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Hydrometric network design based on Copula and entropy
Published in Chongfu Huang, Zoe Nivolianitou, Risk Analysis Based on Data and Crisis Response Beyond Knowledge, 2019
Wenqi Wang, Dong Wang, Yuankun Wang
Gathering hydrologic data from hydrometric networks is the first step for water resources and management. Reliable and representative hydrometric data are fundamental and important for the effective management of water resources, which calls for careful evaluation and design of monitoring networks in hydrology and hydrometeorology. Information theory is widely used in the design of monitoring networks because it provides a quantitative measure of the information content within a hydrometric network (Markus et al., 2003; Li et al., 2012; Alfonso et al., 2014). The Copula theory offers a flexible way to construct a joint distribution independent from marginal distributions (Nelsen, 1999). The main advantage of this approach is that it is free from constraints of different marginal distributions, which is common in different hydrological variables. Due to this property, the application of copulas in bivariate and multivariable hydrological analysis has grown rapidly in the past decade.
Informational analysis of the Canadian National Hydrometric program monitoring network
Published in Canadian Water Resources Journal / Revue canadienne des ressources hydriques, 2023
James M. Leach, Jongho Keum, Jeffrey Karn, Megan Garner, Paulin Coulibaly
The National Hydrometric Network (NHN) in Canada has developed and expanded over time based on the needs of its various stakeholders, partner agencies, and data users, but with limited strategy for the overall design and optimization of the Canadian NHN (CNHN) (Kimmet 2021). Having an optimal hydrometric network is essential for water resources and environment management; information provided by the network is necessary for several sectors including infrastructure design, water allocation, agriculture, power generation, tourism, and research. There are several important aspects to optimal hydrometric network design, including network density, station location, monitoring frequency, operational efficiency, station and management cost, and information content. Coulibaly et al. (2013), following a call for the evaluation of the CNHN by the Auditor General of Canada (Office of the Auditor General of Canada (OAGC) 2010), performed a previous evaluation of the CNHN, in which they evaluated the network density based on the World Meteorological Organization (WMO) station density guidelines for mountains (1000 km2/station), interior plains (1875 km2/station), and hilly/undulating physiographic units (1875 km2/station) (WMO 2008). They found that roughly 12% of the land area of Canada meets the WMO network density guidelines, with 49% to be poorly gauged, and 39% to be ungauged. Additionally they found that in none of the 15 ecozones in Canada did the network meet the WMO 2008 minimum network density guidelines, the areas with the most critical deficit being in the north.
Using the digital elevation model (DEM) and coastlines for satellite monitoring of small reservoir filling
Published in Cogent Engineering, 2020
Alexey Terekhov, Nikolai Makarenko, Alexander Pak, Nurlan Abayev
Reservoirs are important in the economy of the territories. The water stored in the reservoir is mainly used for power generation and irrigation of arable land, which leads to seasonal variations in the reservoir’s water deposit. To determine the current water deposit, we need to know how the water level and the area of the mirror changes. The area of the water mirror can be easily monitored by satellite monitoring. The water level in a reservoir can be determined in several ways: at a hydrometric station, as the distance between the water surface and a reference level; using remote radar altimetry (satellites, aircraft, etc.); or using DEM, when the position of the coastline is compared with a digital terrain model. The proposed method is a variation of the DEM-based water level assessment methodology. When considering small reservoirs, changes in the position of the coastline may be insignificant, up to a few pixel positions in the DEM matrix. To reduce the level of errors, the altimetric reference of the water mirror is based not on comparing the position of the coastline with single DEM pixels, but by taking into account its position on a long uniform slope. The slope of an extended territory can be determined using DEM with fewer errors than the single pixels of the DEM matrix. For altimeter linking of water mirrors at different water levels, we must to choose a fragment of the periodically drained bottom of the reservoir, which is a plain with a constant angle of inclination. The riverbed can often be described using this model. The transported suspended material in the river is deposited on the bends of the slope (if any), which ensures that the slope is uniform.