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The article discusses the paper, titled "Weathering of granite," by Bryan Ruxton and Leonard Berry, which emphasizes what they had seen in excavations across the territory of Hong Kong, China in 1957. The paper addresses various problems, the significance as well the relevance of which were augmented with time. The authors assert that this particular research offers a useful methodical approach to weathering mantles. They also observe that granite is altered to great depth. Moreover, they show that gully erosion, which is a threat in Hong Kong, developed in weathered in situ granite. The stability of the weathering mantle is likewise noted.

To reverse the soil degradation problems resulting from overexploitation, ecological soil rehabilitation has already been an important pursuit in ecological and environmental research and applications. Based on journal publications and a meta-analysis approach, this paper investigates the effects, and their spatiotemporal variations, of different land covers on red soil rehabilitation in China. Results indicate that all the land covers used in red soil rehabilitation had been effective in improving degraded red soils but the degrees of effectiveness varied. Soil organic carbon was the most sensitive of the three major soil nutrients considered with regard to land-cover change during ecological rehabilitation. Coniferous and broadleaf mixed forest was detected as the most effective land cover in red soil rehabilitation. Some spatiotemporal trends of land-cover effectiveness on red soil rehabilitation exist in a statistically significant sense. These findings are important for land use and ecological rehabilitation decision-making such as the selection of a soil rehabilitation pathway and the determination of priority areas for ecological rehabilitation. [ABSTRACT FROM AUTHOR]

Exploring prehistoric variation in human–environmental interaction is critical for understanding the historical patterns and mechanisms of long-term human–land evolution. In this paper we review the published radiocarbon and optically stimulated luminescence (OSL) data from Late Paleolithic, Neolithic and Bronze Age sites in China, analyze the spatial–temporal distribution of these sites, and compare it with the results of recent paleoclimatic and archaeological studies. We seek to study the trajectory and influencing factors of human–environmental interactions in late prehistoric China. We detect changing patterns in the relationship between humans and the environment during different phases of the prehistoric era in China. Climate change clearly affected the environment of hunter-gatherer groups between 50,000–10,000 BP (before present, defined as 1950AD), and variation in human population in Neolithic China (∼10,000–4000 BP) was likely influenced primarily by the development of agriculture, in addition to substantial climate events. The spatial scale of human settlements expanded in the Bronze Age (∼4000–2200 BP) in a period of cooling climate. During this time the impact of human activities on the environment increased significantly, primarily caused by technological innovations related to the onset of prehistoric transcontinental cultural exchange in Eurasia. [ABSTRACT FROM AUTHOR]

Seventeen sustainable development goals (SDGs) were put forward at the United Nations Development Summit in 2015 when releasing "Transforming our world: The 2030 Agenda for Sustainable Development". However, the international community still lacks understanding of how to make a bridge between scientific research and SDGs. China has experienced 40 years of rapid economic growth and social development, which have imposed considerable challenges on sustainable development. Although many disciplines have made contributions to promoting sustainable development in China, how to bridge SDGs and scientific research is still not fully clear. In this paper, we review the contribution of geographers to this issue to provide references for further international efforts towards meeting the SDGs. We consider three aspects in particular: the sensitive process capture of regional responses and feedbacks to global change; the cognition and geographical solution of human–environment conflicts; and the mutual promotion of spatial governance and geographical practices. The contribution of geography as a discipline to the sustainable development of China is an epitome of geographers' efforts over the world. The practices experienced in China show that geography has played an irreplaceable role in promoting sustainable development, and can deal effectively with the challenges posed to the academic community by SDGs. As a discipline, geography has been deeply integrated into sustainable development. In the future, geography should become a key discipline in integrating many disciplines involved in sustainable development studies, and provide real-time decision support systems for sustainable development by combining big data and artificial intelligence. [ABSTRACT FROM AUTHOR]

The Three Gorges Project has been subject to intense debates regarding its benefits and costs. The environmental impacts of this huge project have been an important focus of these debates since the project planning stage. After the operation of the Three Gorges Dam at full capacity at the end of 2008, new environmental and ecological issues are emerging. This paper gives a brief description of the Three Gorges Project and its environmental impact assessment process, as well as major efforts to control environmental problems brought about by the project. From the long and complicated evaluation process, it is clear that there are large uncertainties and competing opinions regarding the benefits and costs, especially the ecological and environmental ones, of the project even after great research effort. Emphasis here is given to the environmental challenges including: (1) water quality control; (2) water and sediment regulation; (3) biodiversity conservation in the riparian and aquatic ecosystems; (4) environmentally friendly dam operation and regional sustainable development. Opportunities often grow out of the challenges. The Three Gorges Project provides opportunities for grand-scale experiments on the environmental, ecological, and socio-economic impacts of large dams. Local, national, and international concerted efforts and concrete actions should be directed to the mitigation and control of the negative impacts as well as securing the positive contributions of the project across scales. [ABSTRACT FROM AUTHOR]

Land use is one of the key factors affecting soil erosion in the Loess Plateau of China. This paper examines soil erosion under different land uses and land-use combinations using 137Cs tracing in the Yangjuangou Catchment, a tributary of the Yan River in the Loess Plateau of Northern Shaanxi Province. The results show that the order of 137Cs activity in different land uses decreases sequentially from mature forest to grass to young forest to orchard to terrace crop, indicating that the mature forests had the lowest erosion rates while the terraced cropland produced the highest erosion amount. The majority of 137Cs is distributed in the top 0-10 cm of the soil layer. The 137Cs activity in mature forest and grass soil is significantly higher than in other land uses. Three land-use combinations on the hillslope were selected to study the relationship between land-use combination and soil erosion. The mixtures of 'grass (6 years old) + mature forest (25 years old) + grass (25 years old)' and 'grass (6 years old) + young forest (6 years old) + mature forest (25 years old) + grass (25 years old)' are better for soil erosion control, lowering soil erosion amount by 42% compared with a land-use combination of 'grass (6 years old) and shrub (6 years old)'. The results provide an important basis for optimizing land-use combinations to control soil erosion on slopes and may also result in important ecological benefits. [ABSTRACT FROM AUTHOR]

Discharge from the largest karst spring in north China, the Niangziguan Springs, has been declining since the 1950s. This paper examines the response of these springs to climatic change and anthropogenic influence by attempting a model-based discrimination between phases in the stream discharge record. In Niangziguan Springs Basin, the exploitation of karst groundwater began in 1979. Accordingly, the spring discharge data were divided into two phases: pre-1979 and post-1979. In the first phase (1957-78) the spring discharge was believed to be affected solely by climate change, and in the second phase (1979-2007) the spring discharge was influenced by both climate change and human activities. Using grey system theory, a discharge model was estimated for the first phase. Extrapolating the model, we obtained a projection of the spring discharge during the second phase. Using a water balance calculation, we discerned the respective effects of climate change and human activities on depletion of spring discharge for the second phase. The results show that the contribution of climate change to depletion of Niangziguan Springs is 2.30m3/s and the contribution of anthropogenic activities ranges from 1.89 to 2.90 m3/s, although this assumes a constant for the climate change effect. Accordingly, the anthropogenic effects have been approaching and surpassing the effects of climate change during the second phase. With respect to the impact of human activities on spring discharge, groundwater abstraction accounts for only about 34-52% of the declines; 48-66% of the declines are related to other human activities, such as dewatering from coal mining, dam building and deforestation. [ABSTRACT FROM AUTHOR]

The Loess Plateau, China, has long been suffering from serious soil erosion. About 2000 years ago, larger areas were used for grain production and soil erosion was thus becoming severe with increase in human activity. Severe soil and water loss led to widespread land degradation. During the past decades, great efforts were made in vegetation restoration to reduce soil erosion. However, the efficiency of vegetation restoration was not as satisfactory as expected due to water shortage. China initiated another state-funded scheme, the ‘Grain-for-Green’ project in 1999, on the Loess Plateau to reduce soil erosion and improve land quality. However, the control of soil erosion effectively by land-use modification raised problems. In this paper, the lessons and experiences regarding soil and water conservation in the Loess Plateau in the past decades are analysed first. Urgent problems are then elaborated, such as the contradiction between land resource and human population, shortage of water both in amount and tempospatial distribution for vegetation growth, weak awareness of the problems of soil conservation by local officials, and poor public participation in soil and water conservation. Finally, suggestions regarding soil and water conservation in the Loess Plateau are given. In order to control soil erosion and improve vegetation, a scientific and detailed land-use plan for the Loess Plateau has to be made, in the first instance, and then planning for wise use of water resources should be undertaken to control mass movement effectively and to improve land productivity. Methods of improving public awareness of environmental conservation and public involvement in vegetation rehabilitation are also important. [ABSTRACT FROM AUTHOR]

Wind erosion is one of the most important processes associated with land degradation and desertification in the arid, semi-arid and portions of the subhumid regions of China. The total land area experiencing wind erosion is approximately 160.74 x 104 km2, which is 16.7% of the national territory. Wind erosion is recognized as a great threat to land utilization and sustainable social and economic development. Documentation of wind erosion and its negative impacts in China dates back over 2000 years. Since the 1950s Chinese scientists have carried out an integrated investigation of the principal lands susceptible to wind erosion, and have undertaken many laboratory tests and field observations with respect to the stabilization and utilization of soil in desert areas. Since the late 1970s there has been an increasing concern worldwide regarding land desertification caused by climatic changes and human activities. Hence, wind erosion, one of the main processes of desertification, has attracted the attention of Chinese scientists to an even greater extent. Studies have been conducted to investigate the mechanics, causes and control techniques related to wind erosion using wind tunnel simulation tests and field observations in typical areas. Some encouraging achievements have been made. In this paper we summarize the main research results on wind erosion that have come to light in China in recent decades, and put forward some perspectives and suggestions to deal with problems in both research into and control practices of wind erosion in China. [ABSTRACT FROM AUTHOR]

A general framework for modelling morphological responses to perturbation is proposed, based on the underpinning principle that the rates of morphological response in alluvial channels are initially high and then decrease through time as the system relaxes following disturbance. The framework includes three morphological response models, each developed from the fundamental rate law, which has the form of an exponential decay function. These models consider the possibility that characteristic behaviours of the fluvial system, such as delayed response and/or cumulative effects, may affect morphological responses, making them capable of representing relaxation paths and times for a range of morphological response variables, whatever their initial states. To test their utility, the models in the framework were applied to simulate the sequence of geomorphological responses to disruption observed in selected rivers with well-documented histories of morphological perturbation, adjustment and recovery. The results demonstrate that the models in the general framework can successfully simulate temporal and spatial patterns of morphological response in the fluvial system under a range of different circumstances, while also indicating how their reliability could be further improved. [ABSTRACT FROM PUBLISHER]

Urban wetlands play a significant role in the sustainable development of the urban eco-environment. However, accelerated urbanization has caused rapid changes in urban wetland landscape patterns, which may seriously affect their functions. Based on land-use maps, TM images, and field data from the Wuhan wetlands, the spatiotemporal evolution and wetland landscape pattern were quantitatively analyzed, with reference to landscape ecology indices of diversity, fragmentation, dominance, shape, and dimension. The results showed that: (1) the natural wetland area decreased: lakewetlands andmarshwetlands decreased by 18.71% and 50.3% from1987 to 2005, respectively; (2) artificial wetland area increased by 47.75% in Wuhan over the same period; (3) the lake wetland area ofWuhan declined due to the conversion of large lakes tosmaller ones; (4) the value of the diversity index (H), evenness index (E), and fragmentation index (F) decreased,while the value of the dominance index (D) increased from1987 to 2005; (5) the landscape shape index (LSI) and fractal dimension (FD) of the river wetlands, lake wetlands, bottomland wetlands, and marsh wetlands decreased, while the LSI and FD of the reservoir and pond wetlands increased from1987 to 2005; and (6) natural, societal, and economic, as well as human, activities are major factors for the structural changes in the Wuhan wetland landscape, as revealed by canonical correlation analysis.Results suggest that the ecological environment of urban wetlands should be protected to maximize the services of urban wetland ecosystems in Wuhan, China. [ABSTRACT FROM AUTHOR]

There are rich legacies of geographical knowledge in China. However, geography as an independent branch of science was established in the country no earlier than the beginning of the twentieth century. Since 1950s, integrated physical geography as a subdiscipline of physical geography in China has made major theoretical and methodological progress in the areas of physical geographical regionalization, land studies, and the studies of man-nature interactions. Despite this, the discipline as a whole still faces tremendous challenges from the fast changing society in China and scientific advancement in the twenty-first century. The following aims need to be emphasized in order to promote the future development of integrated physical geography: (1) to strengthen long-term monitoring, experiments, surveys and simulations; (2) to improve research on the interactions between geographical patterns and processes; (3) to enhance integrated research on global change effects and regional geographical regimes; and (4) to facilitate the incorporation of the theories and methods of human geography into integrated physical geographical research. [ABSTRACT FROM AUTHOR]

The study of desertification in China began in 1977 with the UN Conference on Desertification. Since then, much progress has been made. This article reviews progress over the last five years in China. A brief description of desertification research in China is given, and developments and changes in the definition of desertification described. Finally, the causes and patterns of desertification are discussed. [ABSTRACT FROM AUTHOR]