The impacts of a changing climate on catchment water balance and forest management

Abstract

Climate change has serious impacts on forest services with regard to the spatial and temporal distribution of water within catchments. Hence, combined forest and catchment management in a changing climate is a crucial concern for people and society. To assess hydrological processes and water resources in two forested headwater catchments in south-west Germany the physical based hydrological model ArcAPEX was calibrated to investigate climate change scenarios for the near (2021-2050) and far (2071-2100) future. Even though the trend in temperature is positive in most regional climate change scenarios for south-west Germany, the precipitation trend is quite ambiguous. Different precipitation scenarios give access to the possible bandwidth between water stress and flood generation. Our results can be used to describe water resources and discharge characteristics under conditions of different land use change scenarios.Management option for a sustainable forestry and flood mitigation will be to "spread the risk" by creating forests with a high biodiversity and a prioritization of forest services and functions. The principle is to find "no-regret" decisions. In this sense, final decisions should not be taken too early, and several options should be kept open, such as dealing with increasingly frequent droughts on one hand and increased runoff generation on the other hand. Thus, it should remain possible for forest and catchment management authorities to react to possible developments in an uncertain future.

Modelling Impacts of a Municipal Spatial Plan of Land-Use Changes on Surface Water Quality—Example from Goriška Brda in Slovenia

“…Vegetative buffer strips are a simple and cost-effective measure to reduce the transfer of eroded soil particles and nutrients to water sources. With this measure, a strip of natural or sown vegetation is established between the source of pollution and the watercourse, catching pollutants present in the surface runoff and increasing the infiltration of water into the soil [41].…”

Possible Increases in Flood Frequency Due to the Loss of Eastern Hemlock in the Northeastern United States: Observational Insights and Predicted Impacts

“…Trees exert a fundamental control on the hydrologic cycle through soil shading, canopy interception and storage, root water uptake of soil and groundwater, partitioning of latent heat losses between evaporation and transpiration, and root modification of soil pore size distributions (Brantley et al, ; Knighton et al, ; Sprenger et al, ). Researchers have considered active forest management as a path toward controlling the distribution of catchment water (e.g., Douglass, ; Ford et al, ; Noordwijk et al, ; Schüler et al, ), yet the viability of forest conservation practices as a means of flood management has been questioned (e.g., Soulsby et al, ).…”

Assessment of the flood hazard arising from land use change in a forested catchment in northern Iran

“…Although there appears to be little actual risk of increased flood discharges in Casilian Catchment because of the negligible impact of selective logging on runoff, Figure shows that moderate return period rainfall events (e.g., 10–100 years) can produce significant flood events with peak discharges of perhaps up to 40 m 3 /s if the rain falls on saturated soils (using the results for scenario 2 and scenario 2 + sm as a guide), particularly during periods of spring snowmelt (Bernsteinová, Bässler, Zimmermann, Langhammer, & Beudert, ). The flash flood hazard is predicted to increase even without LULCC due to climate change, most likely as intense (probably convective) rainfall of relatively limited spatial extent (Hajian et al, ) although the effects may be offset somewhat by higher evapotranspiration arising from higher temperatures (e.g., Schüler et al, ). These general findings are probably applicable to most of northern Iran.…”