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.

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 on the situation and countermeasures of water resources supply and demand in the cities of small and medium-sized river basins along southeast coast of China-taking Xiamen City as an example

The small and medium-sized river basins along southeast coast of China hold comparatively abundant water resources.However,the rapid resources urbanization in recent years has produced a series of water problems such as deterioration of river water quality,water shortage and exacerbated floods,which have constrained urban economic development.By applying the principle of triple supply-demand equilibrium,this paper focuses on the estimation of levels of water supply and demand in 2030 at different guarantee probabilities,with a case study of Xiamen city.The results show that water shortage and inefficient utilization are main problems in the city,as the future water supply looks daunting,and a water shortage may hit nearly 2×10^(8)m^(3)in an extraordinarily dry year.Based on current water supply-demand gap and its trend,this paper proposes countermeasures and suggestions for developing and utilizing groundwater resources and improving the utilization rate of water resources,which can supply as a reference for other southeast middle-to-small-sized basin cities in terms of sustainable water resources and water environment protection.

A Simple Discussion on the Supply and Demand of Water Resources in the Western Region of China

We are accustomed to solve the problem of the water scarcity in the western region by the thought of increasing the effective supply of water to meet the needs of Go-west Campaign. After introducing the dynamic equilibrium principle on supply and demand in economy, we find that we should solve the problem of the water scarcity in the western region through reducing total demand to achieve the dynamic equilibrium of supply and demand. Finally water resources in the western region can be enlarged by an accumulated way.

The 3D simulation and optimized management model of groundwater systems based on eco-environmental water demand

Through the study of mutual process between groundwater systems and eco-environmental water demand, the eco-environmental water demand is brought into groundwater systems model as the important water consumption item and unification of groundwater抯 economic, environmental and ecological functions were taken into account. Based on eco-environmental water demand at Da抋n in Jilin province, a three-dimensional simulation and optimized management model of groundwater systems was established. All water balance components of groundwater systems in 1998 and 1999 were simulated with this model and the best optimal exploitation scheme of groundwater systems in 2000 was determined, so that groundwater resource was efficiently utilized and good economic, ecologic and social benefits were obtained.

Irrigation Water Demand Model as a Comparative Tool for Assessing Effects of Land Use Changes for Agricultural Crops in Fraser Valley, Canada

Available water for human needs and agriculture is a growing global concern. Agriculture uses approximately 70% of global freshwater, mainly for irrigation. The Lower Fraser Valley (LFV), British Columbia, is one of the most productive agricultural regions in Canada, supporting livestock production and a wide variety of crops. Water scarcity is a growing concern that threatens the long-term productivity, sustainability, and economic viability of the LFV’s agriculture. We used the BC Agriculture Water Demand Model as a tool to determine how crop choice, irrigation system, and land-use changes can affect predicted water requirements under these different conditions, which can aid stakeholders to formulate better management decisions. We conducted a comparative assessment of the irrigation water demand of seven major commercial crops, by distinct soil management groups, at nineteen representative sites, that use both sprinkler vs drip irrigation. Drip irrigation was consistently more water-efficient than sprinkler irrigation for all crops. Of the major commercial crops assessed, raspberries were the most efficient in irrigation water demand, while forage and pasture had the highest calculated irrigation water demand. Significant reductions in total irrigation water demand (up to 57%) can be made by switching irrigation systems and/or crops. This assessment can aid LFV growers in their land-use choices and could contribute to the selection of water management decisions and agricultural policies.

Comparison and Assessment of Success of Models in Watershed Simulation and Management

In Jordan, Zarqa River Basin (ZRB) has been taken as a case study for applying water management models because of its limited water resources and due to the fact that the basin is dwelling with about 52% of Jordan’s population. The surface water resources are mainly used for agriculture because they are mixed with treated water and cannot be used for domestic purposes. This paper aims to demonstrate the contributions of Models in watershed management that provide indirect ways of assessing and confirming the success of models in water flow simulation. The method includes transferring the computed hydrologic parameters for Zarqa basin’s sub-catchments within Watershed Modeling System (WMS) into Water Resources Model (WRM) and HEC-1 models. Then the results of the HEC-1 and WRM models are compared according to their basin’s simulation with the real basin. The study includes description of the HEC-1, WRM models philosophy, the models representation, and simulation results and analysis of the Zarqa River Basin. Comparing the results of WRM and HEC-1 models proved their simulation efficiency in predicting the flow of Zarqa River Basin. Nevertheless, the philosophy of HEC-1 is a single storm event and is based on values of curve number, while WRM philosophy describes the water flow and availability, and demand and supply balance on a daily basis across the basin. The models’ predictions for the real flow definitely establish the modeling certainty and help the water resources’ developers to incorporate different basin features for watershed representation, simulation, and management. Hence, the certainty of the results in modeling provides indirect ways of assessing the success of models’ simulations.

Jordan’s Water Resources: Increased Demand with Unreliable Supply

Jordan is a small county located in the Middle East. Jordan has borders with Saudi Arabia, Syria, Iraq, and Israel (Figure 1). Jordan was established in 1921 and has very limited natural resources. Jordan’s current (2008) population is 6.5 million. The country has a total land area of 750,000 km2, about one third (92,300 km2) of which is dry land while the other two thirds (329,000 km2) are irrigated land. Jordan is considered as a water poor country due to unreliable and shortages in the supply of water sector. This makes it very difficult to meet the required and steadily increasing demand. Impact of climate change adds a layer to the uncertainty on the supply side of Jordan’s water portfolio. This paper addresses the water supply challenges that Jordan faces and what has been accomplished to improve supply and/or reduce demand. Many projects were undertaken or planned by the Jordanian government to increase the water supply and improve its reliability. Completing the proposed projects will result in Jordan meeting its water demand [1]. Otherwise, the Jordanian Government implement some or all the proposed short term solutions as presented in this paper.

Primary logistics planning of oil products under the imbalance of supply and demand

This paper intends to complete the primary logistics planning of oil products under the imbalance of supply and demand. An integrated mathematical programming model is developed to simultaneously find the balance between supply and demand, and optimize the logistics scheme. The model takes minimum logistics cost and resource adjustment cost as the objective function, and takes supply and demand capacity, transportation capacity, mass balance, and resource adjustment rules as constraints.Three adjustment rules are considered in the model, including resource adjustment within oil suppliers,within oil consumers, and between oil consumers. The model is tested on a large-scale primary logistics of a state-owned petroleum enterprise, involving 37 affiliated refineries, 31 procurement departments,286 market depots and dedicated consumers. After the unified optimization, the supply and demand imbalance is eased by 97% and the total cost is saved by 7%, which proves the effectiveness and applicability of the proposed model.

Application of WEAP Simulation Model to Hengshui City Water Planning

Like many river basins in China, water resources in the Fudong Pai River are almost fully allocated. This paper seeks to assess and evaluate water resource problems using water evaluation and planning (WEAP) model via its application to Hengshui Basin of Fudong Pai River. This model allows the simulation and analysis of various water allocation scenarios and, above all, scenarios of users' behavior. Water demand management is one of the options discussed in detail. Simulations are proposed for diverse climatic situations from dry years to normal years and results are discussed. Within the limits of data availability, it appears that most water users are not able to meet all their requirements from the river, and that even the ecological reserve will not be fully met during certain years. But the adoption of water demand management procedures offers opportunities for remedying this situation during normal hydrological years. However, it appears that demand management alone will not suffice during dry years. Nevertheless, the ease of use of the model and its user-friendly interfaces make it particularly useful for discussions and dialogue on water resources management among stakeholders.

Problems for water resources development in typical small karst drainage basins and countermeasures

In karst area water deficit is one of the main factors constraining sustainable economic development. In 1979 the comprehensive karstic observational field station was set up in Houzhai drainage basin located,\ in Puding county of Guizhou Province, which can represent most of the small karst drainage basins on the dividing line of the Guizhou Plateau. Geomorphology, water resources and water chemistry were investigated and observed. Based on comparisons of water supply with water demand and analysis of the main problems in water exploitation and utilization. it is found out that the water deficiency was not directly caused by the scarcity of natural water resources. The true reason is the insufficient capacity of water supply caused by the dismatch of the water and soil water resources which can be dealt with by building more irrigation works. Some solutions such as to build scientific basis for water exploitation and utilization and sustainable economic development in karst drainage basins on dividing line of the Guizhou Plateau.

Water Resources Development and Water Utilization in the Gavkhuni River Basin, Iran

Analysis of water supplies and demand over the past 50 years in the Gavkhuni River Basin（GRB） indicate that despite large investments in water resources development the basin remains just as vulnerable to drought as it always has been. During the period of analysis two transbasin diversions and a storage reservoir have been constructed which have more or less doubled the annual supply to water to the basin. But with each water resource development extractive capacity for irrigation, urban and industrial use has increased by the same amount, so that all new water is allocated as soon as it is available. The most recent developments, since 1980, have actually increased vulnerability to drought because extractive capacity is greater than average flow into the basin. Whenever demand exceeds supply all water is extracted from the basin and the tail end dries up. During the past 50 years flows into the salt pan at the downstream end of the basin have been negligible for more than half the time. Prospects for the future are bleak because once the current phase of water resources development is completed no further water supplies are likely, but demand continues to rise at a steady rate. Ultimately agriculture will have to concede water to urban, industrial and environmental demands.

Evaluation of Potential Impacts of Agricultural Policy Reforms on Sustainability of Groundwater Resources of Saudi Arabia

Saudi Arabia has achieved extensive development and expansion in agriculture sector and achieved self sufficiency in a number of agricultural crops including wheat, fodders, dates, some vegetables and fruits. Considering the future growing need for food and water, government of Saudi Arabia has formulated and implemented a number of policy reforms for conservation, optimal utilization and sustainable development of natural resources of the Kingdom. The present study focuses on potential future impacts on natural resources conservations and strategic planning due to recent policy reforms （Council of Ministers （CoM） on Water Resources Management and Conservation （Decision No. 335）） issued on September 2008. The modeling of wheat agriculture was performed based on detailed analysis of water application practices in wheat growing regions/districts and future projection of wheat irrigation in context of recent government water resources conservation strategy. The results clearly indicated a significant positive impact will be occurred in terms of huge relief on highly stressed and limited national strategic groundwater resources. The present study estimated a saving and conservation of more than 51.0 billion cubic meters （BCM） of non-renewable groundwater resources during next 11 years.

Modeling demand/supply of water resources in the arid region of northwestern China during the late 1980s to 2010

Water demand increases continuously with an increasing population and economic development. As a result, the difference between water supply and demand becomes a sig- nificant issue, especially in arid regions. To figure out the utilization of water resources in the arid region of northwestern China （ARNWC）, and also to provide methodologies to predict the water use in future, three models were established in this study to calculate agricultural irri- gation, industrial and domestic water use in the ARNWC from the late 1980s to 2010. Based on river discharges in the region, the supply and demand of water resources at the river basin level were analyzed. The results indicated that agricultural irrigation demand occupies more than 90% of the total water use in the ARNWC. Total water demand increased from 31.97 km3 in the late 1980s to 48.19 km3 in 2010. Most river basins in this arid region were under me- dium and high water stress. Severe-risk river basins, such as the Shiyang river basin and the eastern part of the northern piedmont of the Tianshan Mountains, were found in this region. It was revealed that the water supply became critical from April to May, which was the season of the lowest water supply as determined by comparing monthly water consumption.

Improved Water Network Macroscopic Model Utilising Auto-Control Adjusting Valve by PLS

In order to overcome the low precision and weak applicability problems of the current municipal water network state simulation model, the water network structure is studied. Since the telemetry system has been applied increasingly in the water network, and in order to reflect the network operational condition more accurately, a new water network macroscopic model is developed by taking the auto-control adjusting valve opening state into consideration. Then for highly correlated or collinear independent variables in the model, the partial least squares (PLS) regression method provides a model solution which can distinguish between the system information and the noisy data. Finally, a hypothetical water network is introduced for validating the model. The simulation results show that the relative error is less than 5.2%, indicating that the model is efficient and feasible, and has better generalization performance.

Analog simulation of urban construction land supply and demand in Chang-Zhu-Tan Urban Agglomeration based on land intensive use

Urban land intensive use is an important indicator in harmonizing the relationship between land supply and demand. The system dynamics(SD) can be used to construct the feedback loop between urban construction land supply and demand and index variable function. Based on this, this study built a supply and demand system dynamic model of urban construction land for Chang-Zhu-Tan urban agglomeration. This model can simulate the change trends of supply and demand of construction land, industrial land, and residential land in 2016–2030 by three scenarios of low, medium, and high intensity modes. The results showed that the scale of construction land of urban agglomeration is expanding, with a rapid increase rate for the urban construction land. The scale and speed of land use based on the three intensity modes existed differences. The large scale and supply of construction land in the low intensity mode caused easily the waste of land resources. In high intensity mode, the scale and supply of construction land were reduced against the healthy development of new-type urbanization. In the medium intensity mode, the scale and supply of land use adapted to the socio-economic development and at the same time reflected the concept of modern urban development. In addition, the results of this study found that the proportion of industrial land in construction land ranged from 15% to 21%, which increased year by year in the low intensity mode, and decreased slowly and stabilized in medium and high intensity modes. The proportion of residential land in construction land ranged from 27% to 35%, which decreased in the low and the medium intensity modes, and maintained a high level in the higher intensity mode. This study contributes to provide scientific reference for decision-making optimization of land supply and demand, urban planning, and land supply-side reform.

Optimization research on supply and demand system for water resources in the Chang-Zhu-Tan urban agglomeration

Using system analysis theory and methods, a dynamic model of a water resource supply and demand system was built to simulate trends in the supply and demand of water in the Changsha-Zhuzhou-Xiangtan （Chang-Zhu-Tan） urban agglomeration for the period 2012 to 2030. Four scenarios were examined; namely, a traditional development model, an economic development model, a water-saving model, and a coordinated development model. （i） The problem of balancing water resource supply and demand is becoming increasingly conspicuous with a growing population and a rapidly developing economy. （ii） By 2030, water demand is set to reach a total of 105.1 × 10^8 m^3, with a water supply of 5.4 × 10^8 m^3. A coordinated development model for water resource supply could meet the growing demands of socio-economic development, and generate huge comprehensive benefits. This will be the best solution for the development and utilization of a water resource supply and demand system in the Chang-Zhu-Tan urban agglomeration. （iii） We should accelerate the construction of water conservation projects, strengthen the management of water conservation, optimize economic structures, enhance our awareness of the importance of protecting water resources, hasten the recycling of waste water and environmental improvement, and promote utilization efficiency, and support the capabilities of water resources to meet our expectations.

Water Resources Operation and Management Model and Its Simulation Process Research

Based on the status quantity of water resources in Xi′an region, a commentary on many math models is given for water resources operation and management, and the visual model is provided to solve practical problems. In this model, the information for decision is visible in GIS (Geographic Information Systems) and topological figures. With object orientation methods, the objects are described in proprieties, methods, relations and time periods. The simulation process of the model is developed with Delphi and MapInfo, and the real decision scheme could be examined and practice decision process can be simulated from which. Decision analysis conducted from visual conditions is believable. The exploration to visual model is a beginning of practice research, much more study of which still needs to do.

Quantifying the Cloud Water Resource:Methods Based on Observational Diagnosis and Cloud Model Simulation

Based on the concepts of cloud water resource(CWR)and related variables proposed in the first part of this study,this paper provides details of two methods to quantify the CWR.One is diagnostic quantification(CWR-DQ)based on satellite observations,precipitation products,and atmospheric reanalysis data;and the other is numerical quantification(CWR-NQ)based on a cloud resolving model developed at the Chinese Academy of Meteorological Sciences(CAMS).The two methods are applied to quantify the CWR in April and August 2017 over North China,and the results are evaluated against all available observations.Main results are as follows.(1)For the CWR-DQ approach,reference cloud profiles are firstly derived based on the Cloud Sat/CALIPSO joint satellite observations for 2007–2010.The NCEP/NCAR reanalysis data in 2000–2017 are then employed to produce three-dimensional cloud fields.The budget/balance equations of atmospheric water substance are lastly used,together with precipitation observations,to retrieve CWR and related variables.It is found that the distribution and vertical structure of clouds obtained by the diagnostic method are consistent with observations.(2)For the CWR-NQ approach,it assumes that the cloud resolving model is able to describe the cloud microphysical processes completely and precisely,from which four-dimensional distributions of atmospheric water vapor,hydrometeors,and wind fields can be obtained.The data are then employed to quantify the CWR and related terms/quantities.After one-month continuous integration,the mass of atmospheric water substance becomes conserved,and the tempospatial distributions of water vapor,hydrometeors/cloud water,and precipitation are consistent with observations.(3)Diagnostic values of the difference in the transition between hydrometeors and water vapor(Cvh-Chv)and the surface evaporation(Es)are well consistent with their numerical values.(4)Correlation and bias analyses show that the diagnostic CWR contributors are well correlated with observations,and match their numerical counterparts as well,indicating that the CWR-NQ and CWR-DQ methods are reasonable.(5)Underestimation of water vapor converted from hydrometeors(Chv)is a shortcoming of the CWR-DQ method,which may be rectified by numerical quantification results or by use of advanced observations on higher spatiotemporal resolutions.

NUMERICAL SIMULATION OF WATER QUANTITY AND QUALITY FOR RIVER-TYPE RESERVOIRS

River-type reservoir is narrow and long in shape and has many reservoir bends and confluence of tributaries. On the basis of Saint-Venant equation and differential equation for longitudinal diffusion and in consideration of the influence of confluences and bends, in order to predict the water quantity and quality, an one-dimensional unsteady mathematical model was established in this paper. The model consists of a hydrodynamic model and a water quality model. The average hydraulic characteristics and water quality parameters were calculated for a reservoir with two confluences and four bends. Computed results are in good agreement with field observation data. The model can be applied to predict the water quantity, water level and water quality of the river-type reservoirs.