While not usually stated, detailed topographic maps show well-mapped anomalous drainage system and other erosional landform evidence the accepted North American Cenozoic geologic and glacial history paradigm (accepted...While not usually stated, detailed topographic maps show well-mapped anomalous drainage system and other erosional landform evidence the accepted North American Cenozoic geologic and glacial history paradigm (accepted paradigm) does not permit geomorphologists to satisfactorily explain. A new and fundamentally different paradigm able to explain the drainage system and other erosional landform evidence has recently emerged, but requires what the accepted paradigm considers to be the preglacial (and probably mid-Cenozoic) Bell River drainage system to have formed on a melting continental ice sheet’s floor. The new paradigm’s melting ice sheet had previously eroded bedrock underneath it and caused crustal warping that raised continental regions and mountain ranges so as to create and occupy a deep “hole” while massive and prolonged meltwater floods flowed across rising continental regions and mountain ranges to the south. The new paradigm leads to a completely different middle Cenozoic geologic and glacial history than the accepted paradigm describes and the two paradigms are analyzed according to good science expectations such as using evidence anyone can see, applying common sense logic during each research step, producing consistent results, and simplicity of paradigm generated explanations. The new paradigm uses topographic map evidence anyone can see, appears to use common sense logic during each research step, and produces remarkably consistent results leading to a simpler Cenozoic northern Missouri River drainage basin region geologic and glacial history than what the accepted paradigm describes. Further work is needed to test the new paradigm’s ability to explain drainage system and erosional landform evidence in other geographic regions such as in the Ohio River drainage basin.展开更多
Introduction:Long-term drought in the southern Great Plains increases the vulnerability of coupled human-environment systems at a variety of scales.Developing better understandings of the dynamics at regional scales w...Introduction:Long-term drought in the southern Great Plains increases the vulnerability of coupled human-environment systems at a variety of scales.Developing better understandings of the dynamics at regional scales will become increasingly important as long-established land-use regimes break down in the face of climate change,resource depletion,and evolving governance.To demonstrate differential vulnerability during drought periods,this study hypothesized that observed increases in woody vegetation in grasslands would vary across land-tenure regimes.We argue that differences in State Trust Land governance,in part,lead to differential land management practices that contribute to landscape change.Methods:The study area encompasses adjacent counties,Cimarron County in Oklahoma and Union County in New Mexico,with similar climate variability and agricultural economies.We analyzed National Land Cover Database(NLCD)land-cover maps from 1992 and 2011 to assess changes in landscape composition and structure between 1992 and 2011.Results:During both years under consideration,each county in the study region,across various land-tenure regimes,was dominated by herbaceous vegetation.However,there were changes in both composition and structure across the whole study area,in particular losses of herbaceous vegetation and increases in woody vegetation.The greatest gains in woody vegetation occurred in State Trust Lands of Cimarron County.Overall,the data suggest a fragmentation of herbaceous vegetation and a coalescing of shrubland patches.Conclusions:Research about the influence of land tenure on land management decisions,specifically the role of State Trust Land leases in overgrazing,informs the broader context of drought management in the southern Great Plains.Recommendations include continued research to highlight the specific mechanisms of land-tenure governance that drive landscape change.展开更多
文摘While not usually stated, detailed topographic maps show well-mapped anomalous drainage system and other erosional landform evidence the accepted North American Cenozoic geologic and glacial history paradigm (accepted paradigm) does not permit geomorphologists to satisfactorily explain. A new and fundamentally different paradigm able to explain the drainage system and other erosional landform evidence has recently emerged, but requires what the accepted paradigm considers to be the preglacial (and probably mid-Cenozoic) Bell River drainage system to have formed on a melting continental ice sheet’s floor. The new paradigm’s melting ice sheet had previously eroded bedrock underneath it and caused crustal warping that raised continental regions and mountain ranges so as to create and occupy a deep “hole” while massive and prolonged meltwater floods flowed across rising continental regions and mountain ranges to the south. The new paradigm leads to a completely different middle Cenozoic geologic and glacial history than the accepted paradigm describes and the two paradigms are analyzed according to good science expectations such as using evidence anyone can see, applying common sense logic during each research step, producing consistent results, and simplicity of paradigm generated explanations. The new paradigm uses topographic map evidence anyone can see, appears to use common sense logic during each research step, and produces remarkably consistent results leading to a simpler Cenozoic northern Missouri River drainage basin region geologic and glacial history than what the accepted paradigm describes. Further work is needed to test the new paradigm’s ability to explain drainage system and erosional landform evidence in other geographic regions such as in the Ohio River drainage basin.
基金funded by a National Science Foundation(NSF)research grant(#CMMI-1266381)and fellowship(#SMA-1415368).
文摘Introduction:Long-term drought in the southern Great Plains increases the vulnerability of coupled human-environment systems at a variety of scales.Developing better understandings of the dynamics at regional scales will become increasingly important as long-established land-use regimes break down in the face of climate change,resource depletion,and evolving governance.To demonstrate differential vulnerability during drought periods,this study hypothesized that observed increases in woody vegetation in grasslands would vary across land-tenure regimes.We argue that differences in State Trust Land governance,in part,lead to differential land management practices that contribute to landscape change.Methods:The study area encompasses adjacent counties,Cimarron County in Oklahoma and Union County in New Mexico,with similar climate variability and agricultural economies.We analyzed National Land Cover Database(NLCD)land-cover maps from 1992 and 2011 to assess changes in landscape composition and structure between 1992 and 2011.Results:During both years under consideration,each county in the study region,across various land-tenure regimes,was dominated by herbaceous vegetation.However,there were changes in both composition and structure across the whole study area,in particular losses of herbaceous vegetation and increases in woody vegetation.The greatest gains in woody vegetation occurred in State Trust Lands of Cimarron County.Overall,the data suggest a fragmentation of herbaceous vegetation and a coalescing of shrubland patches.Conclusions:Research about the influence of land tenure on land management decisions,specifically the role of State Trust Land leases in overgrazing,informs the broader context of drought management in the southern Great Plains.Recommendations include continued research to highlight the specific mechanisms of land-tenure governance that drive landscape change.
