Balance of Water Supply-demand in Paddy Fields in Hilly Regions in Sichuan Province

[Objective] The aim was to study the effects of water supply and consumption on water saving and drought resistance. [Method] Controlling field experiment was conducted to explore water balance between supply and demand in paddy fields in hilly regions in Sichuan Province. [Result] Rainfall in hilly areas was 3 611.10 m3/hm2; water for irrigation was 6 299.25 m3/hm2; evapotranspiration of rice was 6 424.95 m3/hm2; deep leakage was 2 459.55 m3/hm2; overflowing amount was 1 026.00 m3/hm2. In addition, water consumption totaled 8 884.50 m3/hm2 during rice production; water use was 0.99 kg/m3 and use efficiency of irrigated water was 1.40 kg/m3. [Conclusion] Water supply and consumption should be further organized to save water and fight against drought in hilly areas in Sichuan Province.

THE BALANCE BETWEEN SUPPLY AND DEMAND OF WATER RESOURCES AND THE WATER-SAVING POTENTIAL FOR AGRICULTURE IN THE HEXI CORRIDOR

The Hexi Corridor is an important base of agriculture development inNorthwest China. According to recent statistics, there are 65. 94 x 10~8m^3 of water resourcesavailable in the Hexi Corridor. At present, net consumption in development and utilization is 43. 33x 10~8m^3. Water supply and demand reach a balance on the recent level of production, but loss ofevaporation and evapotranspiration is as much as 25. 69 x 1010~8m^3. So net use efficiency of waterresources is 59% Based on analyzing balance between water and land considering ecologicalenvironment at present, there exists the serious water shortage in the Shiyang River system whereirrigation lands have overloaded. There is a comparative balance between supply and demand of waterresource in the Heihe River system; and the Sule River system has some surplus water to extendirrigation land. Use of agriculture water accounts for 83. 3% and ecological forest and grass for 6.9% . The Hexi Corridor still has a great potential for water saving in agriculture production.Water-saving efficiency of irrigation is about 10% by using such traditional technologies as furrowand border-dike irrigation and small check irrigation, and water-saving with plastic film cover andtechniques of advanced sprinkler and drip/micro irrigation etc. can save more than 60% of irrigatedwater. Incremental irrigation area for water-saving potential in the Hexi Corridor has beenestimated as 56% - 197% to original irrigation area. So the second water sources can be developedfrom water saving agriculture in the Hexi Corridor under Development of the Western Part of China inlarge scale. This potential can be realized step by step through developing the water-savingmeasures, improving the ecological condition of oasis agriculture, and optimizing allocation ofwater resources in three river systems.

Analysis of Water Resources Supply and Demand and Security of Water Resources Development in Irrigation Regions of the Middle Reaches of the Heihe River Basin, Northwest China

Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance of water supply and demand in the region was established, and the security of water resource was assessed, from which the results that the effects of unified management of water resources in the Heihe River basin between Gansu Province and Inner Mongolia on regional hydrology are significant with a decrease in water supply diverted from Heihe River and an increase in groundwater extracted. In addition, it was found that the groundwater level has been steadily decreasing due to over pumping and decrease in recharges. In present year （2003）, the volume of potential groundwater in the irrigation districts is far small because of the groundwater overdraft; even in the particular regions, there is no availability of groundwater resources for use. By 2003, water supply is not sufficient to meet the water demand in the different irrigation districts, the sustainable development and utilization of water resources are not secured, and the water supply crisis occurs in Pingchuan irrigation district. Achieving water security for the sustainable development of society, agriculture, economy, industry, and livelihoods while maintaining or improving the abilities of the management and planning of water resources, determining of the reasonable percentage between water supply and groundwater utilization and water saving in agricultural irrigation are taken into account. If this does not occur, it is feared that the present performance of water development and planning may further aggravate the problem of scarcities of water resources and further damage the fragile ecological system.

Technical System Construction in the Market Trading System for Demand Response Based on the Energy Internet

With the explosive growth of variable renewable energy,the balance between the supply and demand of the power grid is faced with new challenges.Based on the development experience from typical countries and the state quo in China,this paper further analyzes the system architecture and development trend of demand response under the background of Energy Internet.Five dimensions are considered:Energy Internet platform,demand response application scenarios,system architecture,information technology system construction,and demand response development trend.The results show that the application of the Energy Internet platform can effectively solve the problems of data acquisition and processing,“terminal-edge-network-cloud”cooperation of demand response,etc.The system architecture of the demand response platform that supports user resource management,user information access,control instruction receiving,control strategy issuing,and response process monitoring is proposed in this paper.It is also helpful to provide a feasible technical choice for expanding the application services of Energy Internet towards government and society.

Spatial and Temporal Patterns of Supply and Demand Balance of Water Supply Services in the Dongjiang Lake Basin and Its Beneficiary Areas

Water-related ecosystem services is a hot topic in ecological research. Water supply services are crucial to regional water cycles and water quantity balance. The Dongjiang Lake basin is a national priority river basin in China where ecological compensation pilot programs concerning water resources and water supply services are top priorities for ecosystem service protection. We analyzed spatial and temporal patterns associated with generation and use of water supply services in the Dongjiang Lake basin using the In VEST model, socio-economic data and water resource data. We found that between 1995 and 2010, water yield in the Dongjiang Lake basin and its beneficiary areas increased before declining, varying 9350–12 400 m3 ha-1 y-1; average water yield peaked in 2000. The spatial distribution patterns of water yield during these years are similar, progressively decreasing from upstream to downstream with a remarkable reduction in surrounding areas of city clusters. Average water consumption of the basin and its beneficiary areas ranged from 2900–4450 m3 ha-1 y-1 between 1995 and 2010; the spatial distribution patterns of water consumption during these years are similar, dropping gradually from urban construction land to its surroundings with a stronger gradient between urban and rural areas. More water was consumed on both banks and surroundings of the lake. From 1995 to 2010, water supply fell short of demand for urban construction land and its proximity as well as areas along the lake. Water supply services were able to satisfy needs in other regions. The Changsha-Zhuzhou-Xiangtan city cluster suffers from the most strained water supply.

Land Use Allocation Based on Interval Multi-objective Linear Programming Model: A Case Study of Pi County in Sichuan Province

Adjusting and optimizing land use structure is one of the essential approaches to solve the conflict between land supply and demand. In this study,an uncertain interval multi-objective linear programming model was established and applied to analyzing the suitability of land use structure in Pi County of Sichuan Province. An adjustment scheme for optimizing land use structure was proposed on the basis of development planning drawn up by the local government. The results are summarized as follows: 1) the optimal adjustment scope for cropland area ranges from 27 976.75 ha to 31 029.08 ha,and the current area is less than the lower limit of the scope; 2) the optimal adjustment scope for garden land area ranges from 4 736.49 ha to 12 967.11 ha,and the current area is less than the lower limit; 3) the optimal adjustment scope for construction land ranges from 7 761.95 ha to 10 393.18 ha,and the current area is greater than the upper limit; 4) the optimal adjustment scope for industry and mining land ranges from 557.29 ha to 693.54 ha,and the current area exceeds the upper limit; and 5) the areas of forest land,grassland and other agricultural land are within the optimal adjustment scope. In order to maximize comprehensive benefit with the limited resources and the demand of sustainable development,the areas of cropland and garden land are supposed to be expanded properly,while the construction land should be controlled and reduced gradually,and the forest land and other agricultural land can be maintained at the current level in short period.

Ecosystem service of green infrastructure for adaptation to urban growth:function and configuration

Objectives:(1)to explore what kind of green infrastructure(GI)meets the demand for urban ecological security of rapid urbanization areas;(2)to figure out how to determine the specific function and configuration of GI from ecosystem service requirements of urban ecological security.Methods:(1)Through the literature review,this article summarizes the function and structure evolution of GI in order to adapt to urban growth.(2)Standing on the imperfect ecological functions and unreasonable spatial configurations,this article builds up a conceptual model for the optimization of green infrastructure ecosystem services to meet the demand for the green infrastructure pattern needed by urban growth.Results:The optimization framework consists of four central function modules and its regulating and controlling mechanisms,incuding:(1)Balancing supply and demand of GI's ecosystem service;(2)Measuring and evaluating GI's ecosystem services;(3)Elevating and optimizing GI's ecosystem service;(4)Building urban ecological security patterm with high efficiency of GI's ecosystem services.Moreover,this framework provides guidance for the planning and design of GI and the urban ecological security pattern building in rapid urbanization areas based on ba lancing supply and demand of GI's ecosystem services.Conclusion:The conceptual model of Gl's ecosystem service optimization based on balan-cing supply and demand shows a new path to meet the needs of urban growth and build a city's ecological security pattern through upgrading and optimizing GI.