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Book ChapterDOI: 10.1201/9781315370989-14

Delineation and zonation of flood prone area using geo-hydrological parameters: A case study of lower ghaghara river valley

01 Jan 2016-pp 78-100
About: The article was published on 2016-01-01. It has received 3 citation(s) till now. The article focuses on the topic(s): Flood myth. more

Topics: Flood myth (55%)

Journal ArticleDOI: 10.1016/J.RSASE.2018.06.001
Abstract: Floods are one of the most destructive and land sculpting phenomena around the globe and different aspects of them are being studied at different spatial and temporal scales. Magnitude and frequency of floods, the two important components in flood studies, have been studied with enhanced accuracy and quickness because of commencement and advancement in geospatial technology. Accentuation in the studies of floods and hazardous impacts thereof, at different temporal and spatial scales, have been achieved due to increased temporal and spatial resolution of remotely sensed satellite images. Advancement in computational power has also helped us to perform such analysis quickly. Even after such enhanced capabilities and facilities, flood studies at local levels (village or town) are not very common. Lack of such studies poses a serious challenge to hydrologists, climate scientists, geoscientists, planners and policy makers. The present work proceeds to achieve twofold objectives to ease the challenge faced: 1) to assess the flood hazard of August 20, 2016 flood event of Satna district of Madhya Pradesh at village/town level; and 2) to devise a flood hazard index (FHI) using linear combination of only two parameters i.e. flooded area and qualitative turbidity. The flooded areas have been derived from Landsat 8 OLI-TIRS image of August 20, 2016 using tasseled cap wetness index and modified normalised difference water index (MNDWI). The values of MNDWI have been taken as a proxy for qualitative turbidity. Association of FHI with flood-affected arable land and built-up area is positive and statistically significant at 0.01 level that justified the method of FHI computation. As compared to the four parameters-based FHI, devised by Kumar (2016), this study found that the FHI computed with only two parameters is also effective, easy to compute and this approach may be tested in other flood-affected parts of the globe. more

Topics: Flood myth (54%)

12 Citations

Book ChapterDOI: 10.1007/978-3-319-99882-4_6
Rajesh Kumar1Institutions (1)
01 Jan 2019-
Abstract: Globally, the flood magnitude and flood-induced damage are increasing. Hence, the geospatial technology has been used to minimise the adverse effects of floods and to plan the floodplain for the betterment of floodplain dwellers. One of the major causes of floods in the Rapti River basin is heavy rainfall induced by the break-in-monsoon condition. These days, geoscientists and planners use Sentinel-1A IW GRD synthetic-aperture radar (SAR) image for flood extent mapping. Gauge level and flood duration data recorded at Bhinga, Balrampur, Bansi, Regauli, Birdghat, Kakarahi, Uska Bazar and Trimohinighat sites provide the basis for the selection of SAR images. Extensive floods occurred in the Rapti River basin during August 13–September 01, 2017. The flood duration in the Rapti River basin varied from 3 (Bhinga) to 18 days (Birdghat) in 2017. The flood duration, normally, increases from the upstream to downstream along the Rapti River due to decreasing slope and discharges contributed by the tributaries. In this study, Sentinel-1A GRD SAR images of August 21 and 25, 2017, have been selected for flood mapping in the Indian part of the Rapti River basin. The water level of rivers was above the danger level (DL) at Bansi, Regauli, Birdghat, Kakarahi, Uska Bazar and Trimohinighat gauge and discharge (G/D) sites on August 21 and 25, 2017. The propagation of flood peaks and affected areas has been analysed using water level data and SAR images for the mentioned periods. The actual flooded areas covered 2046.7 km2 area of the Indian part of the Rapti River basin during August 21–25, 2017. The validation of flooded areas has been done using GPS way points collected during field survey (November 2017) and Landsat 7 ETM+ images (August 24, 2017). Breach sites in flood-prone areas have been mapped using Sentinel-2A and B MSI images. The z-score method has been used for the standardisation of development block-wise flooded areas (km2) and number of flood-affected villages. After standardisation, these two parameters have been added to formulate development block-wise flood hazard index (FHI). High to very high FHI values have been observed in Siddharthnagar and Gorakhpur districts. more

Topics: Floodplain (61%), Flood myth (55%), Tributary (53%) more

7 Citations

Book ChapterDOI: 10.1007/978-981-13-3179-4_10
01 Jan 2019-
Abstract: Wetlands are one of the most productive and fragile ecosystems on the Earth’s surface. They have been providing essential services (irrigation, groundwater recharge, flood control and drinking water) to the society since the beginning of civilisation. The middle Ghaghara River basin is located in middle Ganga alluvial plain and is mainly drained by Ghaghara, Sarju, Rapti, Burhi Rapti and Kuwano rivers. In this study, Landsat 5 and 8 images of the post-monsoon months of 1989 and 2015 were used to extract the open water bodies of wetlands. Density slicing of the shortwave infrared band and the modified normalised water difference index (MNDWI) were utilised for the extraction of open water bodies. The total area of open water bodies was 472 km2 in 1989, while it reduced to 317 km2 in 2015. Thus, the reduction in open water bodies of wetlands is about 33%. more

Topics: Wetland (56%), Groundwater recharge (55%), Drainage basin (53%) more

1 Citations