Earthquakes Triggered by Dams

internationalrivers.org

Exposing the Hidden Dangers of Dam-Induced Earthquakes

Earthquakes can be induced by dams. Globally, there are over 100 identified cases of earthquakes that scientists believe were triggered by reservoirs (see Gupta 2002). The most serious case may be the 7.9-magnitude Sichuan earthquake in May 2008, which killed an estimated 80,000 people and has been linked to the construction of the Zipingpu Dam.

How Do Dams Trigger Earthquakes?

In a paper prepared for the World Commission on Dams, Dr. V. P Jauhari wrote the following about this phenomenon, known as Reservoir-Induced Seismicity (RIS): “The most widely accepted explanation of how dams cause earthquakes is related to the extra water pressure created in the micro-cracks and fissures in the ground under and near a reservoir. When the pressure of the water in the rocks increases, it acts to lubricate faults which are already under tectonic strain, but are prevented from slipping by the friction of the rock surfaces.”

Given that every dam site has unique geological characteristics, it is not possible to accurately predict when and where earthquakes will occur. However, the International Commission on Large Dams recommends that RIS should be considered for reservoirs deeper than 100 meters.

What Are Some Characteristics of RIS?

A leading scholar on this topic, Harsh K. Gupta, summarized his findings on RIS worldwide in 2002:

  • Depth of the reservoir is the most important factor, but the volume of water also plays a significant role in triggering earthquakes.
  • RIS can be immediately noticed during filling periods of reservoirs.
  • RIS can happen immediately after the filling of a reservoir or after a certain time lag.

Many dams are being built in seismically active regions, including the Himalayas, Southwest China, Iran, Turkey, and Chile (see map). International Rivers calls for a moratorium on the construction of high dams in earthquake-prone areas.

Click here for the factsheet on RIS worldwide.

Problems With Big Dams

By 2015, the dam industry had choked more than half of the Earth’s major rivers with some 57,000 large dams. The consequences of this massive engineering program have been devastating. The world’s large dams have wiped out species; flooded huge areas of wetlands, forests and farmlands; and displaced tens of millions of people.


Courtesy of James Syvitski at Colorado University, who produced the video with Bob Stallard of the USGS and Albert Kettner at CSDMS. Data from Alex de Sherbinin (CIESIN, University of Colorado), and Bernhard Lehner (Department of Geography, McGill University).

The “one-size-fits-all” approach to meeting the world’s water and energy needs is also outdated: better solutions exist. While not every dam causes huge problems, cumulatively the world’s large dams have replumbed rivers in a massive experiment that has left the planet’s freshwaters in far worse shape than any other major ecosystem type, including tropical rainforests. In response, dam-affected communities in many parts of the world are working to resolve the legacies of poorly planned dams. Elsewhere (and especially in North America), communities are starting to take down dams that have outlived their usefulness, as part of a broader river restoration movement.

Impacts of Dams

Dam Basics

Fact sheets:

Human disruption to Earth’s freshwater cycle has exceeded the safe limit 

theconversation.com

Green water – the rainwater available to plants in the soil – is indispensable for life on and below the land. But in a new study, we found that widespread pressure on this resource has crossed a critical limit.

The planetary boundaries framework – a concept that scientists first discussed in 2009 – identified nine processes that have remained remarkably steady in the Earth system over the last 11,700 years. These include a relatively stable global climate and an intact biosphere that have allowed civilisations based on agriculture to thrive. Researchers proposed that each of these processes has a boundary that, once crossed, puts the Earth system, or substantial components of it, at risk of upset.

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Nhiều thủy điện ồ ạt xả lũ, dân trở tay không kịp

Plo.vn

Thứ Tư, ngày 1/12/2021 – 06:30

(PLO)- Nhiều thủy điện ở Tây Nguyên thuộc lưu vực sông Ba bất ngờ xả lũ xuống hạ du, gây ngập nặng nhiều vùng ở Phú Yên, người dân không kịp ứng phó.

Thông tin với Pháp Luật TP.HCM, ông Trần Hữu Thế, Chủ tịch UBND tỉnh Phú Yên, cho hay đến tối 30-11, nhiều vùng ven sông Ba thuộc TP Tuy Hòa, các huyện Phú Hòa, Sơn Hòa, Tây Hòa, Đông Hòa đã bị ngập nặng. Hàng ngàn căn nhà bị ngập sâu trong nước, hàng loạt xã, khu dân cư bị lũ cô lập. Quốc lộ 25, quốc lộ 29 từ TP Tuy Hòa đi Tây Nguyên, phần lớn các tuyến giao thông trọng yếu đã bị tê liệt, ách tắc do ngập sâu trong nước, sạt lở.

Tiếp tục đọc “Nhiều thủy điện ồ ạt xả lũ, dân trở tay không kịp”

What does the data tell us about electricity pricing in Laos?

mekongeye.com

By Ekaphone Phouthonesy12 October 2021 at 1:30 (Updated on 18 October 2021 at 15:00)

Through a variety of data sources an evidence-based picture of electricity pricing and the electricity-generation business in Laos is revealed.

A 42-year-old resident of Thongsanang village in central Vientiane, nicknamed To, was upset after receiving an electricity bill in May that was almost twice as high as normal.

“I’m going to send a letter to EDL asking them to investigate this unusual increase in my bill,” he told friends at a local coffee shop.

“Normally, I pay around 900,000 kip (US$95) a month, but this month I had to pay 1.6 million kip (US$168),” said Mr To, a worker with a monthly salary of about 1.8 million kip (US$190).

Tiếp tục đọc “What does the data tell us about electricity pricing in Laos?”

Bản đồ hoá hiện trạng nước mặt toàn cầu: Mapping long-term global surface water occurrence

ec.europa.eu_In an article published in Nature on 7 December 2016, JRC scientists describe how, in collaboration with Google, they have quantified changes in global surface waters and created interactive maps which highlight the changes in the Earth’s surface water over the past 32 years.

The data show that the impacts of climate on where and when surface water occurs can be measured, and that the presence of surface water can be substantially altered by human activities.The data show that the impacts of climate on where and when surface water occurs can be measured, and that the presence of surface water can be substantially altered by human activities.
©EU/Google 2016

Based on over three million satellite scenes (1 823 Terabytes of data) collected between 1984 and 2015, the Global Surface Water Explorer was produced using 10 000 computers running in parallel. The individual images were transformed into a set of global maps with a 30-metre resolution, which enable users to scroll back in time to measure the changes in the location and persistence of surface water globally, by region, or for a specific area. The maps are available for all users, free of charge. Tiếp tục đọc “Bản đồ hoá hiện trạng nước mặt toàn cầu: Mapping long-term global surface water occurrence”