Noxious weeds threaten the Sheyenne National Grassland (SNG) ecosystem and therefore herbicides have been used for control. To protect groundwater quality, the herbicide application is restricted to areas where the water table is less than 10 feet (3.05 m) below the ground surface in highly permeable soils, or less than 6 feet (1.83 m) below the ground surface in low permeable soils. A local MODFLOW model was extracted from a regional GFLOW analytic element model and used to develop depth-to-groundwater maps in the SNG that are representative for the particular time frame of herbicide applications. These maps are based on a modeled groundwater table and a digital elevation model (DEM). The accuracy of these depth-to-groundwater maps is enhanced by an artificial neural networks (ANNs) interpolation scheme that reduces residuals at 48 monitoring wells. The combination of groundwater modeling and ANN improved depth-to-groundwater maps, which in turn provided more informed decisions about where herbicides can or cannot be safely applied.

A 500‐m2 watershed on a deposit of coal refuse was instrumented for measurements of runoff and sediment yield and monitored for 15 months. The range of 42 storm period sediment yields was greater for the watershed as a whole (16 to 3,480 g m−2) than for a 4.65‐m2 portion of interfluve surface (15 to 1,596 g m−2). The ratio of sediment yield values (watershed:interfluve) was not constant. Ratios of about 7:1 occurred in late spring, when gully floors were flushed of colluvium that had accumulated during winter. The ratio remained above 2:1 in summer, when intense runoff caused gully incision. Estimates of annual sediment yield from three reaches of gully (82 to 160 kg m−2 yr−1) are about an order of magnitude greater than an estimate for interfluves (12 kg m−2 yr−1). A correlation analysis indicated that 78% of the observed variance in watershed sediment yield values is associated with characteristics of storm rainfall and runoff.

Fresh water shortage to meet human and ecosystem needs is recognized globally (Gosling & Arnell, 2016;Vörösmarty et al., 2000). Water stress is already common in the dry western United States (U.S.; Milly & Dunne, 2020). With rapid population growth and climate change, water stress is predicted to increase even in the water-rich southeastern U.S (Brown et al., 2019;G. Sun et al., 2008). Annual total water withdrawal in the U.S. increased from about 300 billion m 3 in 1950 to 580 billion m 3 in 2010 (Dieter & Maupin, 2017), coinciding with a doubling of the U.S. population (U.S. Census Bureau, 2010). Even though total water consumption per capita has decreased since 1980 in the conterminous United States (CONUS; Dieter & Maupin, 2017), water demand is projected to grow with population, and water withdrawals are projected to increase (Brown et al., 2013) except in areas where water supply is already overallocated. Exurban growth, as the most persistent and permanent land use change, increased considerably over the past four decades (

This paper relates some of the considerations in the planning of the Andover, Maine, earth station. It describes the station layout, the operating plan and the Long Lines interconnections. Power facilities, air conditioning, healing and dehumidification arrangements are also covered.

No abstract