Coupling relationships: Hillslope–fluvial linkages in the Hodder catchment, NW England

Variations in the coupling of sediment transfer between different parts of a fluvial catchment, e.g., hillslope to axial stream, can hamper understanding but are an integral part of the geomorphological record. Depositional environments respond to a combination of land use, climate, storms (floods), and autogenic conditioning. The distribution of sediment in the upland landscapes of NW England is out of equilibrium with contemporary climate and geomorphological processes; more a function of peri- and paraglacial mobilisation of glacigenic deposits. Soil and vegetation development after deglaciation have interrupted any progression toward sediment exhaustion with sediment release controlled largely by extrinsic perturbation, with late Holocene anthropogenic activity, climate and extreme hydrological events the likely candidates. This paper presents a new radiocarbon-dated Holocene geomorphological succession for the River Hodder (NW England), alongside evaluating new palaeoecological and geoarchaeological data to discern the impacts of human activity. These data show a late Holocene expansion in human occupation and use of the landscape since the Iron Age (700–0 cal. B.C.), with more substantial changes in the character and intensity of upland land use in the last 1300 years. The geomorphological responses in the uplands were the onset of considerable and widespread hillslope erosion (gullying) and associated alluvial fan development. Interpretation of the regional radiocarbon chronology limits gullying to four, more extensive and aggressive phases after 500 cal. B.C. The downstream alluvial system has responded with considerable valley floor deposition and lateral channel migration that augmented sediment supply by remobilising the existing floodplain terraces and led to the aggradation of a series of inset alluvial terraces. The timing of these changes between states of aggradation and incision in alluvial reaches reflects the increased connectivity between the hillslope and alluvial systems. Aspects of both the regional climate and land use histories are conducive to increasing discharge and sediment flux, but the region wide lowering of erosion thresholds appears a key driver conditioning these sediment-rich conditions and producing a landscape that was more susceptible to erosion under lower magnitude flows.     

Simulation and analysis of river runoff in typical cold regions

It is generally agreed that global warming is taking place, which has caused runoff generation processes and apparently total runoff amount changes in cold regions of Northwestern China. It is absolutely necessary to quantify and analyze earth surface hydrological processes by numerical models for formulating scientific sustainable development of water resources. Hydrological models became established tools for studying the hydrological cycle, but did not consider frozen soil or glacier hydrology. Thus, they should be improved to satisfy the simulation of hydrological processes in cold regions. In this paper, an energy balance glacier melt model was successfully coupled to the VIC model with frozen soil scheme, thus improving the models performance in a cold catchment area. We performed the improved VIC model to simulate the hydrological processes in the Aksu River Basin, and the simulated results are in good agreement with observed data. Based on modeling hydrological data, the runoff components and their response to climate change were analyzed. The results show: (1) Glacial meltwater recharge accounts for 29.2% of runoff for the Toxkan River, and 58.7% for the Kunma Like River. (2) The annual total runoff of two branches of the Aksu River show increasing trends, increased by about 43.1%, 25.95×10⁶ m³ per year for the Toxkan River and by 13.1%, 14.09×10⁶ m³ per year for the Kunma Like River during the latter 38 years. (3) The annual total runoff of the Toxkan River increased simply due to the increase of non-glacial runoff, while the increase of annual total runoff of the Kunma Like River was the result of increasing glacial (42%) and non-glacial runoff (58%).     

Role of fluvial and structural processes in the formation of the Wahiba Sands, Oman: A remote sensing perspective

The Wahiba Sands in northeastern Oman are bordered on the north, south and west by highlands. Remote sensing data are used to characterize the region between 19–23.5°N and 56.5–60°E by mapping surface and near-surface drainage, faults and fractures and aeolian features. It is suggested that the sands were originally deposited with surface runoff from the principal wadis and fluvially reworked fault zones, which define the northeastern and southwestern margins. These fluvial processes resulted in the accumulation of the vast groundwater resources now stored there. During dry climates, wind became the principal modification regime and it began to sort and shape the sediments into the dune forms that characterize today's Wahiba region. The thickness of the sands reflects the depth of the basin in which they lie. The center of the basin is filled with the thickest sand (the High Sands) and contains the highest groundwater concentrations. Presently, aeolian reworking dominates in the Wahiba region, although the Low and the Peripheral Sands continue to experience some fluvial action from occasional, seasonal rainfall. Even though dry conditions dominate today, it is clear that similar to the Sahara of North Africa, the surface sands of the Wahiba basin are indicators of groundwater occurrence.     

The role of soil erosion and fluvial processes in the post-fallout redistribution of Chernobyl-derived caesium-137: a case study of the Lapki catchment, Central Russia

The central area of the Russian Plain received substantial amounts Cs-137 fallout as a result of the Chernobyl accident in 1986, with inventories exceeding 40 kBq m⁻² in many of the areas close to Chernobyl. Concern over the longer-term fate of this contamination has focused attention on the need to predict the post-fallout redistribution of the radiocaesium and, thus, future changes in the spatial distribution of contamination in the landscape. Since radiocaesium reaching the land surface as fallout is rapidly and strongly adsorbed by soil and sediment particles, any attempt to predict its post-fallout redistribution must focus on erosion and sediment delivery processes and must rely heavily on a knowledge of the geomorphological processes involved. This paper reports a detailed investigation of post-fallout Cs-137 redistribution in the 2.18-km² Lapki catchment in the Middle-Russian Upland, which has required consideration of soil erosion processes, sediment delivery pathways, sediment delivery ratios and sediment sinks. The time elapsed since the Chernobyl accident is currently insufficient to result in significant reduction of Cs-137 inventories in eroding areas, but areas of deposition on both the lower slopes and on the balka sides and bottoms are already marked by significant increases in Cs-137 inventories. The results obtained emphasise that any attempt to develop meaningful predictions of the longer-term redistribution of Chernobyl-derived Cs-137 fallout within the Russian Plain must be based on a sound and detailed understanding of the linkage between the slopes and the balka systems and the fate of sediment entering the balka systems.     

Morphology and structure of a landslide complex in an active margin setting: The Waitawhiti complex, North Island, New Zealand

Multi-scale gravitational instabilities are widespread in the Coastal Ranges of the North Island of New Zealand. We document here a detailed analysis of the Waitawhiti landslide complex, located in the core of the Tawhero syncline, and investigate the potential landslides triggering factors in the area. Four contiguous large slides form the Waitawhiti complex. These slides involve fine-grained Miocene sandstones and massive fractured siltstones. Sliding occurs mostly along nearly horizontal strata. All slides are bounded laterally and/or distally by deep-incised valleys. Three gas seeps evidencing thermogenic gas release have been discovered in the vicinity of the slides. We propose that river incision, continuously removing distal buttresses, is the main destabilizing factor in the area. However, additional factors, such as tectonic activity and intense rainfall, cannot be excluded. We also propose that fluid overpressure, reducing the effective shear strength at the base of low-permeability layers, may have influenced the triggering of landslides in the Waitawhiti area.     

Origin of glacial–fluvial landforms in the Azas Plateau volcanic field, the Tuva Republic, Russia: Role of ice–magma interaction

The basaltic Azas Plateau volcanic field is located in the Tuva Republic of the Russian Federation. The area was glaciated multiple times, and the field is characterized by the formation of subglacial volcanoes called tuyas, but subaerial volcanoes and lava fields also exist. A combined study of remote sensing and field observations in the vicinity of the tuyas in the southeastern Azas Plateau volcanic field identified landforms that are best explained by the jökulhlaup hypothesis. The landforms include elongated hills, paleochannels, and butte and basin topography. These landforms are hypothesized to have formed by both erosion and deposition caused by high-energy water streams. The triggering for the hypothesized jökulhlaups was either melting of ice by subglacial volcanism and/or destabilization of ice-dammed/subglacial reservoirs. The age estimation of the flood events is difficult, but they probably occurred during the ice ages of the Quaternary, as late as in the Middle-Late Pleistocene.     

黑河流域地理观测分析——复杂性科学视角（英文）

Since 2005,dozens of geographical observational stations have been established in the Heihe River Basin(HRB),and by now a large amount of meteorological,hydrological,and ecological observations as well as data pertaining to water resources,soil and vegetation have been collected.To adequately analyze these available data and data to be further collected in future,we present a perspective from complexity theory.The concrete materials covered include a presentation of adaptive multiscale filter,which can readily determine arbitrary trends,maximally reduce noise,and reliably perform fractal and multifractal analysis,and a presentation of scale-dependent Lyapunov exponent(SDLE),which can reliably distinguish deterministic chaos from random processes,determine the error doubling time for prediction,and obtain the defining parameters of the process examined.The adaptive filter is illustrated by applying it to obtain the global warming trend and the Atlantic multidecadal oscillation from sea surface temperature data,and by applying it to some variables collected at the HRB to determine diurnal cycle and fractal properties.The SDLE is illustrated to determine intermittent chaos from river flow data.     

Analyses of geographical observations in the Heihe River Basin: Perspectives from complexity theory

Journal of Geographical Sciences - Since 2005, dozens of geographical observational stations have been established in the Heihe River Basin (HRB), and by now a large amount of meteorological,...     

Crossing the divide: Representation of channels and processes in reduced-complexity river models at reach and landscape scales

Reduced-complexity models have considerable potential as tools for elucidating river behaviour over periods of 10⁰–10⁴ years and, consequently, for addressing fundamental questions concerning the scale-dependent nature of explanation in geomorphology. This paper proposes a simple subdivision of reduced-complexity models of river behaviour into two categories that mirror methodological developments in fluvial geomorphology over the past 50 years. First, high-resolution cellular approaches that are implemented within a framework that resolves process-form feedbacks at small time and space scales. Second, models that incorporate section-averaged representations of channel geometry and processes, and that are typically underpinned by regime theory and equilibrium concepts. Examples of both model types are presented here, in the form of a cellular representation of stream braiding and a combined lattice-network model of alluvial fan evolution. Simulations conducted using these models demonstrate how small-scale process-form interactions determine the emergence of larger-scale channel and fan morphology and, in so doing, regulate system response to external forcing. In this sense, both models demonstrate that internal feedbacks play a critical role in controlling river responses to environmental change over historic and Holocene timescales. However, both classes of model are characterised by uncertainty in their parameterisation of geomorphic processes, such that internal feedbacks and thresholds for channel response to external forcing may vary substantially between competing models. Methods of refining both approaches are considered, and hybrid models based on lattice-network structures and mechanistic representations of channel process-form interactions are identified as a means of addressing the shortcomings of existing strategies.     

基于行动者网络理论的乡村绅士化演化过程与机制解析——以广西巴马盘阳河流域为例

乡村绅士化是城乡要素双向流动背景下乡村转型与振兴的新型路径。基于对广西巴马盘阳河流域乡村绅士化现象的历时性田野调查,采用行动者网络理论解析乡村绅士化演化的过程、类型与机制。研究表明：在巴马盘阳河流域乡村人类行动者与非人类行动者、“草根”行动者与机构行动者共同缔结的行动者网络的转换过程中,伴随关键行动者从“候鸟人”先锋、屯社精英向地方政府、投资开发商的更替,乡村绅士化路径从“草根”绅士化向机构绅士化演替,乡村产业从接待“候鸟人”、发展旅游转向大健康产业融合发展,乡村绅士化类型从单一的舒适移民绅士化向舒适移民、旅游和地产共构的“一地多类”绅士化演化。关键行动者更替及其功能角色转换、绅士化路径变迁和主导产业更替与融合发展、宏观乡村发展制度与地域自然人文环境共同作用于乡村绅士化的阶段演替与类型共生。行动者网络理论与方法利于呈现乡村绅士化的阶段演替脉络与共生演化特征,并揭示乡村绅士演化的一般机制与地域机制。     

Land subsidence and caprock dolines caused by subsurface gypsum dissolution and the effect of subsidence on the fluvial system in the Upper Tigris Basin (between Bismil–Batman, Turkey)

Karstification-based land subsidence was found in the Upper Tigris Basin with dimensions not seen anywhere else in Turkey. The area of land subsidence, where there are secondary and tertiary subsidence developments, reaches 140 km². Subsidence depth ranges between 40 and 70 m. The subsidence was formed as a result of subsurface gypsum dissolution in Lower Miocene formation. Although there are limestones together with gypsum and Eocene limestone below them in the area, a subsidence with such a large area is indicative of karstification in the gypsum. The stratigraphical cross-sections taken from the wells and the water analyses also verify this fact. The Lower Miocene gypsum, which shows confined aquifer features, was completely dissolved by the aggressive waters injected from the top and discharged through by Zellek Fault. This resulted in the development of subsidence and formation of caprock dolines on loosely textured Upper Miocene–Pliocene cover formations. The Tigris River runs through the subsidence area between Batman and Bismil. There are four terrace levels as T1 (40 m), T2 (30 m), T3 (10 m) and T4 (4–5 m) in the Tigris River valley. It was also found that there were some movements of the levels of the terraces in the valley by subsidence. The subsidence developed gradually throughout the Quaternary; however no terrace was formed purely because of subsidence.     

博弈理论在水资源管理中的应用——以黑河流域为例

区域的地理差异使得水资源在分布上时空不均,造成水资源供给的有限性;用水主体的开发利用和效率低下使得水资源呈现过量需求,造成不必要的浪费,此两者成为了水问题产生的主要原因。博弈理论应用的目的就是通过博弈分析寻找主体之间的博弈均衡点,实现博弈主体之间的效率与利益的最大化,选出最优策略组合。本文将博弈理论应用于水问题突出的黑河流域,通过对中游地区、下游地区和流域管理局3个主体之间的博弈分析得出流域管理局的介入和中游采取合作态度成为了解决水问题实现流域可持续利用的可行性策略。为了使中游地区采取合作态度,政府可以通过制定政策与奖惩措施来控制中游地区的行为,实现流域内部的生态效益与经济效益最大化,达到区域间的合作共赢。     

The construction of human–animal relations: National Jumps Day 2013 at Te Rapa,Hamilton, New Zealand

New Zealand is an important place for thoroughbred breeding and racing. Most races are on the flat, but jumps racing is conducted in the cooler months. The 2013 National Jumps Day at Te Rapa, Hamilton, was a significant space for the construction of human–animal relations. Drawing on three bodies of accounts, we ask whether social media contributes to the realignment of perspectives or reinforces existing human–animal relations. We explore competing narratives and demonstrate how animals, people, activities and places are constructed, including making animal deaths unrecognisable to perpetuate activities that are questioned by contemporary animal geographies.     

Physiogeographic features of the Oubangui catchment and environmental trends reflected in discharge and floods at Bangui 1911–1999, Central African Republic

Varying discharges of large rivers observed over long periods can reflect environmental trends like ‘climate change’ within the catchment (e.g. ongoing aridification results in a reduced discharge). The present study on the Oubangui River in Central Africa first lines out some physiogeographic features of the almost 500 000 km² large catchment situated on the vast north equator rise. Subsequently, a discharge record from 1911–1999 of Qmax. and Qmin., covering data for 73 years from the gauge station Bangui, is examined. Annual variability of Oubangui floods is generally high and shows over the past years, especially since the mid to end 1960s, a less significant trend to a slight depletion of maximum discharge. Frequency analysis (Gauss, Gumbel, Weibull) of floods resulted in return periods between 7 and 35 years. Distributions calculated after Gumbel generally gave the best results. No linear and simple evidence exist of the tendency of the river to reduce discharge because of a depletion of rain fall as the Oubangui's floods are again increasing since the mid 1990s. Finally, the consequences of Oubangui flood hazards for the growing town of Bangui are discussed. Flooding of urban areas from exceptional high Qmax. discharge is spatially reconstructed for the floods in 1916, 1962, and 1999.     

珠江三角洲旅游创新的协调发展研究——基于二象对偶理论视角

以珠江三角洲九城市为研究对象,借用区域创新二象对偶评价模型,构建区域旅游创新评价指标体系,测算区域旅游创新综合发展水平以及协调发展水平。通过对区域旅游创新的综合发展水平、协调水平进行评价,发现珠三角九市旅游创新发展呈现U型的不协调发展态势。其中广州、中山的旅游创新能力较强,但是协调度不高;深圳的旅游创新能力较强,协调度较高;其他6城市的旅游创新综合水平较低,协调度较高。据此,应采取加大旅游业创新投入、强化旅游产业创新支撑、加速旅游创新扩散,加强广州、深圳与其他城市之间的合作创新等相关措施,大力推动珠江三角洲九市旅游创新的协调发展,以提升区域旅游创新的整体水平。     

Chronology of relict lake deposits in the Spiti River, NW Trans Himalaya: Implications to Late Pleistocene–Holocene climate-tectonic perturbations

The Spiti River that drains through the arid Trans-Himalayan region is studied here. The relict deposits exposed along the river provide an opportunity to understand the interaction between the phases of intense monsoon and surface processes occurring in the cold and semi arid to-arid Trans-Himalayan region. Based on geomorphological observation the valley is broadly divided into the upper and lower Spiti Valley. The braided channel and the relict fluvio-lacustrine deposits rising from the present riverbed characterize the upper valley. The deposits in the lower valley occur on the uplifted bedrock strath and where the channel characteristics are mainly of meandering nature. Conspicuous is the occurrence of significantly thick lacustrine units within the relict sedimentary sequences of Spiti throughout the valley. The broad sedimentary architecture suggests the formation of these palaeolakes due landslide-driven river damming. The Optically Stimulated Luminescence (OSL) dating of quartz derived from the bounding units of the lacustrine deposits suggests that the upper valley preserves the phase of deposition around 14–6 ka and in the lower valley around 50–30 ka. The review of published palaeoclimatic palaeolake chronology of Spiti Valley indicates that the lakes were probably formed during the wetter conditions related to Marine Isotope Stage III and II. The increased precipitation during these phases induced excessive landsliding and formation of dammed lakes along the Spiti River. The older lacustrine phase being preserved on the uplifted bedrock strath in the lower valley indicates late Pleistocene tectonic activity along the Kaurick Chango normal fault.     

Water quantity-quality combined evaluation method for rivers&rsquo|water requirements of the instream environment in dualistic water cycle: A case study of Liaohe River Basin

In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed, and compared with the meaning of unitary water cycle. Based on the analysis of the relationship between environmental flows of river re-quirements, the efficiency of water resource usage, the consumption coefficient, and the concentration of waste water elimination, the water quantity and water quality calculation method of the environmental flows of river requirements in dualistic water cycle is developed, and the criteria for environmental flows of river requirements are established, and therefore the water quantity-quality combined evaluation of natural river flows requirements are realized. Taking the Liaohe River as a model, the environmental flows of river requirements for Xiliao River, Dongliao River, mainstream Liaohe River, Huntai River and northeast rivers along the coasts of the Yellow and Bohai seas in unitary water cycle are calculated, each taking up 39.3%, 63.0%, 43.9%, 43.3% and 43.5% of runoff respectively. Evaluated according to Tennant recommended flow, the results show that: except Xiliao River is “median”, the rest are all upon “good”, the Dongliao River is even “very good”. The corresponding results in dualistic water cycle are that, the proportion of natural flows for each river is 57.5%, 74.1%, 60.8%, 60.3% and 60.4%; while the combined evaluation results show that: considering “quantity”, except Xiliao River, the rest rivers can all achieve the “quantity” criteria of the en-vironmental flows of river requirements, but if considering the aspect of “quality”, only Dongliao River can reach the “quality” standard. By water quantity-quality combined evalua-tion method, only Dongliao River can achieve the criteria. So the water quality is the main factor that determines whether the environmental flows can meet the river ecosystem de-mands.     

行动者网络理论与农村空间商品化——以北京市麻峪房村乡村旅游为例

乡村旅游作为农村空间商品化的表现形式之一,在增加农民收入、阻止农村衰退、振兴农村经济方面发挥着重要作用。为此本文以北京市昌平区麻峪房村的乡村旅游为例,借助行动者网络理论分析农村空间商品化的形成与演变,并讨论农户在此过程中的参与。麻峪房村在从农民生活空间转变为城市居民消费空间的过程中,形成了以区旅游局、乡旅游公司为关键行动者,并吸纳了多个人类和非人类行动者所构成的行动者网络。在网络形成的过程中农户参与乡村旅游的程度逐渐提高,由此推动了麻峪房村农村空间商品化的发展。麻峪房村演变为城市居民消费空间后,由于行动者网络发生变化使农村空间商品化发生变化,导致麻峪房村农村空间商品化程度降低。同时新的行动者网络中的各行动者的不对等性明显,各行动者之间存在很多异议,使该网络趋于僵化、丧失活力,不足以支撑麻峪房村乡村旅游继续发展。在麻峪房村农村空间商品化的形成过程中,农户的院落区位、年龄与原有工作等对农户参与乡村旅游的意愿产生不同的影响。当农村地区行动者网络中的关键行动者与行动者利益共通且紧密联系时,其空间商品化就得到强化,反之亦然。     

气候和土地利用变化对径流变化影响研究——以伊洛河流域伊河上游地区为例

在实际调查基础上,利用遥感和地理信息系统技术,分析伊洛河流域伊河上游地区气候和土地利用变化对径流变化的影响。结果显示,在研究区域中,林地面积最大,1987-2008年,林地、库塘和建设用地面积持续增加,草地、河流和未利用地面积持续减少,耕地面积则先增加后减少。20世纪80年代以来,土地利用变化在不同阶段都使得年平均径流量减小;80-90年代,气候变化使得年平均径流量减小,而90年代到2000年以后,气候变化使得年平均径流量增加,这与90年代年平均降水量减少,而2000年以后年平均降水量增加密切相关。     

渭河流域关中段潜在蒸发量时空变化特征

根据渭河流域关中段11个主要代表气象站点1955~2012年逐日气象数据,以FAO Penman-Monteith 公式得出潜在蒸发量,分析渭河流域关中段潜在蒸发量的时空变化特征。结果表明：① 渭河流域关中段年平均潜在蒸发量在1 073.9~1 284.1 mm,流域内多年平均蒸发量随着海拔的降低逐渐增高。② 夏季潜在蒸发量在327.6~547.2 mm,占全年的34%~42%,变化趋势与全年潜在蒸发量变化趋势高度一致。③ 渭河关中段随气温上升,潜在蒸发量减少。④ 年均潜在蒸发量与日较差、平均气温、平均风速、日照时数呈正相关,与相对湿度和水汽压呈负相关。