黑龙江省粮食生产的时空格局及动因分析

采用空间自相关、聚类分析和多元回归模型等方法,论文探讨了2000 年以来黑龙江省粮食生产的时空动态及其主要影响因素.结果表明:① 黑龙江省粮食生产规模持续扩大,其中,大豆播种面积及其占农作物总播种面积的比重均经历了“上升-下降”的波动过程,玉米和水稻播种面积不断扩大,但其占农作物播种面积的比重分别在2009 和2011 年超过大豆;② 黑龙江省粮食生产具有一定的空间相关性,大豆空间集聚最显著,玉米次之,水稻最不明显;③ 粮食生产区域化和专门化态势增强,松嫩平原北部及大小兴安岭地区、松嫩平原东南部和三江平原北部分别形成了以大豆、玉米和水稻为主的粮食生产类型区;④ 多元回归分析表明,农业投入、经济环境、技术水平、市场因素是影响黑龙江省粮食生产及其结构时空变化的主要因素.     

呼伦贝尔典型草原区植物生长旺季地上干物质量估算的地面光谱模型

为促进地面高光谱遥感在草地估产方面的应用,采用美国ASD公司生产的Fieldspec 3光谱仪,于2009年7月下旬在呼伦贝尔典型草原区进行了高光谱遥感地面观测试验. 运用单变量线性、非线性和逐步回归分析方法,建立植物生长旺季归一化植被指数(NDVI)与地上干物质量(ANPP)间的地面光谱模型. 结果表明,基于判定系数(R2)判断,线性函数和指数函数拟合较理想,R2分别达到0.729 5和0.720 3. 误差分析表明,标准误差(SE)最大的是对数函数,其SE为24.82 g/m2;最小的是幂函数,其SE为22.63 g/m2. 平均误差系数(MEC)最大的是对数函数,其MEC为0.249 7;指数函数最小,其MEC为0.193 2. 综合分析后,选用一元线性回归方程作为呼伦贝尔典型草原区的植物生长旺季最优地面光谱模型:ANPP406.08NDVI-101.64,其R2为0.729 5,SE为23.61 g/m2,MEC为0.220　9,P<0.001.      

Toxicokinetic-toxicodynamic modelling in an individual based context—Consequences of parameter variability

Toxicokinetic-toxicodynamic (TKTD) models simulate the time-course of toxicant concentration in the organism and toxicity at the level of the organism. A link between TKTD models that simulate survival and individual based models for populations (IBMs) is proposed which allows TKTD parameters to vary between individuals. The TKTD-IBM predicts different survival in response to toxicants when TKTD parameters vary amongst individuals compared to the survival predicted with fixed TKTD parameters. The model with fixed parameters represents the concept of stochastic death whereas the model with variable parameters behaves, at least partly, according to the individual tolerance distribution concept. The whole set of TKTD parameters of an individual can be interpreted as constituting “individual tolerance”.     

Adding rigor to ecological network models by evaluating a set of pre-balance diagnostics: A plea for PREBAL

The widespread use of ecological network models (e.g., Ecopath, Econetwrk, and related energy budget models) has been laudable for several reasons, chief of which is providing an easy-to-use set of modeling tools that can present an ecosystem context for improved understanding and management of living marine resources (LMR). Yet the ease-of-use of these models has led to two challenges. First, the veritable explosion of the use and application of these network models has resulted in recognition that the content and use of such models has spanned a range of quality. Second, as these models and their application have become more widespread, they are increasingly being used in a LMR management context. Thus review panels and other evaluators of these models would benefit from a set of rigorous and standard criteria from which the basis for all network models and related applications for any given system (i.e., the initial, static energy budget) can be evaluated. To this end, as one suggestion for improving network models in general, here I propose a series of pre-balance (PREBAL) diagnostics. These PREBAL diagnostics can be done, now, in simple spreadsheets before any balancing or tuning is executed. Examples of these PREBAL diagnostics include biomasses, biomass ratios, vital rates, vital rate ratios, total production, and total removals (and slopes thereof) across the taxa and trophic levels in any given energy budget. I assert that there are some general ecological and fishery principles that can be used in conjunction with PREBAL diagnostics to identify issues of model structure and data quality before balancing and dynamic applications are executed. I humbly present this PREBAL information as a simple yet general approach that could be easily implemented, could be considered for further incorporation into these model packages, and as such would ultimately result in a straightforward way to evaluate (and perhaps identify areas for improving) initial conditions in food web modeling efforts.     

Generation time and the maximum growth rate for populations with age-specific fecundities and unknown juvenile survival

In age-classified population models where all parameters are known, the generation time and growth rate are calculated in a straightforward manner. For many populations, some parameters, such as juvenile survival, are difficult to estimate accurately. In a simplified population model where fecundity and survival are constant from the onset of breeding, it is known that generation time may be calculated given only adult survival, age at first reproduction, and the population growth rate. However, the assumption of constant fecundity from the onset of breeding does not hold for many populations. An extended population model allows calculation of generation time with the additional knowledge of the ratio of age-specific fecundities compared to a maximum fecundity rate. When these relative fecundities are unknown, an ad hoc adjustment to the simplified model performs well.When the study population is in an ideal environment, the optimal generation time and maximum growth rate are linked, and both may be approximated knowing only adult survival, age at first reproduction, and the relative fecundities. The maximum growth rate has important conservation implications, and calculating it correctly is therefore important. Improper use of the simplified population model to calculate the maximum growth rate, combined with a simple decision rule, leads to an average overharvest of 36%, and >60% for three of six bird species studied, compared to the full population model. By comparison, using the approximation from the extended or adjusted models results in average overharvests of only 8% (extended model) and 5% (adjusted model), and <50% for all six species (either model).     

环境模型与GIS的集成技术研究

首先介绍了环境模型发展现状,重点论述了环境模型与GIS集成的必要性和优势;环境模型与GIS集成的方式、集成系统的体系结构以及它们各自的优缺点,最后以福建省海岸带环境决策支持系统为例具体介绍了环境模型与GIS的集成,并对环境模型与GIS集成未来发展提出了几点看法。     

基于GIS和模型的流域非点源污染控制区划

采用GIS技术和USLE,SCS-CN,污染物流失经验模型及AnnAGNPS机理模型相结合,对农业集约化程度较高的南方中等尺度流域进行农业非点源污染控制区划.结果表明:利用GIS和经验模型回答了流域农业非点源污染氮磷来源与贡献,标识了农业非点源污染氮磷等污染物的关键源区,发挥了经验模型所需模型参数少、研究尺度较大、效率较高的优点,通过GIS的栅格数据空间分析功能,实现了流域非点源污染的分布式模拟,识别了NPS的关键源区.借助AnnAGNPS机理模型,在模型得以校验的前提下,模拟了非点源污染管理措施方案.以模型和GIS的定量结果为依据,对九龙江流域农业非点源污染控制进行了区划,共划分了水土流失控制区、生猪养殖+水土流失控制区、化肥施用+生猪养殖控制区、水土流失+化肥施用控制区及化肥施用+水土流失控制区5类控制单元.      

Analyzing the Effects of Groundwater Pumping on an Urban Stream‐Aquifer System

When the cone of influence of a pumping well reaches a nearby river, the resulting hydraulic gradient can induce enhanced seepage of streamflow into the aquifer. The rate of seepage is often modeled using analytical solutions that are simple to apply but may not reproduce field data due to mathematical assumptions not being met in the field. Furthermore, the appropriateness of such models has not been investigated in detail due to difficulty in measuring streamflow loss in the field. In this study, a field experiment was conducted on a reach of the South Platte River near Denver, Colorado to estimate pumping‐induced streamflow loss. A network of stream gauges, monitoring wells, and in situ measurements was used to observe streamflow rates, groundwater levels, and temperature to assess if pumping wells have a significant impact on streamflow, and to compare observed streamflow depletion against analytical solutions. Data collected suggest that pumping wells have a noticeable impact on streamflow. The analytical solutions proved accurate if streamflow was low and constant but performed poorly if streamflow was high and variable. Therefore, for this reach, the use of analytical solutions to predict streamflow may only be appropriate under low‐flow, constant‐flow conditions. Methods and results can be used to guide other streamflow depletion studies and to inform cases of pumping‐induced streamflow depletion, particularly in regard to water rights.     

种群水平生态风险评价方法概述及其在环境管理中的应用

生态风险评价的目的是保护生态系统功能的完整性、稳定性和持久性,为环境风险管理提供理论依据。然而,目前常见的用于保护生物的化学污染物浓度阈值大多是以个体水平的毒性试验结果为基础,忽略了物种在时间和空间相互作用等因素,不能够完全保护生态环境安全和生态系统功能的延续性。本文从生态风险评价的概念、目的和意义引出种群水平生态风险评价在环境管理应用的重要性,综述了种群水平生态风险评价的科学问题(如密度依赖、遗传变异和空间结构等),归纳了种群水平风险评价主要模型方法及其应用(如Euler-Lotka方程、预测矩阵、个体模型、空间模型和动态能量预算模型等),列举了各国现有法律法规中关于种群水平生态风险评价的规定,以期为种群水平生态风险评价方法研究及在环境管理中的应用提供有益借鉴。     

江淮地区秋季一次典型污染过程分析

结合2018年10月15—20日国控站点监测数据、气象资料及激光雷达走航观测结果,对江淮地区一次重度污染过程进行了分析。利用拉格朗日粒子扩散模型和拉格朗日混合单粒子轨迹模型定性分析了区域污染来源,分别基于激光雷达和空气站实测数据提出了外来源占比的估算方法,结合嵌套网格空气质量预报模式(NAQPMS)的源解析结果,对比分析了外来源占比。以淮北市为例,结合NAQPMS和单颗粒气溶胶质谱的PM2.5在线源解析结果,对比分析此次污染过程的行业来源。结果表明,本地污染累积时段,主要以燃煤和机动车尾气混合源为主(占比>70%);受北方污染输送时段,机动尾气占比显著升高,从19.4%(16日00:00)升至66.7%(17日11:00),淮北市、蚌埠市、合肥市3个城市污染物外来输送占比分别为52.2%~70.6%、48.8%~58.8%、41.5%~59.0%。