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The coastal zone is a precious area that sustains many people and various ecosystems of high biological and economic importance. However, ecosystems and human settlements in coastal regions can be vulnerable to natural disasters such as tsunamis. Around Indonesia, seismic activity under the Indian Ocean has caused frequent earthquakes and tsunamis. In this paper, we describe a GISbased multi-criteria analysis of tsunami vulnerability for the Jembrana Regency in Bali, Indonesia. We used multiple geospatial variables of topographic elevation and slope, topographic relation to tsunami direction, coastal proximity, and coastal shape. We also incorporated expert knowledge by the Analytic Hierarchy Process (AHP) to construct a weighting scheme for the geospatial variables. In order to examine tsunami vulnerability in relation to land use, we overlaid an official land-use map on the tsunami vulnerability map. Buildings as well as residential and agricultural areas were found to be particularly at risk in our study area. GISbased analyses can aid in a wide range of disaster assessment and facilitate regional planning for management and mitigation of natural disasters such as tsunamis. We expect that the tsunami vulnerability map presented here will contribute to preliminary tsunami mitigation and management efforts in the Jembrana Regency.

This study developed a smartphone application that provides wireless communication, NRTIP client, and RTK processing features, and which can simplify the Network RTK-GPS system while reducing the required cost. A determination method for an error model in Network RTK measurements was proposed, considering both random and autocorrelation errors, to accurately calculate the coordinates measured by the application using state estimation filters. The performance evaluation of the developed application showed that it could perform high-precision real-time positioning, within several centimeters of error range at a frequency of 20 Hz. A Kalman Filter was applied to the coordinates measured from the application, to evaluate the appropriateness of the determination method for an error model, as proposed in this study. The results were more accurate, compared with those of the existing error model, which only considered the random error.

SUMMARYFrom an analysis of the International Comprehensive Ocean-Atmosphere Data Set, we were able to confirm salient features of the tropical Atlantic decadal oscillation illustrated in previous works. These features include antisymmetric behaviour of surface air pressure and sea surface temperature with two centres of action residing in the tropical North and South Atlantic Oceans. In addition to the recognized features of the oscillation, we found a new aspect: the principal mechanism regulating the oscillation differs between the north and south centres of action. Decadal components of the relative humidity time series show a maximum value of lag cross-correlation at a lag of −2 years. Such a temporal evolution was irrespective of the centres of action and the reference time series. The two reference series employed are the sunspot numbers and the southerlies over the western equatorial Atlantic. Associated with this, statistically significant phase shifts between the decadal components of variables exist, especially in the tropical North Atlantic Ocean. For the decadal oscillation, relative humidity change was dominated by specific humidity change over the tropical North Atlantic and by air temperature change over the tropical South Atlantic. For the frequency band of the solar cycle, the variation of relative humidity seemed to amplify the Earth's response to the sun's radiation changes that had previously been considered too small to affect the Earth's climate. By incorporating our new findings with the known features of the oscillation, we can suggest that the variability of solar radiation may be crucial as an originator, or at least as a regulator, of the oscillation in combination with the climate distribution of clouds and water vapour over the tropical Atlantic.

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