Soil Water Modelling In Arid/Semiarid Regions of Northern China Using Land Information System (LIS) - A Minor Field Study in Shiyang River Basin

At present China suffers from severe desertification or land degradation. About 27% of the total territory was exposed in 2004, mainly the northern provinces. Consequences of desertification, such as floods or sandstorms, require huge effort and financial assets. Soil moisture understanding plays a key role in combating desertification and is necessary in order to implement a sustainable water management. Land Surface Models (LSMs) are one approach to survey and quantify soil moisture. A LSM calculates the surface state from physical conceptual equations based on satellite derived input. Land Information System (LIS) is a framework for global modelling with LSMs. LIS has a high spatial and temporal resolution and the ability to simulate soil moisture and other water related parameters in a near real time manner. There are several kinds of LSMs but currently only two are implemented in the Land Information System (LIS); namely Noah and CLM. LIS is designed to be flexible in terms of atmospheric input data and can use one of many sources. The main aim with this thesis is to investigate LIS as a tool in water management in arid /semiarid regions. The two LSMs within LIS were simulated and compared over several investigation points widely distributed over Shiyang river basin, northern China. This was done in order to find possibilities and limitations with LIS and potential differences between the LSM interpretations in this setting. The study consists of two parts. Part one is a field study in an arid area in Gansu, China, during September 2006. Part two is computer simulations using the model framework LIS and its different LSMs with altered atmospheric input over the Shiyang river basin. The aims of the simulations were first to find a good configuration for modelling the area and then to investigate differences in LSM interpretation. Noah and CLM were compared in a four year simulation starting January 1st 2000 and in a created rain scenario to observe infiltration patterns. The field measurements showed average soil moisture of 6.6% in the top ten cm and 11.8% in the 10-30 cm layer during September. The simulations showed the forcing option GDAS to give best performance of precipitation interpolation accuracy. A slightly higher initial soil moisture value than the regional average could give a quicker spin up time. The four-year simulation indicated differences between Noah and CLM in spin up time and soil moisture patterns. The constructed rain event revealed Noah to percolate more rapidly and to a greater extent than CLM. CLM lost water and the reason could be traced to surface and subsurface runoff, rather than evaporation. LIS is still in a developing state and updates are released regularly. Necessary input data was unavailable during the research, due to server problems. Further investigation of soil moisture fluctuation is therefore needed to ensure if any LSM is more preferable in this region. One advantage using LIS is however the possibility to run simulations with different set up and consider all results

When the Wells Ran Dry: A Treadmill Analysis of Political Capitalism and Environmental Degradation in the Minqin Oasis

My dissertation is a case study examining how changes in land tenure and taxation policies created underdevelopment in the region worst affected by desertification in China: the Minqin oasis in the Gansu province. I argue that the tragedy of the commons occurred due to the significant decline in institutional credibility of land tenure in the oasis, driven by central-local tensions embedded in a tax farming system. My dissertation discusses the concepts of political capitalism and its application to the changing roles of the communist state on resource management during the collective and tax reform eras in China. I first examined the environmental history of the oasis, showing the intricate yet repetitive pattern of interactions between the state extraction policy and the ecology of the oasis from the 14th century to the communist collective era. I then used Weber’s analysis of center-periphery relations to dissect the treadmill of production in a politically-oriented capitalist regime. I show that the institutional disarray in the 1980s created a fiscal crisis that pushed the central government to decentralize public goods provisions. Under constant pressure to increase tax revenues, the unitary bureaucracy intensified the collection of unregulated fees and levies from farmers. They also encouraged cash-cropping in massive land reclamation projects by contracting the rights for use of wastelands and the groundwater underneath. Local state agents prohibited the traditional customs of water-sharing among villagers and operated higher tax rates in mutually cultivated areas as compared to privately reclaimed areas. The disruption of productive relations reduced the institutional credibility of land rights among the peasantry and, together with the ever-increasing need to accumulate capital for industrialized farming, created the homo economicus and corporatist state in the ecological catastrophe. In conclusion, I discuss how the case study of Minqin adds to the vibrant literature about the treadmill of accumulation theory in environmental sociology, and the impact of institutional transformation in post-socialist societies on nature is also discussed. The data came from an 18 month-long ethnography, 157 oral history interviews conducted with three generations of peasants living in the Minqin oasis, and 7,237 policy documents gathered from provincial and county record offices in northwestern China. Data gathering was completed in 2013

Water loss due to increasing planted vegetation over the Badain Jaran Desert, China

© 2018 by the authors. Water resources play a vital role in ecosystem stability, human survival, and social development in drylands. Human activities, such as afforestation and irrigation, have had a large impact on the water cycle and vegetation in drylands over recent years. The Badain Jaran Desert (BJD) is one of the driest regions in China with increasing human activities, yet the connection between human management and the ecohydrology of this area remains largely unclear. In this study, we firstly investigated the ecohydrological dynamics and their relationship across different spatial scales over the BJD, using multi-source observational data from 2001 to 2014, including: total water storage anomaly (TWSA) from Gravity Recovery and Climate Experiment (GRACE), normalized difference vegetation index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS), lake extent from Landsat, and precipitation from in situ meteorological stations. We further studied the response of the local hydrological conditions to large scale vegetation and climatic dynamics, also conducting a change analysis of water levels over four selected lakes within the BJD region from 2011. To normalize the effect of inter-annual variations of precipitation on vegetation, we also employed a relationship between annual average NDVI and annual precipitation, or modified rain-use efficiency, termed the RUEmo. A focus of this study is to understand the impact of the increasing planted vegetation on local ecohydrological systems over the BJD region. Results showed that vegetation increases were largely found to be confined to the areas intensely influenced by human activities, such as croplands and urban areas. With precipitation patterns remaining stable during the study period, there was a significant increasing trend in vegetation greenness per unit of rainfall, or RUEmo over the BJD, while at the same time, total water storage as measured by satellites has been continually decreasing since 2003. This suggested that the increased trend in vegetation and apparent increase in RUEmo can be attributed to the extraction of ground water for human-planted irrigated vegetation. In the hinterland of the BJD, we identified human-planted vegetation around the lakes using MODIS observations and field investigations. Four lake basins were chosen to validate the relationship between lake levels and planted vegetation. Our results indicated that increasing human-planted vegetation significantly increased the water loss over the BJD region. This study highlights the value of combining observational data from space-borne sensors and ground instruments to monitor the ecohydrological dynamics and the impact of human activities on water resources and ecosystems over the drylands

Quantitative Assessment of Desertification Using Landsat Data on a Regional Scale – A Case Study in the Ordos Plateau, China

Desertification is a serious threat to the ecological environment and social economy in our world and there is a pressing need to develop a reasonable and reproducible method to assess it at different scales. In this paper, the Ordos Plateau in China was selected as the research region and a quantitative method for desertification assessment was developed by using Landsat MSS and TM/ETM+ data on a regional scale. In this method, NDVI, MSDI and land surface albedo were selected as assessment indicators of desertification to represent land surface conditions from vegetation biomass, landscape pattern and micrometeorology. Based on considering the effects of vegetation type and time of images acquired on assessment indictors, assessing rule sets were built and a decision tree approach was used to assess desertification of Ordos Plateau in 1980, 1990 and 2000. The average overall accuracy of three periods was higher than 90%. The results showed that although some local places of Ordos Plateau experienced an expanding trend of desertification, the trend of desertification of Ordos Plateau was an overall decrease in from 1980 to 2000. By analyzing the causes of desertification processes, it was found that climate change could benefit for the reversion of desertification from 1980 to 1990 at a regional scale and human activities might explain the expansion of desertification in this period; however human conservation activities were the main driving factor that induced the reversion of desertification from 1990 to 2000

Sustainability in China: Bridging Global Knowledge with Local Action

China’s road to sustainability has attracted global attention. Since the “Reform & Opening Up” policy, China’s rapid pace of both urbanization and industrialization has made its being the second largest economy but meantime a heavy environmental price has been paid over the past few decades for addressing the economic developmental target. Today, as the biggest developing country, China needs to take more responsibilities for constructing its local ecological-civilization society as well as for addressing the global challenges such as climate change, resources scary and human beings well-fare; therefore, we need to have deeper understandings into China’s way to sustainability at very different levels, both spatially and structurally, concerns ranging from generating sustainable household livelihoods to global climate change, from developing technological applications to generate institutional changes. In this spirit, this publication, “Sustainability in China: Bridging Global Knowledge with Local Action” aims to investigate the intended and spontaneous issues concerning China’s road to sustainability in a combined top-down and bottom-up manner, linking international knowledge to local-based studies

The world’s earliest Aral-Sea type disaster: the decline of the Loulan Kingdom in the Tarim Basin

The presented data are accessible in the PANGAEA database, https://doi.pangaea.de/10.1594/PANGAEA.871173.Remnants of cities and farmlands in China’s hyperarid Tarim Basin indicate that environmental conditions were significantly wetter two millennia ago in a region which is barren desert today. Historical documents and age data of organic remains show that the Loulan Kingdom flourished during the Han Dynasty (206 BCE–220 CE) but was abandoned between its end and 645 CE. Previous archaeological, geomorphological and geological studies suggest that deteriorating climate conditions led to the abandonment of the ancient desert cities. Based on analyses of lake sediments from Lop Nur in the eastern Tarim Basin and a review of published records, we show that the Loulan Kingdom decline resulted from a man-made environmental disaster comparable to the recent Aral Sea crisis rather than from changing climate. Lop Nur and other lakes within the Han Dynasty realm experienced rapidly declining water levels or even desiccation whilst lakes in adjacent regions recorded rising levels and relatively wet conditions during the time of the Loulan Kingdom decline. Water withdrawal for irrigation farming in the middle reaches of rivers likely caused water shortage downstream and eventually the widespread deterioration of desert oases a long time before man initiated the Aral Sea disaster in the 1960s.Funding was provided by China’s NSF projects (40830420, 41471003), the State key project (2003BA612A-06–15) of the Ministry of Science and Technology of China and the German Research Foundation (DFG grant Mi 730/16-1). We thank two anonymous reviewers who provided very constructive comments on an earlier version of this paper.Peer Reviewe

Deserts and Desertification

A desert is an ecosystem in an arid zone in which sand dunes cover the land and sandstorms often occur. Although desert vegetation is sparse, it plays an important role in ecosystem structure and function. Desertification is one of the most severe environmental problems today. Land desertification can be controlled through many measures, such as eco-villages, eco-agriculture, biodiversity conservation, and the combination of engineering and biology. This edited volume provides new insights into the pattern of desert ecosystems and the progress of desertification control. It is a useful resource for researchers in ecology, forestry, and land desertification control