Dynamic growth model for Scots pine (Pinus sylvestris L.) plantations in Galicia (north-western Spain)

In this study we developed a dynamic growth model for Scots pine (Pinus sylvestris L.) plantations in Galicia (north-western Spain). The data used to develop the model were obtained from a network of permanent plots, of between 10 and 55-year-old, which the Unidade de Xestión Forestal Sostible (Sustainable Forest Management Unit) of the University of Santiago de Compostela has set up in pure plantations of this species of pine in its area of distribution in Galicia. In this model, the initial stand conditions at any point in time are defined by three state variables (number of trees per hectare, stand basal area and dominant height), and are used to estimate stand volume, classified by commercial classes, for a given projection age. The model uses three transition functions expressed as algebraic difference equations of the three corresponding state variables used to project the stand state at any point in time. In addition, the model incorporates a function for predicting initial stand basal area, which can be used to establish the starting point for the simulation. This alternative should only be used when the stand is not yet established or when no inventory data are available. Once the state variables are known for a specific moment, a distribution function is used to estimate the number of trees in each diameter class, by recovering the parameters of the Weibull function, using the moments of first and second order of the distribution (arithmetic mean diameter and variance, respectively). By using a generalized height–diameter function to estimate the height of the average tree in each diameter class, combined with a taper function that uses the above predicted diameter and height, it is then possible to estimate total or merchantable stand volume.     

大气超级站网建设及在江苏区域的集成应用实践

当前全球大气环境问题趋于复杂化,区域性灰霾、酸雨和以臭氧、二次有机气溶胶生成为主的光化学污染问题成为大气环境保护领域关注的重点、热点问题。江苏省大气污染由过去单一的煤烟型污染逐步转变为多种污染物、多种作用机制同时存在且相互影响的复合型污染,成为影响广大人民群众身体健康和生态文明发展的重要因素。笔者对欧美和中国关于大气超级站网设计和建设进行了简要评述和比较分析,提出适合江苏省环境监测体系现状的大气复合型超级站网建设、区域数据综合集成及应用发展等方面的建设理论。     

2013年秦皇岛连续两次降水过程对比分析

利用常规气象观测资料、自动站资料及卫星资料,从大尺度环流背景和水汽、动力、热力条件出发,对2013年8月底东北冷涡影响下秦皇岛两次降水过程进行对比分析。结果表明：由于处在东北冷涡发展的不同阶段,中低层温度场配置不同,两次过程降水特点极不相同。8月27日降水是一次连续的区域性降水过程,以层状云降水为主,降水均匀连续,8月31日至9月2日是冷涡后部西北气流影响下的数日局地性对流降水,具有很强的突发性。     

基于外部性视角的区域生态补偿理论问题研究

当面对实现区域协调发展这一重大科学和实践命题时,生态补偿自然要同时解决人地关系中的区域关系,这就是区域生态补偿问题。地理运动构造了地理环境的整体性,而现实中的区域都具有产权区域属性,产权区域分割地理环境的整体性,使跨区域的地理运动演化为一个区域对其他区域的影响,即区域外部性问题。区域外部性所要解决的核心问题是判断外部性的“作用区域”,从而讨论外部性的空间特性,包括作用方向、范围和空间格局,并最终得到关于区域分布和区域关系的更加深入的认识。区域外部性理论能从特定的角度回答诸如为什么要实施区域生态补偿,如何确定补偿中的责任主体,如何设计补偿方式和确定补偿标准等区域生态补偿中的一些基本理论问题,从而成为其重要的理论基础。     

Bankfull Regional Curves for the Inner and Outer Bluegrass Regions of Kentucky1

Brockman, Ruth R., Carmen T. Agouridis, Stephen R. Workman, Lindell E. Ormsbee, and Alex W. Fogle, 2012. Bankfull Regional Curves for the Inner and Outer Bluegrass Regions of Kentucky. Journal of the American Water Resources Association (JAWRA) 48(2): 391‐406. DOI: 10.1111/j.1752‐1688.2011.00621.x Abstract: Bankfull regional curves that relate channel dimensions and discharge to watershed drainage area are useful tools for assisting in the correct identification of bankfull elevation and in stream restoration and reconstruction. This study assessed 28 stable streams located in two physiographic regions of Kentucky: the Inner Bluegrass and the Outer Bluegrass. Bankfull channel dimensions, discharge, and return period as well as average channel slope, median bed material size, sinuosity, Rosgen stream classification, and percent impervious area were determined. Significant relationships were found between drainage area and the bankfull characteristics of cross‐sectional area, width, mean depth, and discharge for both the Inner Bluegrass and Outer Bluegrass regions (α = 0.05). It was also found that the percent impervious area in a watershed had minimal effect on bankfull dimensions, which is attributed to the well‐vegetated nature of the streambanks, cohesive streambank materials, and bedrock control. No significant differences between any of the Inner Bluegrass and Outer Bluegrass regional curves were found (α = 0.05). Comparisons were made between the Inner Bluegrass and Outer Bluegrass curves and others developed in karst‐influenced areas in the Eastern United States. Although few significant differences were found between the regional curves for bankfull discharge and width, a number of the curves differed with regards to bankfull cross‐sectional area and mean depth.     

秦峪滑坡的时空格局研究

秦峪滑坡是国道212线上最严重的滑坡之一,以前对其研究程度较浅,认识深度不够,导致该滑坡至今未得到有效治理。以地球系统科学为指导,在大量现场调研、现场测试和室内试验的基础上,对该滑坡进行了系统研究,研究成果表明,秦峪滑坡是一个在断裂带基础上发育的一个多层次、多期次大型滑坡群组合体。同时从物质和能量的转换角度,恢复演化时序,建立了滑坡的时空格局,并进而探讨其演化机制。研究结果获得了秦峪滑坡客观的本质认识,为国道212线秦峪滑坡的治理以及拟建兰州—海口高速公路的选线和设计提供理论依据。     

正交曲线坐标下Boussinesq方程的研究

从质量守恒方程和Euler方程出发,推导出包含底摩擦耗能、波浪破碎效应和亚格湍流效应的改进型Boussinesq方程,并对该方程以及边界条件进行了正交曲线转换,建立了正交曲线坐标系下的二维波浪模型并用实验地形对本文模型进行了验证,计算结果与实测数据吻合很好,说明模型可以较好地模拟波浪传播过程中的浅水变形、折射、绕射和反射等现象.     

若尔盖盆地地球化学元素分布规律研究

通过对若尔盖盆地区域地质背景研究和野外取样调查与遥感解译,结合1:20万区域化探扫面成果编制的若尔盖盆地数字地球化学图研究发现,Zn、Sb、Hg、Pb、As、Au、Ag等绝大多数元素在若尔盖盆地古湖区显示为明显的低背景分布,是四川省西部典型的表生元素缺乏的地球化学区。大多数元素在若尔盖盆地内的变化系数CV<30%,呈分散状态,缺少后期地球化学作用的叠加。而具有显著不均匀分布特征的Hg、As、Sb、Mn、Au、Sr等元素的变化系数在50.5%-92.8%之间,反映出的集中分布趋势主要同金、铀等成矿作用有一定的关系。根据若尔盖盆地特殊的自然环境特征研究发现,影响元素分布特征的主要因素是气候条件中的温度与湿度以及沼泽、泥炭等有机质的强烈还原环境。     

区域环境与资源经济协调发展的定量分析研究

常用环境与资源经济协调发展的定量分析方法,在评价环境与经济协调程度之间存在一定的局限性.为有效解决该问题,通过确定区域环境系统的综合发展指数、对系统间协调度的研究,完成对区域环境的定量分析;通过分析建模思想、建立模型,完成资源经济协调发展分析优化模型的实现.设计对比实验结果表明,通过上述方式建立的定量分析优化模型,打破经济与环境之间的制约关系,改善环境与经济协调程度之间存在的局限性.     

基于熵权法的节水型社会建设区域类型分析

针对节水型社会建设中重点不突出、目标不明确的问题,通过熵权法及模糊综合评价法建立了节水型社会区域类型评价模型。从水资源、社会经济和节水潜力3个方面构建了包含12项指标的节水型社会区域类型评价体系。采用熵权法计算区域类型评价指标的权重向量,通过模糊综合评价法计算出不同区域在水资源条件、社会经济条件、节水潜力大小的评价值,进而得到相应的节水型社会建设区域类型。将模型应用到陕西省节水型社会建设区域类型划分中,从结果可以得出关中为“中度缺水-中度发达-潜力较小”型、陕北为“严重缺水-较发达-潜力较大”型、陕南为“轻度缺水-欠发达-潜力较大”型。该模型能够较客观地反映出节水型社会建设的区域特点及建设重点,应用实例具有普遍适用性。