Nature based solutions
Natural base solutions are a phenomenal approach for sustainable land
management by considering the whole processes like erosion processes
(detachment, transportation and deposition) and predict its long-term
effect on landscape dynamics that determine sediment and water
connectivity and its infraction within landscape. It has two types of
measures: landscape and soil solutions. Landscape solutions mainly focus
on hillslope morphology, runoff pathways, topographic wetness and water
and sediment sinks (Ballard et al., 2013; Keesstra et al., 2018). The
soil-based solution is mainly based on soil health, which can be
explained by soil stability and soil roughness reduce overland flow and
associated sediment transport. Vegetative and integrated SWC measures
like grass strips trappings of sediment with vegetation and transform
over time into a terrace can be seen as nature-based solutions which
determines the potential for water and sediment to be transported and
trapped through the system (Cerdà & Doerr, 2005; Masselink et al.,
2016; Mekonnen et al., 2016). Within the nature-based solutions organic
farming is a key management as allow the growth of vegetation and then
reduce the raindrop detachment, overland flow velocity and enhance
infiltration (Cerdà et al., 2018; Cerdà et al., 2018; Kirchhoff et al.,
2017).
Conclusion
To overcome land degradation through sustainable land management, many
efforts have been made globally. On the basis of these efforts many
research articles have been published to understand the implication of
different SWC measures on the biophysical dynamics of the watershed. A
critical review was carried out from scientific journal articles to the
effect of physical, agronomic, vegetative and integrated SWC measures on
soil properties, surface runoff and soil loss. The synthesis reveals
that, vegetative and agronomic measures play an important role for soil
fertility enhancement and thereby improving soil quality for better
production. Whereas structural measures such as terraces, bunds, fanya
juu, and conservation tillage have a significant impact on runoff
reduction by increasing the time of concentration and decreasing the
velocity of running water. The combined implementation of SWC (physical,
vegetative and agronomic) measures have also decreased soil erosion and
improves the sediment trapping capacity of the landscape.
From this synthesis, research gaps have been identified. The evaluation
of SWC measures on soil properties, runoff and, erosion and soil loss
should mainly focus on larger scale on the bases of long-term evidences.
In addition, the effect of different SWC measures should consider the
connectivity concept to understand erosion and hydrological processes at
large-scale, which can be addressed using field investigation and
modeling tools. This approach finally leads to developing and promoting
ecologically sound, economically viable and socially acceptable
conservation measures for sustainable land management in agricultural
watersheds.