Mud Flow Dynamics at Gas Seeps (Nirano Salse, Italy)

The Nirano Salse, known since the Roman Times, are one of the most beautiful and scenic mud volcanoes areas of Italy with thousands of visitors every year. In this work, we apply hydrogeological techniques to characterize mud levels in the Salse by means of GPS-RTK positioning and continuous level logging within mud conduits. Our results suggest that different mud levels in mud volcanoes clusters are due to the different gas-liquid ratio in the conduits and not necessarily exclude interconnection at depth, a hypothesis, on the other hand, that seems strengthened by mud level time series correlations. The presence of shallow aquifers at a depth of 5 to 30 m is also supported by our field data. These shallow aquifers may provide a temporary storage for the ascending gas and when fluid pressure in these aquifers exceeds the tensional strength of the sedimentary rock, leakage of fluids to the surface would occur.

Kajian Perbandingan Luas Hasil Pengukuran Bidang Tanah Menggunakan GPS RTK-Radio dan RTK-NTRIP

Dengan berkembangnya teknologi dalam survei pemetaan seperti halnya penggunaan GPS Geodetik, maka penerapan dari teknologi untuk kebutuhan survei perlu memperhatikan faktor-faktor tertentu seperti ketersediaan alat, sumber daya manusia hingga kondisi lapangan. GPS atau biasa dikenal dengan Global Positioning System merupakan teknologi/alat atau sistem yang memberikan informasi berupa posisi kepada pengguna secara global dan real-time di permukaan bumi yang berbasis data satelit. Dengan teknologi tersebut diperoleh ketelitian yang tinggi dengan waktu yang singkat dalam penentuan sebuah posisi. Penelitian ini bertujuan untuk mengetahui ketelitian hasil pengukuran luas bidang tanah menggunakan teknologi GPS RTK-Radio dan GPS RTK NTRIP sebagai sikap pengambilan keputusan. Penelitian dilakukan terhadap daerah dengan obstruksi dan tanpa obstruksi fisik. Nantinya, dari penelitian ini diperoleh nilai-nilai koordinat (X,Y) dari GPS RTK-NTRIP maupun RTK-Radio, yang kemudian dihitung luasnya dan dibandingkan dari hasil pengukuran menggunakan ETS (Electronic Total Station) terhadap standar ketelitian luas dari BPN. Hasil perhitungan selisih luas lahan baik dengan obstruksi secara fisik maupun tidak, masih masuk dalam toleransi ketelitian BPN, walaupun untuk lahan yang terdapat obstruksi fisik memiliki selisih antara pengukuran menggunakan GPS dan ETS yang cukup besar yaitu hampir mencapai 5 m2.

Analysis of Underwater Topographic Survey of Stilling Basin Based on Unmanned Survey System

The combination of Global Positioning System-Real Time Kinematic (GPS-RTK) and depth sounder is an important technical method of modern underwater topographic survey. In this paper, the combined technology was integrated with unmanned surface vehicle (USV) technology to construct an unmanned survey system suitable for underwater topographic survey in stilling basin, and it was applied to survey the underwater topography of the stilling basin of Tingzikou hydrojunction project. Based on the surveying and mapping data and 3D model, the trend of elevation change of the stilling basin including apron, end sill, antiscour section, and river convergence section was analyzed. The results show that, for the surface outlet stilling basin of Tingzikou, after flood, the structure is complete, the boundaries are clear, the water quality is good, and there is little sediment on the surface of apron from overflow dam section to end sill. Furthermore, no obvious sediment or structural abnormality has been found in the still basin. Affected by the bedrock and cofferdam cobble gravel sediment, the elevation of the antiscour section and the downstream convergence section of the surface outlet stilling basin increased significantly. For the bottom outlet stilling basin of Tingzikou, there is large sediment within a range of 20 m∼40 m from the bottom sill and the maximum height of it reaches 2.04 m, while there is no obvious sediment or structural abnormality in the remaining region of basin. The critical sedimentation height can effectively judge the safety grade of the sedimentation height in stilling basin and provide a reliable support for assessing the overall safety of stilling basin. The application of unmanned survey technology improves the accuracy and timeliness of underwater topography and sedimentation distribution of stilling basin, which has significant application research value and promotion significance.

GPS-RTK测量技术在水利工程测绘中的应用

近年来，在多方面利好因素的影响下我国综合国力得到了显著的进步，为科学技术的发展带来了诸多的机遇，从而使得大量的新型科学技术被人们研发出来，并被运用到多个领域之中取得了良好的成绩。GPS-RTK技术是当前最为先进的一种科学技术，将其合理的运用到水利工程测绘工作之中，不但可以促进测绘结果的准确性的提升，而且还可以增强水利工程对环境和天气不良因素的抵御能力，保证水利工程测绘工作能够按照既定的计划有序的进行。GPS技术实际运用操作相对较为简单，并且能够较为高效的对被测物体的各方面信息加以收集，能够将被测目标三维坐标准确的加以判断，正是因为具有较强的优越性，所以逐渐的替代了之前原始的测量方式，被人们在水利工程测绘工作中大范围的加以运用。借助GPS-RTK技术能够将测绘数据的误差维持在厘米级的范围之内，最大限度的提升了测绘工作的效率，避免了数据测量不准确而造成二次返工的情况发生。

浅论全站仪联合GPS-RTK测绘山区地形图

现代测绘技术可谓是日新月异，但是像中国甘肃这样的高原地区，很多数字测图项目依旧需要灵活运用各种测图手段。论文结合甘肃盘区县某林区数字地形图测绘项目阐述了全站仪测图、RTK测图的优缺点，将两种手段灵活、有效地结合形成优势互补，大大提高了工作效率，以供同行在进行相似山区地形时参考并共同探讨。

ỨNG DỤNG GPS ĐỘNG VÀ MÁY TOÀN ĐẠC ĐIỆN TỬ XÂY DỰNG LƯỚI KHỐNG CHẾ PHỤC VỤ LẬP BẢN ĐỒ TRÍCH ĐO ĐỊA CHÍNH TẠI VIỆN NGHIÊN CỨU VÀ PHÁT TRIỂN, TRƯỜNG ĐẠI HỌC NÔNG LÂM, ĐẠI HỌC HUẾ

Nghiên cứu được thực hiện nhằm ứng dụng kết hợp công nghệ GPS động và máy toàn đạc điện tử để xây dựng lưới khống chế, tạo cơ sở thống nhất và chính xác về mặt toạ độ phục vụ công tác đo vẽ thành lập bản đồ trích đo địa chính sau thu hồi đất thuộc dự án đầu tư xây dựng đoạn Cam Lộ - La Sơn tại Viện nghiên cứu và Phát triển, Trường Đại học Nông Lâm, Đại học Huế. Từ 02 điểm địa chính cơ sở, nghiên cứu đã thiết kế lưới địa chính và lưới khống chế đo vẽ phục vụ lập bản đồ trích đo tại Viện. Việc đo lưới địa chính được thực hiện bằng máy định vị vệ tinh GPS RTK 2 tần số Trimble R4 GNSS và đo lưới khống chế đo vẽ bằng máy toàn đạc điện tử South NTS-332R4. Sau đó, số liệu đo lưới địa chính được bình sai bằng phần mềm Trimble Business Center và số liệu đo lưới khống chế đo vẽ được bình sai bằng phần mềm HHMAPS. Kết quả đánh giá độ chính xác lưới khống chế đều đảm bảo theo đúng quy phạm xây dựng bản đồ địa chính. Việc ứng dụng công nghệ GPS động kết hợp sử dụng toàn đạc đã góp phần đẩy nhanh tiến độ xây dựng lưới khống chế phục vụ lập bản đồ trích đo tại Viện Nghiên cứu và Phát triển.

Application of correlation and regression analysis between GPS - RTK and environmental data in processing the monitoring data of cable - stayed

Structural Health Monitoring system - SHMs has been playing a vital role in monitoring large - scale structures during their performance in a lifetime, especially with the long - span bridge, such as a suspended bridge or cable - stayed bridge. In a SHM system, many kinds of sensors are used to set up at the specific locations in order to monitor and detect any changes of structures in real - time based on the changes of monitoring data as well as the changes of correlation among monitoring data types. This paper proposes a method of applying the correlation and regression analysis for processing the displacement monitoring data acquired by GPS - RTK considering the effects of environmental factors such as temperature and wind - speed. The results show that the air - temperature has high correlation with the displacements of a cable - stayed bridge acquired by GPS - RTK measurement along to specific directions while the wind - speed has low correlation. Then the general displacement of the target bridge could be recognized and regression equation is also built to predict the bridge displacement under effects of the air temperature.