will be useful to delineate potential sites of drought and will be helpful to reduce the risk of future drought conditions.

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Cyclone Lahar and its associated wave characteristics with special reference to Andaman Islands - A Numerical modelling approach

Hussain Hamid and Balaji S.

Page No. 57-63

Natural hazards, especially tropical cyclones, are persistent visitors of Bay of Bengal which result in significant loss of life, damage to infrastructure, marine life and biodiversity. This study discusses the development of a cyclone model for the Bay of Bengal and adjoining the Andaman Sea, especially to understand the wave characteristics during cyclones of Andaman Islands.

The study simulated the nearshore spectral wave characteristics of South Andaman during the Cyclone Lahar which hit the Islands from 23rd November 2013 to 26th November 2013. The spectral wave model of MIKE 21 developed by Danish Hydraulic Institute is used to simulate the wave characteristics of Bay Bengal and the Andaman Sea and the observed wave characteristics of a Wave Rider Buoy located at Port Blair Andaman are used for the validation of the model. A maximum simulated significant wave height of approximately 18 m was observed from the model due to the cyclone and a maximum simulated significant wave height around 3.5 m was observed on the nearshore coastal waters of Port Blair Andaman Islands.

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Image analysis and Geospatial risk assessment of seismicity in Kashmir Basin, NW Himalaya

Ayaz Mohmood Dar and Kaiser Bukhari

Page No. 64-76

The study aims to infer the consequences related to structural discrepancies, seismicity and settlement in the Kashmir Basin based on correlative methods adopted through image analysis, digital and visual image interpretations and seismic data analysis. The total of 130 lineaments was assessed whereas numerous long linear lineaments can be associated with structural discrepancies related to tectonic faults. The region has not witnessed the greater magnitude earthquake from a century except the one of 7.6 magnitude outside its periphery at Muzaffarabad in 2005 which was felt as excruciating.

The depth of the earthquake epicenters occurred from the last 100 years was found averaging at ~30-40km whereas the region has witnessed ~44 earthquakes of 3.2 to 5.2 magnitudes during this time. The study found 13% of the total land occupied by settlements whereas the large portions of these settlements depict higher consequences of slope instabilities.

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