Successful long-term wetland restoration efforts require consideration of hydrology and surrounding land use during the site selection process. This article describes an approach to initial site selection in the San Luis Rey River watershed in southern California that uses watershed-level information on basin topography and land cover to rank the potential suitability of all sites within a watershed for either preservation or restoration. This approach requires the use of a geographic information system (GIS) to map relative wetness and land cover within a watershed. Relative potential wetness values were derived from U.S. Geological Survey (USGS) 30-m digital elevation models by calculating the flow that would potentially accumulate at all 30-m X 30-m pixels within the watershed. Land cover was derived from a Landsat scene covering the 1500 km2 study area. We ranked sites 56

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Physical unclonable functions (PUFs), a form of physical security primitive, enable digital identifiers to be extracted from devices, such as field programmable gate arrays (FPGAs). Many PUF implementations have been proposed to generate these unique n-bit binary strings. However, they often offer insufficient uniqueness and reliability when implemented on FPGAs and can consume excessive resources. To address these problems, in this article we present an efficient, lightweight, and scalable PUF identification (ID) generator circuit that offers a compact design with good uniqueness and reliability properties and is specifically designed for FPGAs. A novel post-characterisation methodology is also proposed that improves the reliability of a PUF without the need for any additional hardware resources. Moreover, the proposed post-characterisation method can be generally used for any FPGA-based PUF designs. The PUF ID generator consumes 8.95% of the hardware resources of a low-cost Xilinx Spartan-6 LX9 FPGA and 0.81% of a Xilinx Artix-7 FPGA. Experimental results show good uniqueness, reliability, and uniformity with no occurrence of bit-aliasing. In particular, the reliability of the PUF is close to 100% over an environmental temperature range of 25 • C to 70 • C with ±10% variation in the supply voltage. CCS Concepts: • Security and privacy → Tamper-proof and tamper-resistant designs; Hardwarebased security protocols; Embedded systems security;

This paper presents a new technique for objectively identifying pools and riffles. The technique is termed the bed form differencing technique and as its data base has bed elevations surveyed at a fixed interval along the channel. These elevations are differenced, and the difference or elevation change values are used to identify pools and riffles. Where the cumulative elevation change since the last bed form exceeds a certain tolerance value, a new bed form is considered to exist, the type of bed form being determined by the direction of the elevation change. Analysis of a small stream in western New York suggests that the most realistic pool‐riffle sequence is obtained where the tolerance value is 0.75 times the standard deviation of the difference values. The bed form differencing technique can be used to identify bed forms other than pools and riffles, such as ripples and dunes, by simply modifying the surveying interval to reflect the scale of the bed forms.

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