THE PARLOR IN THE WILDERNESS: DOMESTICATING AN ICONIC AMERICAN LANDSCAPE*

ABSTRACT. Thirty years ago D. W. Meinig argued that certain landscapes “are part of the iconography of nationhood.” From the earliest European settlement, the North American “wilderness” forged the crucible that shaped U.S. culture. By the early nineteenth century romantic aesthetic theories and nationalistic patriotism influenced American perspectives on the emerging cultural landscape. Artists, writers, and travelers sought out places for their healthful and scenic qualities as well as for moral instruction from nature. The locus of this confluence of politics, philosophy, and art was the Hudson River Valley of New York State. Guesthouses and hotels, especially in and around the Catskill Mountains, accommodated these travelers. This article examines the cultural basis of the mountain resort in its appropriation and marketing of a regional landscape and its incorporation as a national icon, with a specific history of the development of Mohonk Mountain House by the Smiley family from 1869 to 2008.     

Paleocurrent and fabric analyses of the imbricated fluvial gravel deposits in Huangshui Valley, the northeastern Tibetan Plateau, China

Gravel deposits on fluvial terraces contain a wealth of information about the paleofluvial system. In this study, flow direction and provenance were determined by systematic counts of more than 2000 clasts of imbricated gravel deposits in the Xining Region, northeastern Tibetan Plateau, China. These gravel deposits range in age from the modern Huangshui riverbed to Miocene-aged deposits overlain by eolian sediments. Our major objectives were not only to collect first-hand field data on the fluvial gravel sediments of the Xining Region, but also to the reconstruct the evolution of the fluvial system. These data may offer valuable information about uplift of the northeastern Tibetan Plateau during the late Cenozoic era. Reconstructed flow directions of the higher and lower gravel deposits imply that the river underwent a flow reversal of approximately 130–180°. In addition, the lithological compositions in the higher gravel deposits differ significantly from the lower terraces, suggesting that the source areas changed at the same time. Eolian stratigraphy overlying the gravel deposits and paleomagnetic age determination indicate that this change occurred sometime between 1.55 Ma and 1.2 Ma. We suggest that tectonic activity could explain the dramatic changes in flow direction and lithological composition during this time period. Therefore, this study provides a new scenario of fluvial response to tectonic uplift: a reversal of flow direction. In addition, field observation and statistical analyses reveal a strong relationship between rock type, size and roundness of clasts.     

Mapping and assessing crop diversity in the irrigated Fergana Valley,Uzbekistan

Crop diversity (e.g. the number of agricultural crop types and the level of evenness in area distribution) in the agricultural systems of arid Central Asia has recently been increased mainly to achieve food security of the rural population, however, not throughout the irrigation system. Site-specific factors that promote or hamper crop diversification after the dissolvent of the Soviet Union have hardly been assessed yet. While tapping the potential of remote sensing, the objective was to map and explain spatial patterns of current crop diversity by the example of the irrigated agricultural landscapes of the Fergana Valley, Uzbekistan. Multi-temporal Landsat and RapidEye satellite data formed the basis for creating annual and multi-annual crop maps for 2010–2012 while using supervised classifications. Applying the Simpson index of diversity (SID) to circular buffers with radii of 1.5 and 5 km elucidated the spatial distribution of crop diversity at both the local and landscape spatial scales. A variable importance analysis, rooted in the conditional forest algorithm, investigated potential environmental and socio-economic drivers of the spatial patterns of crop diversity. Overall accuracy of the annual crop maps ranged from 0.84 to 0.86 whilst the SID varied between 0.1 and 0.85. The findings confirmed the existence of areas under monocultures as well as of crop diverse patches. Higher crop diversity occurred in the more distal parts of the irrigation system and sparsely settled areas, especially due to orchards. In contrast, in water-secure and densely settled areas, cotton-wheat rotations dominated due to the state interventions in crop cultivation. Distances to irrigation infrastructure, settlements and the road network influenced crop diversity the most. Spatial explicit information on crop diversity per se has the potential to support policymaking and spatial planning towards crop diversification. Driver analysis as exemplified at the study region in Uzbekistan can help reaching the declared policy to increase crop diversity throughout the country and even beyond.     

伊犁河谷2001-2014年地表温度时空分异特征

地表温度是地表能量平衡、区域和全球尺度地表物理过程的一个重要因子。为了辨析中国西北干旱区“天山湿岛”——伊犁河谷的地表温度时空分异,采用趋势分析法和空间数据统计法,探讨了2001-2014年不同土地利用/覆盖类型下地表温度时空变化规律,分析地表温度的时空分异特征及原因。结果表明：（1） MODIS LST产品的精度（平均R²=0.90）能够满足伊犁河谷地表温度时空变化分析的要求;（2）空间上,地表温度呈现出中部高四周低的变化趋势,高温区面积约占总面积的41%,低温区面积约占总面积的23%;时间上,伊犁河谷平均地表温度的年际波动较大,以2013年、2006年、2007年和2008年尤为突出;地表温度的年内变化呈现出单峰型分布,地表温度高值集中在3-8月,最高值出现在7月;（3）不同土地利用/覆盖类型下年均地表温度分布的总体特征为建设用地最高,稀疏草地、旱地等次之,冰川/积雪最低;（4）伊犁河谷地表温度变化趋势呈严重减少、基本不变和轻微增加区域面积分别占5%、37%和26%,以基本不变和轻微增加为主。伊犁河谷地表温度时空变化不仅受大尺度气候变化影响,还受土地类型差异影响,两者共同构成了不同地理区域及景观的温场格局,绿色植被对地表温度时空分布具有重要的调节作用。     

汉江上游谷地与渭河谷地黄土化学风化程度比较

比较汉江上游谷地及渭河谷地典型黄土剖面的元素组成、化学风化强度及常量元素迁移特征,揭示秦岭南北两侧黄土-古土壤剖面的成壤强度及其所指示的环境演变特征,两者差异及共性如下：① 两剖面化学组成均以SiO₂、Al₂O₃和Fe₂O₃为主,元素组成均一且高度混合,与上部陆地壳（UCC） 的化学成分十分接近,该些证据均指示两区域黄土是来源广泛并经过充分混合的风尘堆积产物。② 据CIA 值可判定MTS 及YHC 剖面均经历了中等风化作用,比较两剖面CIW值、A-CN-K三角图投点特征及元素迁移率知,汉江上游谷地的黄土-古土壤序列经历的化学风化作用更强,Ca 及Na 元素的丢失率更高,Al、Na、Mg、Si 等常量元素的迁出率更大。③ 依据Fe、Na迁移率的全剖面变化曲线知,汉江上游谷地与渭河谷地自全新世以来经历了相同的气候演变阶段,均记录了6000-5000a BP的干冷气候事件。     

青藏高原河谷地区历史时期耕地格局重建方法探讨——以河湟谷地为例

青藏高原受其特殊自然地理环境条件的限制,耕地主要分布在自然环境条件相对优越的河谷地区,人为因素对耕地分布范围的作用和影响极其微弱,尤其是在历史时期生产力水平较低的前提下,耕地的空间分布主要取决于土地的宜垦程度。本文将影响青藏高原河谷地区耕地分布的因子按其性质分为限制性因子和非限制性因子,并以此为基础排除了高原河谷地区不适宜耕作的地区,在适宜耕作的地区根据土地的宜垦程度,按"先优后劣"的原则将历史时期的耕地数据分配到空间上。选取青藏高原农业发展历史悠久的河谷地区之一河湟谷地作为实例,重建该区1726年耕地空间格局。将重建结果与已有的M模型重建结果进行对比分析,两者重建的耕地在空间分布上呈现出一致性,但重建结果在垦殖范围与垦殖强度上存在一定的差异;M模型的重建主要是以现代耕地分布格局为基础重建,忽略了现代耕地空间分布受现代农业技术的影响;而本文模型则是从低生产力水平前提下影响历史时期耕地分布的因子出发,重建结果更具合理性。     

An explanation for USGS Station 6 record, 1979 Imperial Valley earthquake: a caustic induced by a sedimentary wedge

Summary. The largest earthquake-induced acceleration yet recorded occurred at the United States Geological Survey's (USGS) Strong Motion Array Station 6 during the 1979 October 15, Imperial Valley, California earthquake. This large acceleration (1.74 g, vertical component) is anomalously strong considering the low magnitude of the event ( M = 6.4), and the fact that receivers in the immediate neighbourhood of Station 6 recorded much lower accelerations. Previous studies of the records by other investigators have suggested a number of explanations for the anomaly, several of which implicate the near-receiver geological structure.
We present a detailed time and frequency domain analysis of the acceleration records at Stations 6, 5, 7, 8 and Diff Array to suggest that the anomalous acceleration is the consequence of the focusing of the incoming body waves by the lens-like effect of the sedimentary wedge between Imperial Valley and Brawley faults. The analyses include a detailed comparison of observed particle motions between neighbouring stations. Narrow band-pass filtered particle motions at Station 6 reveal the interaction of multipath arrivals as well as the frequency-dependent interference between them. Three-dimensional ray tracing experiments confirm the fact that the faulted sedimentary wedge is capable of focusing P -waves near Station 6. The interpretation that best combines theoretical and observed results is that amplification was due to the formation of an elliptic umbilic caustic with focus near the surface.