Search Results (3)

Despite the declining hunger in Central Asia, food insecurity remains an important issue due to the dry climate. Taking Kazakhstan, Uzbekistan, Kyrgyzstan, Turkmenistan, and Tajikistan as examples, this study assesses their land-water resources carrying capacity in 1999, 2009, and 2018, on the premise that agricultural water and farmland are spatially matched based on the “buckets effect”, using the ecological footprint and water footprint methods. Results show the following: (1) the total farmland area in Central Asia is sufficient to achieve food self-sufficiency; the available farmland area is 2.45 times that of the farmland required for self-sufficiency in 1999, which decreased to 1.71 times in 2009, but slightly increased to 1.92 times in 2018. Specifically, Kazakhstan maintains a surplus of more than 15 × 10⁶ ha in farmland, while the other 4 countries could not achieve self-sufficiency. (2) The water resources pressure rises; the available agricultural water resource (AAWR) in Central Asia is 3.07 times that of the water demand for agricultural irrigation (WDAI), and 3.06 times that of the water demand for irrigation and environmental purification (WDIEP) in 1999, which decreased to 1.69 times of WDAI and to 1.60 times of WDIEP in 2018. Tajikistan has the highest level of water surplus, followed by Kyrgyzstan and Kazakhstan. Turkmenistan and Uzbekistan do not have enough water to sustain agricultural production. (3) The trend of land-water resources carrying capacity declines in Central Asia. In 1999, 2009, and 2018, the land-water resources could support the population’s food demand in this region when only considering farmland matched with WDAI. However, the population carrying capacity deficit would emerge if we considered the matching farmland with WDIEP. Full article

In this study, the Amu Darya river basin, Syr Darya river basin and Balkhash lake basin in Central Asia were selected as typical study areas. Temporal/spatial changes from 2002 to 2016 in the terrestrial water storage (TWS) and the groundwater storage (GWS) were analyzed, based on RL06 Mascon data from the Gravity Recovery and Climate Experiment (GRACE) satellite, and the sum of soil water content, snow water equivalent and canopy water data that were obtained from Global Land Data Assimilation System (GLDAS). Combing meteorological data and land use and cover change (LUCC) data, the joint impact of both human activities and climate change on the terrestrial water storage change (TWSC) and the groundwater storage change (GWSC) was evaluated by statistical analysis. The results revealed three findings: (1) The TWS retrieved by CSR (Center for Space Research) and the JPL (Jet Propulsion Laboratory) showed a decreasing trend in the three basins, and the variation of TWS showed a maximum surplus in spring (March–May) and a maximum deficit in autumn (September–November). (2) The decreasing rates of groundwater storage that were extracted, based on JPL and CSR Mascon data sets, were −2.17 mm/year and −3.90 mm/year, −3.72 mm/year and −4.96 mm/year, −1.74 mm/year and −3.36 mm/year in the Amu Darya river basin, Syr Darya river basin and Balkhash lake basin, respectively. (3) In the Amu Darya river basin, annual precipitation showed a decreasing trend, while the evapotranspiration rate showed an increasing trend due to an increasing temperature, and the TWS decreased from 2002 to 2016 in most areas of the basin. However, in the middle reaches of the Amu Darya river basin, the TWS increased due to the increase in cultivated land area, water income from flooded irrigation, and reservoir impoundment. In the upper reaches of the Syr Darya river basin, the increase in precipitation in alpine areas leads to an increase in glacier and snow meltwater, which is the reason for the increase in the TWS. In the middle and lower reaches of the Syr Darya river basin, the amount of evapotranspiration dissipation exceeds the amount of water replenished by agricultural irrigation, which leads to a decrease in TWS and GWS. The increase in precipitation in the northwest of the Balkhash lake basin, the increase in farmland irrigation water, and the topography (higher in the southeast and lower in the northwest) led to an increase in TWS and GWS in the northwest of the Balkhash lake basin. This study can provide useful information for water resources management in the inland river basins of Central Asia. Full article

Food security is essential for human survival and sustainable development. Due to rapid urbanization and industrialization, the farmland loss in Yangtze River Delta Urban Agglomeration (YRDUA) has threatened food security. Thus, this study intended to quantify the farmland loss and assess its impacts on food security in the YRDUA from 2000 to 2020 at three scales based on the Google Earth Engine platform. Our results show that the area of farmland in YRDUA is decreasing at a rather high speed in the past 20 years and the trend is getting worse. At the urban agglomeration scale, there was a farmland deficit of 0.44 million ha in 2000, followed by larger farmland deficits in 2010 and 2020. At the city scale, Shanghai had the largest scarcity of farmland. At the urban subgroup scale, Subgroup I in the west and Subgroup II in the north always maintained an oversupply of farmland, while Subgroup III in the east and Subgroup IV in the south faced serious food security problems. Our study suggests that farmland must be protected in YRDUA in order to ensure food self-sufficiency and promote regional sustainability. Full article