English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Recurrent rill and gully erosion have been observed on some reclaimed surface-mined land in northwestern Colorado. Surface coal mining and reclamation activities have resulted in substantial changes in geology, geomorphology, pedology, vegetation, and hydrology; accelerated erosion of some reclaimed lands may be a result of these changes. Rill erosion and gully erosion of hillslopes and valley floors were studied at the Trapper, Hayden Gulch, Grassy Gap, Seneca II, CYCC, and Edna Mines in Moffat and Routt Counties. Data were collected from reclaimed and nearby unmined areas. Reclaimed and unmined hillslopes were similar geographically; however, reclaimed hillslopes had greater topsoil bulk densities, lower topsoilinfiltration rates, less woody vegetation, and a greater occurrence of rill erosion. Most reclaimed hillslopes had straight or convex hillslope profiles, whereas most unmined hillslopes had complex profiles. Rills on reclaimed hillslopes generally have developed on the mid-hillslope to lower hillslope segments, on segments of steep gradient, or on segments below recent surface disturbances. Total-rill density was positively correlated with the product of hillslope length and hillslope gradient and inversely correlated with age since reclamation. Gullies on some reclaimed hillslopes developed on steep or convex hillslope segments and below subtle topographic depressions that may have functioned as moisture-collection areas. Valleys in reclaimed drainage basins were re-created by spoil-material handling and lacked resistant geologic controls. Reclaimed valleys often were narrow or v-shaped in cross section. Most stable reclaimed valley floors could be distinguished from unstable reclaimed valley floors on the basis of three geomorphic variables; drainage area, valley gradient, and valley-floor width. The area-gradient index, the product of drainage area and valley gradient, is a geomorphic index of the potential total stream power acting on a valley-floor reach. The relation between valley-floor width and areagradient index and the clustering of data from stable and unstable valleyfloor reaches defined the valley-erosion threshold. Reclaimed valley floors that had valley-floor width less than the valley-erosion threshold were more likely to be gullied than reclaimed reaches that had valley-floor width greater than the valley-erosion threshold. Valley-erosion indices that quantified the relative stability or instability of reclaimed valley-floor reaches were calculated with reach-specific geomorphic data and the coefficient and exponents of the valley-erosion threshold. Empirically derived geomorphic relations may be useful as planning tools in future reclamation projects or in mitigating existing erosional instability.

Geomorphic evaluation of erosional stability at reclaimed surface mines in northwestern Colorado