An integrated indicator on regional ecological civilization construction in China

China has come up with ecological civilization as one of major goals to improve its ecological sustainability during development in future. Under this broad framework, social, economic and natural ecosystems are expected to develop in harmony. However, there is lack of evaluation mechanism for this newly proposed strategy. Therefore, in this article, ecosystem services, Ecological Footprint and gross domestic product per capita were selected in order to reflect the resource endowment, human occupation on natural capital, and the economic growth. Thus, an integrated indicator was constructed from the three indexes based on the linear correlation among them, and we provided comprehensive evaluation on ecological civilization construction in the provinces and municipalities in China in 2010. When it comes to the indicator of ecological civilization construction, Hainan province has the greatest value which is 0.5091 and Beijing municipality has the smallest value which is 0.0377. At last, the article analyzed the ecological pressure and efficiency in ecological civilization construction in China. The results contribute to scientific and objective evaluation of regional ecological civilization construction in order to properly make decisions and take actions

Wavelet-Based Hydrological Time Series Forecasting

These days wavelet analysis is becoming popular for hydrological time series simulation and forecasting. There are, however, a set of key issues influencing the wavelet-aided data preprocessing and modeling practice that need further discussion. This article discusses four key issues related to wavelet analysis: discrepant use of continuous and discrete wavelet methods, choice of mother wavelet, choice of temporal scale, and uncertainty evaluation in wavelet-aided forecasting. The article concludes with a personal reflection on solving the four issues for improving and supplementing relevant wavelet studies, especially wavelet-based artificial intelligence modeling. (C) 2016 American Society of Civil Engineers

An improvement of the Ts-NDVI space drought monitoring method and its applications in the Mongolian plateau with MODIS, 2000-2012

Surface soil moisture is a key variable to describe water and energy exchanges at the surface/atm interface and measure drought and aridification. The Ts-NDVI space is an effective method to monitor regional surface soil moisture status. Due to the disturbance of multiple factors, the established dry or wet boundary with monotemporal remote sensing data is unstable. This paper developed a Ts-NDVI triangle space with MODIS NDVI dataset to monitor soil moisture in the Mongolian Plateau in 2000-2012. Based on the temperature vegetation dryness index (TVDI), the spatiotemporal variations of drought were studied. The results indicated that (1) the general Ts-NDVI space method is an effective way to monitor regional soil moisture. However, if the single time space shows perfect structure, there would be no differences between the inverted results of the single time space and the general space. (2) The TVDI calculated in the paper is expected to show the water deficit for the region from low (bare soil) to high (full vegetation cover) NDVI values, and it is found to be in close negative agreement with precipitation and soil moisture; changes in the TVDI are dependent on the water status in the study area. (3) In the Mongolian Plateau, TVDI presented a zonal distribution with changes in Land Use/Land Cover types, vegetation cover, and latitude. Drought was serious in bare land, construction land, and grassland. Drought was widely spread throughout the Mongolian Plateau, and there was aridification in the study period. Vegetation degradation, overgrazing, and climate warming could be considered as the main reasons

Spatial Downscaling of MODIS Land Surface Temperatures Using Geographically Weighted Regression: Case Study in Northern China

Land surface temperatures (LSTs) at high spatial resolution are crucial for hydrological, meteorological, and ecological studies. Downscaling LSTs from coarse resolution to finer resolution is an alternative way to obtain LSTs at high spatial resolution. In this paper, we proposed a new algorithm based on geographically weighted regression (GWR) to downscale Moderate Resolution Imaging Spectroradiometer LST data from 990 to 90 m. Unlike previous LST downscaling algorithms, this algorithm built the nonstationary relationship between LST and other environmental factors (including the normalized difference vegetation index and a digital elevation model) using geographically varying regression coefficients. The uncertainty in this algorithm was evaluated with a sensitivity analysis. The results show that the total uncertainty in this algorithm is less than 2 K. The performance of the GWR-based algorithm was assessed using concurrent ASTER LST data as a reference LST data set. Moreover, this algorithm was compared against the TsHARP algorithm, which was widely used for LST downscaling. The results indicate that the GWR-based algorithm outperforms the TsHARP algorithm in terms of statistical results. The root mean square error (mean absolute error) value decreases from 3.6 K (2.7 K) for the TsHARP algorithm to 3.1 K (2.3 K) for the GWR-based algorithm

Major migration corridors of mesoscale ocean eddies in the South China Sea from 1992 to 2012

It has become a routine to automatically identify mesoscale ocean eddies in the world's oceans and reconstruct their trajectories from remote sensing data. However, the major migration pathways along which eddies mainly propagate are not clear, particularly in the South China Sea (SCS). This study utilized a trajectory partition-and group method to quantitatively measure and group trajectories of eddies in the SCS from 1992 to 2012 to extract their major migration corridors. The trajectories were first simplified into segments using the minimum description length (MDL) principle, their origin and destination (OD) points, and their trajectory partitions (TP) between two consecutive tracking times, respectively. The MDL-, OD-, and TP-based segments were then respectively grouped into clusters using the density-based spatial clustering of applications with noise (DBSCAN) algorithm. Representative trajectories, i.e., the major migration corridors, were then extracted from different clusters. Results show that the MDL-based corridors are the most tenable in revealing the migration corridors of eddies in the SCS. The major MDL-based migration corridors of both anticyclonic and cyclonic eddy in the SCS mainly extend westward and show a meridional propagation toward the equator. The different major migration corridors in the northern, central, and southern SCS could be attributed to the various influences of seabed topography and/or background currents in these regions. (C) 2016 Elsevier B.V. All rights reserved

Effects of land use change on the spatiotemporal variability of soil organic carbon in an urban-rural ecotone of Beijing, China

Understanding the effects of land use changes on the spatiotemporal variation of soil organic carbon (SOC) can provide guidance for low carbon and sustainable agriculture. In this paper, based on the large-scale datasets of soil surveys in 1982 and 2009 for Pinggu District an urban-rural ecotone of Beijing, China, the effects of land use and land use changes on both temporal variation and spatial variation of SOC were analyzed. Results showed that from 1982 to 2009 in Pinggu District, the following land use change mainly occurred: Grain cropland converted to orchard or vegetable land, and grassland converted to forestland. The SOC content decreased in region where the land use type changed to grain cropland (e.g., vegetable land to grain cropland decreased by 0.7 g kg-1; orchard to grain cropland decreased by 0.2 g kg(-1)). In contrast, the SOC content increased in region where the land use type changed to either orchard (excluding forestland) or forestland (e.g., grain cropland to orchard and forestland increased by 2.7 and 2.4 g kg(-1), respectively; grassland to orchard and forestland increased by 4.8 and 4.9 g kg(-1), respectively). The organic carbon accumulation capacity per unit mass of the soil increased in the following order: grain cropland soil<vegetable land/grassland soil<orchard soil<forestland soil. Therefore, to both secure supply of agricultural products and develop low carbon agriculture in a modern city, orchard has proven to be a good choice for land using

Holocene climate controls on water isotopic variations on the northeastern Tibetan Plateau

On the Tibetan Plateau, applications of delta D and delta O-18 values in paleoclimate studies tend to be complicated due to multiple processes influencing isotopic compositions in paleoclimatic archives. In this study, isotopic compositions of modern waters in the eastern Qaidam Basin on the northeastern Tibetan Plateau, and delta D values of n-fatty acids (n-FA delta D) from a sediment core at Hurleg Lake were systematically analyzed to infer hydroclimate controls during the Holocene. The modern water isotopic results show a major contribution of snowmelt water originating from high-elevation mountains to the north of the Qaidam Basin via river and groundwater discharge, and the importance of evaporation in affecting lake water budget in this region. n-C-26 FA delta D values tend to be more negative at millennial-scale warm-dry periods during the Holocene, and vice versa, opposite to what is commonly expected. Assisted with modern water isotopic results, we infer amplified contribution of snowmelt water to the soil water around this open lake system at warm-dry periods. Meanwhile, changes in n-C-16 FA delta D values at Hurleg Lake reflect the evolution of isotopic compositions of lake water, thus we use the isotopic difference between n-C-26 and n-C-16 FA (Delta DC16-C26) to infer hydroclimate and evaporation variations in this region. Based on our data, relatively low n-C-26 FA delta D and n-C-16 FA delta D values at 10-6 cal ka BP indicate large contribution of snowmelt water into the lake during the Holocene Climate Optimum. After 6 cal ka BP, changes in evaporation became the major control on lake hydrology and led to larger fluctuations of Delta DC16-C26. Our study highlights the importance of systematic analysis on modern processes before using stable isotopes for paleoclimate reconstructions, and demonstrates that delta D difference between long-chain and short-chain n-FA might be an effective way to better understand the controlling factor of hydrological variations in a climatic complex region like the Tibetan Plateau. (C) 2016 Elsevier B.V. All rights reserved

Deep challenges for China's war on water pollution

China's Central government has released an ambitious plan to tackle the nation's water pollution crisis. However, this is inhibited by a lack of data, particularly for groundwater. We compiled and analyzed water quality classification data from publicly available government sources, further revealing the scale and extent of the crisis. We also compiled nitrate data in shallow and deep groundwater from a range of literature sources, covering 52 of China's groundwater systems; the most comprehensive national-scale assessment yet. Nitrate pollution at levels exceeding the US EPA's maximum contaminant level (10 mg/L NO3-N) occurs at the 90th percentile in 25 of 36 shallow aquifers and 10 out of 37 deep or karst aquifers. Isotopic compositions of groundwater nitrate (delta N-15 and delta O-18(NO3) values ranging from -14.9 parts per thousand to 35.5 parts per thousand and -8.1 parts per thousand to 51.0 parts per thousand, respectively) indicate many nitrate sources including soil nitrogen, agricultural fertilizers, untreated wastewater and/or manure, and locally show evidence of de-nitrification. From these data, it is clear that contaminated groundwater is ubiquitous in deep aquifers as well as shallow groundwater (and surface water). Deep aquifers contain water recharged tens of thousands of years before present, long before widespread anthropogenic nitrate contamination. This groundwater has therefore likely been contaminated due to rapid bypass flow along wells or other conduits. Addressing the issue of well condition is urgently needed to stop further pollution of China's deep aquifers, which are some of China's most important drinking water sources. China's new 10-point Water Pollution Plan addresses previous shortcomings, however, control and remediation of deep groundwater pollution will take decades of sustained effort. (C) 2016 Published by Elsevier Ltd

Re-interpretation of the classical geopolitical theories in a critical geopolitical perspective

Struggling for supremacy between great powers and the rise or fall and regime change of great powers are all subject to the Geopolitical Law. Geographers should keep in step with the times, accurately grasp the national interests, and seize the opportunity to contribute to the great rejuvenation of our nation. However, due to lack of criticism on the history and philosophy of geopolitics, we can neither accurately understand the geopolitical theory, nor effectively put the geopolitical theory into practice. This paper introduces the development of critical geopolitics, summarizes the three characteristics of critical geopolitics, and interprets the four classical geopolitical theories accordingly. In order to simplify the interpretation process, this paper firstly presents an analytical framework for interpretation of four classical geopolitical theories; secondly, focuses on interpretation of "The Geographical Pivot of History" put forward by Mackinder according to the analytical framework; finally, critically summarizes the four classical geopolitical theories. Through the critical interpretation, this paper draws a conclusion that there are the scientific, hypothetical and conceptual classical geopolitical theories. The construction of classical geopolitical theories is based on the international geopolitical structure, spatial distribution of national interests and inter-state spatial conflict, in order to show the identity of theoretical constructor, so as to reflect the historicality, sociality, situationality and geographical knowledge -power structure of geopolitical theories

Drying-rewetting cycles alter carbon and nitrogen mineralization in litter-amended alpine wetland soil

Wetting-drying cycles can influence decomposition of litter and soil organic carbon (SOC) and their mineralization, but such effects have seldom been explored in alpine wetland soils. We conducted a 120-day incubation experiment with alpine wetland soils to which we added litter or not. These soil samples were assigned to two constant moisture treatments (60% or 100% soil water-holding capacity, WHC) or to a wetting-drying treatment that cycled between 60% and 100% WHC. Drying-rewetting cycles significantly accelerated carbon (C) mineralization and nitrogen (N) immobilization compared to soil under saturated soil moisture conditions. Litter addition greatly increased C mineralization and N immobilization, but the intensity of mineralization was regulated by soil moisture through microbial biomass. A significantly negative relationship between C and N mineralization became more pronounced when litter was added. Thus, drying-rewetting cycles can alter C and N mineralization, and this effect can strongly depend on litter in alpine wetlands. This indicates that future climate change could affect C stocks in alpine wetland soil through altering moisture and litter production. (C) 2016 Elsevier B.V. All rights reserved