(personal observation by the authors in Pang Ma Pha District, Thailand, 2011) and
suggests that land use classes should be reviewed critically as proxies for process
domains (Table 3.2), particularly when discussing resource conservation strategies.
Case studies: The case studies in this chapter exemplify the concerns raised
about natural resource management with regard to water, nutrients and synthetic
agrochemicals. A more integrated view on floods and risk management is shown in
Case Study 1, which focuses on the issue of reservoir management and the problem
of maximizing the water available for dry-season irrigation, whilst minimizing the
risk of flooding caused by late season storms, plus on how people’s perceptions
relate to the scientific view on the causes of floods and the opportunities for flood
risk mitigation (Schad et al. 2012). Closely linked to flooding and reservoir
management, Case Study 2 analyzes the upland-lowland run-off components of
water, the corresponding nutrient and sediment reallocation and delivery pathways,
and the impact of these on agronomic management (Schmitter et al. 2010, 2011,
2012). While Case Study 2 infers upland lowland nutrient fluxes, Case Study 3
investigates C stocks on a range of scales and land use types (LUTs), to reveal a
basis for C management (see also Chap. 2). To add to nutrient stocks and flows in
response to land use intensification, Case Study 4 investigates the fate of pesticides
under intensified highland agriculture regimes, and identifies the pathways taken by
pesticide residues from the fields to stream waters at the catchment scale.
3.2 The Study Sites
2
3.2.1 Local Climate
The main Uplands Program research sites (in Thailand, Mae Sa and Bor Krai, and in
Vietnam, Chieng Koi and Muong Lum) are located in the outer tropics of the
northern hemisphere (see Chap. 1). A common way to describe the climate characteristic of a location in a graphical way is to use the so-called Walter-Lieth diagram
(Walter and Lieth 1964) (Fig. 3.1). In a Walter-Lieth diagram, monthly air temperature and precipitation averages are plotted against the months of the year. For sites
located in the northern hemisphere, the diagram starts with January in the left
corner of the diagram, while for sites south of the Equator, the diagram starts
with July; therefore, the astronomic summer is always shown in the middle of the
diagram. Air temperature is plotted on the left y-axis, and precipitation is plotted on
the right y-axis. Both y-axes are scaled in such a way that 20 mm of monthly
precipitation are equal to 10
C average air temperature. If the precipitation curve
falls below the temperature curve, the space between both curves is shown in red,
indicating a dry season. In the opposite case, where the precipitation curve lies
2 Written by Joachim Ingwersen and Holger L. Fro ¨hlich.
3 Water and Matter Flows in Mountainous Watersheds of Southeast Asia:. . .
115
suggests that land use classes should be reviewed critically as proxies for process
domains (Table 3.2), particularly when discussing resource conservation strategies.
Case studies: The case studies in this chapter exemplify the concerns raised
about natural resource management with regard to water, nutrients and synthetic
agrochemicals. A more integrated view on floods and risk management is shown in
Case Study 1, which focuses on the issue of reservoir management and the problem
of maximizing the water available for dry-season irrigation, whilst minimizing the
risk of flooding caused by late season storms, plus on how people’s perceptions
relate to the scientific view on the causes of floods and the opportunities for flood
risk mitigation (Schad et al. 2012). Closely linked to flooding and reservoir
management, Case Study 2 analyzes the upland-lowland run-off components of
water, the corresponding nutrient and sediment reallocation and delivery pathways,
and the impact of these on agronomic management (Schmitter et al. 2010, 2011,
2012). While Case Study 2 infers upland lowland nutrient fluxes, Case Study 3
investigates C stocks on a range of scales and land use types (LUTs), to reveal a
basis for C management (see also Chap. 2). To add to nutrient stocks and flows in
response to land use intensification, Case Study 4 investigates the fate of pesticides
under intensified highland agriculture regimes, and identifies the pathways taken by
pesticide residues from the fields to stream waters at the catchment scale.
3.2 The Study Sites
2
3.2.1 Local Climate
The main Uplands Program research sites (in Thailand, Mae Sa and Bor Krai, and in
Vietnam, Chieng Koi and Muong Lum) are located in the outer tropics of the
northern hemisphere (see Chap. 1). A common way to describe the climate characteristic of a location in a graphical way is to use the so-called Walter-Lieth diagram
(Walter and Lieth 1964) (Fig. 3.1). In a Walter-Lieth diagram, monthly air temperature and precipitation averages are plotted against the months of the year. For sites
located in the northern hemisphere, the diagram starts with January in the left
corner of the diagram, while for sites south of the Equator, the diagram starts
with July; therefore, the astronomic summer is always shown in the middle of the
diagram. Air temperature is plotted on the left y-axis, and precipitation is plotted on
the right y-axis. Both y-axes are scaled in such a way that 20 mm of monthly
precipitation are equal to 10
C average air temperature. If the precipitation curve
falls below the temperature curve, the space between both curves is shown in red,
indicating a dry season. In the opposite case, where the precipitation curve lies
2 Written by Joachim Ingwersen and Holger L. Fro ¨hlich.
3 Water and Matter Flows in Mountainous Watersheds of Southeast Asia:. . .
115