scholarly journals Uma Forma de Convivência com a Seca: Bacia Hidrográfica do Rio Brígida - Pernambuco - Brasil (A Form of the Living with Drought: Brigida River Watershed-Pernambuco-Brasil)

2014 ◽  
Vol 7 (4) ◽  
pp. 724
Author(s):  
Alegnoberto Leite Fechine ◽  
Josiclêda Domiciano Galvíncio
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Climate Variability ◽  
Surface Runoff ◽  
Climate Changes ◽  
Vulnerable Area ◽  
River Watershed ◽  
Northern Portion ◽  
Increasing Temperature ◽  
Semi Arid

Mudanças no clima, provocada por aumento da temperatura, é uma realidade. Estudos recentes têm mostrado mudanças perceptíveis na temperatura, no regime de chuvas, nos recursos hídricos, no escoamento superficial e na agricultura; com consequências severas para as populações. Como água é mal distribuída e com a intensificação das secas a situação se agravará cada vez mais, chegando a um ponto de famílias inteiras migrarem para outras áreas. Sendo assim, o objetivo deste escopo é expor e analisar as diversas formas de convivências com a variabilidade do clima na bacia hidrográfica do rio Brígida.A área em análise possui clima semiárido e está localizada no Nordeste do Brasil, estado de Pernambuco. De acordo com o estudo a área mais vulnerável da bacia é a porção sul, onde o uso da terra se dá de forma desorganizada e despreparada. Já a porção norte é a menos vulnerável, pois, é mais propicia a receber maiores valores de precipitação. Sendo assim, a convivência com as mudanças do clima a exemplo: captação de água da chuva e a agroecologia são opções necessárias.A B S T R A C T - Changes in climate caused by increasing temperature, is a reality. Recent studies have shown noticeable changes in temperature, rainfall patterns, water resources, surface runoff and agriculture; with severe consequences for the populations. As water is poorly distributed and the intensification of droughts will worsen the situation increasingly, reaching a point of entire families migrate to other areas. Therefore, the aim of this scope is to expose and analyze the various forms of cohabitation with climate variability in the basin of river Bridget. The area in question has semi-arid climate and is located in the northeast of Brazil, Pernambuco state. According to the study the most vulnerable area of the basin is the southern portion, where the land use occurs in a disorganized and unprepared shape. Already the northern portion is less vulnerable because it is most facilitates receive larger amounts of precipitation. Thus, the interaction with the climate changes such: capturing rainwater and agroecology options are necessary. Keywords: coexistence, capture rainwater, semiarid. 

scholarly journals Effect of land use/land cover and climate changes on surface runoff in a semi-humid and semi-arid transition zone in Northwest China

2016 ◽  
Author(s):  
Jing Yin ◽  
Fan He ◽  
YuJiu Xiong ◽  
GuoYu Qiu
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Land Cover ◽  
Transition Zone ◽  
Surface Runoff ◽  
Climate Changes ◽  
Northwest China ◽  
Land Use Land Cover ◽  
Lulc Change ◽  
Semi Arid

Abstract. Water resources, which are substantially affected by land use/land cover (LULC) and climate changes, are a key limiting factor for ecosystems in arid and semi-arid regions exhibiting high vulnerability. It is crucial to assess the impact of LULC and climate changes on water resources in these areas. However, conflicting results on the effect of the LULC and climate changes on runoff have been reported for relatively large basins, e.g., in the Jinghe River Basin (JRB), a typical large catchment (> 45000 km2) located in a semi-humid and arid transition zone on the central Loess Plateau, Northwest China. In this study, we focused on quantifying both the combined and isolated impacts of LULC and climate changes on surface runoff. It is hypothesized that under climatic warming and drying conditions, LULC change, which is primarily caused by intensive human activities, such as the conversion of cropland to forest and grassland program (CCFGP), will alter runoff markedly in the JRB. The Soil and Water Assessment Tool (SWAT) was adopted to perform simulations. The simulated results indicated that although runoff increased very little between the 1970s and the 2000s due to the combined effects of LULC and climate changes, LULC and climate changes affected surface runoff differently in each decade, i.e., runoff increased with elevated precipitation between the 1970s and the 1980s (precipitation contributed 88 % to the increased runoff). Thereafter, runoff decreased and became increasingly influenced by LULC change, with a 44 % contribution between the 1980s and the 1990s and a 71 % contribution between the 1990s and the 2000s. Our findings revealed that large-scale LULC under the CCFGP since the late 1990s has had an important effect on the hydrological cycle and that the conflicting findings on the effect of the LULC and climate changes on runoff in relatively large basins are likely caused by uncertainty in hydrological simulations.

scholarly journals Effects of land use/land cover and climate changes on surface runoff in a semi-humid and semi-arid transition zone in northwest China

2017 ◽  
Vol 21 (1) ◽  
pp. 183-196 ◽  
Author(s):  
Jing Yin ◽  
Fan He ◽  
Yu Jiu Xiong ◽  
Guo Yu Qiu
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Land Cover ◽  
Surface Runoff ◽  
Climate Changes ◽  
Northwest China ◽  
Land Use Land Cover ◽  
Grain For Green ◽  
Runoff Changes ◽  
Semi Arid

Abstract. Water resources, which are considerably affected by land use/land cover (LULC) and climate changes, are a key limiting factor in highly vulnerable ecosystems in arid and semi-arid regions. The impacts of LULC and climate changes on water resources must be assessed in these areas. However, conflicting results regarding the effects of LULC and climate changes on runoff have been reported in relatively large basins, such as the Jinghe River basin (JRB), which is a typical catchment (> 45 000 km2) located in a semi-humid and arid transition zone on the central Loess Plateau, northwest China. In this study, we focused on quantifying both the combined and isolated impacts of LULC and climate changes on surface runoff. We hypothesized that under climatic warming and drying conditions, LULC changes, which are primarily caused by intensive human activities such as the Grain for Green Program, will considerably alter runoff in the JRB. The Soil and Water Assessment Tool (SWAT) was adopted to perform simulations. The simulated results indicated that although runoff increased very little between the 1970s and the 2000s due to the combined effects of LULC and climate changes, LULC and climate changes affected surface runoff differently in each decade, e.g., runoff increased with increased precipitation between the 1970s and the 1980s (precipitation contributed to 88 % of the runoff increase). Thereafter, runoff decreased and was increasingly influenced by LULC changes, which contributed to 44 % of the runoff changes between the 1980s and 1990s and 71 % of the runoff changes between the 1990s and 2000s. Our findings revealed that large-scale LULC under the Grain for Green Program has had an important effect on the hydrological cycle since the late 1990s. Additionally, the conflicting findings regarding the effects of LULC and climate changes on runoff in relatively large basins are likely caused by uncertainties in hydrological simulations.

scholarly journals Quantitative Analysis of Hydrological Responses to Climate Variability and Land-Use Change in the Hilly-Gully Region of the Loess Plateau, China

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 82 ◽  
Author(s):  
Youcai Kang ◽  
Jianen Gao ◽  
Hui Shao ◽  
Yuanyuan Zhang
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Climate Variability ◽  
Soil Water ◽  
Loess Plateau ◽  
Surface Runoff ◽  
Water Resource Management ◽  
Assessment Tool ◽  
Upstream Region ◽  
The Loess Plateau

Climate and land-use change are the two main driving forces that affect watershed hydrological processes. Separately assessing their impacts on hydrology is important for land-use planning and water resource management. In this research, the SWAT (Soil and Water Assessment Tool) and statistical methods were applied to evaluate the effects of climate and land-use change on surface hydrology in the hilly-gully region of the Loess Plateau. The results showed that surface runoff and soil water presented a downward tendency, while evapotranspiration (ET) presented an upward tendency in the Yanhe watershed from 1982 to 2012. Climate is one the dominant factors that influence surface runoff, especially in flooding periods. The average contribution rate of surface runoff on stream flow accounted for 55%, of which the flooding period accounted for 40%. The runoff coefficient declined by 0.21 after 2002 with the land-use change of cropland transformed to grassland and forestland. The soil water exhibited great fluctuation along the Yanhe watershed. In the upstream region, the land-use was the driving force to decline soil water, which reduced the soil water by 51%. Along the spatial distribution, it converted from land-use change to climate variability from northwest to southeast. The ET was more sensitive to land-use change than climate variability in all sub-basins, and increased by 209% with vegetation restoration. To prevent the ecosystem degradation and maintain the inherent ecological functions of rivers, quantitative assessment the influence of climate variability and land-use change on hydrology is of great importance. Such evaluations can provide insight into the extent of land use/cover change on regional water balance and develop appropriate watershed management strategies on the Loess Plateau.

scholarly journals Quantifying the Effect of Land Use Change and Climate Variability on Green Water Resources in the Xihe River Basin, Northeast China

2019 ◽  
Vol 11 (2) ◽  
pp. 338 ◽  
Author(s):  
Leting Lyu ◽  
Xiaorui Wang ◽  
Caizhi Sun ◽  
Tiantian Ren ◽  
Defeng Zheng
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Land Use Change ◽  
Climate Variability ◽  
River Basin ◽  
Water Flow ◽  
Water Storage ◽  
Green Water ◽  
Efficiency Coefficient ◽  
Relative Change

Based on a land use interpretation and distributed hydrological model, soil and water assessment tool (SWAT), this study simulated the hydrological cycle in Xihe River Basin in northern China. In addition, the influence of climate variability and land use change on green water resources in the basin from 1995 to 2015 was analyzed. The results show that (1) The ENS (Nash-Sutcliffe model efficiency coefficient) and R2 (coefficient of determination) were 0.94 and 0.89, respectively, in the calibration period, and 0.89 and 0.88, respectively, in the validation period. These indicate high simulation accuracy; (2) Changes in green water flow and green water storage due to climate variability accounted for increases of 2.07 mm/a and 1.28 mm/a, respectively. The relative change rates were 0.49% and 0.9%, respectively, and the green water coefficient decreased by 1%; (3) Changes in green water flow and green water storage due to land use change accounted for increases of 69.15 mm and 48.82 mm, respectively. The relative change rates were 16.4% and 37.2%, respectively, and the green water coefficient increased by 10%; (4) Affected by both climate variability and land use change, green water resources increased by 121.3 mm and the green water coefficient increased by 9% in the Xihe River Basin. It is noteworthy that the influence of land use change was greater than that of climate variability.

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