Impacts of climate and land use changes on river discharge in a small watershed: a case study of the Lam Chi subwatershed, northeast Thailand

River discharge changes, in addition to natural variability, depend on several factors. Three factors are the most important: climate change (CC), changes in human use of water (HU), and land use changes (LU). River discharge has hydraulic connection with its alluvial sources and both are sensitive to climate and other changes. Alluvial water sources (ALWSs) are often used for water supplying purposes. The question is what could we expect in the future? Are they more or less sensible on climate change and other two factors, compare to river discharge changes, or it differ from case to case?

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The Effect of Wateshed Condition Change To River Discharge - Case Study Jatigede Reservoir Catchtment Area

MEDIA KOMUNIKASI TEKNIK SIPIL ◽

10.14710/mkts.v26i1.28989 ◽

2020 ◽

Vol 26 (1) ◽

pp. 95-103

Author(s):

Robert Johannes Kodoatie

Keyword(s):

Land Use ◽

Rainy Season ◽

River Discharge ◽

Land Use Changes ◽

Curve Number ◽

Scs Curve Number ◽

Flood Discharge ◽

Reservoir Watershed ◽

Using Data

Changes in land use in the upstream of Jatigede watershed cause discharge and sedimentation problems in the Jatigede Reservoir. The objective of this study is to analyse the affect of land use changes in the Jatigede Reservoir watershed to the inflow and sediment to the reservoir. SCS Curve Number method and HEC-HMS modeling system are used to discharge analysis. Flood discharges in the reach of Cimanuk River close to the reservoir using data of 2009 are Q2=1,751.5 m3/sec, Q5=2,280 m3/sec, Q25=3,064.5 m3/sec, Q50=3,589 m3/sec. Flood discharges in the reach of Cimanuk River close to the reservoir using data of 2018 are Q2=2,053.8 m3/sec, Q5= 2,616.7 m3/sec, Q25 = 3,439.2 m3/sec, Q50=3,984.9 m3/sec. Discharges increase in 10 years (based on 2009 data and 2018 data). For example discharge increment for Q25 is 375 m3/sec. The increment is due to the increment of CN number as the consequences of land use changes. In other words along with the time, flood discharge in the rainy season increases, however discharge in the drought season decreases.

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Rural-Spatial Restructuring Promoted by Land-Use Transitions: A Case Study of Zhulin Town in Central China

Land ◽

10.3390/land10030234 ◽

2021 ◽

Vol 10 (3) ◽

pp. 234

Author(s):

Dong Han ◽

Jiajun Qiao ◽

Qiankun Zhu

Keyword(s):

Land Use ◽

Rural Development ◽

Structural Changes ◽

Land Use Changes ◽

Central China ◽

Rural Space ◽

Spatial Restructuring ◽

Local Actors ◽

The Impact

Rural-spatial restructuring involves the spatial mapping of the current rural development process. The transformation of land-use morphologies, directly or indirectly, affects the practice of rural restructuring. Analyzing this process in terms of the dominant morphology and recessive morphology is helpful for better grasping the overall picture of rural-spatial restructuring. Accordingly, this paper took Zhulin Town in Central China as a case study area. We propose a method for studying rural-spatial restructuring based on changes in the dominant and recessive morphologies of land use. This process was realized by analyzing the distribution and functional suitability of ecological-production-living (EPL) spaces based on land-use types, data on land-use changes obtained over a 30-year observation period, and in-depth research. We found that examining rural-spatial restructuring by matching the distribution of EPL spaces with their functional suitability can help to avoid the misjudgment of the restructuring mode caused by the consideration of the distribution and structural changes in quantity, facilitating greater understanding of the process of rural-spatial restructuring. Although the distribution and quantitative structure of Zhulin’s EPL spaces have changed to differing degrees, ecological- and agricultural-production spaces still predominate, and their functional suitability has gradually increased. The spatial distribution and functional suitability of Zhulin are generally well matched, with 62.5% of the matched types being high-quality growth, and the positive effect of Zhulin’s spatial restructuring over the past 30 years has been significant. We found that combining changes in EPL spatial area and quantity as well as changes in functional suitability is helpful in better understanding the impact of the national macro-policy shift regarding rural development. Sustaining the positive spatial restructuring of rural space requires the timely adjustment of local actors in accordance with the needs of macroeconomic and social development, and a good rural-governance model is essential.

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