Relative contribution of land use change and climate variability on discharge of upper Mara River, Kenya

Mwangi, Hosea M.; Jülich, Stefan; Patil, Sopan; McDonald, Morag; Feger, Karl‐Heinz

doi:10.1016/j.ejrh.2015.12.059

Cited by 68 publications

(57 citation statements)

References 84 publications

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“…Previous studies have reported that deforestation and expansion of agriculture have affected the hydrology of the watershed [6,27,28]. For example, Mati et al [28] found that land-use change between 1973 and 2000 increased the peak flow of Mara River by 7%.…”

Section: Impact Of Land-use Change On Watershed Hydrology and Biodivementioning

confidence: 99%

“…In this study, commission errors were estimated using Equations (3) and (4) while omission errors were calculated using Equations (5) and (6). When observed transition of i was greater than uniform gain of n, the size and the intensity of commission of category i error were estimated using Equations (3) and (4), respectively.…”

Section: Error Analysismentioning

confidence: 99%

“…The land-use changes, especially deforestation in the Mau Forest at the headwaters in Kenya, have been blamed for change in the flow regime of the Mara River as well as deterioration of river water quality [26,27]. Mwangi et al [6] estimated that about 97% of change in the streamflow of the Nyangores River, a tributary of the Mara River, was caused by land-use change, particularly deforestation and expansion of agriculture. In a previous study, Mati et al [28] reported that large-scale deforestation occurred in the upper Mara and conversion of rangelands to agriculture in the mid regions of the basin between 1973 and 2000.…”

Section: Introductionmentioning

confidence: 99%

“…It is of interest to many fields of science including hydrology and related water resources management [3][4][5][6], biology with special focus on biodiversity [7], conservation [8,9], and agriculture including (agro)forestry [10]. Expansion of agricultural land is one of the main causes of land use/cover changes.…”

Section: Introductionmentioning

confidence: 99%

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Characterizing the Intensity and Dynamics of Land-Use Change in the Mara River Basin, East Africa

Mwangi

Lariu

Jülich

et al. 2017

Forests

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Abstract:The objective of this study was to analyze patterns, dynamics and processes of land-use/cover changes in the transboundary Mara River Basin in East Africa. We specifically focused on deforestation and expansion of agriculture in the watershed. The intensity analysis approach was used to analyze data from satellite imagery-derived land-use/cover maps. Results indicate that swap change accounted for more than 50% of the overall change, which shows a very dynamic landscape transformation. Transition from closed forest to open forest was found to be a dominant landscape change, as opposed to a random change. Similarly, transition from open forest to small-scale agriculture was also found to be a dominant transition. This suggests a trend (pathway) of deforestation from closed forest to small-scale agriculture, with open forest as a transitional land cover. The observed deforestation may be attributed to continuous encroachment and a series of excisions of the forest reserve. Transition from rangeland to mechanized agriculture was found to be a dominant land-use change, which was attributed to change in land tenure. These findings are crucial for designing strategies and integrated watershed management policies to arrest further deforestation in the forest reserves as well as to sustainably control expansion of agriculture.

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Section: Impact Of Land-use Change On Watershed Hydrology and Biodivementioning

confidence: 99%

Section: Error Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characterizing the Intensity and Dynamics of Land-Use Change in the Mara River Basin, East Africa

Mwangi

Lariu

Jülich

et al. 2017

Forests

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“…This has supposedly led to changes in flow regime (Baldyga et al, 2004;Mango et al, 2011;Mwangi et al, 2016) and increased 10 surface runoff (Baker and Miller, 2013). These observations strongly suggest changes in dominant flow paths as a consequence of land use change, but no scientific evidence is available to confirm this.…”

Section: Stable Water Isotopes ( 2 Hmentioning

confidence: 77%

Land use alters dominant water sources and flow paths in tropical montane catchments in East Africa

Jacobs¹,

Timbe²,

Weeser³

et al. 2018

Preprint

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Abstract. Conversion of natural forest to other land uses could lead to significant changes in catchment hydrology, but the nature of these changes has been insufficiently investigated in tropical montane catchments, especially in Africa. To address 20 this knowledge gap, we identified stream water sources and flow paths in three tropical montane sub-catchments (27-36 km²) with different land use (natural forest, smallholder agriculture and commercial tea plantations) within a 1 021 km² catchment in the Mau Forest Complex, Kenya. Weekly samples were collected from stream water, precipitation and soil water for 75 weeks and analysed for stable water isotopes (δ 2 H and δ 18 O) for mean transit time estimation, whereas trace element samples from stream water and potential end members were collected over a period of 55 weeks for end member mixing analysis. 25Stream water mean transit time was similar (~4 years) in the three sub-catchments, and ranged from 3.2-3.3 weeks in forest soils and 4.5-7.9 weeks in pasture soils at 15 cm depth to 10.4-10.8 weeks in pasture soils at 50 cm depth. The contribution of springs and wetlands to stream discharge increased from 18, 1 and 48 % during low flow to 22, 51 and 65 % during high flow in the natural forest, smallholder agriculture and tea plantation sub-catchments, respectively. The dominant stream water source in the tea plantation sub-catchment was spring water (56 %), while precipitation was dominant in the smallholder 30 agriculture (59 %) and natural forest (45 %) sub-catchments. These results confirm that catchment hydrology is strongly influenced by land use, which could have serious consequences for water-related ecosystem services, such as provision of clean water.Hydrol. Earth Syst. Sci. Discuss., https://doi

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On the Sensitivity of Annual Streamflow to Air Temperature

Milly

Kam

Dunne

2018

Water Resources Research

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Although interannual streamflow variability is primarily a result of precipitation variability, temperature also plays a role. The relative weakness of the temperature effect at the annual time scale hinders understanding, but may belie substantial importance on climatic time scales. Here we develop and evaluate a simple theory relating variations of streamflow and evapotranspiration (E) to those of precipitation (P) and temperature. The theory is based on extensions of the Budyko water‐balance hypothesis, the Priestley‐Taylor theory for potential evapotranspiration ( Ep), and a linear model of interannual basin storage. The theory implies that the temperature affects streamflow by modifying evapotranspiration through a Clausius‐Clapeyron‐like relation and through the sensitivity of net radiation to temperature. We apply and test (1) a previously introduced “strong” extension of the Budyko hypothesis, which requires that the function linking temporal variations of the evapotranspiration ratio (E/P) and the index of dryness ( Ep/P) at an annual time scale is identical to that linking interbasin variations of the corresponding long‐term means, and (2) a “weak” extension, which requires only that the annual evapotranspiration ratio depends uniquely on the annual index of dryness, and that the form of that dependence need not be known a priori nor be identical across basins. In application of the weak extension, the readily observed sensitivity of streamflow to precipitation contains crucial information about the sensitivity to potential evapotranspiration and, thence, to temperature. Implementation of the strong extension is problematic, whereas the weak extension appears to capture essential controls of the temperature effect efficiently.

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Relative contribution of land use change and climate variability on discharge of upper Mara River, Kenya

Cited by 68 publications

References 84 publications

Characterizing the Intensity and Dynamics of Land-Use Change in the Mara River Basin, East Africa

Characterizing the Intensity and Dynamics of Land-Use Change in the Mara River Basin, East Africa

Land use alters dominant water sources and flow paths in tropical montane catchments in East Africa

On the Sensitivity of Annual Streamflow to Air Temperature

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