Doctoral Dissertation Research: High-Resolution Climate and Land-Use Records from Cave Stalagmites and County Gazetters for China Over the Last 2,000 Years

博士论文研究：中国近2000年洞穴石笋和县志的高分辨率气候和土地利用记录

• 批准号: 0002433
• 负责人: George Brook
• 金额: $ 1万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0002433&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Resolution; Climate

A major concern of contemporary scientists is distinguishing global environmental changes associated with natural variations in climate from those that resulting from human activities. Land-use and land-cover changes are among the most important changes instigated by humans, but studies of these changes generally have been limited to the last 10 to 30 years, a very short period compared with the history of human activity. An urgent need therefore exists for high-resolution climate data over the last few thousand years and for information on land-use and land-cover changes over the same time period. This doctoral dissertation research project will explore the degree to which cave stalagmites can provide both high-resolution climate and land-use data for the areas near and above caves, thereby allowing a more accurate assessment of the role of humans in environmental change. Working in Guizhou Province of south central China, a region dominated by karst features, including many caves with speleothems. The doctoral candidate will study stalagmites from areas that still have natural vegetation cover and that have not been affected directly by human activities, particularly agriculture. Stalagmite annual layer thickness, gray-scale, stable isotope, and UV laser-induced luminescence proxy measures of climate will be taken and compared with meteorological records drawn from county gazetteers, which provide meteorological information for periods of more than 2,000 years. These comparisons will be used to determine which variables best reflect variations in rainfall and temperature. Appropriate proxy measures then will be compared with gazetteer data dealing with extreme climate events, such as floods and droughts, hail, freezing of rivers and lakes, and snow. Preliminary studies of one stalagmite have identified variations in summer rainfall and shown evidence of major floods back to ca. AD 1430. Investigations also will be made of stalagmites from caves in agricultural areas, particularly locations for which there have been significant changes in land use at a known times in the past, as determined from satellite images, aerial photographs, historical maps, and interviews with local residents. This part of the project will aim at identifying whether information about land use and land cover above the caves can be determined from speleothem records, thereby lengthening the periods over which land uses can be inferred back in time beyond reliable historical records. In addition to providing valuable information about relationships among climate, land-use, and natural vegetative processes over long periods for southern China, the project will make significant methodological contributions by assessing the degree to which cave deposits can be used to provide high-resolution climate and land-use and land-cover data. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

当代科学家的主要关注点是区分与人类活动所产生的自然变化相关的全球环境变化。 土地利用和土地覆盖的变化是人类煽动的最重要的变化之一，但是这些变化的研究通常仅限于过去10至30年，这与人类活动史相比非常短。 因此，在过去的几千年中，迫切需要对高分辨率气候数据，以及在同一时期内有关土地使用和土地覆盖变化的信息。 该博士学位论文研究项目将探索洞穴石塔米特人可以在洞穴附近和上方的区域提供高分辨率气候和土地利用数据的程度，从而更准确地评估人类在环境变化中的作用。 在中南中南部的吉州省工作，该地区由喀斯特特征主导，其中包括许多带有speleothems的洞穴。 博士候选人将研究仍然有天然植被覆盖的地区，尚未直接受到人类活动（尤其是农业）影响的地区。 石质岩石年度层厚度，灰度，稳定的同位素和紫外线激光诱导的气候发光代理量度将与来自县观察员绘制的气象记录进行比较，这些记录提供了2,000多年的气象信息。 这些比较将用于确定哪些变量最能反映降雨和温度的变化。 然后，将将适当的代理措施与涉及极端气候事件的宪报数据进行比较，例如洪水和干旱，冰雹，河流和湖泊的冻结以及雪。 对一台静态岩的初步研究已经确定了夏季降雨的变化，并显示出重大洪水的证据回到了大约。公元1430年。还将对农业地区洞穴的石匠进行调查，尤其是过去已知时代的土地利用发生重大变化的地点，这是根据卫星图像，空中照片，历史地图和对当地居民的访谈确定的。 该项目的这一部分将旨在确定是否可以从Speleothem记录中确定有关土地使用和土地覆盖的信息，从而延长可以在可靠的历史记录之外推断出土地使用的时期。 除了在长期为中国南部的气候，土地利用和自然植物过程之间提供有关关系之间的关系的宝贵信息外，该项目还将通过评估可以使用洞穴沉积物来提供高分辨率的气候以及土地利用和土地覆盖数据的程度来做出重大的方法论贡献。 作为博士学位论文研究改进奖，该奖项还将提供支持，使有前途的学生能够建立强大的独立研究职业。