Yangwen Jia

Can China Cope with Its Water Crisis?—Perspectives from the North China Plain

by Chunmiao Zheng1,2,3, Jie Liu3, Guoliang Cao2, Eloise Kendy4, Hao Wang5, and Yangwen Jia5 1Corresponding author: Department of Geological Sciences, University of Alabama, Tuscaloosa, AL 35487; (205) 348-0579; fax: (205) 348-0818; czheng@ua.edu 2Department of Geological Sciences, University of Alabama, Tuscaloosa, AL 35487. 3Center for Water Research, Peking University, Beijing 100871, China. 4Environmental Flow Program, The Nature Conservancy, Helena, MT 59601. 5Department of Water Resources, China Institute of Water Resources & Hydropower Research, Beijing 100038, China.

A WebGIS-based system for rainfall-runoff prediction and real-time water resources assessment for Beijing

A WebGIS-based system designed to predict rainfall-runoff and assess real-time water resources for Beijing was developed to provide support for scientific decision making regarding solving water shortages while effectively reducing urban flood threats in the city. The system adopts a Browse Server (B/S) structure and combines the distributed hydrologic modeling and WebGIS techniques. For this system, a distributed hydrologic model of Beijing that adopts a grid cell-size of 1km by 1km and covers the citys entire area of 16,400km^2 was developed and validated. This model employs a simple, yet practical rainfall-runoff correlation curve method to predict runoff, as well as prediction approaches for rainfall, evaporation, subsurface runoff and recharge to groundwater. In addition, a framework for the assessment of real-time water resources assessment based on hydrologic monitoring stations and the distributed model was established. Finally, a WebGIS-based system for rainfall-runoff prediction and real-time water resources assessment for Beijing was developed by integrating a data platform, the professional models and the WebGIS techniques. This system was successfully integrated into the hydrologic prediction practices of the General Station of Hydrology, Bureau of Beijing Water Affairs in 2005, and the demonstration version of the system can be seen on the Web at http://123.127.143.23/enewRF/login/login.aspx?ReturnUrl=%2fenewRF%2ftemp.aspx.

Integrating Remote Sensing Information Into A Distributed Hydrological Model for Improving Water Budget Predictions in Large-scale Basins through Data Assimilation

This paper investigates whether remote sensing evapotranspiration estimates can be integrated by means of data assimilation into a distributed hydrological model for improving the predictions of spatial water distribution over a large river basin with an area of 317,800 km2. A series of available MODIS satellite images over the Haihe River basin in China are used for the year 2005. Evapotranspiration is retrieved from these 1×1 km resolution images using the SEBS (Surface Energy Balance System) algorithm. The physically-based distributed model WEP-L (Water and Energy transfer Process in Large river basins) is used to compute the water balance of the Haihe River basin in the same year. Comparison between model-derived and remote sensing retrieval basin-averaged evapotranspiration estimates shows a good piecewise linear relationship, but their spatial distribution within the Haihe basin is different. The remote sensing derived evapotranspiration shows variability at finer scales. An extended Kalman filter (EKF) data assimilation algorithm, suitable for non-linear problems, is used. Assimilation results indicate that remote sensing observations have a potentially important role in providing spatial information to the assimilation system for the spatially optical hydrological parameterization of the model. This is especially important for large basins, such as the Haihe River basin in this study. Combining and integrating the capabilities of and information from model simulation and remote sensing techniques may provide the best spatial and temporal characteristics for hydrological states/fluxes, and would be both appealing and necessary for improving our knowledge of fundamental hydrological processes and for addressing important water resource management problems.

The economic impact of water tax charges in China: a static computable general equilibrium analysis

This paper presents a static computable general equilibrium model of the Chinese economy with water as an explicit factor of production. This model is used to assess the broad economic impact of a policy based on water demand management, using water tax charges as a policy-setting tool. It suggests that imposing water taxes can redistribute sectoral water use and lead to shifts in production, consumption, value added, and trade patterns. Another important finding is that water taxes imposed on the agricultural sector drive most of the effects.

Assessing climate change impacts on the ecohydrology of the Jinghe River basin in the Loess Plateau, China

Abstract Quantifying the impacts of climate change on the hydrology and ecosystem is important in the study of the Loess Plateau, China, which is well known for its high erosion rates and ecosystem sensitivity to global change. A distributed ecohydrological model was developed and applied in the Jinghe River basin of the Loess Plateau. This model couples the vegetation model, BIOME BioGeochemicalCycles (BIOME-BGC) and the distributed hydrological model, Water and Energy transfer Process in Large river basins (WEP-L). The WEP-L model provided hydro-meteorological data to BIOME-BGC, and the vegetation parameters of WEP-L were updated at a daily time step by BIOME-BGC. The model validation results show good agreement with field observation data and literature values of leaf area index (LAI), net primary productivity (NPP) and river discharge. Average climate projections of 23 global climate models (GCMs), based on three emissions scenarios, were used in simulations to assess future ecohydrological responses in the Jinghe River basin. The results show that global warming impacts would decrease annual discharge and flood season discharge, increase annual NPP and decrease annual net ecosystem productivity (NEP). Increasing evapotranspiration (ET) due to air temperature increase, as well as increases in precipitation and LAI, are the main reasons for the decreasing discharge. The increase in annual NPP is caused by a greater increase in gross primary productivity (GPP) than in plant respiration, whilst the decrease in NEP is caused by a larger increase in heterotrophic respiration than in NPP. Both the air temperature increase and the precipitation increase may affect the changes in NPP and NEP. These results present a serious challenge for water and land management in the basin, where mitigation/adaption measures for climate change are desired. Editor Z.W. Kundzewicz; Associate editor D. Yang Citation Peng, H., Jia, Y.W., Qiu, Y.Q., and Niu, C.W., 2013. Assessing climate change impacts on the ecohydrology of the Jinghe River basin in the Loess Plateau, China. Hydrological Sciences Journal, 58 (3), 651–670.

Coupling crop growth and hydrologic models to predict crop yield with spatial analysis technologies

This paper analyzes climate change impact on crop yield of winter wheat, a main crop in the water-stressed Haihe River Basin in North China. An integrated analysis was carried out by coupling the World Food Studies (WOFOST) crop growth model and the distributed hydrological model describing the water and energy transfer processes in large river basins (WEP-L). Various spatial analysis technologies, including remote sensing and geographical information system, were woven together to support model calibration and validation. The WOFOST model was calibrated and validated using the winter wheat data collected in two successive years. Effort was then extended to calibrate and validate the WEP-L distributed hydrologic model for the whole basin. Such an effort was collectively supported by using the remote sensing evapotranspiration and biomass data, the in situ river flow data, and the wheat yield statistical data. With this integration, the wheat yield from 2010 to 2030 can be predicted under the given climate change impact corresponding to Intergovernmental Panel on Climate Change A1B, A2, and B1 scenarios. Given the prescribed climate change scenarios, at the basin-scale, the winter wheat yield may increase in terms of the annual average; however, the long-term trend is geared toward a decreasing yield with significant fluctuations. The colder hilly areas with current lower yield may significantly increase due to possible future temperature rise while the warmer plain areas with current higher yield may slightly increase or decrease. Despite the data collected thus far, it is evident that further studies are needed to reduce the uncertainties of these predictions of climate change effect on winter wheat grain yield.

Assessing the economic impact of North China’s water scarcity mitigation strategy : a multi - region, water - extended computable general equilibrium analysis

This paper describes a multi-region computable general equilibrium model for analyzing the effectiveness of measures and policies for mitigating North China’s water scarcity with respect to three different groups of scenarios. The findings suggest that a reduction in groundwater use would negatively affect economic growth and household incomes. A planned water-transfer project would improve economic development and reduce the over-exploitation of local water resources, while water demand management policies would improve water-use efficiency through reallocating water to those sectors having a higher marginal product value. Several important policy implications are drawn from these findings.

Assessing economic impacts of China's water pollution mitigation measures through a dynamic computable general equilibrium analysis

In this letter, we apply an extended environmental dynamic computable general equilibrium model to assess the economic consequences of implementing a total emission control policy. On the basis of emission levels in 2007, we simulate different emission reduction scenarios, ranging from 20 to 50% emission reduction, up to the year 2020. The results indicate that a modest total emission reduction target in 2020 can be achieved at low macroeconomic cost. As the stringency of policy targets increases, the macroeconomic cost will increase at a rate faster than linear. Implementation of a tradable emission permit system can counterbalance the economic costs affecting the gross domestic product and welfare. We also find that a stringent environmental policy can lead to an important shift in production, consumption and trade patterns from dirty sectors to relatively clean sectors

Assessing groundwater vulnerability and its inconsistency with groundwater quality, based on a modified DRASTIC model: a case study in Chaoyang District of Beijing City

Depth to water, net recharge, aquifer media, soil media, topography, impact of the vadose zone media, and hydraulic conductivity of the aquifer (DRASTIC) model based on a geographic information system (GIS) is the most widely adopted model for the evaluation of groundwater vulnerability. However, the model had its own disadvantages in various aspects. In this work, several methods and the technologies have been introduced to improve on the traditional model. The type of the aquifer was replaced by the thickness of the aquifer, and the index of topography was removed. The indexes of the exploitation of the groundwater and the type of land use that reflected the special vulnerability were added to the system. Furthermore, considering the wideness of the study area, the fixed weights in the DRASTIC model were not suitable. An analytic hierarchy process (AHP) method and an entropy weight (Ew) method were introduced to calculate the weights of parameters. Then, the Spearman Rho correlation coefficients between IVI and the Nemerow synthetical pollution index (NI) of the groundwater quality were significantly improved, after the four steps of modification. The level differences with little gaps between Nemerow comprehensive pollution indexes and groundwater vulnerability occupied the proportion of the area from 75.68 to 84.04%, and finally, a single-parameter sensitivity analysis for the two models was used to compute the effective weights of these parameters. By comparison, the DRMSICEL model seems to perform better than the DRASTIC model in the study area. And the results show discrepancies between the vulnerability indices and groundwater quality as indicated by existence of vulnerable areas with bad water quality and vice versa.

An analysis of water consumption and pollution with an input-output model in the Haihe river basin, China

It is widely believed that the economic success in China is achieved at the expense of natural resources and has resulted in severe pollution of the environment, especially water resources. This study applies a hybrid input-output (IO) model linking economic and ecological systems in order to analyze water consumption and wastewater discharge in the Haihe River Basin. Within the environmental IO framework, a series of assessment indicators is calculated to assist in tracking both direct and indirect effects of freshwater consumption and wastewater discharge in the economic sector, as well as to distinguish the economic sectors that have greatest influence on water demand and pollution. Assessment results indicate that water consumption and pollution can be reduced by readjusting the structure of production, consumption and trade in the Haihe River Basin. It is concluded that in order to achieve sustainable development in the Haihe River Basin with its very poor water endowment, not only the direct but also the indirect effects on water demand and pollution should be considered when production, consumption and trade policies are formulated.