Effect of deforestation on watershed water balance: hydrological modelling-based approach / Vplyv odlesnenia na vodnú bilanciu povodia: prístup na báze hydrologického modelovania

Abstract

Changes in land cover, including deforestation, can have significant effect on watershed hydrology. We used hydrological model with distributed parameters to evaluate the effect of simulated deforestation on water balance components in the watershed Ulička (97 km 2 , 84.3% forest cover) located in the eastern Slovakia. Under the current land cover, average interception accounted for 21.1% of the total precipitation during the calibration period 2001-2013. Most of the precipitation (77%) infiltrated into the soil profile, and less than half of this amount percolated into the ground water aquifer. The surface runoff accounted for 1.2% of the total precipitation only, while the interflow accounted for ca. 12%. The largest proportion of the precipitation contributed to the base flow (23%). Watershed`s deforestation induced significant decrease in the interception and evapotranspiration (by 76% and 12%, respectively). At the same time, total runoff, surface runoff, interflow and base flow increased by 20.4, 38.8, 9.0 and 25.5%, respectively. Daily discharge increased by 20%. The deforestation significantly increased peak discharge induced by a simulated extreme precipitation event with the recurrence interval of 100 years. In the deforested watershed, the peak discharge was higher by 58% as compared with the current land cover. Peak discharge occurred in 432 minutes with the current land cover and in 378 minutes with deforestation, after the precipitation event had started. The presented assessment emphasized the risk of adverse effect of excessive deforestation on watershed hydrology. At the same time, the developed model allows testing the effect of other land cover scenarios, and thus supports management in the investigated watershed. abstrakt Zmeny vo vegetačnom kryte a využívaní krajiny, vrátane odlesnení, môžu mať významný vplyv na hydrologickú bilanciu povodí. V tejto štúdii bol na analýzu vplyvu simulovaného odlesnenia na jednotlivé zložky vodnej bilancie použitý hydrologický model s distribuovanými parametrami. Výskum bol realizovaný v povodí Ulička na východnom Slovensku (97 km 2 , lesnatosť 84,3 %). Pri súčasnom využívaní krajiny pripadalo na intercepciu v priemere 21,1 % z celkového úhrnu zrážok počas kalibračného obdobia 2001 -2013. Najväčší podiel zrážok (77 %) bol infiltrovaný do pôdneho profilu a necelá polovica z tohoto množstva prenikla do vodonosnej vrstvy podzemnej vody. Zatiaľ čo podpovrchový odtok tvoril z celkového úhrnu zrážok približne 12 %, v prípade povrchového odtoku išlo len o 1,2 % podiel. Najvyššia časť úhrnu zrážok prispela k tvorbe základného odtoku (23 %). Simulované odlesnenie povodia vyvolalo významný pokles intercepcie (o 76 %) a evapotranspirácie (o 12 %). Celkový, povrchový, podpovrchový a základný odtok zároveň vzrástli o 20,4; 38,8; 9,0 a 25,5 %. Denný prietok sa v priemere zvýšil o 20 %. Odlesnenie významne ovplyvnilo kulminačný prietok vyvolaný simulovanou extrémnou zrážkovou udalosťou s pravdepodobnosťou výskytu 100 rokov. V odlesnenom povodí bol kulminačný prietok o 58 % vy...

Determining the effect of deforestation on sustainable water supply in a semi-arid mountainous watershed by using storm water management model

“…Agriculture contributed 48% of total runoff, while shrub-land, grassland and forest contribute 40%, 11% and about 1% of it respectively (Githui et al, 2009). Hlásny et al (2015) indicated that total runoff increased by 38.8% and peak discharge time was 54 min earlier, when the forest was converted to grassland. When Figure 6 was investigated, it was seen that increase ratio in runoff was lower during a rainfall of 20 mm/day compared to those during a rainfall of 10 mm/day for all conversion scenarios.…”

Hydrological Variability in the El Cielo Biosphere Reserve, Mexico: A Watershed-Scale Analysis Using Tree-Ring Records

“…Hydrological resources are some of the most essential environmental services provided by forest ecosystems [1]; however, in the last few decades, an increase in deforestation, overgrazing, logging, and other land-use changes, along with climate warming, has disrupted the hydrological cycle in most of the ecosystems worldwide [2,3]. These changes affect the amount and distribution of rainfall, increasing evapotranspiration rates and decreasing water quality for different human uses [4,5].…”

Effects of deforestation on dissolved organic carbon and nitrate in catchment stream water revealed by wavelet analysis

“…Dissolved organic matter is generally the primary form of labile C in temperate and boreal terrestrial ecosystems and it serves as an important transport vector for organically bound nutrients to microorganisms within water bodies (Mostovaya et al, 2017;Guo et al, 2020;Burger et al, 2021). Furthermore, studies suggest that deforestation may increase the runoff generation in a catchment, e.g., due to a decrease in rainfall interception, evapotranspiration and soil compaction (Gholami, 2013;Hlásny et al, 2015;Wiekenkamp et al, 2016Wiekenkamp et al, , 2019, and it can also reshape the land-surface energy-flux partitioning (Yuan et al, 2021). With regards to the impact on the N cycle, stream nitrate concentration might increase due to the increase in soil nitrate from higher N mineralization after vegetation clearing, which may leach into the groundwater or be transported via surface runoff to receiving surface water bodies (Rusinga et al, 2008).…”