Tailoring a Geomodel for Analyzing an Urban Skyline

Landscape and Urban PlanningLandscape and Urban Planning, Volume 105, Issues 1–2, 30 March 2012, Pages 160-173

Caner Guney, Suzan Akdag Girginkaya, Gulen Cagdas, Sinem Yavuz

“Highlights

  • GIS technology is used to gather a DEM with building models to evaluate the skyline of a city.
  • GIS technology is used to perform visibility occlusion tests.
  • This study created a geomodel which represents urban skylines.
  • The geomodel evaluates beforehand the impact of a high-rise building in terms of urban esthetics.
  • The conceptual model expressed with UML standard as a generic method to be applied to other projects.

“A skyline is a unique fingerprint of a city. The mentalities, diversity, and cultures in a city can often be perceived from its skyline. Istanbul’s iconic skyline forms an essential part of the character and appearance of this mega city, so much so that Istanbul’s historical silhouette is instantly recognizable; it is a unique asset that is important to protect. Impressive minarets and domes dominate the skyline of Istanbul. On the other hand, Istanbul’s skyline has changed dramatically over the last decade since land has become increasingly an opportunity for investment and building of taller structures has become one way to multiply this profit.

Shadow analysis of the tall buildings within the study area.

Shadow analysis of the tall buildings within the study area.

“For those who focus on the esthetics of cities, the analysis of the skyline is not a recent phenomenon. However, skyline extraction and analysis has not usually been available in current GIS functionality. This article investigates the esthetics the urban skyline and its transformation due to high-rise buildings. It does this by tailoring a geomodel within a GIS environment. It is believed that the geomodel developed in this study will form a solid foundation which can be applied to many of the urban skylines and urban areas in Turkey and other cities of the world.”

Spatio-temporal Analysis and Impact Assessment of Trawl Bycatch of Karnataka to Suggest Operation Based Fishery Management Options

Indian Journal of FisheriesIndian Journal of Fisheries, Vol 59, No 2 (2012)

Dineshbabu A.P., Sujitha Thomas, and E.V. Radhakrishnan

“The term ‘trawl by-catch’ is losing significance from commercial view point, since every fish landed is in demand. However, from the resource conservation and fishery sustainability point of view, the magnitude of resource damage caused by trawl bycatch is alarming. At Mangalore Fisheries Harbour, it was estimated that, in 2008-2009, single day operating trawlers (SDT) landed 3,515 t of fishes, out of which only 2,246 t (64%) were landed for edible purpose and the rest was rated as low value bycatch (LVB) used for miscellaneous purposes. Multiday trawlers (MDT) landed an estimated 2,20,678 t of fishes of which 1,83,145 t was retained for commercial purpose and 37,533 t (17%) was discarded. Of the retained fish, 1,67,810 t were marketed for edible use and 15,335 t (7% of the catch and 9% of the landings) was marketed as “low value bycatch” (LVB) mainly for fish meal production. Low value bycatch landed in Mangalore increased from 3% in 2008 to 17% in 2009, but the discards showed a reduction from 23 to 18%. From the discarded catch, 116 species of finfishes, 31 species of gastropods, 4 species of bivalves, 7 species of cephalopods, 13 species of shrimps, 3 species of stomatopods, 21 species of crabs, 3 species of lobsters and juveniles of unidentified sharks and rays were recorded. Juveniles of commercially important species formed 34% of the trawl discards by weight (44% by number). An estimated 2,733 t (464 million in number) of Platycephalus juveniles and 1341 t (333 million in number) of Nemipterus randalli were discarded by MDT operated from Mangalore during 2008-2009.

Composition of commercial catch, low valued bycatch and discards from MDT at Mangalore Fisheries harbour during 2008-2009

Composition of commercial catch, low valued bycatch and discards from MDT at Mangalore Fisheries harbour during 2008-2009

“Spatio-temporal analysis of bycatch data from fishing grounds off Karnataka revealed that the grounds trawled during the month of August 2009 had high discard rate in terms of quantity discarded (biomass loss) and operations during March 2008 had the highest loss of biota (biodiversity loss) in terms of number of species. The paper advocates bycatch management through effort reduction in areas and during months of high dominance of bycatch.”