CHINA'S AGRICULTURAL WATER SCARCITY : EFFECTS ON INTERNATIONAL MARKETS

Water shortages in important grain-producing regions of China may significantly affect China's agricultural production potential and international markets. This paper provides an overview of how water scarcity could affect China's agricultural production and trade. The paper identifies the areas where available water resources are most overexploited and the crops most vulnerable to reductions in irrigation. We present preliminary results from modeling a decline in irrigated land in water scarce areas in China and the effect this would have on China's production and trade. Wheat and cotton are most vulnerable to a decrease in irrigated area in water scarce regions, and production for these crops could fall by 7-10 percent under a severe cutback in irrigation. The effect this will have on international markets will depend largely on the openness of China's border to imports. In addition, we describe recent conservation policies and how these may affect crop production in China.Resource /Energy Economics and Policy,

Groundwater overexploitation in the North China Plain: A path to sustainability

Over-pumping of aquifers is a worldwide problem, mainly caused by agricultural water use. Among its consequences are the falling dry of streams and wetlands, soil subsidence, die-off of phreatophytic vegetation, saline water intrusion, increased pumping cost and loss of storage needed for drought relief. Stopping or reversing the trend requires management interventions. The North China Plain serves as an example. A management system is set up for a typical county. It contains three components: monitoring, decision support based on modelling, and implementation in the field. Besides all monitoring data, the decision support module contains an irrigation calculator, a box model, and a distributed groundwater model to project the outcomes of different water allocation scenarios. In view of grain security, a solution combines an adaptation of the cropping system with imports of surface water from the South. The Open Access book does not only describe the problem and the path to its solution. It also gives access to nine manuals concerning methods used. They include computer programs and the game Save the Water. The Chinese experience should be of considerable interest to other regions in the world which suffer from over-pumping of aquifers

Impacts of, and Vulnerability and Adaptation to, Climate Change in Water Resources and Agricultural Sectors in China

human development, climate change

Characteristics of coastline changes in mainland China since the early 1940s

Based on multi-temporal topographic maps, remote sensing images and field surveys covering the entire coastal zone of mainland China, the coastlines of six periods since the early 1940s were extracted. Coastline changes over the last 70 years were then analyzed in terms of coastline structure, coastline fractals, coastline change rates, land-sea patterns, and bay areas. The results showed that mainland coastline structure changed dramatically, and due to the significant coastline artificialization mainly driven by sea reclamation and coastal engineering, the remaining natural coastline merely accounts for less than one third at present. Coastline fractal dimension represented an overall spatial pattern of "north < entirety < south"; however, the discrepancy between the north and south coast was apparently narrowed due to dramatic coastline artificialization of northern China which in turn altered the whole pattern. Patterns and processes of land-sea interchange along the mainland coast were complex and varied spatially and temporally, with over 68% advancing toward sea and 22% retreating toward land. The net growth of land area was nearly 14.2 x10(3) km(2) with an average growth rate of 202.82 km(2) a(-1); and coast retreat was characterized by area decrease of 93 bays with a magnitude of 10.1 x10(3) km(2) and an average shrinking rate up to 18.19% or an average shrinking speed up to 144.20 km(2) a(-1), among which the total area of Bohai shrunk by 7.06%, with an average annual loss amounting to 82 km(2). The dramatic coastline changes along mainland China have brought about kinds of challenges to the coastal environment, therefore the integrated management, effective environment protection and sustainable utilization of coastlines is urgent

TOPICS IN MODELLING ADAPTATION DYNAMICS OF CHINESE AGRICULTURE TO OBSERVED CLIMATE CHANGE

Chinese farmers have adopted multiple adaptation measures to mitigate the negative impact of, and to capture the opportunities brought by, the observed climate change in the last several decades. Such adaptations will continue in the coming decades given the foreseeing climate change. Scientifically assessing such dynamism of suitable agricultural adaptation requires unprecedented efforts of the research community to simulate and predict the interactions among crop growth dynamics, the environment and crop management, and cropping systems at and across various scales. This calls for efforts aiming to quantify the interactions of agro-ecological processes across different scales. This dissertation intends to make scientific contributions in this direction. The leading goal of this dissertation is to develop a cross-scale modeling framework that is capable of incorporating the field agricultural advances into the design and evaluation of regional cropping system adaptation strategies. It then applies this framework to identify feasible cropping system adaptation strategies under observed warmer climate and quantify their potential benefits to the grain production and water sustainability in the major cropping regions in north China. Three objectives of this study are: (1) Develop a cross-scale model-coupling framework between the site level DSSAT model and the regional level AEZ model to improve the AEZ performance in capturing the northern expansion of japonica rice under a warmer climate in the Northeast China Plain. (2) Construct a new wheat-maize cropping systems adaptation strategy to meet the double challenge of maintaining the regional grain production level and recovering local groundwater table in the semi-arid North China Plain, where the persistent overexploitation of groundwater has caused severe environmental damages. (3) Establish a dynamic adaptation strategy to identify the desired water sustainable cropping systems across different localities and to meet the challenge of recovery local groundwater table and minimize the output losses of wheat and then total grain production in the Hebei Plain, where the irrigation water shortage has threatened wheat production and thus potentially compromising China’s food security. This dissertation will improve our understanding of the interactions and interlinkage across multi-scale agro-ecosystems in mitigating the environmental risks associated with the irrigation-intensive farming and in adapting to climate change. The cropping systems adaptation strategies proposed by this dissertation provide scientific basis for future agricultural adaptation policy design compatible with local agro-climatic, land and soil conditions across China

Coastal flood risks in China through the 21st century – An application of DIVA.

China experiences frequent coastal flooding, with nearly US$77 billion of direct economic losses and over 7,000 fatalities reported from 1989 to 2014. Flood damages are likely to grow due to climate change induced sea-level rise and increasing exposure if no further adaptation measures are taken. This paper quantifies potential damage and adaptation costs of coastal flooding in China over the 21st Century, including the effects of sea-level rise. It develops and utilises a new, detailed coastal database of China developed within the Dynamic Interactive Vulnerability Assessment (DIVA) model framework. The refined database provides a more realistic spatial representation of coasts, with more than 2,700 coastal segments, covering 28,966 km of coastline. Over 50$ 67-3,308 billion damages/yr are projected without upgrade to defences. In contrast, maintaining the current protection level would reduce those numbers to 0.2-0.4 million people flooded/yr and US$22-60 billion/yr flood costs by 2100, with a protection investment costs of US$ 8-17 billion/yr. In 2100, maintaining current protection levels, dikes costs are two orders of magnitude smaller than flood costs across all scenarios, even without accounting for indirect damages. This research improves on earlier national assessments of China by generating a wider range of projections, based on improved datasets. The information delivered in this study will help governments, policy-makers, insurance companies and local communities in China understand risks and design appropriate strategies to adapt to increasing coastal flood risk in an uncertain world

River Ecological Restoration and Groundwater Artificial Recharge

Three of the eleven papers focused on groundwater recharge and its impacts on the groundwater regime, in which recharge was caused by riverbed leakage from river ecological restoration (artificial water replenishment). The issues of the hydrogeological parameters involved (such as the influence radius) were also reconsidered. Six papers focused on the impact of river ecological replenishment and other human activities on river and watershed ecology, and on groundwater quality and use function. The issues of ecological security at the watershed scale and deterioration of groundwater quality were of particular concern. Two papers focused on water resources carrying capacity and water resources reallocation at the regional scale, in the context of the fact that ecological water demand has been a significant topic of concern. The use of unconventional water resources such as brackish water has been emphasized in the research in this issue

Pro-poor intervention strategies in irrigated agriculture in Asia: poverty in irrigated agriculture: issues and options: China

Irrigated farming / Poverty / Households / Income / Irrigation management / Institutions / Conflict / Legal aspects / Water policy / Water allocation / Price policy / Water rights / Water market / Irrigation programs / Public ownership / Models / Regression analysis / Farm size / Labor / Productivity / China

Book of short Abstracts of the 11th International Symposium on Digital Earth

The Booklet is a collection of accepted short abstracts of the ISDE11 Symposium