Eco-environmental Degradation Research Articles

Transient social–ecological dynamics reveal signals of decoupling in a highly disturbed Anthropocene landscape

Understanding the transient dynamics of interlinked social-ecological systems (SES) is imperative for assessing sustainability in the Anthropocene. However, how to identify critical transitions in real-world SES remains a formidable challenge. In this study, we present an evolutionary framework to characterize these dynamics over an extended historical timeline. Our approach leverages multidecadal rates of change in socioeconomic data, paleoenvironmental, and cutting-edge sedimentary ancient DNA records from China's Yangtze River Delta, one of the most densely populated and intensively modified landscapes on Earth. Our analysis reveals two significant social-ecological transitions characterized by contrasting interactions and feedback spanning several centuries. Initially, the regional SES exhibited a loosely connected and ecologically sustainable regime. Nevertheless, starting in the 1950s, an increasingly interconnected regime emerged, ultimately resulting in the crossing of tipping points and an unprecedented acceleration in soil erosion, water eutrophication, and ecosystem degradation. Remarkably, the second transition occurring around the 2000s, featured a notable decoupling of socioeconomic development from ecoenvironmental degradation. This decoupling phenomenon signifies a more desirable reconfiguration of the regional SES, furnishing essential insights not only for the Yangtze River Basin but also for regions worldwide grappling with similar sustainability challenges. Our extensive multidecadal empirical investigation underscores the value of coevolutionary approaches in understanding and addressing social-ecological system dynamics.

Rapid Urbanization Induced Extensive Forest Loss to Urban Land in the Guangdong-Hong Kong-Macao Greater Bay Area, China

China has experienced rapid urbanizations with dramatic land cover changes since 1978. Forest loss is one of land cover changes, and it induces various eco-environmental degradation issues. As one of China’s hotspot regions, the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) has undergone a dramatic urban expansion. To better understand forest dynamics and protect forest ecosystem, revealing the processes, patterns and underlying drivers of forest loss is essential. This study focused on the spatiotemporal evolution and potential driving factors of forest loss in the GBA at regional and city level. The Landsat time-series images from 1987 to 2017 were used to derive forest, and landscape metrics and geographic information system (GIS) were applied to implement further spatial analysis. The results showed that: 1) 14.86% of the total urban growth area of the GBA was obtained from the forest loss in 1987–2017; meanwhile, the forest loss area of the GBA reached 4040.6 km2, of which 25.60% (1034.42 km2) was converted to urban land; 2) the percentages of forest loss to urban land in Dongguan (19.14%), Guangzhou (18.35%) and Shenzhen (15.81%) were higher than those in other cities; 3) the forest became increasingly fragmented from 1987–2007, and then the fragmentation decreased from 2007 to 2017); 4) the landscape responses to forest changes varied with the scale; and 5) some forest loss to urban regions moved from low-elevation and gentle-slope terrains to higher-elevation and steep-slope terrains over time, especially in Shenzhen and Hong Kong. Urbanization and industrialization greatly drove forest loss and fragmentation, and, notably, hillside urban land expansion may have contributed to hillside forest loss. The findings will help policy makers in maintaining the stability of forest ecosystems, and provide some new insights into forest management and conservation.

Prediction modelling of riverine landscape dynamics in the context of sustainable management of floodplain: a Geospatial approach

ABSTRACT Presently, sustainability of floodplain, a diverse element of the riverine landscape, provides an ideal research setting for investigating complex interaction between anthropogenic disturbance and eco-environmental degradation. Nowadays, these floodplains are continually degraded and fragmented on account of unsustainable land use. To analyse the spatial and temporal changes of landuse/landcover, a supervised classification (maximum likelihood algorithm) method has been made for the period 1998 to 2018. Present research simulates and predicts landuse/landcover dynamics of lower stretch of the Ganges river up to 2038 to analyse future riverine landscape dynamics stressed by various natural and socio-economic factors based on Cellular Automata-Artificial Neuron Network (CA-ANN) model clubbed with Modules for Land Use Change Evaluation (MOLUSCE) plugin of QGIS software. Outcome of research reveals that the trend of agriculture land, sand, and inland waterbody areas is reduced by 15.75, 5.71, and 1.95%, whereas, for orchard, agricultural fallow and bare land areas increased by 7.94, 7.92, and 5.69% for the period from 1998 to 2018. The simulation model predicted a continuation of the similar trend till 2038. The significant reduction of agricultural land and sand areas is largely an attribute to floodplain degradation in an altered hydrological regime. Ultimately, hydro-morphological changes, increasing population pressure, and agriculture intensification in floodplain landscape were identified as main driving forces in temporal landuse/landcover changes. The prediction of future forecast indicates that if the present rate of landuse/landcover trend persists in the study stretch of Ganges river without appropriate sustainable development practice, severe floodplain degradation will ensue. This study provides a holistic measure for understanding long-term environmental degradation related to anthropogenic activities and impact of climate changes in floodplain landscape at local and regional scale.

Effects of hydrological alteration on fish population structure and habitat in river system: A case study in the mid-downstream of the Hanjiang River in China

Fish resources in the mid-downstream of the Hanjiang River have showed a serious decline in past decades due to eco-environmental degradation. This study aims to analyze the effects of hydrological alteration on fish population structure and habitat by combining the IHA-RVA method, the FLOWS method and the fish resources survey. Based on the change-points (the years 1990 and 2012) detected in the runoff time-series of the Huangzhuang hydrological station, we divided the study period into three periods: 1956–1989 (Period I), 1990–2011 (Period II), and 2012–2017 (Period III). The percent change in runoff D0 between the different periods (I-II, II-III, I-III) are 42.2%, 69.28%, and 81.68%, respectively. The monthly average flow increased during the dry season but decreased in the wet season. The rise rate of flow showed a 46% and 35% reduction in Period (II) and Period (III), respectively. The average 1-day maximum flow reduced from 12473.6 m3/s to 4466.7 m3/s, while its occurrence time also changed from July and mid-September to mid-August. The average high pulse count in Period (III) had a 38% reduction compared to that in Period (I). The number of species of fish spawning drifting eggs decreased by 6 species, so did the carnivorous fish. In addition, the spawning grounds in the Yicheng-Zhongxiang section was seriously deteriorating. The proportion of omnivorous fish and small fish increased by 16.5% and 24.5% during the past 62 years, respectively. The trend of miniaturization and aging of fish was significant. For Coreius heterodon, the number of suitable fish habitat sections in the study area has decreased from three to zero, while Cyprinus carpio could adapt to changing environment. Our results provide important clues for a better understanding of the changes in fish population structure and habitat under hydrological alteration.

The nexus between regional eco-environmental degradation and rural impoverishment in China

Regional environmental degradation and impoverishment interact and restrict each other. While acknowledging this relationship, little is known about the extent of their impact. By integrating multi-source data, this study used econometric models and spatial analysis techniques to explore the geographical distribution pattern of rural poverty in China, identify the key factors affecting rural improvement and quantitatively reveal the relationship between regional eco-environmental degradation and improvement. The results show that complex geographical environment, fragile ecological environment, frequent natural disasters, endemic diseases prevalent and the aging of social subjects do affect and even aggravate rural impoverishment in China. Terrain relief degree was identified as a determinative factor of rural poverty in China, and the rural poverty rate increases by 0.3–0.45% for every 1-m increase in terrain fluctuation. Further analysis showed that distribution of poverty-stricken population in rural China overlaps spatially with areas with fragile ecology, high incidence of geological disasters, poor geographical environment and aging population. The impact of eco-environmental degradation on poverty depends on the types of eco-environmental problems faced by the poor. The types of poverty-stricken areas in rural China can be divided into five categories: disaster-driven, endemic disease-driven, eco-environment degradation-driven, ecological protection restricted and grain-producing restricted. Poverty alleviation, disaster risk prevention, disease reduction and ecological environmental protection need to be promoted in collaboration. Differentiated and targeted anti-poverty measures for different types of poverty are urgently needed.

River health assessment of the Yellow River source region, Qinghai-Tibetan Plateau, China, based on tolerance values of macroinvertebrates

For decades, the river health of the Yellow River source region (YRSR) on the Qinghai-Tibetan Plateau has been a focal issue owing to its unique geographic location and ecological functions. This study investigated the ecological status of the headwater streams, the main stem, and the tributaries of the Yellow River in the YRSR using the tolerance values of macroinvertebrates and those related to biotic indices. The macroinvertebrate assemblages of the headwater streams were characterized by lower biodiversity than the tributaries downstream, based on comparisons of taxonomical composition, functional feeding group composition, and the pollution-tolerant capacity of taxa. The headwater streams had a lower ratio (16%) of pollution-sensitive macroinvertebrate taxa than that of the tributaries downstream (30%). The biotic indices (family- and genus-level biotic indices) indicated that the ecological health of the headwater streams was comparably poorer than that of the downstream tributaries. The combined effect of vulnerable natural conditions and increasing human disturbance is likely the main cause of eco-environmental degradation in the Yellow River headwater streams.

Impact Assessment and Dynamic Management towards Sustainable Tourism in Antarctica

Over the past two decades, Antarctica has experienced a severe eco-environmental degradation due to tourism impacts. The new, diverse and complex tourism activities and technological advancements demonstrate the current regulatory system is insufficient. This study aims to analyse the Antarctic tourism impact, investigate the assessment methods and propose a dynamic management system. This paper suggests two assessment indicators i.e. ATEF and ATECC along with nine management strategies. A flowchart demonstrates the dynamic process of impact analyses, assessment and management. This system can be deployed to design a dynamic regulatory system toward sustainable Antarctic tourism.

A GIS-Based Evaluation of Environmental Sensitivity for an Urban Expressway in Shenzhen, China

Abstract Urban eco-environmental degradation is becoming inevitable due to the extensive urbanization, population growth, and socioeconomic development in China. One of the traffic arteries in Shenzhen is an urban expressway that is under construction and that runs across environmentally sensitive areas (ESAs). The environmental pollution from urban expressways is critical, due to the characteristics of expressways such as high runoff coefficients, considerable contaminant accumulation, and complex pollutant ingredients. ESAs are vulnerable to anthropogenic disturbances and hence should be given special attention. In order to evaluate the environmental sensitivity along this urban expressway and minimize the influences of the ongoing road construction and future operation on the surrounding ecosystem, the environmental sensitivity of the relevant area was evaluated based on the application of a geographic information system (GIS). A final ESA map was classified into four environmental sensitivity levels; this classification indicates that a large proportion of the expressway passes through areas of high sensitivity, representing 11.93 km or 52.3% of the total expressway, and more than 90% of the total expressway passes through ESAs. This study provides beneficial information for optimal layout schemes of initial rainfall runoff treatment facilities developed from low-impact development (LID) techniques in order to minimize the impact of polluted road runoff on the surrounding ecological environment.

模拟降雨下植被盖度对坡面流水动力学特性的影响

Soil and water loss has caused severe land resources depletion and eco-environment degradation in many areas of China,which leads to reduction of local agricultural and industrial productivity. Furthermore,as a severe environmental problem,soil and water loss will affect many respects,such as nature,economy,society and science. Many factors are influencing the degree of soil erosion,Plant vegetation coverage,rainfall intensity and duration,soil type and texture,etc.In this study we chose slope,rainfall intensity and vegetation coverage as impact factors to the degree of soil erosion. Plant ryegrass is one of the feasible measures to avoid soil and water loss. In order to understand the process of runoff movement under the complex surface conditions and the effect of flow and different surface conditions on hydraulics parameters,we utilized the artificial rainfall approach to study the process of runoff and sediment yield and its hydraulic characteristics to explore how ryegrass play a role in the work of soil and water conservation. The experiment was designed with 30 mm / h and60 mm / h rainfall intensity and slopes of 10° and 20° with different coverage of ryegrass(0,20%,40%,60%,80% and100%) in Jiufeng experimental forest farm of Beijing Forestry University. During the simulated rainfall process,the runoff samples were collected at fixed time: in the first ten minutes,the runoff was sampled every two minutes due to the fast increase of runoff amount,and then the runoff was sampled every five minutes in the last fifty minutes as the change of runoff amount went slow. At the end of the experiment,the volume of runoff was measured,and then standing the runoff samples were placed and dried for 24 hours,respectively,to obtain the amount of sediment. During the simulated rainfallprocess,the velocity of overland flow was measured every ten minutes. Then the surface runoff and hydraulic parameters were calculated with runoff,sediment and surface runoff velocity. By choosing Reynolds number,Froude number and drag coefficient as factors to characterize the water advance and water recession process,the results showed that: the Reynolds number increases with the slope degree and rainfall intensity. The increase of ryegrass could play important roles in both the decrease of the Reynolds number and the Froude number,and the Reynolds number and the Froude number under different coverage are: bare land 20% 40% 60% 80% and bare land 20% 40% 60% 80%,respectively. The drag coefficient and sediment yield rate were well-fitting,and the sediment yield rate decreased as the drag coefficient increased.When the drag coefficient was between zero and one,the growth rate of sediment yield was larger than the drag coefficient.By this study,we know that ryegrass has a great significance to soil and water conservation. Moreover,the increase of ryegrass coverage leads to the enhancement of the soil and water conservation function. The results of the ryegrass regulating runoff and preventing soil erosion in this study have theoretical significance to understanding the process of soil erosion.

Sediment Flux and Its Environmental Implications

Sediment transport in fluvial systems is a key driver of basin-wide global soil loss, river sedimentation, and the movement and transformation of organic, inorganic, and nutrient materials, all of which can contribute to severe eco-environmental degradation. Since the late 1800s, much research effort has focused on the physics of sediment entrainment, transport, and deposition by river flows. This paper reviews ongoing research aimed at considering the simultaneous physical, chemical and biological processes that characterize riverine sediment flux. Four related issues are considered: riverine sediment flux; soil erosion and chemical transport; fluxes of dissolved organic carbon; and sediment-induced CO2 emission/sequestration. Modelling of sediment flux has moved beyond empirical and statistical approaches to that of a generalized form of the universal integral solution of the basic flux equation, which is now anticipated to lead to a wide range of applications. Whereas soil erosion and riverine chemical transport are now known to cause soil degradation and reduced water quality, limited progress has been made to date on the quantification of erosion rates. As soils erode, CO2 is emitted at erosion and transport sites and sequestered at deposition sites, the net effect being carbon sequestration. However, the rates of CO2 emission/sequestration vary widely, owing to the large spatial variations in soil type, land-slope, rainfall intensity, etc. It is now well established that dissolved organic carbon (DOC) concentrations and fluxes have been increasing over the past two decades, due to reduced atmospheric sulphur concentration, climate warming, and changes in precipitation patterns. The research discussed herein provides insight into the interaction between sediment and multiple material substances, leading to a better understanding of fluvial river ecosystems, which is essential for maintaining river health.

Analysis of streamflow variations in the Heihe River Basin, northwest China: Trends, abrupt changes, driving factors and ecological influences

Abstract Study Region The Heihe River Basin (HRB) is the second largest inland river basin of China located in northwest China with a minor portion in Mongolia. Study Focus With increasing water demands from domestic, agricultural, and industrial sectors, the HRB has been increasingly undergoing water resources shortage and eco-environmental degradation, especially in the lower HRB. Discerning the trends and any abrupt changes in the streamflow over the river basin could help unravel the causes and effects of historical variations of the water resources. Statistical methods for detecting trends, abrupt and gradual changes were applied to the long-term streamflow, precipitation and temperature data over the HRB to analyze and understand annual and seasonal hydroclimatic variations over the past five decades. New Hydrological Insights for the Region The findings of this study indicated that although the streamflow coming from the upper reaches have risen, those flowing to the lower reaches have declined significantly. Analysis of the correlation between climatic factors and streamflow variations and the assessment of the development of socioeconomics revealed that: (1) rising temperature and precipitation are the main cause to explain the increases in streamflow in the upper HRB; and (2) human activities in the middle reaches of the HRB rather than climate changes were primarily responsible for the water shortage and ecological deterioration of the lower HRB.

Responses of runoff to climate change and human activities in the Ebinur Lake Catchment, western China

Based on hydrological and climatic data covering the period from 1961 to 2008, this paper studies the hydrological responses to climate change and to human activities in the Ebinur Lake Catchment. The results show that the annual runoff of three rivers in Ebinur Lake Catchment exhibited different change trends. Specifically, in Jinghe River and Kuytun River exhibited a slightly increasing trend, but an adverse trend in Bortala River, and the variation trend has been the most dramatic since the mid-1990s. The observed variation in the runoff was resulted from the elevated alpine precipitation, rather than rising temperature, and that precipitation is a major factor for runoff generation. The runoff CAR model proposed by this paper can be used to predict the annual runoff in three rivers, and demonstrated annual runoff in Bortala River and Jinghe River will display an increased trend, while a less decreasing trend in Kuytun River under the climate change scenarios of warm-humid variation. In addition, the exploitation of the area of cultivated land led to more water resources consumption, primarily for agriculture irrigation, is the cause of the persistently ecoenvironment degradation, which have reached in a critical state thus, a more pressing concern is the development a scientifically reasonable and administratively practical water resource management scheme.

Groundwater dynamics under water-saving irrigation and implications for sustainable water management in an oasis: Tarim River basin of western China

Abstract. Water is essential for life. Specifically in the oases of inland arid basins, water is a critically limited resource, essential for the development of the socio-economy and the sustainability of eco-environmental systems. Due to the unique hydrological regime present in arid oases, a moderate groundwater table is the goal of sustainable water management. A shallow water table induces serious secondary salinization and collapse of agriculture, while a deep water table causes deterioration of natural vegetation. From the hydrological perspective, the exchange flux between the unsaturated vadose zone and groundwater reservoir is a critical link to understanding regional water table dynamics. This flux is substantially influenced by anthropogenic activities. In the Tarim River basin of western China, where agriculture consumes over 90% of available water resources, the exchange flux between the unsaturated vadose zone and groundwater reservoir is influenced strongly by irrigation. Recently, mulched drip irrigation, a sophisticated water-saving irrigation method, was widely applied in the Tarim River basin, which greatly impacted the exchange flux and thus the regional groundwater dynamics. Capitalizing on recent progress in evaporation measurement techniques, we can now close the water balance and directly quantify the exchange flux at the field scale, thus gaining a better understanding of regional groundwater dynamics. In this study, comprehensive observations of water balance components in an irrigated cropland were implemented in 2012 and 2013 in a typical oasis within the Tarim River basin. The water balance analysis showed that the exchange flux and groundwater dynamics were significantly altered by the application of water-saving irrigation. The exchange flux at the groundwater table is mostly downward (310.5 mm year−1), especially during drip irrigation period and spring flush period, while the upward flux is trivial (16.1 mm year−1) due to the moderate groundwater table depth (annual average depth 2.9 m). Traditional secondary salinization caused by intense phreatic evaporation (fed by upward exchange flux) is alleviated. However, a new form of secondary salinization may be introduced unwittingly if there is lack of water for periodic flushing, especially when brackish water is used in the irrigation. Furthermore, the water saved via drip irrigation has been used in further growth of irrigated lands instead of supporting the ecological system. This could lead to an increased risk of eco-environmental degradation and calls for improved governance schemes. The insights gained from this study can be potentially applied to other arid inland areas (e.g., central Asia) which face similar water shortages and human development problems.

Modelling LULC for the period 2010-2030 using GIS and Remote sensing: a case study of Tikrit, Iraq

This study extends upon the results of [1] to include the modeling of Land use/ Land cover (LULC). This study looks at the changes that occurred from 2010 to 2030 in Tikrit district, Iraq by predicting LULC for the year target 2030 by using the classified images for two points of time (2000 – 2010) as a foundation for the modeling process. The projected map, in comparison with 2010 LULC map, shows a significant decrease in vegetation area (45.11 km2) which must be regulated in order to maintain a green environment, and increase in the urban area (58.42 km2) which should be monitored to have sustainable development and control the eco-environment degradation. Also, in this study, it is shown clearly that the use of Geographic Information System (GIS) and remote sensing (specially IDRISI software) in modeling LULC is a suitable approach to understand the future pattern.

REMOTE SENSING CLASSIFICATION METHOD OF WETLAND BASED ON AN IMPROVED SVM

Abstract. The increase of population and economic development, especial the land use and urbanization bring the wetland resource a huge pressure and a serious consequence of a sharp drop in the recent years. Therefore wetland eco-environment degradation and sustainable development have become the focus of wetland research. Remote sensing technology has become an important means of environment dynamic monitoring. It has practical significance for wetland protection, restoration and sustainable utilization by using remote sensing technology to develop dynamic monitoring research of wetland spatial variation pattern. In view of the complexity of wetland information extraction performance of the SVM classifier, this paper proposes a feature weighted SVM classifier using mixed kernel function. In order to ensure the high-accuracy of the classification result, the feature spaces and the interpretation keys are constructed by the properties of different data. We use the GainRatio (featurei) to build the feature weighted parameter h and test the different kernel functions in SVM. Since the different kernel functions can influence fitting ability and prediction accuracy of SVM and the categories are more easily discriminated by the higher GainRatio, we introduce feature weighted ω calculated by GainRatio to the model. Accordingly we developed an improved model named "Feature weighted & Mixed kernel function SVM" based on a series of experiments. Taking the east beach of Chongming Island in Shanghai as case study, the improved model shows superiority of extensibility and stability in comparison with the classification results of the experiments applying the Minimum Distance classification, the Radial Basis Function of SVM classification and the Polynomial Kernel function of SVM classification with the use of Landsat TM data of 2009. This new model also avoids the weak correlation or uncorrelated characteristics' domination and integrates different information sources effectively to offer better mapping performance and more accurate result. The accuracy resulted from the improved model is better than others according to the Overall Accuracy, Kappa Coefficient, Omission Errors and Commission Errors.

Assessment of Antarctic Tourism Waste Disposal and Management Strategies towards a Sustainable Ecosystem

Over the past two decades, Antarctica has experienced a severe eco-environmental degradation due to tourism impacts. The new, diverse and complex tourism activities and technological advancements demonstrate the current regulatory system is insufficient. This study aims to analyze the Antarctic tourism impact, investigate the assessment methods and propose a dynamic management system. This paper suggests two assessment indicators i.e. Antarctic ecological footprint (ATEF) and Antarctic tourism environmental carrying capacity (ATECC) along with nine management strategies. A flowchart demonstrates dynamic process of impact analyses, assessment and management. This system can be deployed to design a dynamic regulatory system toward sustainable Antarctic tourism.

Spatial Analyze of Soil Erosion Assisted by Remote Sensing Data and GIS in Zuli River Basin

Serious soil erosion is both the cause and the result of Eco-environment degradation in Chinese Loess Plateau.In this paper,the soil erosion of Zuli River Basin in 1999 and 2001 were estimated by modified SEMMED model which input the remote sensing data and observed precipitation data and under GIS environment.It indicates that the most serious soil erosion areas include Gejiacha,Caotan,Gejiazai and Jingyuan.The soil erosion in central and Southern part is less than that of Northern part.The Quwu Mountain,Yueliang Mountain and Huajialing have high vegetation cover and less soil erosion.The results suggest that the great annual fluctuation of soil erosion due to the fluctuation of precipitation.

Impact of aridization on soil cover transformation of the Aral Sea and the modern Syr-Darya Delta

The effects of human activities on the soil cover transformation in the eastern part of Kazakhstan were investigated during the period of 1956−2008. The results of the research for different soil types in Priaralye indicated that there was 643.3×10 3 hm 2 solonchaks, accounting for 38.5 % of the total 2 ) and grey-brown desert soils and solonetzes (146.7×10 3 hm 2 ). In 2001 the area of solonchak was 755×10 3 hm 2 and decreased to 643.3×10 3 hm 2 in 2008, which due to the shrinkage of the Aral Sea, the areas of marsh and lakeshore solonchaks decreased with the increase of dried bottom of the Aral Sea. The level of soil cover transformation in the modern delta of the Syr-Darya River can be seen from the comparison of the results obtained from the different years in the study area. The area of solon- chaks increased by 10×10 3 hm 2 and the area of alluvial-meadow salinizied soils increased by 17.9×10 3 hm 2 during the period of 1956-1969. It means that many non-salinizied soils were transformed into salinizied ones. Striking changes occurred in the structure of soil cover as a result of aridization. So, the researches in1969 significantly determined the areas of hydromorphic soils subjected to desertification (it was not fixed on the map before 1956). Later, these soils were transformed into takyr-like soils. The area of takyr-like soils increased almost by 3 times for 34 years (from 1956 to 1990). The long-term soil researches on soil cover transformation in Priaralye have shown that the tendencies of negative processes (salinization and deflation) are being kept and lead to further soil and eco-environment degradation in the region.

Eco-environmental change detection by using remote sensing and GIS techniques: a case study Basrah province, south part of Iraq

This study examines the temporal and spatial dynamics of eco-environment degradation processes and change detection as evident from land use survey datasets (1990–2003) for the Basrah province, Iraq was taken as a case. Using a combination of techniques of RS, GIS, and GPS, the study identifies five prominent eco-environment degradation processes, namely: desertification, secondary salinization, urbanization, vegetation degradation, and loss of wetlands. Rates of conversion were calculated and distribution patterns were mapped with the aid of GIS. The results suggest that wind erosion was the dominant cause of eco-environment degradation in more than half of the study area. Coupled with this were increases in salinization processes, affecting 17.6% of the land area in 2003. Overall, severe eco-environment degradation was noticed to be the dominant eco-environment degradation grade (61.9% of total area), followed by moderate eco-environment degradation (18.9% of total area) in 2003. Incorporation of both natural and anthropogenic factors in the analysis provided realistic assessment of the risk of land degradation. The study area, in general, is exposed to a high-risk of eco-environment degradation.

Multi-scale variability and trends of precipitation in North China

The issue of water shortage and related eco-environmental degradation in North China is one of the major emerging problems in China. Precipitation is the most key factor for water resources. Based on the historical flood/dryness grade dataset during the period of 1470–2000 obtained from 25 gauging stations in North China, the multi-scale variability and trends are analyzed by means of power spectral and continuous wavelet transform. It is found that the precipitation is characterized by obvious seasonal changes, quasi biennial oscillations, inter-annual 4–7 year component and inter-decadal 19-year periodicity. The MK test results showe that step changes occurred around 1914 and 1964 in the annual precipitation. As for the historical flood/dryness grade time series, it is characterized by 4∼5 year ENSO mode inter-annual oscillation, quasi-10 year inter-decadal variability, quasi-24 year component and 50–80 year centurial periodicity. However, the scales of these variations have decreased significantly since the 1970s. The trend for precipitation change in North China has been negative for last 30 years. Further research shows that North China will continue to become dryer until 2015 and may change to a wetter regime after 2020. These findings should be helpful for future decision-making to ensure sustainable water resource management in North China.