Minimum forest cover for sustainable water flow regulation in a watershed

2017 ◽  
Author(s):  
Anonymous
Keyword(s):  
Water Flow ◽  
Forest Cover ◽  
Flow Regulation ◽  
Water Flow Regulation

scholarly journals Minimum forest cover for sustainable water flow regulation in a watershed under rapid expansion of oil palm and rubber plantations

2017 ◽  
Author(s):  
Suria Tarigan ◽  
Kerstin Wiegand ◽  
Keyword(s):  
Land Use ◽  
Water Flow ◽  
Oil Palm ◽  
Forest Cover ◽  
Flow Regulation ◽  
Rapid Expansion ◽  
Forest Land ◽  
Direct Runoff ◽  
Regulation Function ◽  
Water Flow Regulation

Abstract. In many tropical regions, rapid expansion of monoculture plantations has led to a sharp decline of forest cover, which potentially degraded the water flow regulation function of watersheds. The flow regulation function of a watershed is defined as the ability of the watershed to store the rain water, therefore reducing the direct runoff and sustaining the baseflow during dry season. In the tropical region where rainfall is highly seasonal, water flow regulation is an important ecosystem function of a watershed. It determines the proportion of direct runoff of the rainfall and the proportion of the baseflow in the streamflow. The higher the proportion of the direct runoff of the rainfall the higher the probability that water resources problems occur such as flooding in the wet season and drought in the dry season. Therefore proper water flow regulation function of a watershed is a key factor for water resources management. It is generally known that forest land use improves the water flow regulation function of a watershed. The contribution of forest land use on water flow regulation function of a watershed depends primarily on its proportion in the entire watershed. In a watershed where expansion of agricultural plantations occurs rapidly, the spatial planner needs to know the minimum proportion of forest cover required to maintain proper water flow regulation function of a watershed. Research dealing with this issue is still rare, especially in the tropical area where oil palm expansion occurs at alarming rate. We employed the SWAT hydrological model to calculate two indicators of water regulation function of a watershed: the proportion of the direct runoff to the rainfall (C) and the proportion of the baseflow in the total streamflow (BFI). Using regression analysis, we show a strong correlation between indicators of water flow regulation (C and BFI values) with the proportion of forest cover and agricultural plantation cover in a watershed. To achieve the required C value of less than 0.35, the proportion of forest cover in the entire watershed should be greater than 30 % and the proportion of plantation cover should be less than 40 %. The results of this study are very useful as a guide for spatial planners to determine the minimum proportion of forest conservation area to maintain a sustainable ecosystem service of water flow regulation in a watershed.

scholarly journals Assessment of Soil Physical Quality and Water Flow Regulation under Straw Removal Management in Sugarcane Production Fields

2022 ◽  
Vol 14 (2) ◽  
pp. 841
Author(s):  
Martha Lustosa Carvalho ◽  
Felipe Bonini da Luz ◽  
Renato Paiva de Lima ◽  
Karina Maria Vieira Cavalieri-Polizeli ◽  
João Luís Nunes Carvalho ◽  
...  
Keyword(s):  
Water Flow ◽  
Soil Compaction ◽  
Production Systems ◽  
Soil Bulk Density ◽  
Flow Regulation ◽  
Water Infiltration ◽  
Soil Functions ◽  
Straw Management ◽  
Sugarcane Production ◽  
Water Flow Regulation

Removing sugarcane straw to increase bioenergy production can generate significant income to the industry. However, straw contributes to the regulation of soil functions and consequently supports the provision of ecosystem services, such as water flow regulation. Thus, straw removal may hinder the provision of these services, especially in mechanized sugarcane production systems, which have soil compaction problems due to machinery traffic. In this study, we assess a six-year experiment in Brazil with four rates of straw removal: 0 Mg ha−1 (TR), 5 Mg ha−1 (HR), 10 Mg ha−1 (LR), and 15 Mg ha−1 (NR) remaining straw. Using attributes, such as soil bulk density, porosity, water infiltration, runoff, saturated hydraulic conductivity and available water-holding capacity, as indicators of key soil functions, we calculated a soil-related ecosystem service (ES) index for water flow regulation provision. The ES index revealed that water flow regulation was low regardless of the straw management (0.56, 0.63, 0.64 and 0.60 for TR, HR, LR and NR, respectively). It can be a consequence of soil compaction caused by machinery traffic throughout the successive cycle, whose straw was unable to mitigate this issue. Thus, by the end of the sugarcane cycle (sixth ratoon), straw removal had little effect on soil physical and hydraulic indicators, and consequently had little impact on the provision of the soil-related ES associated with water flow regulation. Nevertheless, straw management should be planned to consider other functions and soil-related ES benefited by straw retention.

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