scholarly journals The second Chinese glacier inventory: data, methods and results

2015 ◽  
Vol 61 (226) ◽  
pp. 357-372 ◽  
Author(s):  
Wanqin Guo ◽  
Shiyin Liu ◽  
Junli Xu ◽  
Lizong Wu ◽  
Donghui Shangguan ◽  
...  

AbstractThe second Chinese glacier inventory was compiled based on 218 Landsat TM/ETM+ scenes acquired mainly during 2006–10. The widely used band ratio segmentation method was applied as the first step in delineating glacier outlines, and then intensive manual improvements were performed. The Shuttle Radar Topography Mission digital elevation model was used to derive altitudinal attributes of glaciers. The boundaries of some glaciers measured by real-time kinematic differential GPS or digitized from high-resolution images were used as references to validate the accuracy of the methods used to delineate glaciers, which resulted in positioning errors of ±10 m for manually improved clean-ice outlines and ±30 m for manually digitized outlines of debris-covered parts. The glacier area error of the compiled inventory, evaluated using these two positioning accuracies, was ±3.2%. The compiled parts of the new inventory have a total area of 43 087 km2, in which 1723 glaciers were covered by debris, with a total debris-covered area of 1494 km2. The area of uncompiled glaciers from the digitized first Chinese glacier inventory is ∼8753 km2, mainly distributed in the southeastern Tibetan Plateau, where no images of acceptable quality for glacier outline delineation can be found during 2006–10.

2011 ◽  
Vol 52 (59) ◽  
pp. 144-152 ◽  
Author(s):  
F. Paul ◽  
H. Frey ◽  
R. Le Bris

AbstractMeltwater from glaciers in the European Alps plays an important role in hydropower production, and future glacier development is thus of economic interest. However, an up-to-date and alpine-wide inventory for accurate assessment of glacier changes or modelling of future glacier development has not hitherto been available. Here we present a new alpine-wide inventory (covering Austria, France, Italy and Switzerland) derived from ten Landsat Thematic Mapper (TM) scenes acquired within 7 weeks in 2003. Combined with the globally available digital elevation model from the Shuttle Radar Topography Mission, topographic inventory parameters were derived for each of the 3770 mapped glaciers, covering 2050 km2. The area-class frequency distribution is very similar in all countries, and a mean northerly aspect (NW, N, NE) is clearly favoured (arithmetic counting). Mean glacier elevation is ~2900 m, with a small dependence on aspect. The total area loss since the previous glacier inventory (acquired around 1970±15 years) is roughly one-third, yielding a current area loss rate of ~2%a–1. Digital overlay of the outlines from the latest Austrian glacier inventory revealed differences in the interpretation of glacier extents that prohibit change assessment. A comparison of TM-derived outlines with manually digitized extents on a high-resolution IKONOS image returned 1.5% smaller glaciers with TM.


FLORESTA ◽  
2019 ◽  
Vol 49 (2) ◽  
pp. 325
Author(s):  
Gabriel Americo Cassettari ◽  
Tadeu Miranda De Queiroz

This study aimed to perform the Jauquara river watershed morphometric characterization. To watershed delimitation was used SRTM 30 type Digital Elevation Model (Shuttle Radar Topography Mission, with spatial resolution of 30 m) provided by USGS Earth Explorer platform. The geographic information system used to watershed delimitation process and maps generation was ArcGIS 10.1 from ESRI®. The morphometric variables calculus was based on classic methodologies of Applied Hydrology. The watershed has an area of 1408,03 km2 and perimeter of 288,43 km with compactness coefficient and circularity index of Kc = 2.15 and Ic = 0.21, respectively, which show an elongated shape. The drainage was classified as 5th order, reinforcing the configuration of the drainage network with a wide hydric distribution. The predominant altitude range is between 368 and 552 m, which corresponds to an area of 478.10 km2. It was observed that there is a predominance of smooth-wavy and undulated reliefs (3-8%, 8-20% slope), which correspond to 38,05% and 23,04% of the total basin area respectively. The morphometric characterization of the basin made it possible to obtain unpublished information that contributes to the decision making regarding the effective water management in the studied area, being this a guiding study for other works


Polar Record ◽  
2002 ◽  
Vol 38 (204) ◽  
pp. 53-55 ◽  
Author(s):  
Philip T. Giles

AbstractIn the article by Hall and others (1995), a topographic correction factor (C) was developed for estimating actual land area by taking into account the effect of sloping terrain. An error that was made during image processing resulted in values of C being exaggerated. For this note, values of C for the example landscape in Glacier National Park were recalculated, and the results with and without the error are compared. It is shown that the error caused the mean value of C reported for the example landscape to be exaggerated by a factor of 2.62 times.


Author(s):  
Michał Wasilewski ◽  
Jarosław Chormański

The Shuttle Radar Topography Mission Digital Elevation Model as an alternative data source for deriving hydrological characteristics in lowland catchment — Rogożynek catchment case study This paper describes possibility of supplementing digital topography data needed for hydrologic modeling (WetSpa model) of lowland catchment with existing, freely available DEM data obtained from Shuttle Radar Topography Mission launched on February 11th, 2000. Rogożynek basin (Upper Biebrza) as case study is given. Authors compared three DEMs: topographic — TOPO DEM 20 (20 m resolution), radar — SRTM DEM 90 (90 m res.) and resampled radar — SRTM DEM 20 (20 m res.). There were several characteristics compared and analyzed like: relative height differences, slopes, generated river network and generated subwatersheds (subbasins).


2002 ◽  
Vol 34 ◽  
pp. 355-361 ◽  
Author(s):  
Frank Paul ◽  
Andreas Kääb ◽  
Max Maisch ◽  
Tobias Kellenberger ◽  
Wilfried Haeberli

AbstractA new Swiss glacier inventory is to be compiled from satellite data for the year 2000. The study presented here describes two major tasks: an accuracy assessment of different methods for glacier classification with Landsat Thematic Mapper (TM) data and a digital elevation model (DEM); the geographical information system (GIS)-based methods for automatic extraction of individual glaciers from classified satellite data and the computation of three-dimensional glacier parameters (such as minimum, maximum and median elevation or slope and orientation) by fusion with a DEM. First results obtained by these methods are presented in Part II of this paper (Kääb and others, 2002). Thresholding of a ratio image from TM4 and TM5 reveals the best-suited glacier map. The computation of glacier parameters in a GIS environment is efficient and suitable for worldwide application. The methods developed contribute to the U. S. Geological Survey-led Global Land Ice Measurements from Space (GLIMS) project which is currently compiling a global inventory of land ice masses within the framework of global glacier monitoring (Haeberli and others, 2000).


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3535
Author(s):  
Elmer Calizaya ◽  
Abel Mejía ◽  
Elgar Barboza ◽  
Fredy Calizaya ◽  
Fernando Corroto ◽  
...  

Effects of climate change have led to a reduction in precipitation and an increase in temperature across several areas of the world. This has resulted in a sharp decline of glaciers and an increase in surface runoff in watersheds due to snowmelt. This situation requires a better understanding to improve the management of water resources in settled areas downstream of glaciers. In this study, the snowmelt runoff model (SRM) was applied in combination with snow-covered area information (SCA), precipitation, and temperature climatic data to model snowmelt runoff in the Santa River sub-basin (Peru). The procedure consisted of calibrating and validating the SRM model for 2005–2009 using the SRTM digital elevation model (DEM), observed temperature, precipitation and SAC data. Then, the SRM was applied to project future runoff in the sub-basin under the climate change scenarios RCP 4.5 and RCP 8.5. SRM patterns show consistent results; runoff decreases in the summer months and increases the rest of the year. The runoff projection under climate change scenarios shows a substantial increase from January to May, reporting the highest increases in March and April, and the lowest records from June to August. The SRM demonstrated consistent projections for the simulation of historical flows in tropical Andean glaciers.


2019 ◽  
Author(s):  
Giuseppe Amatulli ◽  
Daniel McInerney ◽  
Tushar Sethi ◽  
Peter Strobl ◽  
Sami Domisch

Topographical relief is composed of the vertical and horizontal variations of the Earth's terrain and drives processes in geography, climatology, hydrology, and ecology. Its assessment and characterisation is fundamental for various types of modelling and simulation analyses. In this regard, the Multi-Error-Removed Improved Terrain (MERIT) Digital Elevation Model (DEM) is the best global, high-resolution DEM currently available at a 3 arc-seconds (90 m) resolution. This is an improved product as multiple error components have been corrected from the underlying Shuttle Radar Topography Mission (SRTM3) and ALOS World 3D - 30 m (AW3D30) DEMs. To depict topographical variations worldwide, we developed the Geomorpho90m dataset comprising of different geomorphometry features derived from the MERIT-DEM. The fully standardised geomorphometry variables consist of layers that describe (i) the rate of change using the first and second order derivatives, (ii) the ruggedness, and (iii) the geomorphology landform. To assess how remaining artefacts in the MERIT-DEM could affect the derived topographic variables, we compared our results with the same variables generated using the 3D Elevation Program (3DEP) DEM, which is the highest quality DEM for the United States of America. We compared the two data sources by calculating the first order derivative (i.e., the rate of change through space measured in degrees) of the difference between a MERIT-derived vs. a 3DEP-derived topographic variable. All newly-created topographic variables are readily available at resolutions of 3 and 7.5 arc-seconds under the WGS84 geographic system, and at a spatial resolution of 100 m under the Equi7 projection. The newly-developed Geomorpho90m dataset provides a globally standardised dataset for environmental models and analyses in the field of geography, geology, hydrology, ecology and biogeography.


2011 ◽  
Vol 8 (1) ◽  
pp. 1929-1949
Author(s):  
P. L. Guth

Abstract. A suite of 42 geomorphometric parameters for each of 26 272 drainage basins larger than 100 km2 from the Hydrosheds Shuttle Radar Topography digital elevation model shows the global distribution of Strahler order for streams and drainage basins; the largest basins are order 9. Many common parameters depend both on the size of the basin, and the scale of the digital elevation model used for the computations. These drainage basins display the typical longitudinal stream profiles, but the major basins tend to be more convex than the smaller basins.


2017 ◽  
Vol 9 (2) ◽  
pp. 109
Author(s):  
Agung Kurniawan

The melting of ice layers, as a direct impact on global warming, is indicated from a lesser thickness of ice layers is specifically causing an increase on the sea level. Lampung, as a province that has an ecosistem of regional coast, can be estimated to submerge. Flood modelling can be done to know the estimated flood range. The model of the flooded region is taken from Shuttle Radar Topography Mission(SRTM) data, which is nomalized to get the visualisation of Digital Elevation Model (DEM). The purpose of this research is to know the estimated region of provincial coast of Lampung that is going to be flooded because of the raising of sea surface. This research uses flood inundation technique that uses one of the GIS mapping software. The result can be used as consideration to achieve policy in the building of regional coast. The regions that are flooded based on the scenario of the raising of two and three meter surface sea level are East Lampung Regency, West Lampung Regency, South Lampung Regency, Tanggamus Regency, Pesawaran Regency, and Bandar Lampung.


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