scholarly journals An integrated water-conveyance system based on Web GIS

2017 ◽  
Vol 20 (3) ◽  
pp. 668-686 ◽  
Author(s):  
Zhang Nan ◽  
Jin Sheng ◽  
Ai Congfang ◽  
Ding Weiye

Abstract To provide support for scientific decision-making about scheduling to keep a water-conveyance project running safely in Beijing, China, a Web geographic information system (GIS)-based conveyance system (WGCS) is proposed. The development of WGCS involves three primary modules. First, the pipe-channel hydrodynamic model with various types of hydraulic structure (reservoir, sluice, and inverted siphon) control equations is established as the engine to simulate a variety of flow regimes and hydraulic responses for different conveyance scenarios. Then, a relatively lightweight Web GIS platform without expensive mature GIS packages is implemented through rendering vector map layers based on Silverlight painting technology for model setting, simulation and data visualization. Furthermore, the employment of an asynchronous refresh mechanism facilitates the performance of particle motion animation. Finally, the database platform is used to record initial information, configuration parameters, hydraulic structure parameters converted to the hydrodynamic model for computation, result data received from the hydrodynamic model for analysis, attribute data and spatial data for map publishing and visualization. WGCS represents an effective attempt to integrate large-scale hydrodynamic numerical calculations on the web. The functionality of WGCS is illustrated through two case studies on conveyance progress. Currently, this system is successfully operating in Beijing.

2019 ◽  
Vol 19 (2) ◽  
pp. 10-16
Author(s):  
D. Asenso-Gyambibi ◽  
M. Affam ◽  
E. Y. Amoafo

AbstractPerfecting land title refers to the process of securing tenure on land. It refers to the assurance that the land one holds for an agreed period of time and purpose is certain. It requires a level of legitimacy. It is on record that agriculture, forestry and mining sectors constitute about 70% of Ghana’s gross domestic product. However, the lack of several large-scale plantations in Ghana can be partly attributed to the land tenure system. Land rights in rural communities are not secured in that the lands are not themselves well defined and rights are not documented. The study used modern survey methods to clearly map out farms in a systematic manner for farmers under a cooperative for rubber plantation development. The rights of tenant farmers and landholders are clearly and legally documented and registered into the formal land administration system. The spatial and attribute data are incorporated into a Geographic Information System (GIS) that serves as tool for data management on the farmers. The pilot study was successful in improving not only tenure security and data access, but also access to funding by participating farmers. Keywords: Land Tenure Security, Registration, Spatial Data, Attribute Data


2019 ◽  
Vol 6 (03) ◽  
Author(s):  
MANIBHUSHAN MANIBHUSHAN ◽  
AKRAM AHMED

The main aim of this study is to apply geographic information system (GIS) and data mining techniques to get the attribute data in a spatial and tabular form related to district wise availability of standing water bodies in their area and number of Bihar state. An analysis has been done on available spatial data and maps to get non-spatial/ tabular data, which are in a more easily understandable form. Data extracted district-wise related to area and number of standing water bodies according to their size of Bihar state. Study shows that the number and area of standing water bodies in Madhubani, East Champaran and Patna districts are 2185, 1753, 350 and 2355.42, 6752.36 and 8429.68 ham respectively. In this way, number and area of standing water bodies of other districts of Bihar are also extracted from geodatabases and digitized maps. This type of information is more useful than the spatial data because a common person is able to understand these tabular data and they can use this data for their own purposes. These data can be utilized by scientific personnel as well as farmers and that will be used in agriculture for better utilization of water resources to enhance agricultural productivity and income of farmers of Bihar state.


Author(s):  
Yexuan Shi ◽  
Yongxin Tong ◽  
Yuxiang Zeng ◽  
Zimu Zhou ◽  
Bolin Ding ◽  
...  

2021 ◽  
Vol 13 (15) ◽  
pp. 3023
Author(s):  
Jinghua Xiong ◽  
Shenglian Guo ◽  
Jiabo Yin ◽  
Lei Gu ◽  
Feng Xiong

Flooding is one of the most widespread and frequent weather-related hazards that has devastating impacts on the society and ecosystem. Monitoring flooding is a vital issue for water resources management, socioeconomic sustainable development, and maintaining life safety. By integrating multiple precipitation, evapotranspiration, and GRACE-Follow On (GRAFO) terrestrial water storage anomaly (TWSA) datasets, this study uses the water balance principle coupled with the CaMa-Flood hydrodynamic model to access the spatiotemporal discharge variations in the Yangtze River basin during the 2020 catastrophic flood. The results show that: (1) TWSA bias dominates the overall uncertainty in runoff at the basin scale, which is spatially governed by uncertainty in TWSA and precipitation; (2) spatially, a field significance at the 5% level is discovered for the correlations between GRAFO-based runoff and GLDAS results. The GRAFO-derived discharge series has a high correlation coefficient with either in situ observations and hydrological simulations for the Yangtze River basin, at the 0.01 significance level; (3) the GRAFO-derived discharge observes the flood peaks in July and August and the recession process in October 2020. Our developed approach provides an alternative way of monitoring large-scale extreme hydrological events with the latest GRAFO release and CaMa-Flood model.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1006
Author(s):  
Zhenhuan Chen ◽  
Hongge Zhu ◽  
Wencheng Zhao ◽  
Menghan Zhao ◽  
Yutong Zhang

China’s forest products manufacturing industry is experiencing the dual pressure of forest protection policies and wood scarcity and, therefore, it is of great significance to reveal the spatial agglomeration characteristics and evolution drivers of this industry to enhance its sustainable development. Based on the perspective of large-scale agglomeration in a continuous space, in this study, we used the spatial Gini coefficient and standard deviation ellipse method to investigate the spatial agglomeration degree and location distribution characteristics of China’s forest products manufacturing industry, and we used exploratory spatial data analysis to investigate its spatial agglomeration pattern. The results show that: (1) From 1988 to 2018, the degree of spatial agglomeration of China’s forest products manufacturing industry was relatively low, and the industry was characterized by a very pronounced imbalance in its spatial distribution. (2) The industry has a very clear core–periphery structure, the spatial distribution exhibits a “northeast-southwest” pattern, and the barycenter of the industrial distribution has tended to move south. (3) The industry mainly has a high–high and low–low spatial agglomeration pattern. The provinces with high–high agglomeration are few and concentrated in the southeast coastal area. (4) The spatial agglomeration and evolution characteristics of China’s forest products manufacturing industry may be simultaneously affected by forest protection policies, sources of raw materials, international trade and the degree of marketization. In the future, China’s forest products manufacturing industry should further increase the level of spatial agglomeration to fully realize the economies of scale.


2013 ◽  
Vol 680 ◽  
pp. 534-539
Author(s):  
Wei Feng Ma

With the rapid expansion of the campus scale and the increasing of the geographically dispersed campus, how to adopt new theory, new method and new technology to realize the equipment optimized assignment and the information management is a new research challenge. It is the key to safeguard the national fund to use reasonably, and to speed up the development of education healthily. Through analyzing the domestic and foreign related research works, the paper proposed that it can take use of the spatial data expression and analysis with Geographic Information System (GIS) to realize the large-scale and inter-campuses equipment optimized assignment and information management. It discussed the mathematics model and the system architecture. Moreover, the paper described the key implementation technology in great detail such as spatial data mapping with MapInfo professional 9 and the development of WebGIS functions with MapXtreme. The results show that the solution is feasible and effective.


2012 ◽  
Vol 209-211 ◽  
pp. 252-255
Author(s):  
Li Guo ◽  
Hai Ying Zheng ◽  
Yong Hong Wang ◽  
Bin Zhang

Data matching technology is a key technology for spatial data integration and fusion. This paper represents a solution to the complex polygon area, defines the area overlapped rate in the aspect of geometric measure, presents the data matching idea based on area overlapped rate .Then, this paper discusses and realizes the data matching relation of area elements including one to one , many to one and many to many. At last, region targets are set as the study object, large scale data are taken for example. We draw the conclusion: this algorithm is efficient.


2017 ◽  
Vol 21 (1) ◽  
pp. 117-132 ◽  
Author(s):  
Jannis M. Hoch ◽  
Arjen V. Haag ◽  
Arthur van Dam ◽  
Hessel C. Winsemius ◽  
Ludovicus P. H. van Beek ◽  
...  

Abstract. Large-scale flood events often show spatial correlation in neighbouring basins, and thus can affect adjacent basins simultaneously, as well as result in superposition of different flood peaks. Such flood events therefore need to be addressed with large-scale modelling approaches to capture these processes. Many approaches currently in place are based on either a hydrologic or a hydrodynamic model. However, the resulting lack of interaction between hydrology and hydrodynamics, for instance, by implementing groundwater infiltration on inundated floodplains, can hamper modelled inundation and discharge results where such interactions are important. In this study, the global hydrologic model PCR-GLOBWB at 30 arcmin spatial resolution was one-directionally and spatially coupled with the hydrodynamic model Delft 3D Flexible Mesh (FM) for the Amazon River basin at a grid-by-grid basis and at a daily time step. The use of a flexible unstructured mesh allows for fine-scale representation of channels and floodplains, while preserving a coarser spatial resolution for less flood-prone areas, thus not unnecessarily increasing computational costs. In addition, we assessed the difference between a 1-D channel/2-D floodplain and a 2-D schematization in Delft 3D FM. Validating modelled discharge results shows that coupling PCR-GLOBWB to a hydrodynamic routing scheme generally increases model performance compared to using a hydrodynamic or hydrologic model only for all validation parameters applied. Closer examination shows that the 1-D/2-D schematization outperforms 2-D for r2 and root mean square error (RMSE) whilst having a lower Kling–Gupta efficiency (KGE). We also found that spatial coupling has the significant advantage of a better representation of inundation at smaller streams throughout the model domain. A validation of simulated inundation extent revealed that only those set-ups incorporating 1-D channels are capable of representing inundations for reaches below the spatial resolution of the 2-D mesh. Implementing 1-D channels is therefore particularly of advantage for large-scale inundation models, as they are often built upon remotely sensed surface elevation data which often enclose a strong vertical bias, hampering downstream connectivity. Since only a one-directional coupling approach was tested, and therefore important feedback processes are not incorporated, simulated discharge and inundation extent for both coupled set-ups is generally overpredicted. Hence, it will be the subsequent step to extend it to a two-directional coupling scheme to obtain a closed feedback loop between hydrologic and hydrodynamic processes. The current findings demonstrating the potential of one-directionally and spatially coupled models to obtain improved discharge estimates form an important step towards a large-scale inundation model with a full dynamic coupling between hydrology and hydrodynamics.


2018 ◽  
Vol 7 (12) ◽  
pp. 467 ◽  
Author(s):  
Mengyu Ma ◽  
Ye Wu ◽  
Wenze Luo ◽  
Luo Chen ◽  
Jun Li ◽  
...  

Buffer analysis, a fundamental function in a geographic information system (GIS), identifies areas by the surrounding geographic features within a given distance. Real-time buffer analysis for large-scale spatial data remains a challenging problem since the computational scales of conventional data-oriented methods expand rapidly with increasing data volume. In this paper, we introduce HiBuffer, a visualization-oriented model for real-time buffer analysis. An efficient buffer generation method is proposed which introduces spatial indexes and a corresponding query strategy. Buffer results are organized into a tile-pyramid structure to enable stepless zooming. Moreover, a fully optimized hybrid parallel processing architecture is proposed for the real-time buffer analysis of large-scale spatial data. Experiments using real-world datasets show that our approach can reduce computation time by up to several orders of magnitude while preserving superior visualization effects. Additional experiments were conducted to analyze the influence of spatial data density, buffer radius, and request rate on HiBuffer performance, and the results demonstrate the adaptability and stability of HiBuffer. The parallel scalability of HiBuffer was also tested, showing that HiBuffer achieves high performance of parallel acceleration. Experimental results verify that HiBuffer is capable of handling 10-million-scale data.


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