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Land Use/Cover Change in the Middle Reaches of the Heihe River Basin over 2000-2011 and Its Implications for Sustainable Water Resource Management.

Hu X, Lu L, Li X, Wang J, Guo M - PLoS ONE (2015)

Bottom Line: From the 1960s to the 1990s, the downstream flow in the HRB declined as a result of large, artificial changes in the distribution of water and land and a lack of effective water resource management.The results show that the most significant land use/cover change in the middle reaches of the HRB was the continuous expansion of farmland for economic interests.The results of this study can also serve as a reference for the sustainable management of water resources in other arid inland river basins.

View Article: PubMed Central - PubMed

Affiliation: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou, 730000, China.

ABSTRACT
The Heihe River Basin (HRB) is a typical arid inland river basin in northwestern China. From the 1960s to the 1990s, the downstream flow in the HRB declined as a result of large, artificial changes in the distribution of water and land and a lack of effective water resource management. Consequently, the ecosystems of the lower reaches of the basin substantially deteriorated. To restore these degraded ecosystems, the Ecological Water Diversion Project (EWDP) was initiated by the Chinese government in 2000. The project led to agricultural and ecological changes in the middle reaches of the basin. In this study, we present three datasets of land use/cover in the middle reaches of the HRB derived from Landsat TM/ETM+ images in 2000, 2007 and 2011. We used these data to investigate changes in land use/cover between 2000 and 2011 and the implications for sustainable water resource management. The results show that the most significant land use/cover change in the middle reaches of the HRB was the continuous expansion of farmland for economic interests. From 2000 to 2011, the farmland area increased by 12.01%. The farmland expansion increased the water resource stress; thus, groundwater was over-extracted and the ecosystem was degraded in particular areas. Both consequences are negative and potentially threaten the sustainability of the middle reaches of the HRB and the entire river basin. Local governments should therefore improve the management of water resources, particularly groundwater management, and should strictly control farmland reclamation. Then, water resources could be ecologically and socioeconomically sustained, and the balance between upstream and downstream water demands could be ensured. The results of this study can also serve as a reference for the sustainable management of water resources in other arid inland river basins.

No MeSH data available.


Average change in the groundwater level at 42 observation wells in the middle reaches of the HRB.The red line indicates trends over the past ten years.
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pone.0128960.g007: Average change in the groundwater level at 42 observation wells in the middle reaches of the HRB.The red line indicates trends over the past ten years.

Mentions: The middle reaches of the HRB are a water-scarce region, where the available surface water resources are limited. Of the available surface water resources, approximately 90% was used for irrigation, whereas only 6% was used for natural ecosystems. Strong competition for water occurs between irrigated farmland and natural ecosystems in the region [22]. A substantial increase in the farmland inevitably led to the over-extraction of groundwater and a transfer of water from ecosystems. The over-extraction of groundwater has resulted in declining groundwater levels in particular areas of the middle reaches. A groundwater-level analysis of 42 observation wells in the middle reaches of the HRB revealed that the groundwater levels generally decreased between 2000 and 2010 (Fig 7). Additionally, water use data from various sectors showed that the amount of ecological water decreased from 1.76 × 108 m3 in 2000 to 1.14 × 108 m3 in 2010, according to the statistics provided by the Zhangye Water Conservancy Annual Report. The declining groundwater levels and the reduction in ecological water led to the reduction of shrub forests and an increase in grassland desertification in particular areas of the middle reaches. In the field survey, we found that a large area of Elaeagnus forest exhibited drought stress or partial die-out in the tree farms of Jiulong Jiang. This effect was probably due to declining groundwater levels and ecological water. In addition, the large-scale reclamation of farmland and the reduction of available surface water resulted in other changes in land use/cover types, such as a drastic decrease in the grassland area. From 2000 to 2011, the grassland area decreased by 6.26%.


Land Use/Cover Change in the Middle Reaches of the Heihe River Basin over 2000-2011 and Its Implications for Sustainable Water Resource Management.

Hu X, Lu L, Li X, Wang J, Guo M - PLoS ONE (2015)

Average change in the groundwater level at 42 observation wells in the middle reaches of the HRB.The red line indicates trends over the past ten years.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482701&req=5

pone.0128960.g007: Average change in the groundwater level at 42 observation wells in the middle reaches of the HRB.The red line indicates trends over the past ten years.
Mentions: The middle reaches of the HRB are a water-scarce region, where the available surface water resources are limited. Of the available surface water resources, approximately 90% was used for irrigation, whereas only 6% was used for natural ecosystems. Strong competition for water occurs between irrigated farmland and natural ecosystems in the region [22]. A substantial increase in the farmland inevitably led to the over-extraction of groundwater and a transfer of water from ecosystems. The over-extraction of groundwater has resulted in declining groundwater levels in particular areas of the middle reaches. A groundwater-level analysis of 42 observation wells in the middle reaches of the HRB revealed that the groundwater levels generally decreased between 2000 and 2010 (Fig 7). Additionally, water use data from various sectors showed that the amount of ecological water decreased from 1.76 × 108 m3 in 2000 to 1.14 × 108 m3 in 2010, according to the statistics provided by the Zhangye Water Conservancy Annual Report. The declining groundwater levels and the reduction in ecological water led to the reduction of shrub forests and an increase in grassland desertification in particular areas of the middle reaches. In the field survey, we found that a large area of Elaeagnus forest exhibited drought stress or partial die-out in the tree farms of Jiulong Jiang. This effect was probably due to declining groundwater levels and ecological water. In addition, the large-scale reclamation of farmland and the reduction of available surface water resulted in other changes in land use/cover types, such as a drastic decrease in the grassland area. From 2000 to 2011, the grassland area decreased by 6.26%.

Bottom Line: From the 1960s to the 1990s, the downstream flow in the HRB declined as a result of large, artificial changes in the distribution of water and land and a lack of effective water resource management.The results show that the most significant land use/cover change in the middle reaches of the HRB was the continuous expansion of farmland for economic interests.The results of this study can also serve as a reference for the sustainable management of water resources in other arid inland river basins.

View Article: PubMed Central - PubMed

Affiliation: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou, 730000, China.

ABSTRACT
The Heihe River Basin (HRB) is a typical arid inland river basin in northwestern China. From the 1960s to the 1990s, the downstream flow in the HRB declined as a result of large, artificial changes in the distribution of water and land and a lack of effective water resource management. Consequently, the ecosystems of the lower reaches of the basin substantially deteriorated. To restore these degraded ecosystems, the Ecological Water Diversion Project (EWDP) was initiated by the Chinese government in 2000. The project led to agricultural and ecological changes in the middle reaches of the basin. In this study, we present three datasets of land use/cover in the middle reaches of the HRB derived from Landsat TM/ETM+ images in 2000, 2007 and 2011. We used these data to investigate changes in land use/cover between 2000 and 2011 and the implications for sustainable water resource management. The results show that the most significant land use/cover change in the middle reaches of the HRB was the continuous expansion of farmland for economic interests. From 2000 to 2011, the farmland area increased by 12.01%. The farmland expansion increased the water resource stress; thus, groundwater was over-extracted and the ecosystem was degraded in particular areas. Both consequences are negative and potentially threaten the sustainability of the middle reaches of the HRB and the entire river basin. Local governments should therefore improve the management of water resources, particularly groundwater management, and should strictly control farmland reclamation. Then, water resources could be ecologically and socioeconomically sustained, and the balance between upstream and downstream water demands could be ensured. The results of this study can also serve as a reference for the sustainable management of water resources in other arid inland river basins.

No MeSH data available.