Repository logo

Section 2: Climate Change and Hydrology

Permanent URI for this collection

https://hdl.handle.net/10217/181743
This digital collection includes presentations, in English and Mongolian, given at the Building Resilience of Mongolian Rangelands conference held in 2015 for the topic: Climate Change and Hydrology.

Browse

Browsing Section 2: Climate Change and Hydrology by Author "Fassnacht, Steven R., author"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    A journey down the Tuin: the hydraulics of an internal draining river from the Khangai Mountains to the Gobi Desert
    (Colorado State University. Libraries, 2015-06) Fassnacht, Steven R., author; Venable, Niah B. H., author; Odgarav, Jigjsuren, author; Sukhbaatar, Jaminkhuyag, author; Adyabadam, Gelegpil, author; Nutag Action and Research Institute, publisher
    River systems flowing through semi-arid and arid regions provide critical ecosystem services for inhabitants of these areas. In remote and/or difficult to access areas away from population centers, few direct measurements exist to characterize the nature of streamflow in these systems. The Tuin River flows from the rugged high mountain and forest steppe landscape of the Khangai Mountains in central Mongolia to its terminus at Orog Lake in the desert steppe and sand dunes of the northern Gobi Desert. Field measurements taken in June 2012 at numerous locations from river headwaters to mouth were used to characterize streamflow in the main river channel and associated floodplain. From these measurements, channel hydraulic characteristics were estimated and hydrologic properties were assessed using a digital elevation model and other spatial data. These properties include contributing area, slope, hydraulic radius, and channel roughness. During the low flow conditions of the survey, streamflow was decreasing from upstream to downstream. At a point between the Bayankhongor and Bogd gaging stations, streamflow ceased at the surface and reappeared approximately 10 kilometres downstream, exemplifying losing flow conditions and subsurface flow components. The results of this analysis could be scalable to other internally draining river systems, especially for hydrologic modelling.
  • Thumbnail Image
    ItemOpen Access
    Spatial changes in climate across Mongolia
    (Colorado State University. Libraries, 2015-06) Venable, Niah B. H., author; Fassnacht, Steven R., author; Hendricks, Alyssa D., author; Nutag Action and Research Institute, publisher
    Previous research using meteorological station data suggests that temperatures and precipitation have been changing more across the semi-arid and arid country of Mongolia than in many other locations across the globe. We used gridded monthly data to determine the annual and seasonal rate of change in total precipitation (P), maximum temperature (Tmax), and minimum temperature (Tmin), as computed from the non-parametric Thiel-Sen slope estimator method. The significance of those changes were computed from the Mann-Kendall test. The University of East Anglia Climatic Research Unit (CRU) dataset was used for the 50-year time period from 1963 through 2012 at a 0.5 degree (~55 km) resolution. For the first 30 years, 30 to 35 meteorological stations from across Mongolia were used to create the spatially distributed "High Resolution Gridded Data of Month-by-Month Variation in Climate" CRU product; 20 to 30 stations were used for the last 20 years due to a decrease in the number of operational stations. Results are presented as maps of 1) mean total annual P, and mean annual Tmax and Tmin, and ii) annual trends over the length of record (1963-2012) with significance overlain, for the three variables. Rates of change at annual and seasonal time scales varied spatially with more consistent increases in temperature; significant precipitation trends were observed over smaller areas than significant temperature trends.