Most of the world's cities are concentrated in coastal areas. As a special geographical component of the coastal system, island urban spatial expansion is the outcome of interactions between city development and the physical environment. This paper takes Xiamen Island, located in Southeastern China, as an example to analyze island urban spatial expansion and its determinants by combining an analysis of the literature on urban development policies, urban overall plans, population growth and industrial development, with geographical information analysis using historical maps and remote sensing photographs. Firstly, we reviewed the history of the Xiamen City development during the last 100 years, which can be divided into four periods: the embryonic modern city and early development from 1908 to 1949; administrative boundary expansion and infrastructure development from 1950 to 1979; special economic zone construction and rapid urbanization from 1980 to 2003; and Bay City construction since 2003. The dynamic changes to the coastline, island shape, built-up area, transportation, administrative division, and major land use type conversion which occurred during approximately the past 100 years were analyzed and the characteristics of the island urban spatial expansion were concluded: early expansion from a central point, followed by expansion along a section of coastline, and expansion from the coastline inland. Secondly, we discussed the potential determinants of island urban spatial expansion including administrative division adjustment, urban master planning revision, industrial development, topographical factors, coastal area reclamation, transportation expansion, and population growth. Finally, the effects of each potential determinant on island urban spatial expansion were concluded. Island urban spatial expansion is the result of a synthesis of natural and socio-economic factors which are not independent but interacting. Built-up area expansion is the major driver of island land cover and land use changes. By this paper, we hope to provide a scientific reference contributing to the rational understanding of island and coastal sustainable urbanization in China, and the world beyond.

The dust source and transporting system are two indispensable aspects in the process of loess-palaeosol accumulation. It has been proved that the dust of the Loess Plateau mainly comes from the northwestern inland gobi and desert, transported by the East Asia monsoon systems and westerlies. However, there are little researches with respect to the dust source and deposition dynamics of the upper reaches of the Huaihe River. In the present study, we investigated and collected the YPC section with high resolution in the upper reaches of the Huaihe River. The chronological frame was reconstructed by optically stimulated luminescence (OSL) dating and correlated with the published loess time series. By comparison of the magnetic susceptibility (MS) and grain size (GS) of loess-soil profile among YPC profile, XJN profile (western Loess Plateau) and the JYC profile (southern Loess Plateau), we find similar climate change and pedogenic process between the upper reaches of the Huaihe River and the Loess Plateau, both experienced an extreme dry and the weakest pedogenesis during the last glacial, followed by a transitional episodes from the cold-dry last glacial to the warm-humid mid-Holocene and increased pedogenesis in the early Holocene, then a most humid-warm and strong pedogenesis in the mid-Holocene, and climate deterioration and decreased pedogenesis occurred during the late Holocene. But the MS of loess-soil profile sequences in the upper reaches of the Huaihe River was much lower than those in the Loess Plateau, and the GS was much coarser than those in the Loess Plateau. Comparison of GS for these three profiles revealed that there were different dust sources, which belonged to different aeolian transporting systems. The loess in the upper reaches of the Huaihe River was a wind blown deposition of near source, while the coarser dust mainly came from loose alluvial deposits of alluvial and proluvial fans of the Yellow River. The yielding and carrying dynamics of the dust in the Huaihe River is the northeast wind prevails in the winter half year.

From July 2008 to August 2008, 72 leaf samples from 22 species and 81 soil samples in the nine natural forest ecosystems were collected, from north to south along the North-South Transect of Eastern China (NSTEC). Based on these samples, we studied the geographical distribution patterns of vegetable water use efficiency (WUE) and nitrogen use efficiency (NUE), and analyzed their relationship with environmental factors. The vegetable WUE and NUE were calculated through the measurement of foliar δ¹³C and C/N of predominant species, respectively. The results showed: (1) vegetable WUE, ranging from 2.13 to 28.67 mg C g^-1 H₂O, increased linearly from south to north in the representative forest ecosystems along the NSTEC, while vegetable NUE showed an opposite trend, increasing from north to south, ranging from 12.92 to 29.60 g C g^-1 N. (2) Vegetable WUE and NUE were dominantly driven by climate and significantly affected by soil nutrient factors. Based on multiple stepwise regression analysis, mean annual temperature, soil phosphorus concentration, and soil nitrogen concentration were responding for 75.5% of the variations of WUE (p<0.001). While, mean annual precipitation and soil phosphorus concentration could explain 65.7% of the change in vegetable NUE (p<0.001). Moreover, vegetable WUE and NUE would also be seriously influenced by atmospheric nitrogen deposition in nitrogen saturated ecosystems. (3) There was a significant trade-off relationship between vegetable WUE and NUE in the typical forest ecosystems along the NSTEC (p<0.001), indicating a balanced strategy for vegetation in resource utilization in natural forest ecosystems along the NSTEC. This study suggests that global change would impact the resource use efficiency of forest ecosystems. However, vegetation could adapt to those changes by increasing the use efficiency of shortage resource while decreasing the relatively ample one. But extreme impacts, such as heavy nitrogen deposition, would break this trade-off mechanism and give a dramatic disturbance to the ecosystem biogeochemical cycle.

Specific Catchment Area (SCA) is defined as the upstream catchment area of a unit contour. As one of the key terrain parameters, it is widely used in the modeling of hydrology, soil erosion and ecological environment. However, SCA value changes significantly at different DEM resolutions, which inevitably affect terrain analysis results. SCA can be described as the ratio of Catchment Area (CA) and DEM grid length. In this paper, the scale effect of CA is firstly investigated. With Jiuyuangou Gully, a watershed about 70 km² in northern Shaanxi Province of China, as the test area, it is found that the impacts of DEM scale on CA are different in spatial distribution. CA value in upslope location becomes bigger with the decrease of the DEM resolution. When the location is close to downstream areas the impact of DEM scale on CA is gradually weakening. The scale effect of CA can be concluded as a mathematic trend of exponential decline. Then, a downscaling model of SCA is put forward by introducing the scale factor and the location factor. The scaling model can realize the conversion of SCA value from a coarse DEM resolution to a finer one at pixel level. Experiment results show that the downscaled SCA was well revised, and consistent with SCA at the target resolution with respect to the statistical indexes, histogram and spatial distribution. With the advantages of no empirical parameters, the scaling model could be considered as a simple and objective model for SCA scaling in a rugged drainage area.

The study developed a feasible method for large-area land cover mapping with combination of geographical data and phenological characteristics, taking Northeast China (NEC) as the study area. First, with the monthly average of precipitation and temperature datasets, the spatial clustering method was used to divide the NEC into four ecoclimate regions. For each ecoclimate region, geographical variables (annual mean precipitation and temperature, elevation, slope and aspect) were combined with phenological variables derived from the moderate resolution imaging spectroradiometer (MODIS) data (enhanced vegetation index (EVI) and land surface water index (LSWI)), which were taken as input variables of land cover classification. Decision Tree (DT) classifiers were then performed to produce land cover maps for each region. Finally, four resultant land cover maps were mosaicked for the entire NEC (NEC_MODIS), and the land use and land cover data of NEC (NEC_LULC) interpreted from Landsat-TM images was used to evaluate the NEC_MODIS and MODIS land cover product (MODIS_IGBP) in terms of areal and spatial agreement. The results showed that the phenological information derived from EVI and LSWI time series well discriminated land cover classes in NEC, and the overall accuracy was significantly improved by 5.29% with addition of geographical variables. Compared with NEC_LULC for seven aggregation classes, the area errors of NEC_MODIS were much smaller and more stable than that of MODIS_IGBP for most of classes, and the wall-to-wall spatial comparisons at pixel level indicated that NEC_MODIS agreed with NEC_LULC for 71.26% of the NEC, whereas only 62.16% for MODIS_IGBP. The good performance of NEC_MODIS demonstrates that the methodology developed in the study has great potential for timely and detailed land cover mapping in temperate and boreal regions.

The metropolitan resources comprehensive efficiencies (also called comprehensive technical efficiency, short for CTE, thereafter), change trends and causes are investigated using DEA and Malmquist index models, respectively, in China during the period 1990-2006. Firstly, the DEA model results show that the metropolitan CTE was just fair to middling with the characteristics of almost declining from the Eastern Coastal to Western China, and only few metropolises were DEA efficient. Secondly, the results also show that the PTE was correlated with the urban population sizes of metropolises negatively, and the SE correlated positively with the urban population sizes of metropolises in 1990, 2000 and 2006, that is, with urban population sizes getting larger the corresponding PTE was decreasing accordingly, and the SE was increasing consequently and the increasing rate was smaller with the scale increase. Thirdly, the influencing factors of metropolitan efficiency were SE and PTE in 1990 and 2000, respectively. But the PTE became the predominant influencing factor with the rapid expansions of built-up areas and population scales of metropolises in 2006. Fourthly, the Malmquist index results show that the CTE change trends were increasing weakly, the technological change trends were declining, and the TFP change trends were declining obviously during 1990-2006, in which they were all increasing during the sub-period 1990-2000, and all decreasing during the sub-period 2000-2006. Fifthly, the Malmquist index results also demonstrate that the CTE change trend was increasing weakly in the Eastern Coastal China, declining in Central China, and declining evidently in Western China. And with the urban population size increasing the increasing trends of SE became weaker and weaker. And the main causes for the CTE being not too high and its change trends and TFP change trends being increasing weakly lie mainly in the technological degeneracy and PTE change trends declining significantly during 2000-2006. Finally, the analyses show that the China's metropolitan population boom and the rapid spread of built-up area had really caused their resources efficiency losses.

In the urbanizing world, the Yangtze Delta Region (YDR) as one of the most developed regions in China, has drawn a lot of the world’s attention for the remarkable economic development achieved in the past decades. Nevertheless, the rapid economic development was certain to be accompanied by unprecedented consumption and loss of natural resources. Therefore, the analysis of the ecological situation and driving factors of environmental impact was of great significance to serve the local sustainable development decision- making and build a harmonious society. In this paper, the ecological footprint (EF) was taken as the index of the ecological environmental impact. With the help of Geographic Information System (GIS), we studied the spatiotemporal change of ecological footprint at two scales (region and city) and assessed urban sustainable development ability in YDR. Then we discussed the driving factors that affected the change of ecological footprint by the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model. The results showed that increasing trends of regional ecological footprint during 1998-2008 (1.70-2.53 ha/cap) were accompanied by decreasing ecological capacity (0.31-0.25 ha/cap) but expanding ecological deficit (1.39-2.28 ha/cap). The distribution pattern of ecological footprint and the degree of sustainable development varied distinctly from city to city in YDR. In 2008, the highest values of ecological footprint (3.85 ha/cap) and the lowest one of sustainable development index (SDI=1) in YDR were both presented in Shanghai. GDP per capita (A) was the most dominant driving force of EF and the classical EKC hypothesis did not exist between A and EF in 1998-2008. Consequently, increasing in ecological supply and reducing in human demand due to technological advances or other factors were one of the most effective ways to promote sustainable development in YDR. Moreover, importance should be attached to change our definition and measurement of prosperity and success.

The landscape pattern of Beijing wetlands has undergone a significant change as a result of natural and artificial elements. Supported by remote sensing and GIS technology, using multi-temporal TM images from 1984 to 2008 in Beijing, this paper analyzed the dynamic characteristics of wetlands landscape pattern through selected typical indices including patch area, patch average area, fractal dimension index, diversity, dominance, contagion indices and the spatial centroids of each wetlands type were calculated. Finally, the paper explored the evolution mode and driving factors of wetland landscape pattern. The results were obtained as follows: the total wetland area increased during the period 1984-1996, then decline from 1996 to 2004. The wetland area in 1994 accounted for only 47.37% of that in 2004. The proportion of artificial wetland area was larger than that of natural wetland. The proportion of reservoir wetland was 33.50% to 53.73% and had the maximum average area. pond and paddy field wetland type with the least average area accounted for 16.46% to 45.09% of the total wetland area. The driving forces of the natural river wetland were mainly natural elements; its fractal dimension index was greater than the others. The Shannon diversity index of wetland landscape increased from 1.11 in 1992 to 1.34 in 2004, indicating that the difference between proportions of each wetland type decreased and areas of each wetland type were evenly distributed. The contagion index went down from 65.59 to 58.41, indicating that the connectivity degraded. Miyun Reservoir had the largest area and its area change had a great impact on the location of the centroid. Wetland resources degenerated gradually from the joint effects of natural and artificial factors. During the period 2006-2008, the precipitation increased and the drought condition was relieved. The government implemented series of positive policies to save water resources, and the wetland area increased.

To tackle the issues concerning agriculture, farmers, and rural areas, the central government of China initiated a new strategy called ‘new countryside construction’ in 2005. For better understanding its actual effect, this paper analyzes the regional diversity of peasant household response to this new countryside construction strategy based on Kruskal-Wallis H test and sampling survey data from 586 households in the Bohai Rim Region (BRR), Yangtze River Delta Region (YDR), and Pan Pearl River Delta Region (PPR). The result indicates that regional diversity in eastern coastal China (ECC) does exist in the form of recognized priority sequence, policy requirements, expected policy effects, and behavior response. As a result of the deviation between local policy practice and households’ inherent demand, peasants fulfill their de facto demand via individual effort instead of government aid, and therefore the new countryside construction fails to carry out the expected target. It thus needs to shift the current policy priority, ensure the peasants’ mainstay role, and formulate scientific ‘Rules for new countryside construction’.

The paper applies Cobb-Douglas Production Function and Solow-Swan Model to constructing the calculation model of the contribution rate of cultivated land occupation by construction (CLOC) to China’s economic growth, and analyzes the contribution change of CLOC to China’s economic growth qualitatively and quantitatively. The main conclusions are as follows: 1) From 1989 to 2007, the contribution rates of capital, labor, and CLOC to China’s economic growth were 45.76%, 8.47%, and 6.19% respectively. 2) From the period 1989-1996 to the period 1997-2007 the contribution rate of CLOC to China’s economic growth increased from 5.40% to 5.87%. The degree of contribution was enhanced significantly. 3) The contribution of CLOC to China’s economic growth had a spatial distribution characteristic that the contribution rate of eastern coastal regions was the highest, that of central regions came second, and that of western regions the lowest. The paper indicates that in order to enhance the contribution of CLOC to China’s economic growth, some relevant economic and administrative measures might be taken, and land might be used intensively and economically to increase land economic density. The cost of promoting gross domestic product (GDP) growth might be reduced as much as possible to achieve higher GDP growth and lower land resource consumption.

A total of 1362 archaeological sites from the Paleolithic Age to the Warring States time in Hubei Province increase gradually from west to east and from high land to low land. The number of Paleolithic sites with altitude of 50-500 m account for 78% of the whole, while 71%-95% of sites from the Neolithic Age to the Warring States time mainly distribute at the areas of 0-200 m. The temporal-spatial distribution of archeological sites in this area is affected by two factors. For one thing, the human beings of every period need to choose the first or the second terrace as living sites which are near water source and are easy to withstand flood. Additionally, affecting by the regional tectonic uplift since the Holocene, down cutting of rivers can form new river valley, and lateral erosion and accumulation of river in stable time of tectonic movement can result in increasing of many new terraces. So, the human beings migrated to adapt to the change of terrace location, leading to the sites increase gradually in the lower areas of the central and eastern parts of this province. For other things, the temporal-spatial distribution of archeological sites in this area is affected by the climate condition. The Paleolithic sites mostly distribute in the Hanshui River Valley in northeastern Shiyan, southeast of Jinzhou and east of Jinmen, which is because rivers distributed in higher areas in this period. During the Chengbeixi Culture period, the sites are rare in the quondam Paleolithic sites distribution area, but increase obviously along the Yangtze River near the southwest Yichang. The spore-pollen record of Dajiuhu Basin indicates that only 23 Chengbeixi cultural sites may be related to more precipitation and flood during the Holocene wet and hot period. The Daxi Culture, Qujialing Culture and Shijiahe Culture are corresponding to middle and top of the Dajiuhu spore-pollen Zone Ⅳ, during which the climate is in order as a whole and is propitious to agricultural development. In the Qujialing Culture period, 32 of original 34 Daxi cultural sites disappeared, while 90 sites increase abruptly in the higher highlands in the north of Xiangfan-Jinmen-Xiaogan, which may respect with enlarging of water areas. The Chu Culture period is corresponding to Dajiuhu spore-pollen Zone V, which is in warm and dry Holocene phase, but it seems that the climate condition is still propitious to agricultural cultivation and the number of archeological sites increase heavily to 593. In addition, there are the least archaeological sites in the lake areas of southeast Hubei Province because of low-lying topography with altitude of 0-50 m and the severest flood.

Qinghai Lake Watershed (QLW) is a hot place of a series of ecological restoration and environmental remediation programs nowadays. However, little information is available on change of ecosystem service and economic practice in this area. As ecosystem service and natural capital are closely related with social and economic development, an index of concordance between environment and economy (I_CEE) has been proposed to compare the annual variation rate of ecosystem service value (R_ESV) with that of gross domestic product (R_GDP). Using this Index, we have assessed concordance between environment and economy (CEE) for the QLW in the period 1977-2004. The result showed that from 1977 to 2004, the ecosystem service value in the QLW descended from 128.81×10⁸ yuan to 127.32×10⁸ yuan; In contrast, the GDP increased from 0.931×10⁸ yuan to 8.856×10⁸ yuan. The values of the I_CEE were -1.14, -0.22, and -0.14 in the stages of 1977-1987, 1987-2000 and 2000-2004, respectively. The result indicated that during the first stage 1977-1987, the relationship between environment and economy in the QLW was not concordant but at a high conflict; from 1987 to 2004, there was a low conflict between environment and economy, and the CEE appeared to increase slowly. Analysis of the assessment results showed that the national policies and industrial adjustment practice play an important role in the CEE changes.

Spatial scale is a fundamental problem in Geography. Scale effect caused by fractal characteristic of coastline becomes a common focus of coastal zone managers and researchers. In this study, based on DEM and remote sensing images, multi-scale continental coastlines of China were extracted and the fractal characteristic was analyzed. The results are shown as follows. (1) The continental coastline of China fits the fractal model, and the fractal dimension is 1.195. (2) The scale effects with fractal dimensions of coastline have significant differences according to uplift and subsidence segments along the continental coastlines of China. (3) The fractal dimension of coastline has significant spatial heterogeneity according to the coastline types. The fractal dimension of sandy coastline located in Luanhe River plain is 1.109. The dimension of muddy coastline located in northern Jiangsu Plain is 1.059, while that of rocky coastline along southeastern Fujian is 1.293. (4) The length of rocky coastline is affected by scale more than that of muddy and sandy coastline. Since coastline is the conjunction of sea, land and air surface, the study of coastline scale effect is one of the scientific bases for the researches on air-sea-land interaction in multi-scales.

Due to the extremely poor soil cover, a low soil-forming rate, and inappropriate intensive land use, soil erosion is a serious problem in Guizhou Province, which is located in the centre of the karst areas of Southwest China. In order to bring soil erosion under control and restore environment, the Chinese Government has initiated a serious of ecological rehabilitation projects such as the Grain-for-Green Programme and Natural Forest Protection Program and brought about tremendous influences on land-use change and soil erosion in Guizhou Province. This paper explored the relationship between land use and soil erosion in the Maotiao River watershed, a typical agricultural area with severe soil erosion in central Guizhou Province. In this study, we analyzed the spatio-temporal dynamic change of land-use type in Maotiao River watershed from 1973 to 2007 using Landsat MSS image in 1973, Landsat TM data in 1990 and 2007. Soil erosion change characteristics from 1973 to 2007, and soil loss among different land-use types were examined by integrating the Revised Universal Soil Loss Equation (RUSLE) with a GIS environment. The results indicate that changes in land use within the watershed have significantly affected soil erosion. From 1973 to 1990, dry farmland and rocky desertified land significantly increased. In contrast, shrubby land, other forestland and grassland significantly decreased, which caused accelerated soil erosion in the study area. This trend was reversed from 1990 to 2007 with an increased area of land-use types for ecological use owing to the implementation of environmental protection programs. Soil erosion also significantly varied among land-use types. Erosion was most serious in dry farmland and the lightest in paddy field. Dry farmland with a gradient of 6°-25° was the major contributor to soil erosion, and conservation practices should be taken in these areas. The results of this study provide useful information for decision makers and planners to take sustainable land use management and soil conservation measures in the area.

Ecological land rent is the excess profit produced by resource scarcity, and is also an important indicator for measuring the social and economic effects of resource scarcity. This paper, by calculating the respective ecological land rents of all the provinces in China for the years 2002 and 2007, and with the assistance of the software programs ArcGIS and GeoDA, analyzes the spatial differentiation characteristics of ecological land rent; then, the influencing factors of ecological land rent differentiation among the provinces are examined using the methods of traditional regression and spatial correlation analysis. The following results were obtained: First, ecological land rent per unit of output in China shows stable distribution characteristics of being low in the southwestern and northeastern provinces, and high in Hebei and Henan provinces. There is also an increasing tendency in the central and western provinces, and a decreasing one in the eastern provinces. In general, the spatial distribution of ecological land rent per unit of output in China is quite scattered. Second, the total ecological land rent shows significant spatial aggregation characteristics, in particular the provinces in China possessing high total amounts of ecological land rent tend to be adjacent to one another, as do those with low total amounts, and the spatial difference characteristics of the eastern, central and western provinces are distinguished. The Bohai Rim, Yangtze River Delta and Pearl River Delta are shown to be highly clustering regions of total ecological land rent, while the western provinces have very low ecological land rent in terms of total amount. Third, population distribution, economic level and industrial structure were all important influencing factors influencing ecological land rent differentiation among provinces in China. Furthermore, population density, urbanization level, economic density, per capita consumption level and GDP per capita were all shown to be positively related to total ecological land rent, which indicates that spatial clustering exists between ecological land rent and these factors. However, there was also a negative correlation between ecological land rent and agricultural output percentage, indicating that spatial scattering exists between ecological land rent and agricultural output percentage.

The changes in cropland quantity and quality due to land use are critical concerns to national food security, particularly for China. Despite the significant ecological effects, the ecological restoration program (ERP), started from 1999, has evidently altered the spatial patterns of China’s cropland and agricultural productivity. Based on cropland dynamic data from 2000 to 2008 primarily derived from satellite images with a 30-m resolution and satellite-based net primary productivity models, we identified the impacts on agricultural productivity caused by ERP, including “Grain for Green” Program (GFGP) and “Reclaimed Cropland to Lake” (RCTL) Program. Our results indicated that the agricultural productivity lost with a rate of 132.67×10⁴ t/a due to ERP, which accounted for 44.01% of the total loss rate caused by land use changes during 2000-2005. During 2005-2008, the loss rate due to ERP decreased to 77.18×10⁴ t/a, which was equivalent to 58.17% of that in the first five years and 30.22% of the total loss rate caused by land use changes. The agricultural productivity loss from 2000-2008 caused by ERP was more attributed to GFGP (about 70%) than RCTL. Although ERP had a certain influence on cropland productivity during 2000-2008, its effect was still much less than that of urbanization; moreover, ERP was already converted from the project implementation phase to the consolidation phase.

Explicitly identifying the spatial distribution of ecological transition zones (ETZs) and simulating their response to climate scenarios is of significance in understanding the response and feedback of ecosystems to global climate change. In this study, a quantitative spatial identification method was developed to assess ETZ distribution in terms of the improved Holdridge life zone (iHLZ) model. Based on climate observations collected from 782 weather stations in China in the T0 (1981-2010) period, and the Intergovernmental Panel on Climate Change Coupled Model Intercomparison Project (IPCC CMIP5) RCP2.6, RCP4.5, and RCP8.5 climate scenario data in the T1 (2011-2040), T2 (2041-2070), and T3 (2071-2100) periods, the spatial distribution of ETZs and their response to climate scenarios in China were simulated in the four periods of T0, T1, T2, and T3. Additionally, a spatial shift of mean center model was developed to quantitatively calculate the shift direction and distance of each ETZ type during the periods from T0 to T3. The simulated results revealed 41 ETZ types in China, accounting for 18% of the whole land area. Cold temperate grassland/humid forest and warm temperate arid forest (564,238.5 km ²), cold temperate humid forest and warm temperate arid/humid forest (566,549.75 km ²), and north humid/humid forest and cold temperate humid forest (525,750.25 km ²) were the main ETZ types, accounting for 35% of the total ETZ area in China. Between 2010 and 2100, the area of cold temperate desert shrub and warm temperate desert shrub/thorn steppe ETZs were projected to increase at a rate of 4% per decade, which represented an increase of 3604.2, 10063.1, and 17,242 km ² per decade under the RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively. The cold ETZ was projected to transform to the warm humid ETZ in the future. The average shift distance of the mean center in the north wet forest and cold temperate desert shrub/thorn grassland ETZs was generally larger than that of other ETZs, with the mean center moving to the northeast and the shift distance being more than 150 km during the periods from T0 to T3. In addition, with a gradual increase of temperature and precipitation, the ETZs in northern China displayed a shifting northward trend, while the area of ETZs in southern China decreased gradually, and their mean center moved to high-altitude areas. The effects of climate change on ETZs presented an increasing trend in China, especially in the Qinghai-Tibet Plateau.

Being a key ecological security barrier and production base for grassland animal husbandry in China, the balance between grassland forage supply and livestock-carrying pressure in North China directly affects grassland degradation and restoration, thereby impacting grassland ecosystem services. This paper analyzes the spatiotemporal variation in grassland vegetation coverage, forage supply, and the balance between grassland forage supply and livestock-carrying pressure from 2000 to 2015 in North China. We then discuss the spatial pattern of grassland ecological conservation under the impacts of grassland degradation and restoration, and livestock-carrying pressure. Over the last 16 years, the total grassland area in North China decreased by about 16,000 km ², with vegetation coverage degraded by 6.7% of the grasslands but significantly restored by another 5.4% of grasslands. The provisioning of forage by natural grassland mainly increased over time, with an annual growth rate of approximately 0.3 kg/ha, but livestock-carrying pressure also increased continuously. The livestock-carrying pressure index without any supplementary feeding reached as high as 3.8. Apart from the potential livestock-carrying capacity in northeastern Inner Mongolia and the central Tibetan Plateau, most regions in North China are currently overloaded. Considering the actual supplementary feeding during the cold season, the livestock-carrying pressure index is about 3.1, with the livestock-carrying pressure mitigated in central and eastern Inner Mongolia. Assuming full supplementary feeding in the cold season, livestock-carrying pressure index will fall to 1.9, with the livestock-carrying pressure alleviated significantly in Inner Mongolia and on the Tibetan Plateau. Finally, we propose different conservation and development strategies to balance grassland ecological conservation and animal husbandry production in different regions of protected areas, pastoral areas, farming-pastoral ecotone, and farming areas, according to the grassland ecological protection patterns.

Alluviation and sedimentation of the Yellow River are important factors influencing the surface soil structure and organic carbon content in its lower reaches. Selecting Kaifeng and Zhoukou as typical cases of the Yellow River flooding area, the field survey, soil sample collection, laboratory experiment and Geographic Information System (GIS) spatial analysis methods were applied to study the spatial distribution characteristics and change mechanism of organic carbon components at different soil depths. The results revealed that the soil total organic carbon (TOC), active organic carbon (AOC) and nonactive organic carbon (NOC) contents ranged from 0.05-30.03 g/kg, 0.01-8.86 g/kg and 0.02-23.36 g/kg, respectively. The TOC, AOC and NOC contents in the surface soil layer were obviously higher than those in the lower soil layer, and the sequence of the content and change range within a single layer was TOC>NOC>AOC. Geostatistical analysis indicated that the TOC, AOC and NOC contents were commonly influenced by structural and random factors, and the influence magnitudes of these two factors were similar. The overall spatial trends of TOC, AOC and NOC remained relatively consistent from the 0-20 cm layer to the 20-100 cm layer, and the transition between high- and low-value areas was obvious, while the spatial variance was high. The AOC and NOC contents and spatial distribution better reflected TOC spatial variation and carbon accumulation areas. The distribution and depth of the sediment, agricultural land-use type, cropping system, fertilization method, tillage process and cultivation history were the main factors impacting the spatial variation in the soil organic carbon (SOC) components. Therefore, increasing the organic matter content, straw return, applying organic manure, adding exogenous particulate matter and conservation tillage are effective measures to improve the soil quality and attain sustainable agricultural development in the alluvial/sedimentary zone of the Yellow River.

In order to explore the water level variations of Caizi Lake under river-lake isolation, the monthly water level of the Chefuling station in Caizi Lake from 1989 to 2018 and the daily water level, rainfall and flow of local hydrological stations in 2018 were analyzed by using the Mann-Kendall trend test and wavelet analysis. Results showed that the difference of the average water level of Caizi Lake between the flood and dry seasons was 3.34 m, with a multi-year average water level of 10.42 m above sea level. The first and second main periods of the water level of Caizi Lake were 128 and 18 months, respectively, with 4 and 29 “up-down” cycles, respectively. From 2018, the next 3?4 years were likely to be the low water level period. The water level of Caizi Lake was significantly correlated with that of the Anqing hydrological station of the Yangtze River (r=0.824, P<0.01). In addition, the current hydrological staging of Caizi Lake was about 30 days behind than before the sluice was built. Under the dual influences of the river-lake isolation and the Yangtze-to-Huaihe Water Diversion Project (YHWD), the hydrological regime change of Caizi Lake and its eco-environmental effect needed long-term monitoring and research.

Scientifically assessing the economic impact of major public health emergencies, containing their negative effects, and enhancing the resilience of an economy are important national strategic needs. The new coronavirus disease (COVID-19) has, to date, been effectively contained in China, but the threat of imported cases and local risks still exist. The systematic identification of the virus’s path of influence and intensity is significant for economic recovery. This study is based on a refined multi-regional general equilibrium analysis model, which measures the economic and industrial impacts at different epidemic risk levels in China and simulates development trends and the degree of damage to industries and the economy under changes to supplies of production materials and product demand. The results show that, at the macroeconomic level, China’s GDP will decline about 0.4% to 0.8% compared to normal in 2020, with an average drop of about 2% in short-term consumption, an average drop in employment of about 0.7%, and an average increase in prices of about 0.9%. At the industry level, the epidemic will have the greatest short-term impact on consumer and labor- intensive industries. For example, the output value of the service industry will fall 6.3% compared to normal. Looking at the impact of the epidemic on the industrial system, the province most affected by the epidemic is Hubei, which is the only province in China in the level-1 risk category. As the disease spread outward from Hubei, there were clear differences in the main industries that were impacted in different regions. In addition, simulation results of recovery intensity of regional economies under the two epidemic response scenarios of resumption of work and production and active fiscal stimulus policies show that an increase in fiscal stimulus policies produces a 0.3% higher rate of gross regional product growth but it causes commodity prices to rise by about 1.8%. Measures to resume work and production offer a wider scope for industrial recovery.

Understanding the driving forces of regional air pollution and its mechanism has gained much attention in academic research, which can provide scientific policy-making basis for economy-environment sustainability in China. Being an important energy and industrial base, the North China Plain region has been experiencing severe air pollution. Therefore, understanding the relationship between industrialization and air quality in this region is of great importance for air quality improvement. In this study, the average annual concentrations of SO₂, NO₂ and PM₁₀ in 47 sample cities at and above the prefecture level in the North China Plain region from 2007 to 2016 were used to illustrate the spatiotemporal characteristics of air pollution within this region. Furthermore, panel data model, panel vector autoregression model, and impulse response function were used to explore the correlation and driving mechanism between energy-intensive industries and regional air quality. The results show that：first, overall air quality improved in the study area between 2007 and 2016, with a significant greater fall in concentration of SO₂ than that of NO₂ and PM₁₀; second, provincial border areas suffered from severe air pollution and showed an apparent spatial agglomeration trend of pollution; and third, the test results from different models all proved that energy-intensive industries such as the chemical, non-metallic mineral production, electric and thermal power production and supply industries, had a significant positive correlation with concentrations of air pollutants, and indicated an obvious short-term impulse response effect. It concludes that upgradation of industrial structure, especially that of energy-intensive industries, plays a very important role in the improvement of regional air quality, which is recommended to be put in top priority for authorities. Therefore, policies as increasing investments in technological innovation in energy-intensive industries, deepening cooperation in environmental governance between different provinces and cities, and strengthening supervision and entry restrictions are suggested.

Urban planning construction land standard is the technical specification for scientifically allocating various types of urban construction land, and it is the basis for drawing up and revising the overall urban planning scheme. Considering China’s current urban planning construction land standard, many problems exist, such as the gap in the land use control threshold, the lack of regional differences in the climate revision, and failing to consider the topographic factors. To resolve these problems, this study proposed a step-by-step process framework and quantitative calculation method for the establishment and revision of standards in accordance with the principle of Total-Structure control. By setting the conditions, a universal basic standard for construction land was established. Quantitative analysis was then conducted on the relationship between the basic standard and the selected key indicators, such as urban population size, sunshine spacing coefficient, the width of river valleys or inter-montane basins, and terrain slope, among others. Finally, revised standards were formed for climate conditions, topography, and geomorphologic conditions, which were matched with the basic standards. The key results are three-fold: (1) The per capita construction land standard of 95 m ²/person can be used as the total indicator of China’s urban planning basic standard, and the corresponding per capita single construction land comprises 32.50% of residential land, 7.42% of public management and public service land, 22.50% of industrial land, 17.50% of transportation facilities, 12.50% of green space, and 7.58% of other land-use types. The results of the revision of the urban population size indicate that the difference in population size has little effect on the total amount of per capita construction land. (2) The climate revision results of per capita residential land and per capita construction land in major cities reveal that the revised climate value varies greatly between north and south China. The revised climate values of the per capita area of construction land vary by latitude as follows: the value at 20°N is 93 m ²/person, the value at 30°N is 97 m ²/person, the value at 40°N is 103 m ²/person, and the value at 50°N is 115 m ²/person. The basic standard land value of 95 m ²/person is generally distributed across the Xiamen-Guilin-Kunming line. (3) The cities located in mountainous areas, hilly valleys, or inter-montane basins can reduce the allocation of community parks and comprehensive parks when the average width of an existing river valley or inter-montane basin is less than 2 km. When the average width of the valley or inter-montane basin is between 2 km to 4 km, the allocation of the comprehensive parks can be reduced. The revised results of per capita sloping construction land reveal that the terrain slope greatly affects the revised value of per capita construction land. Specifically, the revised value at 3° is 3.68% higher than the basic standard value, and the increase rates at 8°, 15°, and 25° are 11.25%, 26.49%, and 68.47%, respectively.

Desertification process as a great problem affects most of the countries in the world. This process has a high rate in arid and semiarid areas. Today, human societies are encountering the desertification phenomenon as a serious problem which causes various irreparable damages to economic and social sectors. In order to assess desertification results in production of different regional models for their application in another region the indices should be re-investigated and adjusted to local conditions. Several models have been developed for desertification evaluation. The present study, attempts to assess quantitatively the desertification process has in an area located at Sistan plain of Iran (Niatak region as a case study) by using Modified MEDALUS method. The obtained results indicated that of the whole studied region (comprising 4819.6 acres), 2651.56 acres (55%) are located in medium desertification intensity class, 1269.48 acres (26.34%) are positioned in severe desertification intensity class, and 898.54 acres (18.64%) are placed in vary severe desertification intensity class.

The runoff of some rivers in the world especially in the arid and semi-arid areas has decreased remarkably with global or regional climate change and enhanced human activities. The runoff decrease in the arid and semi-arid areas of northern China has brought severe problems in livelihoods and ecology. To reveal the variation characteristics, trends of runoff and their influencing factors have been important scientific issues for drainage basin management. The objective of this study was to analyze the variation trends of the runoff and quantitatively assess the contributions of precipitation and human activities to the runoff change in the Huangfuchuan River Basin based on the measured data in 1960-2008. Two inflection points (turning years) of 1979 and 1998 for the accumulative runoff change, and one inflection point of 1979 for the accumulative precipitation change were identified using the methods of accumulative anomaly analysis. The linear relationships between year and accumulative runoff in 1960-1979, 1980-1997 and 1998-2008 and between year and accumulative precipitation in 1960-1979 and 1980-2008 were fitted. A new method of slope change ratio of accumulative quantity (SCRAQ) was put forward and used in this study to calculate the contributions of different factors to the runoff change. Taking 1960-1979 as the base period, the contribution rate of the precipitation and human activities to the decreased runoff was 36.43% and 63.57% in 1980-1997, and 16.81% and 83.19% in 1998-2008, respectively. The results will play an important role in the drainage basin management. Moreover, the new method of SCRAQ can be applied in the quantitative evaluation of runoff change and impacts by different factors in the river basin of arid and semi-arid areas.

It is essential to establish the water resources exploitation and utilization planning, which is mainly based on recognizing and forecasting the water consumed structure rationally and scientifically. During the past 30 years (1980-2009), mean annual precipitation and total water resource of Beijing have decreased by 6.89% and 31.37% compared with those perennial values, respectively, while total water consumption during the same period reached pinnacle historically. Accordingly, it is of great significance for the harmony between socio-economic development and environmental development. Based on analyzing total water consumption, agricultural, industrial, domestic and environmental water consumption, and evolution of water consumed structure, further driving forces of evolution of total water consumption and water consumed structure are revealed systematically. Prediction and discussion are achieved for evolution of total water consumption, water consumed structure, and supply-demand situation of water resource in the near future of Beijing using Time Series Forecasting Method. The purpose of the endeavor of this paper is to provide scientific basis for the harmonious development between socio-economy and water resources, for the establishment of rational strategic planning of water resources, and for the social sustainable development of Beijing with scientific bases.

Urbanization has been the most important process that changed land cover landscape in Guangzhou since reformation, especially since 1990. It is essential for monitoring and assessing ecological consequences of urbanization to understand landscape quantitative characteristics and its changes. Based on four land-cover type maps interpreted from remote sensing TM images of 1990, 1995, 2000 and 2005, combining gradient analysis with landscape metrics, the quantified spatial pattern and its dynamics of urbanization in Guangzhou was got. Three landscape metrics were computed within different regional areas including the whole study area, two transects along two highways (one N–S and the other W–E) and radiation zones with equal distance outwards the city center were set. Buffer zones for transects N–S and W–E were outlined along highways. The following questions should be answered in this paper: What responses were implied with changing spatial grain size or extent for landscape pattern analysis? Could gradient progress of urbanization be characterized by landscape pattern analysis? Did landscape metrics reveal urban expanding gradually? Were there directional differences in land cover landscape pattern during urbanizing development? The results gave some affirmative answers. Landscape pattern exhibited obviously scale-dependent to grain size and extent. The landscape metrics with gradient analysis could quantitatively approach spatial pattern of urbanization. A precise location for urbanized area, like city center and sub-center, could be identified by multiple landscape metrics. Multiple adjunctive centers occurred as indicated by analysis of radiation zones around the city center. Directional differences of landscape pattern along the two transects (N–S and W–E) came into being. For example, fragmentation of landscape in the transect W–E was obviously higher than that in the transect N–S. All in all, some interesting and important ecological implications were revealed under landscape patterns of two transects or radiation zones, and that was the important step to link pattern with processes in urban ecological studies and the basis to improve urban environment.

The karst landforms distributed on the Qinghai-Xizang (Tibet) Plateau can be genetically classed with the Tertiary underground karst, which were gradually exhumed to the surface with the uplift of the plateau during Quaternary period. The relative deposits of the Tertiary palaeokarst processes, such as the residuum and speleothem, were discovered recently in the southern and southeastern fringe areas of the plateau, where has geological-currently been disintegrated by the headward erosion processes of the modern river systems. The major chemical components of the clay portion of the residuum consist mainly of SiO₂C, Al₂CO₃ and Fe₂O₃. The clay minerals composition of the clay portion belongs to illite-kaolinite pattern for most of the residuum samples, and kaolinite-illite pattern for a few of the samples. It can be judged from the silicic acid index and the clay minerals composition that the formation of the residuum of the Plateau was in its initial phase. However, such a lower chemical weathering index only reflected the weathering degree in the bottom or lower parts of the lateritic weathering crust. The relatively intensive chemical weathering processes of the surface layers of the lateritic weathering crust could be logically speculated. The surface feature textures of quartz grains in the residuum were formed mainly by the chemical erosion, which revealed a long-term humid-tropical environment when the residuum and the palaeokarst formed.

Land use and land cover changes have a great impact on the regional hydrological process. Based on three periods of remote sensing data from the 1960s and the long-term observed data of groundwater from the 1980s, the impacts of land use changes on the groundwater system in the middle reach of Heihe River Basin in recent three decades are analyzed by the perspective of groundwater recharge and discharge system. The results indicate that with the different intensities of land use changes, the impacts on the groundwater recharge were 2.602×10⁸ m3/a in the former 15 years (1969-1985) and 0.218×10⁸ m3/a in the latter 15 years (1986-2000), and the impacts on the groundwater discharge were 2.035×10⁸ m3/a and 4.91×10⁸ m3/a respectively. When the groundwater exploitation was in a reasonable range less than 3.0×10⁸ m3/a, the land use changes could control the changes of regional groundwater resources. Influenced by the land use changes and the large-scale exploitation in the recent decade, the groundwater resources present apparently regional differences in Zhangye region. Realizing the impact of land use changes on groundwater system and the characteristics of spatial-temporal variations of regional groundwater resources would be very important for reasonably utilizing and managing water and soil resources.

Based on the precipitation and temperature data of the 12 meteorological stations in the “Three-River Headwaters” region and the observed runoff data of Zhimenda in the headwater sub-region of the Yangtze River, Tangnaihai in the headwater sub-region of the Yellow River and Changdu in the headwater sub-region of the Lancang River during the period 1965-2004, this paper analyses the trends of precipitation, temperature, runoff depth and carries out significance tests by means of Mann-Kendall-Sneyers sequential trend test. Makkink model is applied to calculate the potential evaporation. The runoff model driven by precipitation and potential evaporation is developed and the influence on runoff by climate change is simulated under different scenarios. Results show that during the period 1965-2004 the temperature of the “Three-River Headwaters” region is increasing, the runoff of the three hydrological stations is decreasing and both of them had abrupt changes in 1994, while no significant trend changes happen to the precipitation. The runoff model suggests that the precipitation has a positive effect on the runoff depth, while the potential evaporation plays a negative role. The influence of the potential evaporation on the runoff depth of the Lancang River is found to be the significant in the three rivers; and that of the Yellow River is the least. The result of the scenarios analysis indicates that although the precipitation and the potential evaporation have positive and negative effects on runoff relatively, fluctuated characteristics of individual effect on the runoff depth in specific situations are represented.