Page 229 - Çevre Şehir ve İklim Dergisi İngilizce - Özel Sayı

Güler Demir

1. Introduction

Climate change is expected to cause more variable weather conditions in
semi-arid regions, leading to an increase in the frequency of droughts and
intense rainfall (Seneviratne et al., 2021). Under such variable conditions,
storing excess water during rainy seasons can enhance the availability of local
water resources during dry periods. Additionally, it can improve agricultural
productivity by mitigating the adverse effects of intra-seasonal dry periods
and facilitate smoother transitions between dry seasons (Kijne et al., 2003).
Any small-scale planning efforts aimed at concentrating, storing, and
collecting surface runoff for domestic or agricultural use are referred to as water
harvesting (Siegert, 1994). Water harvesting techniques are considered an
effective option to help local communities in developing countries adapt to the
expected impacts of climate change on water resources (Lasage et al., 2015).
Water harvesting practices have been used by many civilizations in arid and
semi-arid regions throughout history. Examples of water harvesting structures
built thousands of years ago have been found in regions such as Babylonia,
Israel, Tunisia, China, and America (Bouma et al., 2016). These have been
successfully implemented in various regions of the world in regions with little
or irregular water supplies, particularly in seasonal periods of drought, and
continues to be used in semi-arid climate zones today. In Türkiye, there are local
projects conducted by public institutions and establishments, municipalities,
foundations and societies, and certain academic studies. These projects are
generally conducted to increase crop yield and quality in agricultural fields.
Water harvest practices may vary according to factors like climate, soil, and
slope. Slope is an important limiting factor for water harvesting; when the
slope exceeds 5%, water harvesting is generally not recommended due to the
uneven distribution of flow and the large amount of labor required. Another
limiting factor is soil structure. In areas where micro-watersheds are created,
soils suitable for irrigation need to be sufficiently deep, non-saline, or non-
sodic, and ideally have natural fertility. Sandy soils, however, present a serious
limitation for water harvesting because if the soil infiltration rate exceeds the
rainfall intensity, no runoff will occur (Demir, 2023).
Water harvest is technically categorized under four main headings micro-
catchment water harvesting, macro-catchment water harvesting, roof surface water
harvesting, and floodwater harvesting. It is stated in literature that the differences
in water harvesting largely result from the storage purpose, type of storage, and
whether the water source comes directly from the land or from outside.
This article aims to make a definition of water harvesting in general, classify
it under various purposes such as agricultural crop production, landscaping,

216 Journal of Environment, Urban and Climate