Sampling and testing are conducted on groundwater depth and vegetation coverage in the 670 km² of the Sangong River Basin and semi-variance function analysis is made afterwards on the data obtained by the application of geo-statistics. Results showed that the variance curve of the groundwater depth and vegetation coverage displays an exponential model. Analysis of sampling data in 2003 indicates that the groundwater depth and vegetation coverage change similarly in space in this area. The Sangong River Basin is composed of upper oasis, middle ecotone and lower sand dune. In oasis and ecotone, influenced by irrigation of the adjoining oasis, groundwater level has been raised and soil water content also increased compared with sand dune nearby, vegetation developed well. But in the lower reaches of the Sangong River Basin, because of descending of groundwater level, soil water content decreased and vegetation degenerated. From oasis to abandoned land and desert grassland, vegetation coverage and groundwater level changed greatly with significant difference respectively in spatial variation. Distinct but similar spatial variability exists among the groundwater depth and vegetation coverage in the study area, namely, the vegetation coverage decreasing (increasing) as the groundwater depth increases (decreases). This illustrates the great dependence of vegetation coverage on groundwater depth in arid regions and further implies that among the great number of factors affecting vegetation coverage in arid regions, groundwater depth turns out to be the most determinant one.

The environment evolution of Wuliangsuhai wetland since 1986 is analyzed based on the remote sensing principle. The total water area of Wuliangsuhai lake has been increased during the past 17 years. The open water area had an increasing trend before 1987, and the trend was decreasing up to 1996, then the trend has increased again since 2000; the variation of the water area with dense aquatic weed is basically contradictory to the variation of open water area. The natural reed area had been decreased before 1987, and then it has been increased. The areas of shallow water and swamp have been slightly increased, in fact, the variations are quite steady. The artificial reed area has been increased since the reed plantation was started in 1988. The relationships of the water environment, the climate, hydrology and different types of areas are discussed, and then the technological measures for sustainable development and utilization of Wuliangsuhai lake water environment are proposed.

After dividing the source regions of the Yellow River into 38 sub-basins, the paper made use of the SWAT model to simulate streamflow with validation and calibration of the observed yearly and monthly runoff data from the Tangnag hydrological station, and simulation results are satisfactory. Five land-cover scenario models and 24 sets of temperature and precipitation combinations were established to simulate annual runoff and runoff depth under different scenarios. The simulation shows that with the increasing of vegetation coverage annual runoff increases and evapotranspiration decreases in the basin. When temperature decreases by 2^oC and precipitation increases by 20%, catchment runoff will increase by 39.69%, which is the largest situation among all scenarios.

A statistic analysis predicting coastal change of the Yellow River abandoned delta lobe formed from 1964 to 1976 using Landsat TM imagery was conducted by calculating the coastal erosion/accumulation rates obtained from four different classic profiles and plotting the change curves of coastline with time. The studies showed that the regularity of the evolution of the coastline was very obvious after the delta lobe was abandoned. The coastal evolution can be divided into three different phases: erosion phase, transition phase and cyclical change phase. At present, the coast has evolved to the cyclical change phase. The natural coastline change cycle is 4 years between the dam and is 5 years to the west of the dam. In the cyclical change phase, the quasi-equilibrium line of the coast was located near the coastline of 1996, the current coast may recede 1.79 km to reach the natural equilibrium coastline. Therefore, some measures must be taken to protect the dam or the dam will be destroyed by the force of nature. The curves also revealed the magnitude of erosion/accumulation rates would decrease gradually with time. The results of the study offer guidance for coast protection, and proves that the evolution of silty coast actually was a cyclical change process too.

By using GIS and remote sensing techniques, the paper discusses how human activities have changed along the Yellow River in Henan province, China and how these altered activities have influenced the wetland landscape pattern change from 1987 to 2002. Results show that the total area of the wetland reduces dramatically compared to 1987, the total area of wetland reduces by 19.18%, the number of the patches in 2002 increases by 21.17%, the density increases by 50%, and the total perimeter increases by 1,290,491 m. Disturbed by human activities, landscape diversity index decreases from 1.1740 in 1987 to 0.9803 in 2002. During the last 20 years, the total area of the rice wetland increases, while the others decrease. Among those, the area of the bulrush wetland decreases most. In 1987, it takes 0.5% of the total area, but in 2002, it only takes 0.11%. The interpenetration of human influences on the wetland natural system has been long and close. The impacts of human activities on the spatial pattern of the wetland landscape along the Yellow River in Henan from 1987 to 2002 are great.

The distribution of soil organic matter (SOM) and nitrogen on Gongga Mountain was studied in this paper. The results showed that the content of SOM and nitrogen (N) of A horizon had an ascending trend with the increase of the elevation. The vegetation types distributed higher than the mixed broad-leaved and coniferous forest have the irregular trends. In the transitional zone vegetation such as mixed trees and treeline, the content of SOM and N is higher than other vegetation types. The distribution of SOM and N of A horizon is dependent on the synthetic effect of climate and vegetation types. The vertical distribution of SOM and N in soil profiles has the similar trends for all kinds of vegetation types, i.e., the content of A horizon is higher than that of the B and C horizons, which is the same to the distribution of dead animal and plant in soil. The soil C:N is between 7 and 25, which is relatively low comparing to the appropriate C:N of 25-30. The ratio of soil carbon to nitrogen (C:N) increases with the increase of the elevation, but its vertical distribution in soil horizons varies with different vegetation types. The N exists in SOM mainly in the form of organic nitrogen, and the soil C:N correlates significantly with SOM.

With the long-term data of the geodetic sea level measurements undertaken in the Dongting Basin and the recent sediment data of Dongting Lake, we analyze the tectonic subsidence rate of the Dongting Basin and the sedimentary rate of Dongting Lake. From the point of view of geomorphology and hydrogeology, we distinguish the two different spatial concepts between "the basin of Dongting Lake" and "the Dongting Basin". Then, we discuss the influences of the tectonic subsidence and the siltation on the levees and the space of storing flood. The better quality of levees is required due to the tectonic subsidence and the siltation, and the difficulties of preventing flood disasters are increasing. The space of storing flood is not affected by the tectonic subsidence, but by the siltation. At present, the sedimentary rate of Dongting Lake is higher than the tectonic subsidence rate of the Dongting Basin. The tectonic subsidence capacity of the Dongting Basin counteracts a part of sedimentary capacity, and the shrinking tendency of Dongting Lake is restrained to a certain extent, but the tectonic subsidence is harmful to the situation of preventing flood disasters in the Dongting Lake area.

Sources of uncertainty or error that arise in attempting to scale up the results of laboratory-scale sediment transport studies for predictive modeling of geomorphic systems include: (i) model imperfection, (ii) omission of important processes, (iii) lack of knowledge of initial conditions, (iv) sensitivity to initial conditions, (v) unresolved heterogeneity, (vi) occurrence of external forcing, and (vii) inapplicability of the factor of safety concept. Sources of uncertainty that are unimportant or that can be controlled at small scales and over short time scales become important in large-scale applications and over long time scales. Control and repeatability, hallmarks of laboratory-scale experiments, are usually lacking at the large scales characteristic of geomorphology. Heterogeneity is an important concomitant of size, and tends to make large systems unique. Uniqueness implies that prediction cannot be based upon first-principles quantitative modeling alone, but must be a function of system history as well. Periodic data collection, feedback, and model updating are essential where site-specific prediction is required.

By means of SEDEX, ASPILA and XRF, depth-dependent changes of different phosphorus forms in sediment cores from specific areas of the offshore Changjiang Estuary (Yangtze Estuary) in 1998 were analyzed. Results show that contents of total phosphorus (TP), organic-phosphorus (OP) and iron-phosphorus (Fe-P) decreased down-core, while those of absorbed-phosphorus (Ad-P) and calcium-phosphorus (Ca-P) increased. The distribution tendency of detritus-phosphorus (De-P) is not obvious. Results also show that TP, Fe-P and OP contents at Meso station of the Changjiang Estuary and Hangzhou Bay are higher than that of the other stations. This suggests that the pollutants carried by the Changjiang and the Qiantang rivers from inland have affected the natural environment in offshore area. TP, Fe-P and OP contents of each station become higher from bottom to top, indicating the amount of the terrestrial pollutants carried by the two rivers has been enhanced since the last 30-50 years. Ad-P, Ca-P, Fe-P and OP are all active phosphorus in sediments, and their re-cycling in sediment is closely related to each other.

With the continuous development of man’s ability to reshape nature, human activities have become the third geomorphologic agent in the modern geomorphological process. Man-made landform is a landform unit characterized by human activities and is a result of synergizing human and nature geomorphologic agents under the physical geographical background. This article provides an overview on the major progresses in research on anthropogenic geomorphology from aspects like the origin of anthropogenic geomorphology, man-made landform agents and classification, man-made landform evolution and its influencing mechanism, map presentation of man-made landform, and environmental impact of man-made landforms. In addition, in the article, the future development of anthropogenic geomorphology is forecasted. It is pointed out that future studies on anthropogenic geomorphology should pay more attention to the following directions: construction of discipline system of anthropogenic geomorphology, material composition and morphological features of man-made landforms, spatial expansion process and development laws of man-made landforms, regional disparity and accumulative environmental effects of man-made landforms, and environmental management on man-made landforms and comparative analyses of relevant international management policies.

The frost-free period (FFP), first frost date (FFD) and last frost date (LFD) have been regard as the important climate variables for agricultural production. Understanding the spatio-temporal variations of the FFP, FFD and LFD is beneficial to reduce the harmful impacts of climate change on agricultural production and enhance the agricultural adaptation. This study examined daily minimum temperatures for 823 national-level meteorological stations, calculated the values of FFD, LFD and FFP for station-specific and region-specific from 1951 to 2012, estimated the gradients of linear regression for station-specific moving averages of FFD, LFD and FFP, and assessed station-specific time series of FFP and detected the abrupt change. The results as follows: at both the station level and the regional level, the FFP across China decreases with the increase of latitude from south to north, and with the increase of altitude from east to west generally. At the station level, the inter-annual fluctuations of FFD, LFD and FFP in south and west agricultural regions are greater than those in north and east. At the regional level, excluding the QT region, temporal changes of FFP are relatively small in both the low-latitude and the high-latitude regions, but for the mid-latitude regions. According to the linear trend gradients of the moving average values of station-specific FFD, LFD and FFP, FFD was delayed, LFD advanced, and FFP extended gradually over the 80% of China. Furthermore, the change magnitudes for FFD, LFD and FFP in the north and east agricultural regions are higher than that in the southern and western. Among the 659 station-specific time series of FFP examined by the Mann-Kendall test, 341 stations, located mainly in the north region, have one identifiable and significant abrupt change. And at the 341 stations with identified abrupt changes, most (57%) abrupt changes occurred during 1991-2012, followed by the periods of 1981-1990 (28%), 1971-1980 (12%), and 1951-1970 (3%). The spatio-temporal variations of FFD, LFD and FFP would provide important guidance to agricultural practices.

Sea Level Pressure (SLP) data for the period 1950-2012 at 61 stations located in or around the Balkan Peninsula was used. The main concept is that intra-annual course of SLP represents the best different air masses that are situated over the Balkan Peninsula during the year. The method for differentiation of climatic zones is cluster analysis. A hierarchical clustering technique-average linkage between groups with Pearson correlation for measurement of intervals was employed in the research. The climate of the Balkan Peninsula is transitional between oceanic and continental and also between subtropical and temperate climates. Several major changes in atmospheric circulation over the Balkan Peninsula have happened over the period 1950-2012. There is a serious increase of the influence of the Azores High in the period January-March, which leads to an increase of SLP and enhances oceanic influence. There is an increase of the influence of the north-west extension of the monsoonal low in the period June-September. This leads to more continental climate, but also to more tropical air masses over the Balkan Peninsula. Accordingly, the extent of subtropical climate widens in northern direction. There is an increase of the influence of the Siberian High in the period October-December. This influence covers central and eastern part of the peninsula in October and November, and it reaches western parts in December. Thus, the climate becomes more continental.

Spatio-temporal patterns of flowering in forest ecosystems are hard to quantify and monitor. The objectives of this study were to investigate spatio-temporal patterns (e.g. soils, simple slope classes, slope aspect, and flow accumulation) of flowering around Lake Issaqueena, South Carolina (SC, USA) using plant-flowering database collected with GPS- enabled camera (stored in Picasa 3 web albums and project website) on a monthly basis in 2012 and LiDAR-based topography. Pacolet fine sandy loam had the most flowering plants, followed by Madison sandy loam, both dominant soil types around the lake. Most flowering plants were on moderately steep (17%-30%) and gently sloping (4%-8%) slopes. Most flowering plants were on west (247.5°-292.5°), southwest (202.5°-247.5°), and northwest (292.5°-337.5°) aspects. Most flowering plants were associated with minimum and maximum flows within the landscape. Chi-square tests indicated differences in the distributions of the proportions of flowering plants were significant by soil type, slope, aspect, and flow accumulation for each month (February-November), for all months (overall), and across months. The Chi-square test on area-normalized data indicated significant differences for all months and individual differences by each month with some months not statistically significant. Cluster analysis on flowering counts for nine plant families with the most flowering counts indicated no unique separation by cluster, but implied that the majority of these families were flowering on strongly sloping (9%-16%) slopes, on southwest (202.5°-247.5°) aspects, and low flow accumulation (0-200). Presented methodology can serve as a template for future efforts to quantify spatio-temporal patterns of flowering and other phenological events.

This paper aims to compare the geochemical characteristics of loess-paleosol sequences in the upper reaches of the Hanjiang and Weihe river valleys, which are located in the semi-humid temperate zone and humid subtropical zone, respectively. The Mituosi (MTS) profile in the upper reaches of the Hanjiang River valley and the Yaohecun (YHC) profile in the Weihe River valley were selected for this comparative research. The stratigraphic characteristics, composition, chemical weathering intensity, leaching rates of Ca and Na, mobility of major elements, and transport features of Na and Fe were analyzed with respect to depth and compared between the two profiles. This study reached the following conclusions. (1) The composition of the loess-paleosol sequences in two regions are quite similar to the average composition of the upper continental crust (UCC), indicating that the loess in the two regions came from multiple sources and was mixed well. Therefore, the loess in the two regions is considered aeolian loess. (2) Compared with the loess-paleosol sequence in the Weihe River valley, the loess-paleosol sequence in the upper reaches of the Hanjiang River valley features a darker color; a higher chemical index of alteration (CIA) value; higher leaching rates of Na and Ca; higher migration ratio (relative to K) of Al, Si, Mg, and Na; and lower migration ratio of Fe and Ca. This evidence indicates that the loess-paleosol sequence in the humid subtropical environment experienced stronger chemical weathering intensity than the loess-paleosol sequence in the semi-humid temperate zone. (3) Both the YHC profile and MTS profile record a period of climate deterioration at 6000-5000 a BP. The period punctuated the mid-Holocene Climatic Optimum (8500-3100 a BP) in the study area.

Using the Integrated Biosphere Simulator, a dynamic vegetation model, this study initially simulated the net primary productivity (NPP) dynamics of China’s potential vegetation in the past 55 years (1961-2015) and in the future 35 years (2016-2050). Then, taking the NPP of the potential vegetation in average climate conditions during 1986-2005 as the basis for evaluation, this study examined whether the potential vegetation adapts to climate change or not. Meanwhile, the degree of inadaptability was evaluated. Finally, the NPP vulnerability of the potential vegetation was evaluated by synthesizing the frequency and degrees of inadaptability to climate change. In the past 55 years, the NPP of desert ecosystems in the south of the Tianshan Mountains and grassland ecosystems in the north of China and in western Tibetan Plateau was prone to the effect of climate change. The NPP of most forest ecosystems was not prone to the influence of climate change. The low NPP vulnerability to climate change of the evergreen broad-leaved and coniferous forests was observed. Furthermore, the NPP of the desert ecosystems in the north of the Tianshan Mountains and grassland ecosystems in the central and eastern Tibetan Plateau also had low vulnerability to climate change. In the next 35 years, the NPP vulnerability to climate change would reduce the forest-steppe in the Songliao Plain, the deciduous broad-leaved forests in the warm temperate zone, and the alpine steppe in the central and western Tibetan Plateau. The NPP vulnerability would significantly increase of the temperate desert in the Junggar Basin and the alpine desert in the Kunlun Mountains. The NPP vulnerability of the subtropical evergreen broad-leaved forests would also increase. The area of the regions with increased vulnerability would account for 27.5% of China.

Climate change is one of the most important factors that affect vegetation distribution in North China. Among all climatic factors, drought is considered to have the most significant effect on the environment. Based on previous studies, the climate drought index can be used to assess the evolutionary trend of the ecological environment under various arid climatic conditions. It is necessary for us to further explore the relationship between vegetation coverage (index) and climate drought conditions. Therefore, in this study, based on MODIS-NDVI products and meteorological observation data, the Palmer Drought Severity Index (PDSI) and vegetation coverage in North China were first calculated. Then, the interannual variations of PDSI and vegetation coverage during 2001-2013 were analyzed using a Theil-Sen slope estimator. Finally, an ecoregion perspective of the correlation between them was discussed. The experimental results demonstrated that the PDSI index and vegetation coverage value varied over different ecoregions. During the period 2001-2013, vegetation coverage increased in the southern and northern mountains of North China, while it showed a decreasing trend in the Beijing-Tianjin-Tangshan City Circle area and suburban agricultural zone located in Hebei Province and Henan Province). Over 13 years, the climate of the northeastern part of North China became more humid, while in the southern part of North China, it tended to be dry. According to the correlation analysis results, 73.37% of North China showed a positive correlation between the vegetation coverage and climate drought index. A negative correlation was observed mainly in urban and suburban areas of Beijing, Tianjin, Hebei Province, and Henan Province. In most parts of North China, drought conditions in summer and autumn had a strong influence on vegetation coverage.

The Three-River Headwater Region (TRHR), known as the “Water Tower of China”, is an important ecological shelter for national security interests and regional sustainable development activities for many downstream regions in China and a number of Southeast Asian countries. The TRHR is a high-elevation, cold environment with a unique, but typical alpine vegetation system. Net primary productivity (NPP) is a key vegetation parameter and ecological indicator that can reflect both natural environmental changes and carbon budget levels. Given the unique geographical environment and strategic location of the TRHR, many scholars have estimated NPP of the TRHR by using different methods; however, these estimates vary greatly for a number of reasons. To date, there is no paper that has reviewed and assessed NPP estimation studies conducted in the TRHR. Therefore, in this paper, we (1) summarized the related methods and results of NPP estimation in the TRHR in a systematic review of previous research; (2) discussed the suitability of existing methods for estimating NPP in the TRHR and highlighted the most significant challenges; and (3) assessed the estimated NPP results. Finally, developmental directions of NPP estimation in the TRHR were prospected.

The first-stage of an ecological conservation and restoration project in the Three-River Source Region (TRSR), China, has been in progress for eight years. However, because the ecological effects of this project remain unknown, decision making for future project implementation is hindered. Thus, in this study, we developed an index system to evaluate the effects of the ecological restoration project, by integrating field observations, remote sensing, and process-based models. Effects were assessed using trend analyses of ecosystem structures and services. Results showed positive trends in the TRSR since the beginning of the project, but not yet a return to the optima of the 1970s. Specifically, while continued degradation in grassland has been initially contained, results are still far from the desired objective, ‘grassland coverage increasing by an average of 20%-40%’. In contrast, wetlands and water bodies have generally been restored, while the water conservation and water supply capacity of watersheds have increased. Indeed, the volume of water conservation achieved in the project meets the objective of a 1.32 billion m³ increase. The effects of ecological restoration inside project regions was more significant than outside, and, in addition to climate change projects, we concluded that the implementation of ecological conservation and restoration projects has substantially contributed to vegetation restoration. Nevertheless, the degradation of grasslands has not been fundamentally reversed, and to date the project has not prevented increasing soil erosion. In sum, the effects and challenges of this first-stage project highlight the necessity of continuous and long-term ecosystem conservation efforts in this region.

Global and regional environmental changes such as land use and climate change have significantly integrated and interactive effects on forest. These integrated effects will undoubtedly alter the distribution, function and succession processes of forest ecosystems. In order to adapt to these changes, it is necessary to understand their individual and integrated effects. In this study, we proposed a framework by using coupling models to gain a better understanding of the complex ecological processes. We combined an agent-based model for land use and land cover change (ABM/LUCC), an ecosystem process model (PnET-II), and a forest dynamic landscape model (LANDIS-II) to simulate the change of forest aboveground biomass (AGB) which was driven by land use and climate change factors for the period of 2010-2050 in Taihe County of southern China, where subtropical coniferous plantations dominate. We conducted a series of land use and climate change scenarios to compare the differences in forest AGB. The results show that: (1) land use, including town expansion, deforestation and forest conversion and climate change are likely to influence forest AGB in the near future in Taihe County. (2) Though climate change will make a good contribution to an increase in forest AGB, land use change can result in a rapid decrease in the forest AGB and play a vital role in the integrated simulation. The forest AGB under the integrated scenario decreased by 53.7% (RCP2.6 + land use), 57.2% (RCP4.5 + land use), and 56.9% (RCP8.5 + land use) by 2050, which is in comparison to the results under separate RCPs without land use disturbance. (3) The framework can offer a coupled method to better understand the complex and interactive ecological processes, which may provide some supports for adapting to land use and climate change, improving and optimizing plantation structure and function, and developing measures for sustainable forest management.

This study investigated oasis evolution and the changes of peripheral desert in the Sangong River Basin since the 1950s by rebuilding seven land cover maps derived from black-and-white aerial photographs (1958, 1968, and 1978), a color-infrared aerial photograph (1987), Landsat Thematic Mapper (TM) imagery (1998), Satellite Pour l’Observation de la Terre (SPOT) imagery (2004), and Landsat Operational Land Imager (OLI) imagery (2014). The results showed that: (1) Since 1950, the oasis consecutively expanded more than four times from an alluvial fan to an alluvial plain, causing the shrinkage of desert landscapes that were dominated by a Haloxylon ammodendron Bunge community (HBC) and a Tamarix chinensis Lour community (TLC). Furthermore, the primary (1958-1968) and final (2004- 2014) stages were the most important periods, during which agricultural land experienced the most rapid expansion during the period 1958-1968, and the built-up area showed the most rapid expansion after the 2000s. (2) Two basic management modes, a “local mode” formed by the local governments and a “farm management mode” developed by Xinjiang Production and Construction Corps, together promoted oasis evolution under various land-use and land- cover (LULC) stages. (3) The evolution of the modern oasis during the 1950s-2004 showed the general features of an arid oasis, while during the period of 2004-2014 it was characterized by a large-scale inter-basin water diversion or the import of new water sources. (4) The oasis expanded at the expense of desert vegetation, resulting in distinct variation in the structure of the desert plant community, which will make it more difficult to protect the desert ecosystem.

In this study, we developed a theoretical framework to analyze the provincial differences in eco-compensation and selected appropriate measurement methods to investigate these differences in the operation of the eco-compensation framework. Via the use of the coefficient of variation, Atkinson index, and Gini coefficient, we investigated the overall differences in Chinese provincial eco-compensation time series data from 2004 to 2014 and studied the driving mechanism underlying these differences. The results showed that: (1) The provincial eco-compensation standard has geographical features. For example, the provinces crossed by the “HU Huanyong Line”, or located to its northwestern side, have obtained extensive eco-compensation. (2) There was a trend for differences in eco-compensation to increase over time, but with some fluctuations in 2006, 2009, and 2014 as shown by the coefficient of variation, in 2005, 2007, 2011, 2013, and 2014 as shown by the Gini coefficient, and in 2007, 2008, 2011, and 2012 as shown by the Atkinson index. (3) Time series curves indicated that while the signals from the three metrics (coefficient of variation, Atkinson index, and Gini coefficient) differ in a short-term analysis, they show the same tendency in the longer term. The results indicate that it is necessary to evaluate the differences in eco-compensation at the provincial level over a long period of time. (4) Via the calculation of the virtual Gini coefficient, we found that among the factors that influence provincial differences in eco-compensation, the economic value of eco-resources played the decisive role, explaining more than 73% of the difference. The cost of environmental pollution abatement was the second most important factor, accounting for more than 19% of the difference. The input to environmental pollution abatement had the least influence, accounting for less than 8% of the difference. The results agreed with those obtained from other studies, and could be used as a reference by policy makers.

The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican Mangrove Monitoring System (SMMM) of the National Commission for the Knowledge and Use of Biodiversity (CONABIO) for the years 1970/81, 2005, 2010, and 2015. Our results showed overall dominance of erosion over accretion processes, beaches being the most affected coastal land cover. Emphasis was placed on identification and description of coastline sites in which land was either continuously lost (erosion) or gained (accretion) during the studied time periods. These sites were defined as continuous unidirectional dynamic sites and were compared with previous knowledge about the geodynamics of Mexican coasts. Continuous unidirectional dynamic sites were distributed throughout the study area and within all land cover types, but predominantly corresponded to areas covered by mangroves in the states of Campeche and Nayarit. Finally, we found an intensification of coastal erosion-accretion processes over time; coastline change rates having duplicated between the earliest (1970/81-2005) and the two more recent (2005-2010, and 2010-2015) analysed time periods, with erosion rates for each corresponding period of -3 m/yr, -7.5 m/yr, and -7.3 m/yr, and accretion rates of 2.8 m/yr, 7.3 m/yr, and 6.9 m/yr, respectively.

Wind-driven soil erosion results in land degradation, desertification, atmospheric dust, and sandstorms. The Hunshandake Sandy Land, an important part of the Two Barriers and Three Belts project, plays important roles in preventing desert and sandy land expansion and in maintaining local sustainability. Hence, assessing soil erosion and soil accumulation moduli and analyzing the dynamic changes are valuable. In this paper, Zhenglan Banner, located on the southern margin of the Hunshandake Sandy Land, was selected as the study area. The soil erosion and accumulation moduli were estimated using the ¹³⁷Cs and ²¹⁰Pb_ex composite tracing technique, and the dynamics of soil erosion and soil accumulation were analyzed during two periods. The results are as follows: (1) the regional ¹³⁷Cs reference inventory was 2123.5±163.94 Bq/m ², and the regional ²¹⁰Pb_ex reference inventory was 8112±1787.62 Bq/m ². (2) Based on the ¹³⁷Cs isotope tracing analysis, the erosion moduli ranged from -483.99 to 740.31 t·km ^-2·a ^-1. Based on the ²¹⁰Pb_ex isotope tracing analysis, the erosion moduli ranged from -441.53 to 797.98 t·km ^-2·a ^-1. (3) Compared with the earliest 50 years, the subsequent 50 years exhibited lower soil erosion moduli and accumulation moduli. Therefore, the activities of local sand dunes weakened, and the quality of the local ecological environment improved. The multi-isotope composite tracing technique combining the tracers ¹³⁷Cs and ²¹⁰Pb_ex has potential for similar soil erosion studies in arid or semiarid regions around the world.

Geomorphic evolution often presents a spatial pattern of a “young to old” distribution under certain natural environmental conditions, whereby sampling the geomorphic types and characteristics in spatial sequence can provide evidence for the individual landform evolution and change. This so-called space-for-time substitution has been a methodology in geomorphologic research. This paper firstly introduced the basic concepts and background of the space-for-time substitution, then a full review has been conducted of recent research progress in geomorphic evolution based on the space-for-time substitution, such as fluvial landform, structural landform, estuarine landform and coastal landform. Finally, the basic principle of space-for-time substitution in geomorphology is developed. This review is intended to introduce the achievements of geomorphic evolution research using space-for-time substitution method and to point out the critical research needs to better understand and predict the geomorphic evolution in the future.

Urban agglomerations are formed when a country is in the advanced stages of industrialization and urbanization. They are highly integrated groups of cities that form and develop through a natural, gradual process as the relationship between them changes from one of competition to assimilation following law of natural development. China is currently in a new stage of transitional development characterized by its New-Type Urbanization Plan. It has entered a new era in which it is a global leader in urban agglomeration development, and China’s research and development models are being imitated and adopted by countries around the world. This paper adopts a theoretical approach to propose the basic law governing the formation, development and expansion of urban agglomerations. This includes the stage-based formation and development law, multi-scale intensive-use transmission law, crystal-structure spatial composition law, egg-shaped expansion evolution law, “saplings-to-forest” natural growth law, and sustainable development incremental increase law. Guided by these law, China has created a hierarchical organizational configuration for optimizing the spatial structure of its urban agglomerations. It has also formulated urban agglomeration development plans and proposed research-based measures to resolve problems specific to urban agglomerations and to promote their sustainable development. The law governing the formation, development and expansion of urban agglomerations play an important role in guiding their development in China and will play a greater role in the future.

The cultivation of mountainous land results in water loss and soil erosion. With rapid urbanization and industrialization in China, labor emigration relieves the cultivation of mountainous areas in regions with high poverty and leads to a significant land use transition. This research built an analysis framework for “land use transition - driving mechanism - effects - responses” for mountainous areas of China undergoing land use transition and then proposed the direction of mountainous land consolidation. The results showed that the turning point of land use morphology was the core of rural land use transition in mountainous areas. The expansion of cropland and the contraction of forestland have transitioned to the abandonment of cropland and the expansion of forestland; this transition was the main characteristic of the dominant land use change. Land marginalization and land ecological functional recovery were the main characteristics of the recessive land use transition in mountainous areas. Socioeconomic factors were the primary driving forces during land use transition in mountainous areas, with labor emigration being the most direct force. The rising costs of farming and the challenging living conditions causing labor emigration were fundamental driving forces. Rural land use transition in mountainous areas reduced the vulnerability of the ecological function of land ecosystems. The advantages and disadvantages of the socioeconomic effects should focus on rural development of mountainous areas as well as the livelihood of farmers; this should be further supported by empirical and quantitative research. Rural land use transition of mountainous areas improves natural restoration and is related to socioeconomic development. Rural land consolidation of mountainous areas should conform to land use transition, with the goal of shifting from the increase of cultivated land to the synergies of ecological and environmental protection.

This paper reviews the process of transportation construction in China and investigates the developmental and spatial characteristics of transportation patterns. The principles of transportation evolution including stages, structures and orders are systematically analyzed. The investigation shows that China’s transportation construction mode has upgraded from investment-driven scale expansion to quality improvement driven by efficiency and promotion. The rapid growth and development of transportation networks has significantly influenced economic and social activities in time and space. The resulting spatial convergence and dominance have improved distribution, promoting development of the socioeconomic structure. Regional development that has traditionally been based on corridors has changed into a networked mode centered on cities and metropolitan areas. The transportation pattern follows evolutionary principles. China has been moving from a hierarchical structure to a cascade structure. Simultaneously, the socioeconomic pattern has changed from an axis to a hub-and-spoke structure with a preliminary ordered network. As transportation networks grow, China’s functional spatial structure and ordered network will gradually become stabilized and balanced.

Pastoralism is a viable socio-economic system-shaped by landless and agro-pastoral communities in many pastoral regions of the world. This system is mainly based on seasonal migration of pastoralists and their livestock herds between upland and lowland pastures. Traditionally pastoral activities make significant contributions to mountain livelihood subsistence, regional economies and environmental sustainability. However, the pastoralist’s lifestyle and their economies are increasingly confronted to various socio-political, economic and ecological stresses from the last few decades. Extensive literature reviewed on this subject with the aim to explore the current emerging challenges faced by pastoral communities in different pastoral regions. It has been revealed from literature that the prevalent socio-political and economic stress on pastoralism caused by modernization, insecure land tenure, integration of market economy, civil insecurities and pastoralist’s exclusion in states policies while ecological stress on pastoral activities emerged with increasing focus on nature conservation in pastoral regions and climate change induced hazards and disasters. As a consequence of these challenges, pastoral households are abandoning livestock herding-as a traditional way of life and are in continuous transition to transform their pastoral practices and institutions. Thus, the attention and consultation of key stakeholders are needed toward pastoral resource development that improve and sustain traditional pastoral practices in a socio-politically and ecologically stressed environment of the world.

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 arbi- trary trends, maximally reduce noise, and reliably perform fractal and multifractal analysis, and a presentation of scale-dependent Lyapunov exponent (SDLE), which can reliably dis- tinguish 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 os- cillation 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 deter- mine intermittent chaos from river flow data.