Environmental Geography Seminar Jan.9th

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Human & Ecol. Sys.
Human & Ecol. Sys. : Environmental Geography Seminar Jan.9th
投稿者 : kigaku 投稿日時: 2019-01-08 15:32:23 (23 ヒット)
Dear all,

Hello!

This is an announcement of the upcoming Environmental Geography Seminar.

Please see all the details carefully below.

【Date】 09th. January. Wed. (Time: 15:00~)

【Place】 D101

【Content】

1. Presenters
i. Ding Manhui
Title: Temporal and spatial variability of annual extreme water level in the Pearl River Delta region, China

Authors: Wei Zhang , Yixin Yan, Jinhai Zheng, Ling Li, Xue Dong, Huijuan Cai

Journal:Global and Planetary Change 69 (2009) 35–47

Abstract: This paper is concerned with identifying the spatial and temporal patterns in the annual maximum and

minimum water level in the Pearl River Delta (PRD) region. The Mann–Kendall test and Pettitt test are used

to detect trends and abrupt change points, and the Trend Free Pre-Whitening (TFPW) approach then

eliminates the effect of serial correlation in data series with significant autocorrelation. Approximately fifty

years of the annual hydrological variables from 18 stations in the three major rivers (the West River, the

North River, and the East River) are examined. The changing trends of the extremes in water level show

different features in different parts of the PRD region. Generally speaking, in the upper part of the delta, the

water levels show a decreasing trend while in the middle and lower part there is an increasing trend. This

spatial pattern of the extreme water level variation is unlikely to be due to a long-term change in stream flow

in the PRD region because the water level changes do not always coincide with the extreme stream flow

variations. Sand excavation initiated in the 1980s and continuing for more than 20 years in almost all

tributaries around the PRD region is one of the most serious intensive human activities affecting water levels.

The result of the Pettitt test indicates that most abrupt change points occurred in 1980s–1990s, which

reveals that sand excavation and channel regulation are likely to have been the most significant factors

contributing to the change over this period. These anthropogenic activities modify the annual extreme water

level dramatically in a way that affects the morphology of river channels and estuaries of the PRD and also

the redistribution of discharge. However, there are differences in the geographic locations of significant

trends for the water level investigated, which implies that these impacts are not spatially uniform.

ii. Cui Song
Title: Monitoring tropical debris-covered glacier dynamics from high-resolution unmanned aerial vehicle photogrammetry, Cordillera Blanca, Peru
Author: Oliver Wigmore, Bryan Mark
Journal: The Cryosphere, 11, 2463–2480, 2017
Impact factor: 5.516 (2014)
Abstract
The glaciers of the Cordillera Blanca, Peru, are rapidly retreating and thinning as a result of climate change, altering the timing, quantity and quality of water available to downstream users. Furthermore, increases in the number and size of proglacial lakes associated with these melting glaciers is increasing potential exposure to glacier lake outburst floods (GLOFs). Understanding how these glaciers are changing and their connection to proglacial lake systems is thus of critical importance. Most satellite data are too coarse for studying small mountain glaciers and are often affected by cloud cover, while traditional airborne photogrammetry and lidar are costly. Recent developments have made unmanned aerial vehicles (UAVs) a viable and potentially transformative method for studying glacier change at high spatial resolution, on demand and at relatively low cost.

Using a custom designed hexacopter built for high-altitude (4000–6000 m a. s. l. ) operation, we completed repeat aerial surveys (2014 and 2015) of the debris-covered Llaca Glacier tongue and proglacial lake system. High-resolution orthomosaics (5 cm) and digital elevation models (DEMs) (10 cm) were produced and their accuracy assessed. Analysis of these datasets reveals highly heterogeneous patterns of glacier change. The most rapid areas of ice loss were associated with exposed ice cliffs and meltwater ponds on the glacier surface. Considerable subsidence and low surface velocities were also measured on the sediments within the pro-glacial lake, indicating the presence of extensive regions of buried ice and continued connection to the glacier tongue. Only limited horizontal retreat of the glacier tongue was observed, indicating that measurements of changes in aerial extent alone are inadequate for monitoring changes in glacier ice quantity.

iii. Sha Shuo (Study Progress)
Title: Profiling ecotourists in Daisetsuzan National Park

2. Note this:

Please send me the detailed information about your presentation at least 5 days before your turn.

For a paper review: title and author of the paper, journal name, which volume, pages, also the link (if possible) should be provided.

If a paper written in Japanese is going to be presented, please kindly send me the information both in Japanese and English.

【Notice】

※ In case you are absent from the seminar or late for the seminar, please contact Professors or me in advance. Any absence without permission is not allowed;

※ Please be punctual (very important);

※ Please do your full preparation for the seminar;

※ Your active participation is always appreciated;

※ Please feel free to get in touch with me if you have any questions or comments.

Best Regards,

Chang Liang


Graduate School of Environmental Sceince, Hokkaido University