No abstract

The increasing demands upon groundwater resources due to expanding metropolitan and agricultural areas are a serious challenge, particularly in semiarid and arid regions. In Iran, decades of unrestrained groundwater extraction for domestic, agricultural, and industrial use have resulted in a precipitous depletion of this valuable resource. Here we show that the decline in groundwater levels is associated with land‐surface deformation on local and regional scales. Combining water‐level data with satellite radar observations provides evidence for the prevalence of compacting aquifers in the country. Groundwater level decline is often associated with destruction of the aquifers, which appears to be a common problem in the groundwater basins of central and northeast Iran. Global warming and future climate change will affect arid and semiarid areas in the coming decades, further augmenting hazards associated with groundwater‐induced land subsidence.

No abstract

SUMMARY We derive the rupture history of the 1999 August 17 Izmit (Mw=7.4) and 1999 November 12 Düzce (Mw=7.1) earthquakes in Turkey from teleseismic body waves using broad‐band data of the Global Seismograph Network, aftershock locations and mapped surface breaks. The centroid solutions indicate strike‐slip mechanisms for both events. The Izmit earthquake was characterized by rupture propagating predominantly eastwards. It consisted of a main rupture lasting about 25 s followed within 1 min by two more events of Mw=6.9 and Mw=7.0. With the teleseismic data, we could not resolve the westward extent of rupture into the Marmara Sea. However, an upper bound of the seismic moment release west of the epicentre of the Izmit event is estimated to be  1.9×1019 N m. The Düzce earthquake lasted about 14 s and was characterized by a bilateral mode of rupture, in excellent agreement with mapped surface breaks and aftershock locations.

We propose an integrated approach to estimating building inventory for seismic vulnerability assessment, which can be applied to different urban environments and be efficiently scaled depending on the desired level of detail. The approach employs a novel multi-source method for evaluating structural vulnerability-related building features based on satellite remote sensing and ground-based omnidirectional imaging. It aims to provide a comparatively cost-and time-efficient way of inventory data capturing over large areas. The latest image processing algorithms and computer vision techniques are used on multiple imaging sources within the framework of an integrated sampling scheme, where each imaging source and technique is used to infer specific, scale-dependent information. Globally available low-cost data sources are preferred and the tools are being developed on an open-source basis to allow for a high degree of transferability and usability. An easily deployable omnidirectional camera-system is introduced for ground-based datacapturing. After a general description of the approach and the developed tools and techniques, preliminary results from a first application to our study area, Bishkek, Kyrgyzstan, are presented.