Water Environmental Degradation of the Heihe River Basin in Arid Northwestern China

Qi, Shanzhong; Luo, Fang

doi:10.1007/s10661-005-3912-6

Cited by 93 publications

(60 citation statements)

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“…The exploitation of groundwater in the middle reaches has also increased during recent years to reduce the removal of surface water and maintain a base flow for the downstream environment, in concordance with the water policy of the "water diversion scheme" set by the local government in 1997. The downstream area of the basin is formed by the Alxa High plain at an altitude of about 1000 m. The plain is extremely arid, characterized by only 42 mm yr −1 of annual precipitation based on data from local meteorological stations (Qi and Luo, 2005).…”

Section: Domain Of Studymentioning

confidence: 99%

“…The simulation period was set from 1981 to 2013, corresponding to a period during which the input irrigation dataset was collected, with a time step of 1800 s. The simulation spatial resolution was fixed at 30 arcsec (0.0083 • ). To satisfy the high-resolution process, we replaced the CLM4.5 land cover data with the Multi-source Integrated Chinese Land Cover map available at a 1 km resolution (Ran et al, 2012). We used the Heihe Watershed Allied Telemetry Experimental Research (HiWA-TER) land cover map with 30 m resolution Zhong et al, 2014) to identify the specific crop types (corn, cereals, soybean, or others) from each crop grid.…”

Section: Experimental Designmentioning

confidence: 99%

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Seasonal effects of irrigation on land–atmosphere latent heat, sensible heat, and carbon fluxes in semiarid basin

2017

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Abstract. Irrigation, which constitutes ∼ 70 % of the total amount of freshwater consumed by the human population, is significantly impacting land-atmosphere fluxes. In this study, using the improved Community Land Model version 4.5 (CLM4.5) with an active crop model, two high-resolution (∼ 1 km) simulations investigating the effects of irrigation on latent heat (LH), sensible heat (SH), and carbon fluxes (or net ecosystem exchange, NEE) from land to atmosphere in the Heihe River basin in northwestern China were conducted using a high-quality irrigation dataset compiled from 1981 to 2013. The model output and measurements from remote sensing demonstrated the capacity of the developed models to reproduce ecological and hydrological processes. The results revealed that the effects of irrigation on LH and SH are strongest during summer, with a LH increase of ∼ 100 W m −2 and a SH decrease of ∼ 60 W m −2 over intensely irrigated areas. However, the reactions are much weaker during spring and autumn when there is much less irrigation. When the irrigation rate is below 5 mm day −1 , the LH generally increases, whereas the SH decreases with growing irrigation rates. However, when the irrigation threshold is in excess of 5 mm day −1 , there is no accrued effect of irrigation on the LH and SH. Irrigation produces opposite effects to the NEE during spring and summer. During the spring, irrigation yields more discharged carbon from the land to the atmosphere, increasing the NEE value by 0.4-0.8 gC m −2 day −1 , while the summer irrigation favors crop fixing of carbon from atmospheric CO 2 , decreasing the NEE value by ∼ 0.8 gC m −2 day −1 . The repercussions of irrigation on land-atmosphere fluxes are not solely linked to the irrigation amount, and other parameters (especially the temperature) also control the effects of irrigation on LH, SH, and NEE.

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Section: Domain Of Studymentioning

confidence: 99%

Section: Experimental Designmentioning

confidence: 99%

Seasonal effects of irrigation on land–atmosphere latent heat, sensible heat, and carbon fluxes in semiarid basin

2017

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“…In the middle reaches, the elevation decreases from 2000 to 1000 m and the precipitation correspondingly decreases from 200 mm to less than 100 mm in the direction from south to north (Li et al, 2001). The lower reaches, whose mean altitude is approximately 1000 m, are an arid region with a mean annual precipitation of only 42 mm according to statistics from meteorological stations (Qi and Luo, 2005). In this study, five typical river cross sections were chosen as test sites to simulate using our CLM_RIV model.…”

Section: Study Domainmentioning

confidence: 99%

“…Water is indispensable for ecohydrological system (Milly et al, 2005;Ouyang et al, 2003;Shen and Chen, 2010;Zhao and Cheng, 2002). Among a variety of water resources, aquifer water and stream water, which constitute more than 30 % of the freshwater storage, are key factors in hydrological cycle Schär et al, 1999;Xie et al, 2014;Yu et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Ecohydrological effects of stream–aquifer water interaction: a case study of the Heihe River basin, northwestern China

Zeng

Xie

et al. 2016

Hydrol. Earth Syst. Sci.

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Abstract. A scheme describing the process of streamaquifer interaction was combined with the land model CLM4.5 to investigate the effects of stream water conveyance over riparian banks on ecological and hydrological processes. Two groups of simulations for five typical river cross sections in the middle reaches of the arid-zone Heihe River basin were conducted. The comparisons between the simulated results and the measurements from water wells, the FLUXNET station, and remote sensing data showed good performance of the coupled model. The simulated riparian groundwater table at a propagation distance of less than 1 km followed the intra-annual fluctuation of the river water level, and the correlation was excellent (R 2 = 0.9) between the river water level and the groundwater table at the distance 60 m from the river. The correlation rapidly decreased as distance increased. In response to the variability of the water table, soil moisture at deep layers also followed the variation of river water level all year, while soil moisture at the surface layer was more sensitive to the river water level in the drought season than in the wet season. With increased soil moisture, the average gross primary productivity and respiration of riparian vegetation within 300 m from the river in a typical section of the river increased by approximately 0.03 and 0.02 mg C m −2 s −1 , respectively, in the growing season. Consequently, the net ecosystem exchange increased by approximately 0.01 mg C m −2 s −1 , and the evapotranspiration increased by approximately 3 mm day −1 . Furthermore, the length of the growing season of riparian vegetation also increased by 2-3 months due to the sustaining water recharge from the river. Overall, the stream-aquifer water interaction plays an essential role in the controlling of riparian hydrological and ecological processes.

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“…From 1950 to 2000, irrigated areas in the HRB have increased from 100,000 to 300,000 ha (Heihe River Bureau). As a result, the runoff downstream has declined from 1.5 billion¨m 3 in the 1950s to about 0.6 billion¨m 3 in 1999 [1]. The number of days during which Heihe River is dry increased from 100 to 200 days [2,3].…”

Section: Introductionmentioning

confidence: 99%

Assessment of Water Rights and Irrigation Pricing Reforms in Heihe River Basin in China

Sun

Wang

Huang

et al. 2016

Water

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Abstract:The purpose of this paper is to understand the progress of water rights and irrigation pricing reform in Heihe River Basin (HRB) and their influence on irrigation application. The data came from a village and household level survey conducted in 2009 and 2014 in five counties in Zhangye City, HRB. The main component of reforming water rights was issuing water certificates to individual farmers. However, the share of villages that have done so dropped from 70% in 2004 to 28% in 2014. Water pricing reform raised the price of water. For the pricing of surface water, which consists of an area-based fee and a volumetric price, the volumetric price was increased. Econometric results show that amending water rights substantially reduced irrigation application in the early stage of reform (by 2009) but not in the later phase (by 2014). In contrast, higher water prices lowered irrigation applications significantly at both the early and later stages. Further analysis indicates that due to ineffective implementation, high cost of implementation due to large number of farmers, variations in water supply from year to year, and small farm sizes, little benefit is gained from trading. All of these factors played a role in the failure of water rights reforms.

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Water Environmental Degradation of the Heihe River Basin in Arid Northwestern China

Cited by 93 publications

References 4 publications

Seasonal effects of irrigation on land–atmosphere latent heat, sensible heat, and carbon fluxes in semiarid basin

Seasonal effects of irrigation on land–atmosphere latent heat, sensible heat, and carbon fluxes in semiarid basin

Ecohydrological effects of stream–aquifer water interaction: a case study of the Heihe River basin, northwestern China

Assessment of Water Rights and Irrigation Pricing Reforms in Heihe River Basin in China

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