Archaeological and geological evidence for protohistoric water management in Northeast Louisiana

Native North American Indians built and maintained water control and irrigation facilities, especially in the southwestern United States. However, the use of human-made structures to manage water for agriculture and personal use is rarely documented in the Southeast. Excavations at the protohistoric period Jordan site in Louisiana demonstrate the use of earthworks, ponds, and ditches to channel and direct surface water for drainage and irrigation. The Jordan site is remarkable for its preservation, as well as for having evidence for sophisticated hydraulic engineering, but it is unlikely that it is unique in the Southeast in regard to the degree and kind of earthmoving related to water management. Archaeological and geological contexts provide the background for understanding the Jordan site features. Results of geoarchaeological subsurface investigations demonstrate the scale and nature of the site's aboriginal constructions and provide evidence that they were part of a deliberate plan to make the site area habitable during the immediate post-contact era in the Mississippi Valley.     

Monazite chemistry: evidence for a prehistoric journey

The chemistry of monazite from the black sand deposits of northern Sinai beach suggests that pegmatites and granites of the Eastern Desert of Egypt are the most likely source rocks. The floods associated with the pluvial periods prevailed in Egypt during the Pleistocene were able to erode the source rocks and liberate heavy minerals including monazite. The mineral grains were moved through several wadis and tributaries to the River Nile. At the confluence sites, these heavy minerals were mixed with the Ethiopian and central African heavy mineral assemblages. The grains continued to move together downriver until being deposited in their current locations.     

Land use history and status of land desertification in the Heihe River basin

An analysis, over historical times, of the influence of natural factors such as climate, geological activity, existing landforms, and the activity of aeolian sands on the desertification of oases and other lands in the Heihe River basin of northwestern China revealed that desertification occurred more or less quickly according to whether the prevailing climate was cold or warm, respectively. In the 1990s, the area of desertified lands in the lower reaches of the Heihe River (Ejin region) was 29.1% greater than in the mid 1980s. However, the rate of desertification in the middle reaches of the Heihe River basin was relatively slower, only 9.4% from 1949 to 1990 (or 0.27% per year). Since 1990, the rate of desertification has been stable. By 2000, the total area of land desertification in the mid to lower reaches of the Heihe River basin was 13,508.4 km², or 11.8% of the region monitored. Of the total land desertification area, the regions of Linze, Gaotai, Sunan, Jiuquan, Jia Yuguan, and Jinta accounted for 1.70, 1.71, 1.43, 0.85, 0.28, and 9.39%, respectively, whereas the Ejin region’s 11,434.64 km² accounted for 84.65%, indicating that land desertification in the lower Heihe River basin was particularly severe. The causes responsible for the occurrence and development of land desertification in the Heihe River basin were analyzed.     

气候与土地利用变化对涟水流域径流的影响

以涟水流域为研究对象,选用1990年、2000年、2010年三期土地利用数据资料,将1985-2014年30 a气象条件相应划分为1985-1994年、1995-2004年、2005-2014年三段气象背景时期,并组合细分为7种模拟情景,应用SWAT分布式水文模型模拟不同情景下的径流量,探讨气候和土地利用变化对流域径流的影响。利用PSO粒子群优化算法,以克林效率系数KGE为目标函数,通过湘乡站实测径流数据校准模型参数。运用p-factor、r-factor评价模拟的不确定性,采用相关系数R²、纳什效率系数NS和偏差百分比PBIAS评价模型模拟效果,评价结果表明不同土地利用情景下,校准期和验证期的模拟效果均达到可信程度,模拟的不确定性较小。组合情景间模拟分析结果表明,1985-2014年30 a间,气候变化使涟水流域径流不断减少,土地利用变化使径流有所增加,年径流深总体呈现下降趋势。气候变化对涟水流域径流变化的影响贡献率在逐渐上升,从71.4%上升到了86.3%。土地利用变化对径流变化的影响贡献率则相应下降,从28.6%降低至13.7%。因此,在气候变化背景下,科学管理流域水资源还需要充分考虑流域土地资源空间配置结构和利用方式。     

深圳市国土规划地质环境管理体系的构想

本文从深圳市地区地质环境现状出发,初步查明了开发区活动断裂及隐伏岩溶地面塌陷等多种地质灾害对城市规划建设的影响和危害。市哒,府有关主管部门借鉴了美国、香港的某些管理经验,结合城市地区的环境地质问题及时采取了治理措施,科学、合理地开展国土规划和城市建设,总结出一套城市国土规划和地质环境管理体系。可供同类型城市管理工作借鉴和参考。     

Measures of variability for geological data

Diverse global and local measures of variability appear in the geological literature and, along with methods used to apply them, have been subject to some debate. Measures of variability for three data types—replicate, locational, and compositional—are considered; the source and nature of the variability determine the appropriate type of measure. To illustrate the effects of these measures and expose their inadequacy when improperly applied, the variability of a three-column data set is interpreted under three different suppositions. Geologists need to be aware of the confusion and misleading results that can develop from the use of variance as a measure of variability for locational or compositional data.     

土地利用变化对海河流域典型区域的径流影响

为研究海河流域径流对土地利用变化的响应,以阜平流域、匡门口流域和界河铺流域为研究区,利用1970—2011年的水文气象资料,分析了不同土地利用的时空转移特征,然后结合SWAT(Soil and Water Assessment Tool)模型,设置4种土地利用情景,评价了土地利用变化对径流的影响。结果表明:模型能够较好地模拟全年及汛期月流量过程;多年径流量呈下降趋势,20世纪80年代到90年代中期呈波动性变化;不同的土地利用类型在时空上的转化呈现可逆性,主要是林地增加,草地减少,耕地略有增加;林地的增加和草地的减少会降低汛期径流量以及最大月径流量;汛期径流系数随着林地面积的增加而减小。合理地规划土地利用格局,对控制流域水文事件具有重要意义。     

Sedimentary evidence of prehistoric distant-source tsunamis in the Hawaiian Islands

Over the past 200 years of written records, the Hawaiian Islands have experienced tens of tsunamis generated by earthquakes in the subduction zones of the Pacific ‘Ring of Fire’ (for example, Alaska–Aleutian, Kuril–Kamchatka, Chile and Japan). Mapping and dating anomalous beds of sand and silt deposited by tsunamis in low-lying areas along Pacific coasts, even those distant from subduction zones, is critical for assessing tsunami hazard throughout the Pacific basin. This study searched for evidence of tsunami inundation using stratigraphic and sedimentological analyses of potential tsunami deposits beneath present and former Hawaiian wetlands, coastal lagoons, and river floodplains. Coastal wetland sites on the islands of Hawai΄i, Maui, O΄ahu and Kaua΄i were selected based on historical tsunami runup, numerical inundation modelling, proximity to sandy source sediments, degree of historical wetland disturbance, and breadth of prior geological and archaeological investigations. Sand beds containing marine calcareous sediment within peaty and/or muddy wetland deposits on the north and north-eastern shores of Kaua΄i, O΄ahu and Hawai΄i were interpreted as tsunami deposits. At some sites, deposits of the 1946 and 1957 Aleutian tsunamis are analogues for deeper, older probable tsunami deposits. Radiocarbon-based age models date sand beds from three sites to ca 700 to 500 cal yr bp , which overlaps ages for tsunami deposits in the eastern Aleutian Islands that record a local subduction zone earthquake. The overlapping modelled ages for tsunami deposits at the study sites support a plausible correlation with an eastern Aleutian earthquake source for a large prehistoric tsunami in the Hawaiian Islands.     

基于地质建造探索承德市土地利用优化路径

土地潜力评价是土地利用优化的前提,对土地资源高效利用和生态保护具有重要意义。基于在土壤“地质大循环”过程中,地质建造会影响土壤保持量、质地结构、养分含量和水文条件等,并决定土地资源初始禀赋特征的规律,文章探索建立了以地质建造为基础的土地潜力评价和利用优化路径。将承德市划分为堆积建造（第四系沉积物）、碳酸盐岩类建造、碎屑岩类建造、花岗岩类建造、火山岩类建造、片麻岩建造等六种类型。在不同流域尺度上,开展基于地质建造的土地潜力评价和利用优化实践:全流域上,将承德市滦河流域划分为北部土地沙漠化草地保护修复区、中部水源涵养（中草药）发展区、南部特色林果产业发展和生态林保护区、河谷耕地农业用地发展区等七类保护和利用建议区;小流域上,针对柴白河小流域人工造林用地优化,提出花岗岩、流纹岩建造适宜造林区,砂砾岩建造一般适宜造林区,白云岩建造不适宜造林区;对小滦河小流域的土地沙化和草地退化保护修复用地进行优化,划分出耕地适宜区、湿地保护区、造林适宜区、优质牧草区、草场退化区、生态保护区等六类利用优化建议区。     

Using Landsat data to determine land use changes in Datong basin,China

The aim of this study was to determine land use changes in Datong basin using multitemporal Landsat data for the period of 1977–2006. Four dates of Landsat images from 1977, 1990, 2000, and 2006 were selected to classify the study area. Based on the supervised classification method of maximum likelihood algorithm, images were classified into six classes: water, urban, forest, agriculture, wetland, and barren land. A multidate postclassification comparison change detection algorithm was used to determine changes in land use in four intervals. It is found that (1) urban land area increased 213% due to urbanization that resulted from rapid increase of urban population and high-speed economic development, (2) agriculture area increased 34.0% due to land reclamation that resulted from rapid increase of rural population and improvement of irrigation capacity, (3) forest area decreased 20.9% due to deforestation for urban area and agricultural use, (4) barren land area decreased 78.2% due to cultivation for agricultural use, and (5) water and wetland decreased 39.1 and 67.1%, respectively, due to exploitation of surface water and decrease of recharge from groundwater to surface water that resulted from over exploitation of groundwater.     

湖南大龙洞流域不同岩性不同土地利用类型条件下碳酸盐岩试片的溶蚀速率

选择湖南大龙洞流域寒武系中统熬溪组上段(∈2a3)白云岩、寒武系上统比条组下段(∈3b1)和奥陶系中统牯牛潭组(O2g)灰岩进行野外溶蚀试验,并测试林地和草地类型土壤剖面20cm、50cm深度土壤CO2浓度和有机质含量,以探讨林地、草地土地利用类型条件下试片溶蚀速率的差异特征。结果表明:(1)O2g、∈3b1和∈2a33种试片溶蚀速率在林地和草地土下20cm、50cm深度差异明显,∈3b1g灰岩林地土下20cm试片的溶蚀速率最大,达357.93mg/(m2?d);(2)试片溶蚀速率受岩性影响明显,CaO含量高,溶蚀速率大,O2g、∈3b1灰岩中CaO含量分别为35.38%、47.45%,较∈2a3白云岩的含量32.64%高,因而其溶蚀速率也较∈2a3的大;(3)埋放于林地土壤的试片其溶蚀速率大于草地,表明土地类型对溶蚀速率有较大的影响,植被从草地向林地的正向演替有利于岩溶作用的进行。      

The influence of land use/land cover variability and rainfall intensity in triggering landslides: a back-analysis study via physically based models

Natural Hazards - The objective of this study was to use physically based models to carry out a back-analysis of the set of factors that may have influenced slope instability and the consequent...     

Archaeological evidence for tectonic activity in the region of the Haifa-Qishon Graben, Israel

Thirty-five archaeological sites between Lebanon and Gaza on the Mediterranean shore of Israel were surveyed for evidence of relative changes of sea level; and published and unpublished data were compiled on a further 23 sites. Remains of occupation levels were classified into 13 archaeological periods from Neolithic to Crusader, giving a good dating scale over the last 9000 years. The Bronze Age shoreline (4000 years B.P.) is shown to be very close to the present shore along most of the coast, with vertical changes of less than 1.0 m at most sites. For later periods the accuracy of measurement of relative changes of level was improved to a root sum square error of 28 cm.The mean and modal sea levels derived from all sites of the same archaeological period were plotted against time to indicate the most probable “eustatic” sea-level curve, though it is accepted that hydro-isostatic adjustment and broad-scale slow earth movements cannot be separated statistically from eustatic changes on a 200-km stretch of coast. The relative sea level is shown to have been between −70 cm and present sea level for the last 4000 years, with no evidence for oscillations of amplitude more than ±30 cm at periodicities longer than 400 years, and no high sea level still stands.Relative vertical displacement between sites of the same archaeological age is attributed to tectonism. The sites on the alluvium of the Haifa—Qish on graben show no signs of vertical displacement, but there is maximum activity to north and south. Acco, on the north margin, shows submergence of nearly 2.0 m since A.D. 1300, with probable uplift preceding that date. Mount Carmel, south of the graben, shows signs of only very slight relative change, possibly attributable to eustatic change, in the immediate vicinity of the graben. But the southern flank of the mountain, 20–80 km south of the southern fault of the Graben, shows active vertical movements on the whole coast. Dor and Caesarea indicate multiple vertical movements ranging from 1.0 to 5.0 m in the last 2000 years, and a slump or fault has intersected the harbour area of Caesarea about 150 m offshore.These observations are related briefly to recent geodetic levelling of the coast and graben area; observations on the Dead Sea Rift, and hypotheses of fault control of the linearity of the Israel Mediterranean coastline.     

云海撞击盆地的恢复及其地质演化研究

研究月海撞击盆地,尤其是古老的月海撞击盆地,有助于深入认识月球乃至太阳系中两种动力学即内动力和外动力地质作用的演化过程,也是研究月球早期演化和现今状态的重要纽带。云海撞击盆地为古老的撞击盆地之一,形成于前酒海纪,在后期的内外动力地质作用下,盆地有很大程度的改造。为了恢复云海撞击盆地原貌,深入认识该地区的地质演化过程,本文利用了LRO宽角相机影像数据、LOLA地形数据和GRAIL重力数据等多种类型的遥感数据,开展了云海撞击盆地演化的研究。结果显示,云海盆地是由一次撞击事件形成,具中央隆起的三环结构的撞击盆地,三环直径分别约为740km、500km、340km,盆地中心约为16°W,21°S。云海撞击盆地事件破坏了该地区原始月壳结构,随后岩浆喷出或溢流充填在撞击盆地中形成云海,塑造了现今观察到的云海地形特征和重力异常特征。     

Effects of basin activities and land use on water quality trends in Tahtali Basin, Turkey

Bi-weekly water quality data from seven monitoring stations located within Tahtali Watershed, ?zmir, Turkey and digital land use/land cover data of the same watershed are analyzed in this study. To examine the changes in land use associated with urbanization, the satellite images of the main pool of the Tahtali reservoir prior to filling and subsequent to filling, respectively, are analyzed. Aerial photos of the basin taken in 1995 (October) are compared with images taken in 2005 (November) from the IKONOS satellite through use of several GIS techniques. New residential buildings, greenhouses, and industrial buildings are presented in separate layers, and changes in basin activities are quantified. The effects of urbanization on the water quality are investigated through statistical analysis. The seasonal Kendall test is applied to the water quality parameters monitored bi-weekly at seven stations within the basin for the duration 1997–2005. There was no trend in phosphorus, but there was a negative trend in boron and nitrate and a positive trend in the parameters of biological oxygen demand (BOD) and chemical oxygen demand (COD). The improvement in nitrate concentrations is attributed to the new regulations on the use of fertilizers in greenhouses. However, increase of BOD and COD concentrations is related to the growing settlement areas and industrial zones, which point to the insufficient wastewater treatment within the basin. Soil erosion within the basin is also quantified by the universal soil loss equation using available maps. Estimated total soil loss rate increased about 2.5 times that of 1995 when the changed land use composition in 2005 is considered in the calculations.     

The West Bornholm basin in the Baltic Sea: geological structure and Quaternary sediments

KÖgler, F.-C. & Larsen, B. 1979 03 01: The West Bornholm basin in the Baltic Sea: geological structure and Quaternary sediments. Boreas . Vol. 8, pp. 1–22. Oslo. ISSN 0300–9483.
The West Bornholm basin is an approx. 1000 km² subbasin of the Bornholm basin just north of Bornholm. The basin has been mapped by acoustic profiling and sampling of the sea floor. The basin is eroded down into Mesozoic sediments which are downfaulted between basement horsts in the Fennoscandian Border Zone. The development of the Quaternary morphology is illustrated by maps of the surface of the bedrock, the glacial landscape beneath the varved clays, the recent topography combined with isopach maps of late Glacial and Holocene formations. Quaternary formations are defined and described. The brown, very fine grained varved clay is deposited as a conformable cover on the substratum. It is probably deposited from suspensions carried in the whole water body, while turbidity currents were of minor importance. The recent sedimentary environment is an example of a restricted, but not totally anoxic basin. The recent sediment is chiefly mud rich in organic matter (ca. 4% C_org). According to a rough estimate, the long-term mean sedimentation rate of organic carbon is 6 g/m²/year.     

渭河流域1980~2010年土地利用变化的时空异质性研究

土地利用变化是地球关键带地表过程演变的重要表征。本研究基于渭河流域1980年、1995年和2010年3期土地利用数据、地形数据及河流汇演关系将研究区划分为渭河上游段、泾河段、北洛河段和渭河中下游段4个空间区域,综合利用土地利用动态度、类型动态趋势和土地利用转移矩阵的方法,定量分析了该流域的土地利用变化时空异质特征,并结合地形分布分析了其变化规律。结果表明：渭河上游段地形以丘陵为主,中下游段以山地和平原为主,而泾河段和北洛河段均以丘陵和平原为主。各空间区域土地利用类型均以耕地、草地和林地为主,土地利用转移也主要发生于这3种类型之间。1980~2010年间,渭河流域的耕地面积整体呈减小趋势,草地和林地面积整体上呈增长趋势,而建设用地面积持续增长。其中,耕地面积减少以渭河中下游段最为明显,减少498km²,草地面积在渭河上游段与北洛河段减少,而在中下游段和泾河段有所增长,林地面积在4个区域中均呈增长趋势。在研究时段内,地形分区影响着土地利用类型的转化特征：山地区以耕地向林地和草地的转化为主;丘陵区以草地和耕地向林地的转化为主;平原区则主要以耕地向林地、草地和建设用地三者的转化为主,其中建设用地为主要转入类型。

     

Archaeological evidence for dating the Loma Caldera eruption,Ceren, El Salvador

A Classic Period agricultural village in El Salvador was partially destroyed and encased in pyroclastic debris during the eruption of Loma Caldera about A.D. 590. The eruption was phreatomagmatic in nature, depositing alternating units of “muddy” pyroclastic surge beds and units of air fall lapilli, pumice, and volcanic bombs. This ephemeral eruptive left only a partially eroded collapsed tephra ring. The eruption began with earth tremors and possible steam explosions, giving enough warning to allow the inhabitants of the nearby village to flee, but violent enough that they left behind many of their most valuable personal items. The low temperature of wet ash surge units, which were likely emplaced as “ash hurricanes,” preserved much of the vegetation and other botanical remains surrounding the village. Analysis of the maturity of maize preserved in agricultural fields, and the presence or absence of blossoming and fruiting plants indicates that the eruption occurred in the mid-rainy season, probably late August or September. The placement of artifacts within buildings indicate that the eruption occurred in the early evening, after the inhabitants had returned from their agricultural fields and eaten an evening meal, but before retiring for the night. Although the exact year of the eruption can only be estimated within the uncertainty of radiocarbon dating, the season of the year and the time of day can be identified with unusual precision. © 1996 John Wiley & Sons, Inc.