加利福尼亚州水权制度评介

美国加州水权法是一种独特的混合体系,由多种截然不同的权利组成,包括沿岸权、先占权以及其他类型的水权。文章主要从水权的类型、含义、内容等方面分析了加州水资源管理法律制度框架,并对加州可交易的先占权的获得、行使、变更、转让等问题进行了较为深入的探讨。     

南方草地资源开发利用对策研究

据中国科学院生物学部组织的“南方草地资源开发利用”考察资料，并参考有关考察地区提供的观测或调查资料，针对我国南方草山草坡的生态建设与环境保护和草山草坡资源开发利用的现状，提出建设我国“常绿草地带”高效畜牧业发展的战略，并就草山草坡的开发提出具体对策。     

引起红土表层硅铝比值增大原因的可能性探讨

Si/Al或SiO2 /R2 O3 常常作为表生化学风化作用强度的重要指标。随着化学风化作用的进行 ,硅铝比或硅铝铁率表现出逐渐降低的演化趋势。中国南方的红土风化壳 ,是强烈化学风化作用的产物 ,被认为处于或经历了脱硅富铝化阶段。但是在红土剖面上部常常出现该比值不降反升的现象 ,给运用这一指标指示化学风化强度带来了困难。通过对贵州平坝、新蒲及花溪碳酸盐岩红色风化壳化学风化程度的研究 ,以及对中国南方几种不同结晶母岩上发育的红土的化学风化强度指标的对比讨论 ,探讨了产生这种现象的可能性原因。指出Fe、Al氧化物的下渗和淋失作用及其硅质的相对富集是引起中国南方红土表层出现Si/Al和SiO2 /R2 O3升高的主要原因。     

黄淮海南部第四纪沉积地层与环境演变研究进展

黄淮海南部位于长江、黄河、淮河等重要水系长期相互作用的关键区域,其沉积地层记录了中国东部第四纪构造活动、海平面变化和人类活动等诸多环境演变的信息。研究显示黄淮海南部第四纪广泛发育海侵—海退旋回层序,然而海侵次数和时间仍存在争议,相关层序地层研究开展较少。基于黄淮海南部地区公开发表的34口典型钻孔,结合3个露头剖面,对地层进行了分区。将黄淮海南部第四系岩石地层划分为连云港平原区、里下河平原区、长江三角洲北翼和南黄海陆架区四个地层区。基于钻孔的岩相和生物相特征,识别出暴露相、风暴潮相和浅海相冷水团沉积三个标志性沉积特征,并将地层划分为五个典型的沉积相组合,即河道—河漫滩相组合、潮间—潮下—浅海相组合、滨岸沼泽—障壁海岸—滨海相组合、潮坪—潮上相组合和三角洲前缘—前三角洲相组合。在此基础上,重建了黄淮海南部第四纪的环境演变历史,结果表明首次海侵时间为早更新世（不早于1.9 Ma）,中更新世后才出现明显的海、陆交替特征。最后,还对年代地层的新方法（如宇生核素）和层序地层的建立进行了展望。     

我国南部地区城市水生态环境问题解析及综合整治对策：以深圳市为例

从水环境质量、水资源和水生态 (“三水”) 的角度对我国南部地区城市水生态环境进行了现状调研与问题解析,结果表明：该区域内城市普遍存在管网建设滞后的问题,近五成的城市排水管网密度低于全国平均水平;40%的城市污水处理厂运行负荷落后于全国平均水平;工业污染源以电子、汽车制造、化工和有色金属等重污染行业为主;区域内城市季节性面源污染严重;四分之一的城市属于重度缺水,水量型与水质型缺水并存以及水生态功能脆弱等。结合国家和城市相关规划要求,以深圳市为例构建水环境目标,并采用系统动力学模型对其水环境进行了模拟预测,分析了不同方案策略下目标的可达性。以此得出具体的分阶段治理措施：近期阶段 (到2025年) 重点进行控源减排、加大管网建设力度、污水处理厂提质增效、重污染企业产业升级和清洁生产、加强海绵城市的建设、构建节水型城市,并进行水生态的治理;中期阶段 (到2030年) 在控源减排的基础上重点进行水资源合理利用、建成完整的节水型城市体系、修复水生态系统;远期阶段 (到2035年) 重点进行水生态恢复,通过增加生物多样性等措施提高城市水生态系统功能。本研究可为南部地区同类城市解决水生态环境问题提供参考。     

华北平原南部农村地区黑碳气溶胶浓度及来源

华北平原南部地区是当前我国大气污染的严重区域之一.作为连接南北方大气污染传输的关键区域,其大气环境研究相对薄弱.在华北平原南部某农村点位利用AE-33型黑碳仪,对2018年2～8月的黑碳（BC）气溶胶进行连续监测,采用光度计模型解析了黑碳来源.观测期间ρ（BC）的平均值为（3.51±2.29）μg·m^-3,冬季、春季和夏季的ρ（BC）平均值分别为（8.21±3.26）、（3.49±1.69）和（2.37±0.71）μg·m^-3.BC的季节性变化由气象因素和排放源的季节性变化共同导致.ρ（BC）日变化在08:00[（4.66±3.24）μg·m^-3]和20:00[（4.25±6.73）μg·m^-3]出现峰值,与居民做饭时间一致;在14:00[（2.44±3.33）μg·m^-3]出现谷值,与边界层高度较高有关.气溶胶波长吸收指数（AAE）在1.08～1.66之间,冬季、春季和夏季的AAE平均为1.41±0.08、 1.28±0.10和1.20±0.06,表明该区域的BC来源以化石燃...     

以南疆为例的区域暴恐袭击风险评估

为探寻暴恐袭击高风险区域,推进公共安全精细化管理,以南疆地区为例,采用网格化社会经济数据、遥感数据和兴趣点(POI)数据等多源地理空间数据,从暴恐分子出现可能性、暴恐袭击目标选择偏好和暴恐袭击后果3个方面建立暴恐袭击风险评估指标体系,根据层次分析法(AHP)-Entropy、聚类分区等确定地理空间指标权重,最终得到南疆地区30″×30″(约1 km×1 km)细粒度的暴恐袭击风险的空间分布情况。结果表明:南疆地区的暴恐袭击高风险以上网格主要位于喀什、和田及阿克苏地区的部分市区和县城,与暴恐袭击历史事件的分布较一致,证明风险评估指标体系的合理性和可行性。     

Interactive effects of multiscale diversification practices on farmland bird stress

Farmland diversification practices (i.e., methods used to produce food sustainably by enhancing biodiversity in cropping systems) are sometimes considered beneficial to both agriculture and biodiversity, but most studies of these practices rely on species richness, diversity, or abundance as a proxy for habitat quality. Biodiversity assessments may miss early clues that populations are imperiled when species presence does not imply persistence. Physiological stress indicators may help identify low-quality habitats before population declines occur. We explored how avian stress indicators respond to on-farm management practices and surrounding seminatural area (1-km radius) across 21 California strawberry farms. We examined whether commonly used biodiversity metrics correlate with stress responses in wild birds. We used ∼1000 blood and feather samples and body mass and wing chord measurements, mostly from passerines, to test the effects of diversification practices on four physiological stress indicators: heterophil to lymphocyte ratios (H:L), body condition, hematocrit values, and feather growth rates of individual birds. We then tested the relationship between physiological stress indicators and species richness, abundance, occurrence, and diversity derived from 285 bird point count surveys. After accounting for other biological drivers, landscape context mediated the effect of local farm management on H:L and body condition. Local diversification practices were associated with reduced individual stress in intensive agricultural landscapes but increased it in landscapes surrounded by relatively more seminatural area. Feathers grew more slowly in landscapes dominated by strawberry production, suggesting that nutritional condition was lower here than in landscapes with more crop types and seminatural areas. We found scant evidence that species richness, abundance, occurrence, or diversity metrics were correlated with the individual's physiological stress, suggesting that reliance on these metrics may obscure the impacts of management on species persistence. Our findings underscore the importance of considering landscape context when designing local management strategies to promote wildlife conservation.     

Redesigning harvest strategies for sustainable fishery management in the face of extreme environmental variability

Short-lived, fast-growing species that contribute greatly to global capture fisheries are sensitive to fluctuations in the environment. Uncertainties in exact stock–environment relationships have meant that environmental variability and extremes have been difficult to integrate directly into fisheries management. We applied a management strategy evaluation approach for one of Australia's large prawn stocks to test the robustness of harvest control rules to environmental variability. The model ensemble included coupled environmental-population models and an alternative catchability scenario fitted to historical catch per unit effort data. We compared the efficacy of alternative management actions to conserve marine resources under a variable environment while accounting for fisher livelihoods. Model fits to catch per unit effort were reasonably good and similar across operating models (OMs). For models that were coupled to the environment, environmental parameters for El Niño years were estimated with good associated precision, and OM3 had a lower AIC score (77.61)  than the base model (OM1, 80.39), whereas OM2 (AIC 82.41) had a similar AIC score, suggesting the OMs were all plausible model alternatives. Our model testing resulted in a plausible subset of management options, and stakeholders selected a permanent closure of the first fishing season based on overall performance of this option; ability to reduce the risk of fishery closure and stock collapse; robustness to uncertainties; and ease of implementation. Our simulation approach enabled the selection of an optimal yet pragmatic solution for addressing economic and conservation objectives under a variable environment with extreme events.