Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain (NCP), where the shortage of water is currently disturbing the stability and...Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain (NCP), where the shortage of water is currently disturbing the stability and sustainability of agricultural production with respect to the drying tendency since the 1950s. However, although potential evapotranspiration (ET) has shown a decreasing trend under climate change, actual ET has slightly increased with an acceleration in hydrological cycling. Global climate model (GCM) ensemble projections predict that by the 2050s, the increased crop water demand and intensified ET resulting from global warming will reduce water resources surplus (Precipitation-ET) about 4%-24% and increase significantly the irrigation water demand in crop growth periods. This study assesses possible mitigation and adaptation measures for enabling agricultural sustainability. It is revealed that reducing the sowing area of winter wheat (3.0%-15.9%) in water-limited basins, together with improvement in crop water-use efficiency would effectively mitigate water shortages and intensify the resilience of agricultural systems to climate change.展开更多
The investment opportunities created by economic policies and increasing urbanization have enhanced demand for urban and peri-urban land. Fertile agricultural land is being converted to other uses. Around 1/3 more of ...The investment opportunities created by economic policies and increasing urbanization have enhanced demand for urban and peri-urban land. Fertile agricultural land is being converted to other uses. Around 1/3 more of the existing area under forests is needed to meet the targets of national forest policy. In the last two decades, 9% pastures have disappeared. The hills being removed cause threat to environment. The farmers seem to overuse land and other inputs. In the peri-urban areas agricultural fertile lands are many times forcefully acquired for non-agricultural uses, which result in violent protests and judicial interventions. A few cases of vast land use change, motive forces for such change, effect of change in land use on livelihood and on quality and costs of fresh vegetable supply are discussed in this paper. The partially used and unused data collected for earlier studies and some data collected for this paper have been used. The increase in land prices due to enhanced income of some sections, future need of prime land and returns from other than agricultural uses seem to be the driving force for change in land use, affecting the livelihood of people dependent upon farming who are migrating to nearby areas. Each shift of peri-urban agriculture will result in loss of quality, increase wastage by 6% and enhance costs of leafy vegetables by more than 5.5%. For an ideal urban land use, a balanced multi land use policy emphasizing peri-urban agriculture and forestry is suggested.展开更多
Emissions of gases from industrial activities and even from agriculture activities and from soil as releasing of nitrogen from soils to atmosphere have been increasing steadily therefore, acid rain is the concern thro...Emissions of gases from industrial activities and even from agriculture activities and from soil as releasing of nitrogen from soils to atmosphere have been increasing steadily therefore, acid rain is the concern throughout the world. The hill field at the UCD research farm was chosen as the representative of good versatile, on which moderate to intensive farming is practised in the drier rainfall areas of Ireland. Nutrient contents in rainfall water samples were measurable, although the site of rainfall sample collection is located in the east of the country far away from the Atlantic Ocean. TDP (total dissolve phosphorus) concentrations in rainwater samples were very low. While DRP (dissolve reactive phosphorus) is the main component in some samples, the DUP (dissolve unreactive phosphorus) is dominant in others. DRP values accounted for less than 50% of dissolved phosphorus in rainfall. Sodium (Na) and Chloride (CI) ions had the highest concentration value, because most of Irish rain originates from the Atlantic Ocean. Nitrate (NO3) had the highest value 15.2 lag.mLl but it associated only with mineral fertiliser spreading time.展开更多
The Cross River watershed was disturbed by historic logging activity during the past century, but under the management of the USDA (United States Department of Agriculture) Forest Service, the area has mostly recove...The Cross River watershed was disturbed by historic logging activity during the past century, but under the management of the USDA (United States Department of Agriculture) Forest Service, the area has mostly recovered from ecological disturbance. Today a new threat is being imposed by climate change; changes affect not only the temperature but also more extreme wind and rain In 2012, a mega-storm event passed through the north shore region of Lake Superior overwhelming many watersheds with excessive rain and runoff. As part of a Cross River study for the Forest Service, pre- and post-event hydrologic adjustment of the Cross River watershed were captured. Samples were collected for δD and δ18O during April, July, and September to estimate HRT (hydraulic residence time) using the stable isotopes of hydrogen and oxygen, The results showed that water collected throughout the watershed shifted toward the signature of the mega-event precipitation signature, then slowly diffused with new precipitation and fractionation processes that resumed into the summer and fall.展开更多
基金Acknowledgment This work was supported by the State's Key Project of Research and Development Plan (2010CB428404) and the Natural Science Foundation of China (41471026).
文摘Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain (NCP), where the shortage of water is currently disturbing the stability and sustainability of agricultural production with respect to the drying tendency since the 1950s. However, although potential evapotranspiration (ET) has shown a decreasing trend under climate change, actual ET has slightly increased with an acceleration in hydrological cycling. Global climate model (GCM) ensemble projections predict that by the 2050s, the increased crop water demand and intensified ET resulting from global warming will reduce water resources surplus (Precipitation-ET) about 4%-24% and increase significantly the irrigation water demand in crop growth periods. This study assesses possible mitigation and adaptation measures for enabling agricultural sustainability. It is revealed that reducing the sowing area of winter wheat (3.0%-15.9%) in water-limited basins, together with improvement in crop water-use efficiency would effectively mitigate water shortages and intensify the resilience of agricultural systems to climate change.
文摘The investment opportunities created by economic policies and increasing urbanization have enhanced demand for urban and peri-urban land. Fertile agricultural land is being converted to other uses. Around 1/3 more of the existing area under forests is needed to meet the targets of national forest policy. In the last two decades, 9% pastures have disappeared. The hills being removed cause threat to environment. The farmers seem to overuse land and other inputs. In the peri-urban areas agricultural fertile lands are many times forcefully acquired for non-agricultural uses, which result in violent protests and judicial interventions. A few cases of vast land use change, motive forces for such change, effect of change in land use on livelihood and on quality and costs of fresh vegetable supply are discussed in this paper. The partially used and unused data collected for earlier studies and some data collected for this paper have been used. The increase in land prices due to enhanced income of some sections, future need of prime land and returns from other than agricultural uses seem to be the driving force for change in land use, affecting the livelihood of people dependent upon farming who are migrating to nearby areas. Each shift of peri-urban agriculture will result in loss of quality, increase wastage by 6% and enhance costs of leafy vegetables by more than 5.5%. For an ideal urban land use, a balanced multi land use policy emphasizing peri-urban agriculture and forestry is suggested.
文摘Emissions of gases from industrial activities and even from agriculture activities and from soil as releasing of nitrogen from soils to atmosphere have been increasing steadily therefore, acid rain is the concern throughout the world. The hill field at the UCD research farm was chosen as the representative of good versatile, on which moderate to intensive farming is practised in the drier rainfall areas of Ireland. Nutrient contents in rainfall water samples were measurable, although the site of rainfall sample collection is located in the east of the country far away from the Atlantic Ocean. TDP (total dissolve phosphorus) concentrations in rainwater samples were very low. While DRP (dissolve reactive phosphorus) is the main component in some samples, the DUP (dissolve unreactive phosphorus) is dominant in others. DRP values accounted for less than 50% of dissolved phosphorus in rainfall. Sodium (Na) and Chloride (CI) ions had the highest concentration value, because most of Irish rain originates from the Atlantic Ocean. Nitrate (NO3) had the highest value 15.2 lag.mLl but it associated only with mineral fertiliser spreading time.
文摘The Cross River watershed was disturbed by historic logging activity during the past century, but under the management of the USDA (United States Department of Agriculture) Forest Service, the area has mostly recovered from ecological disturbance. Today a new threat is being imposed by climate change; changes affect not only the temperature but also more extreme wind and rain In 2012, a mega-storm event passed through the north shore region of Lake Superior overwhelming many watersheds with excessive rain and runoff. As part of a Cross River study for the Forest Service, pre- and post-event hydrologic adjustment of the Cross River watershed were captured. Samples were collected for δD and δ18O during April, July, and September to estimate HRT (hydraulic residence time) using the stable isotopes of hydrogen and oxygen, The results showed that water collected throughout the watershed shifted toward the signature of the mega-event precipitation signature, then slowly diffused with new precipitation and fractionation processes that resumed into the summer and fall.